Sarcopenia e fatores associados em idosos brasileiros = do diagnóstico à intervenção = Sarcopenia and associated factors in Brazilian older adults: from diagnosis to intervention

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UNIVERSIDADE ESTADUAL DE CAMPINAS FACULDADE DE EDUCAÇÃO FÍSICA

RICARDO AURÉLIO CARVALHO SAMPAIO

SARCOPENIA E FATORES ASSOCIADOS EM IDOSOS BRASILEIROS: DO DIAGNÓSTICO À INTERVENÇÃO

SARCOPENIA AND ASSOCIATED FACTORS IN BRAZILIAN OLDER ADULTS: FROM DIAGNOSIS TO INTERVENTION

CAMPINAS 2017

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RICARDO AURÉLIO CARVALHO SAMPAIO

SARCOPENIA E FATORES ASSOCIADOS EM IDOSOS BRASILEIROS: DO DIAGNÓSTICO À INTERVENÇÃO

SARCOPENIA AND ASSOCIATED FACTORS IN BRAZILIAN OLDER ADULTS: FROM DIAGNOSIS TO INTERVENTION

Tese apresentada à Faculdade de Educação Física da Universidade Estadual de Campinas como parte dos requisitos exigidos para obtenção do título de Doutor em Educação Física, na área de concentração Atividade Física Adaptada.

ORIENTADOR: PROF. DR. GUSTAVO LUIS GUTIERREZ CO-ORIENTADOR: PROF. DR. MARCO CARLOS UCHIDA

ESTE EXEMPLAR CORRESPONDE À VERSÃO FINAL DA TESE DEFENDIDA PELO ALUNO RICARDO AURÉLIO CARVALHO SAMPAIO, E ORIENTADA PELO PROF. DR. GUSTAVO LUIS GUTIERREZ

CAMPINAS 2017

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Agência(s) de fomento e nº(s) de processo(s): CAPES, 01P04373/2015

Ficha catalográfica

Universidade Estadual de Campinas Biblioteca da Faculdade de Educação Física Dulce Inês Leocádio dos Santos Augusto - CRB 8/4991

Sampaio, Ricardo Aurélio Carvalho, 1986-

Sa47s Sam Sarcopenia e fatores associados em idosos brasileiros: do diagnóstico à intervenção / Ricardo Aurélio Carvalho Sampaio. – Campinas, SP : [s.n.], 2017.

Sam

Orientador: Gustavo Luis Gutierrez. Coorientador: Marco Carlos Uchida.

Tese (doutorado) – Universidade Estadual de Campinas, Faculdade de Educação Física.

Sam

1. Envelhecimento. 2. Força muscular. 3. Aptidão física - Testes. 4. Qualidade de vida. I. Gutierrez, Gustavo Luis. II. Uchida, Marco Carlos. III. Universidade Estadual de Campinas. Faculdade de Educação Física. IV. Título.

Informações para Biblioteca Digital

Título em outro idioma: Sarcopenia and associated factors in Brazilian older adults: from

diagnosis to intervention

Palavras-chave em inglês:

Aging Strength

Physical fitness - Tests Quality of life

Área de concentração: Atividade Física Adaptada Titulação: Doutor em Educação Física

Banca examinadora:

Gustavo Luis Gutierrez [Orientador] Edison Duarte

Flávia Silva Arbex Borim

Vanessa Helena Santana Dalla Déa Reury Frank Pereira Bacurau

Data de defesa: 12-06-2017

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COMISSÃO EXAMINADORA:

Prof. Dr. Gustavo Luis Gutierrez (Faculdade de Educação Física/UNICAMP)

(Presidente)

Dr. Edison Duarte

(Faculdade de Educação Física/UNICAMP) (Membro titular)

Dra. Flávia Silva Arbex Borim (Faculdade de Ciências Médicas/UNICAMP)

(Membro titular)

Dra. Vanessa Helena Santana Dalla Déa (Universidade Federal de Goiás)

(Membro titular)

Dr. Reury Frank Pereira Bacurau (Universidade de São Paulo)

(Membro titular)

A Ata da defesa com as respectivas assinaturas dos membros encontra-se no processo de vida acadêmica do aluno.

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AGRADECIMENTOS

Agradeço imensamente ao Prof. Dr. Gustavo Luis Gutierrez e ao Prof. Dr. Marco Carlos Uchida, pelas orientações, incentivos e assistências que por diversas vezes excederam os limites acadêmicos. Estendo, com mesmo empenho, o agradecimento às suas famílias.

À Priscila e Alice, esposa e filha, maiores parceiras da vida e prontas para qualquer novo desafio.

Aos meus pais e irmãos, por toda a base, afeto e formação que me possibilitou chegar muito longe.

À Silvia Toshie por estar presente nas incontáveis coletas, sempre disposta a ajudar.

A TODOS os amigos integrantes do LCA – Laboratório de Cinesiologia Aplicada e GEPEFAN – Grupo de Estudos e Pesquisa em Exercício Físico e Adaptações Neuromusculares, pelo suporte, compromisso e empenho de estarem presentes em diversas coletas de dados, mesmo que em diferentes cidades.

Aos participantes das pesquisas e aos que viabilizaram a sua execução de alguma forma, sua confiança e colaboração proporcionaram um período de grande aprendizado.

À banca de qualificação e defesa, Dr. Edison Duarte, Dra. Flávia Silva Arbex Borim, Dra. Vanessa Helena Santana Dalla Déa e Dr. Reury Frank Pereira Bacurau pela valiosa contribuição dada ao trabalho.

Aos coordenadores da Pós-graduação, Dra. Cláudia Cavaglieri (anterior) e Dr. Edivaldo Góis (atual), por todo o suporte quando necessário.

À secretária da pós-graduação da FEF, Simone Ide, por sempre estar de bom humor e disposta a ajudar prontamente nas questões burocráticas.

Aos Professores e colegas com quem tive a oportunidade de cursar disciplinas, discutir e aprender bastante durante o período de doutoramento, seja na FEF, seja na Gerontologia/FCM.

À Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (#01P04373/2015), pelo apoio financeiro para a realização e conclusão desta tese.

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RESUMO

O envelhecimento no Brasil representa grande desafio para a saúde pública contemporânea, uma vez que acontece de forma acelerada e pode ser acompanhado de diversas condições adversas, como a sarcopenia, síndrome da fragilidade, e o consequente declínio da qualidade de vida (QV), que frequentemente resultam em institucionalização e mortalidade. Esta tese está estruturada com base em três artigos científicos, além de capítulos de introdução e conclusão. No primeiro artigo, “Cutoff values of appendicular skeletal muscle mass and strength associated to fear of falling in Brazilian older adults”, foram apresentados comparações entre grupos de idade por sexo em relação a aspectos morfofuncionais; e valores específicos de corte para massa muscular apendicular (i.e., soma da massa muscular dos membros) ajustada pelo índice de massa corporal (MMA(IMC)) e força

(i.e., força de preensão manual, absoluta e relativa [ajustada pelo índice de massa corporal]) em associação ao medo de cair em idosos brasileiros (n=578). Níveis de funcionalidade diminuíram com a idade, enquanto a composição corporal variou entre sexos. Associados ao medo de cair, os pontos de corte para MMA(IMC) foram <0,85 para homens e <0,53 para

mulheres; para força de preensão manual absoluta e relativa foram <30,0 kgf e <21,7 kgf; e <1,07 e <0,66, para homens e mulheres, respectivamente. O segundo artigo verificou a associação dos pontos de corte, assim como a combinação desses fatores, com QV (n=577). Lentidão da caminhada foi estabelecida em <0,8 m/s. O artigo foi intitulado “Sarcopenia cutoffs in Brazilian older adults are associated to health-related quality of life”. Em homens, resultados da combinação de força de preensão manual absoluta e/ou velocidade de caminhada foram associados com os domínios função física, aspectos físicos e saúde geral de QV. Em mulheres, a combinação de força de preensão manual (absoluta e relativa) e/ou velocidade da caminhada e MMA(IMC) apresentou associações com os domínios função física,

aspectos físicos, dor corporal, saúde geral e função social. O terceiro artigo analisou a aplicação de exercícios de potência utilizando bandas elásticas (16 semanas), em idosos frágeis (n=11) e residentes em uma instituição de longa permanência. O artigo foi intitulado “Influence of power training on physical function and health-related quality of life in institutionalized frail older adults: a case-study”. Pós-intervenção, mudanças foram observadas nos domínios de QV – função física, aspectos físicos, dor corporal, aspectos emocionais e sumário dos componentes físicos, em homens; e aspectos físicos, aspectos emocionais e saúde mental, em mulheres. Em relação à função física, melhoras na velocidade da caminhada e número de repetições no teste de remada com banda elástica foram

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observadas, em homens; e velocidade da caminhada, repetições no teste de remada com banda elástica e timed up and go, em mulheres. Os dados apresentados podem ser utilizados como referência para pesquisadores ou na prática profissional. Mais ainda, podem servir de referência para o desenvolvimento de políticas públicas relacionadas à saúde e bem estar dos idosos. Pois uma vez conhecidas as demandas, intervenções podem ser melhores destinadas à promoção da saúde dessa população.

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ABSTRACT

Aging in Brazil represents a major challenge for contemporary public health, once happens fast and can be associated with several adverse health conditions, such as sarcopenia, frailty syndrome, and decline in quality of life (QOL), which often result in higher institutionalization and mortality rates. This work is structured on the basis of three-paper format, as well as introduction and conclusion sections. In the first article, "Cutoff values of appendicular skeletal muscle mass and strength associated with fear of falling in Brazilian older adults", we presented comparisons between age groups by sex with regard to morphological and functional aspects; and specific cutoff values for appendicular skeletal muscle mass (i.e., sum of limbs muscle mass) adjusted by body mass index (ASM(BMI)) and

strength (i.e., handgrip strength, absolute and relative [adjusted by body mass index]) in association with fear of falling in Brazilian older adults (n=578). Physical function decreased as age increased, while body composition varied according to sex. In association to fear of falling, cutoff values for ASM(BMI) were <0.85 for men and <0.53 for women; for absolute

and relative handgrip strength were <30.0 kgf and <21.7kgf; and <1.07 and <0.66, for men and women, respectively. The second article verified the association of these cutoff points, as well as the combination of such factors, with QOL (n=577). Slow walking speed was established as <0.8 m/s. The article was entitled "Sarcopenia cutoffs in Brazilian older adults are associated to health-related quality of life". In men, results of the combination of absolute handgrip strength and/or walking speed were associated with physical functioning, role-physical and general health domains of QOL. In women, the combination of handgrip strength (both absolute and relative) and/or walking speed plus ASM(BMI) were associated

with physical functioning, role-physical, bodily pain, general health and social functioning. The third article analyzed the application of power exercises using elastic bands (16 weeks), in frail and institutionalized older people. The article was entitled "Influence of power training on physical function and health-related quality of life in institutionalized frail older adults: a case-study". Post-intervention results showed changes on physical functioning, role-physical, bodily pain, role-emotional and physical component summary QOL domains, in men; and role-physical, role-emotional and mental health, in women. Regarding physical function, improvements on walking speed and number of repetitions in the elastic band rowing test were observed, in men; and waking speed, repetitions in the elastic band rowing test and the timed up and go, in women. The data presented herein might be useful as reference for researchers and in professional practice. Moreover, might be useful for the

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development of public policies related to older adults’ health. Once their demands are known, more efficient intervention can be developed to promote health in this population.

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LISTA DE ILUSTRAÇÕES

Artigo 1

Figure 1. ROC curves for appendicular skeletal muscle (ASM) with different adjustments, and handgrip strength (HGS) (absolute and adjusted by body mass index). Fear of falling was used as outcome variable. Data of men (A-B) and women (C-D) are presented………... 33

Artigo 3

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LISTA DE TABELAS

Artigo 1

Table 1. Older adults’ characteristics………... 27 Table 2. Characteristics according to age in older men (n=122)... 28 Table 3. Characteristics according to age in older women (n=455)... 30 Table S1. Appendicular skeletal muscle adjusted by body mass index vs. Fear of

falling (Men)... 41

Table S2. Absolute handgrip strength vs. Fear of falling (Men)... 41 Table S3. Relative handgrip strength vs. Fear of falling (Men)... 42 Table S4. Appendicular skeletal muscle adjusted by body mass index vs. Fear of

falling (Women)... 42

Table S5. Absolute handgrip strength vs. Fear of falling (Women)... 43 Table S6. Relative handgrip strength vs. Fear of falling (Women)... 43

Artigo 2

Table 1. Subjects’ general characteristics... 49 Table 2. Point biserial correlations for different cutoffs and combinations, and

health-related quality of life (men, n=122)... 51

Table 3. Point biserial correlations for different cutoffs and combinations, and

health-related quality of life (women, n=455)….………. 52

Artigo 3

Table 1. Participants’ general characteristics at baseline according to sex... 66 Table 2. Health-related quality of life pre and post intervention... 67

Table 3. Physical function tests pre and post intervention……….. 69

Table 4. Session rating of perceived effort at the beginning and at the final intensity

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LISTA DE ABREVIATURAS E SIGLAS

ACSM……….... American College of Sports Medicine ANOVA………. Analysis of variance – Análise de variância

ANVISA……… Brazilian Sanitary Agency – Agência de vigilância sanitária ASM………... Appendicular skeletal muscle

ASM(BMI)…..………. Appendicular skeletal muscle mass adjusted by body mass index AUC………... Area under the curve

AVD... Atividade da vida diária

AWGS………... Asian Working Group for Sarcopenia BIA……… Bioelectrical impedance analysis

BMI………... Body mass index

Borg CR-10………... Adapted Borg scale 0-10

BP……….. Bodily pain domain (Short-form 8 and 36) d………. Cohen’s d effect size

EBRT………. Elastic band rowing test

EWGSOP... European Working Group on Sarcopenia in Older People FAST... Functional Assessment Staging of Alzheimer’s disease FNIH……….. Foundation for the National Institutes of Health GH………. General health domain (Short-form 8 and 36) HGS………... Handgrip strength

HGS(ABS)……… Absolute handgrip strength

HGS(BMI)……… Handgrip strength adjusted by body mass index – relative handgrip

strength

HRQOL………. Health-related quality of life

ICD-10... International Classification of Diseases KCL………... Kihon Checklist

LR+……… Positive likelihood ratios LR-………. Negative likelihood ratios LTCI……….. Long term care institution

MCS………... Mental Component Summary (Short-form 36) MH……….… Mental health domain (Short-form 8 and 36) MMA………. Massa muscular appendicular

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MMSE………... Mini-mental State Examination NPV………... Negative predictive value PA/wk……… Physical activity per week

PCS……… Physical Component Summary (Short-form 36)

PF……….. Physical functioning domain (Short-form 8 and 36)

PPV……… Positive predictive value QV... Qualidade de vida

RE……….. Role-emotional domain (Short-form 8 and 36) RM………. Repetition maximum

ROC……….. Receiver Operating Characteristics

RP……….. Role-physical domain (Short-form 8 and 36) Rpb………. Point biserial coefficient of correlation SD……….. Standard deviation

SF………... Social functioning domain (Short-form 8 and 36) SF-8……… Short-form 8 items

SF-36……….. Short-form 36 items

SRPE………. Session rating of perceived effort TUG……….….. Timed up and go

VO2max... Capacidade aeróbia máxima

VT……….. Vitality domain (Short-form 8 and 36) WHO... World Health Organization

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SUMÁRIO

INTRODUÇÃO ... 16

CUTOFF VALUES OF APPENDICULAR SKELETAL MUSCLE MASS AND STRENGTH ASSOCIATED TO FEAR OF FALLING IN BRAZILIAN OLDER ADULTS ... 19 Abstract ……….. 19 Resumo ……….. 20 Introduction ………... 21 Objective ………... 22 Methods ………. 22 Results …….……….. 26 Discussion ……….. 35 Conclusion ………... 38 References ………... 38

SARCOPENIA CUTOFFS IN BRAZILIAN OLDER ADULTS ARE ASSOCIATED TO HEALTH-RELATED QUALITY OF LIFE ……… 44

Abstract ……….. 44 Introduction ………... 45 Methods ……...……….. 45 Results ………... 47 Discussion ……….. 53 References ………. 55

INFLUENCE OF POWER TRAINING ON PHYSICAL FUNCTION AND HEALTH-RELATED QUALITY OF LIFE IN INSTITUTIONALIZED FRAIL OLDER ADULTS: A CASE-STUDY ……... 58

Abstract ……….. 58 Introduction ...……… 59 Methods ………..………... 59 Results ………... 65 Discussion ……….. 70 References ………. 73 CONCLUSÃO ... 77

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REFERÊNCIAS ... 78 ANEXO 1... 82 ANEXO 2... 83

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INTRODUÇÃO

O envelhecimento é constituído e influenciado por mudanças complexas e dinâmicas. Em nível biológico, é associado com o acúmulo gradual de uma ampla variedade de danos moleculares e celulares. Com o tempo, estes danos levam a declínios graduais das reservas fisiológicas, aumentando o risco para diversas doenças, o que resulta num declínio geral na capacidade do indivíduo.1 Diversas condições adversas podem acompanhar o envelhecimento tais como a sarcopenia, síndrome da fragilidade, incapacidade funcional, e o consequente declínio da qualidade de vida (QV);2 que frequentemente resultam em institucionalização e mortalidade.

A sarcopenia é entendida como a progressiva perda de massa muscular e força/funcionalidade com o envelhecimento.2 Durante essa fase da vida, ocorre perda quantitativa de massa muscular e alterações nas propriedades individuais das fibras musculares, em particular, a redução seletiva no número e tamanho das fibras musculares do tipo II, de contração rápida.3 Isso gera uma perda gradativa das capacidades físicas (e.g. força e potência), o que resulta na diminuição do desempenho físico e das atividades da vida diária (AVD), podendo culminar na perda da independência desses idosos.4

Idosos sarcopênicos apresentam risco elevados de quedas e maior prevalência de medo de cair, levando a um ciclo vicioso de sarcopenia, declínio das capacidades físicas, quedas e medo de cair, que resulta em incapacidade.5 Especialmente o medo de cair, é uma condição associada a aspectos físicos e psicológicos, como quedas, perda de confiança, restrição de atividades, isolamento social, que podem levar a dependência e incapacidade;6,7 ainda que não seja uma medida objetiva como os tradicionais desfechos, é uma importante variável sobre condição de saúde dos idosos.

O termo sarcopenia (do grego, perda de carne) foi primeiro proposto por Rosenberg, em 1989, para descrever o declínio de massa muscular associado à idade.8 No entanto, conceitos contemporâneos, ainda que difiram em algumas características, suportam que sarcopenia pode ser definida a partir de aspectos morfofuncionais: quantidade de massa muscular, força muscular e função física. Assim, a quantidade e qualidade muscular são utilizadas para o diagnóstico dos estágios sarcopênicos em idosos. Dentre as publicações referentes à sarcopenia, alguns grupos se destacam no contexto internacional: “European Working Group on Sarcopenia in Older People” (EWGSOP);2

“Society on Sarcopenia, Cachexia and Wasting Disorders (study Sarcopenia with limited Mobility - an International

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Consensus)”;9 “Asian Working Group for Sarcopenia (AWGS)”10 e “Foundation for the National Institutes of Health (FNIH) Sarcopenia Project”.11

A sarcopenia pode atingir cerca de 30% dos indivíduos com 65 anos ou mais e 50% das pessoas a partir dos 80 anos.2 No Brasil, Diz et al. (2016) verificaram uma prevalência de 17%, indicando um alerta, à medida em que o crescimento da população idosa se acentua.12 Tal condição influencia negativamente a QV e a saúde geral dos idosos, através do aumento de incidência de morbidades (e.g. obesidade, hipertensão, diabetes tipo 2, dislipidemias, osteoporose), aumento no risco de quedas e fraturas ósseas, diminuição do condicionamento físico e capacidade aeróbia máxima (VO2max).13

Entende-se que a análise da QV constitui uma das avaliações mais representativas da saúde de um indivíduo, partindo do pressuposto que uma percepção favorável da sua própria saúde pode minimizar as condições que acompanham o processo de envelhecimento.14 Além disso, QV pressupõe boa saúde mental, felicidade e sociabilização; estando associado negativamente a doenças físicas e estados depressivos.15 Interessante, o conceito de QV foi introduzido na pesquisa em saúde para complementar os já tradicionais desfechos médicos, tais como mortalidade e morbidade.16

A literatura sugere que os fatores que contribuem para melhorar a QV de idosos incluem manutenção da independência, autonomia, adaptabilidade, participação social, papel na sociedade e outros.17 Adicionalmente, acredita-se que a prática regular de atividade física pode preservar a saúde, bem–estar, vitalidade e a função social, entre outros fatores importantes para a QV.18

Programas específicos de atividade física representam fator chave para a manutenção das capacidades físicas, desaceleração ou até mesmo reversão dos aspectos de sarcopenia e fragilidade;19,20 e recomendações na última década incluem a prática de exercícios aeróbios, de força, de flexibilidade e de equilíbrio.21,22

É sabido que o treinamento de força possui papel importante na melhora das funções musculares, físicas e até psicológicas, mesmo para idosos mais velhos.23,24 Estudos também demonstraram a importância da utilização de treinos de potência (i.e. força multiplicado pela velocidade, potência= força x velocidade) para idosos. Acredita-se que o treinamento de potência pode promover benefícios adicionais à população idosa do que o treinamento de força convencional,25 uma vez que a produção de força rápida se associa à função física.26 De fato, em estudo de revisão, pesquisadores observaram que a taxa de produção de força aumentou somente nos estudos em que os voluntários realizaram ações explosivas;26 condição também observada em relação à função física.27

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Esta tese está estruturada com base em três artigos. O primeiro, refere-se à pesquisa “Cutoff values of appendicular skeletal muscle mass and strength associated to fear of falling in Brazilian older adults”. Neste artigo, são propostos valores de referência de massa muscular apendicular e força de preensão manual em idosos brasileiros, por acreditar que valores baseados em idosos locais são preferíveis sob aqueles provenientes de estrangeiros, principalmente pela diferença cultural e ambiental que influenciam bastante no estilo de vida da população, o que por sua vez, é um fator determinante para como se envelhece.

Assim, foram apresentados comparações entre grupos de idade no que concerne a aspectos morfológicos e funcionais; e valores específicos de corte para massa muscular apendicular (i.e., soma da massa muscular dos membros) ajustada pelo índice de massa corporal (IMC) e força (i.e., força de preensão manual absoluta e relativa [ajustada pelo IMC]) em associação ao medo de cair, em idosos brasileiros (n=578). A pesquisa foi aprovada no Comitê de Ética da Universidade Estadual de Campinas (UNICAMP) sob o protocolo #39437514.0.0000.5404 (ANEXO 1). Os dados estão também descritos no artigo aceito para publicação no São Paulo Medical Journal/Evidence for Health Care, em maio de 2017.

O segundo artigo, verificou a associação dos pontos de corte específicos para massa muscular apendicular ajustada pelo IMC, força de preensão manual absoluta e relativa, velocidade da caminhada (com base em valores previamente estabelecidos), bem como a combinação desses fatores, com QV (n=577). O artigo, com desenho transversal, foi intitulado “Sarcopenia cutoffs in Brazilian older adults are associated to health-related quality of life”. A pesquisa foi aprovada no Comitê de Ética da UNICAMP sob o protocolo #39437514.0.0000.5404 (ANEXO 1).

O último artigo analisou a aplicação de um programa de exercícios em idosos institucionalizados. O artigo foi intitulado “Influence of power training on physical function and health-related quality of life in institutionalized frail older adults: a case-study”. A hipótese do estudo foi que uma intervenção baseada em exercícios de potência poderia influenciar a função física e melhora da QV. Onze idosos participaram das atividades de intervenção que durou quatro meses. Eles foram avaliados antes do início do programa de exercícios e após (17ª semana). Variáveis de função física e QV, entre outras, foram realizadas. O protocolo de pesquisa foi aprovado pela UNICAMP sob o protocolo #47092115.4.0000.5404 (ANEXO 2).

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CUTOFF VALUES OF APPENDICULAR SKELETAL MUSCLE MASS AND STRENGTH ASSOCIATED TO FEAR OF FALLING IN BRAZILIAN OLDER ADULTS

ABSTRACT

CONTEXT AND OBJECTIVE: Sarcopenia is an emerging public health issue in Brazil. Due to the rising prevalence, and the lack of national data, the objective was to identify cutoff values for appendicular skeletal muscle (ASM), and handgrip strength according to fear of falling in Brazilian older adults.

DESIGN AND SETTING: Cross-sectional study; community.

METHODS: 578 older adults participated in this study. Volunteers underwent to morphological and functional evaluations; and were questioned about the prevalence of falls and fear of falling. Different adjustments of ASM and handgrip strength were used. Slow walking speed was established at <0.8m/s. Gender and age-groups were compared by T tests, analysis of variance (ANOVA), chi-square or Fisher’s Exact Test. Receiver operating characteristic curves identified cutoffs for ASM and handgrip strength in association to fear of falling.

RESULTS: Physical function decreased with increasing age and body composition varied according to gender. In association to fear of falling, ASM adjusted by body mass index (ASM(BMI)) cutoffs were <0.85 for men and <0.53 for women; for absolute

handgrip strength and relative handgrip strength (adjusted by BMI) were 30.0 kgf, and 21.7 kgf; and 1.07, and 0.66, for men and women, respectively.

CONCLUSION: Values of physical function tests and other variables can be used as reference at clinics and practice. Moreover, we encourage the use of ASM(BMI) and to

choose over absolute or relative handgrip strength for both men and women according to study needs.

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RESUMO

CONTEXTO E OBJETIVO: Sarcopenia é um problema de saúde emergente no Brasil. Devido à alta prevalência e falta de valores nacionais, o objetivo foi identificar pontos de corte para massa muscular apendicular (MMA) e força de preensão manual em associação ao medo de cair em idosos brasileiros.

DESENHO E LOCAL: Transversal; comunidade.

MÉTODOS: 578 idosos foram submetidos a análises morfológicas e funcionais e questionados sobre a prevalência de quedas e medo de cair. Diferentes ajustes de MMA e força de preensão manual foram usados. Baixa velocidade da marcha foi estabelecida em <0.8 m/s. Idosos divididos por gênero e idade foram comparados por testes T, análise de variância (ANOVA), teste do qui-quadrado ou Exato de Fisher. Curvas Receiver operating characteristic foram usadas para identificar os pontos de corte para MMA e força de preensão manual em associação ao medo de cair.

RESULTADOS: Níveis de funcionalidade diminuíram com a idade, enquanto a composição corporal variou entre sexos. Associados ao medo de cair, os pontos de corte para MMA ajustada pelo índice de massa corporal (MMA(IMC)) foram <0.85 para homens e <0.53

para mulheres; para força de preensão manual absoluta e relativa (ajustada pelo IMC) foram 30.0 kgf e 21.7 kgf; e 1.07, e 0.66, para homens e mulheres, respectivamente.

CONCLUSÃO: Os valores apresentados podem ser usados como referência na clínica e prática. Recomendamos o uso da MMA (IMC) e a escolha entre força de preensão

manual absoluta ou relativa para homens e mulheres de acordo com as necessidades do estudo.

PALAVRAS-CHAVE: Envelhecimento; Sarcopenia; Músculo esquelético; Força da mão;

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INTRODUCTION

Sarcopenia, defined as progressive loss of muscle mass and strength/functionality with aging, is an emerging public health issue in Brazil.1 The loss of muscle mass and function may result in loss of physical capabilities (e.g. endurance, strength, and muscle power), poor quality of life, unfavorable metabolic effects, falls and fear of falling, frailty, and mortality rate in older adults. Furthermore, sarcopenia is frequently associated with multimorbidities, smoking habit, low body mass index (BMI), malnutrition, and physical inactivity.2

Several consensuses and recommendations have been proposed by different institutions attempting to standardize the conceptual approaches used to diagnose sarcopenia.2,3,4,5 Among those, experts agree that three key factors should be approached: body composition (muscle mass); functionality (e.g. walking speed), and muscle strength (e.g. handgrip strength).

Studies estimate that after the age of 50 the muscle mass decreases consistently at a rate of approximately 1% per year, walking speed at a rate of 2.0 - 2.2% and handgrip strength at a rate of 1.9 - 5.0%, as a result of the transition process of decreasing lean body mass and increasing fat accumulation.6,7 Cutoffs and reference values have also been presented in the consensuses and recommendations. Besides the international characteristics of the studies they compiled, most of them were conducted in developed countries and/or in genetically, ethnically and culturally different countries than Brazil. Even when considering the miscegenation of Brazilian population, inferences of such values in Brazilian older adults are difficult and limited.

Therefore, considering the importance given to sarcopenia that recently culminated in the determination of an International Classification of Diseases (ICD-10) code;8 the rising prevalence in older Brazilians that already achieved 17%;1 and the lack of national preliminary data, the aim of this study was to identify cutoff values for appendicular skeletal muscle (ASM), and handgrip strength according to fear of falling in Brazilian older adults.

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OBJECTIVE

The aim of this study was to identify evidence-based cutoff values for ASM, and handgrip strength according to fear of falling; and secondarily, to verify the morphological and functional characteristics in Brazilian older adults according to gender and age groups.

METHODS

Design

This study had a cross sectional design (frequency study) and data were collected during 2015 and 2016.

Subjects

In total, 578 older adults (male n=122, female n=456) participated in this study. They were recruited voluntarily from four community health centers for older adults in southeastern and southern Brazil; however, individuals represent diversity of ethnicity, other geographic areas, and a range of health and functional states.

The inclusion criteria were: a) community-dwelling people; b) 60 years old or older, from both sexes; c) able to answer the questions, perform the functional and body composition tests. Exclusion criteria were: a) individuals with uncontrolled cardiovascular or pulmonary disease, with conditions associated with risk of falling (i.e. Parkinson’s disease or stroke), physically and cognitively impaired (according to their report of chronical diseases [e.g., presence of condition that might require assistance for basic activities of daily living], and items present in the functional assessment staging of Alzheimer’s disease – FAST, verified onsite); b) individuals using metal prosthesis and/or pacemaker (i.e., interference - bioelectrical impedance analysis).

The present study was approved by the Ethical Committee of the University of Campinas, protocol #39437514.0.0000.5404. All participants signed an informed consent agreeing to participate in the study before data collection.

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Assessments

The assessments were divided into two steps, to quote: a) indirect assessments based on questionnaires, and b) direct assessments based on morphofunctional evaluations (i.e., anthropometric characteristics and physical function). Before the evaluations, all tests were explained in details by an experienced researcher to all participants. Verbal encouragement was provided to assure that volunteers reached the best performance possible.

Indirect assessments

Chronical degenerative diseases, age, fear of falling and falls

A questionnaire was used to obtain data regarding the presence of chronical diseases, age, the fear of falling and the occurrence of falls during the year prior to the research. The questionnaire was based on simple questions, which were answered with binary constructs (i.e., yes or no) avoiding possible misunderstanding among the researchers and the volunteers. First, an extensive list of the most prevalent chronic diseases (e.g., hypertension, diabetes, osteoporosis) in older adults was presented to the volunteers. They then stated yes or no if they presented a previous clinical diagnosis of the chronical condition. These data are not shown and were used solely for exclusion purposes. In relation to fear of falling, the following question was asked: “Are you afraid of falling?”. And the following question was asked about the occurrence of falls: “Have you experienced a fall in the past year?’’. Important to mention, only the question about occurrence of falls was retrospective, so that all the other questions and evaluations were in relation to the period where the study was performed.

Direct assessments

Anthropometrical measures

Height was measured by standard stadiometer and waist and hip circumferences using a measuring tape. The body composition was assessed by bioelectrical impedance analysis (BIA) (Tanita® BC-108, Tokyo, Japan). The equipment provided the weight of the subject, and the height was inserted manually by the researcher. After analysis, values of

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absolute and segmented muscle and fat mass were obtained. The Tanita BIA uses a frequency of 50 kHz to measure the quantity of intra and extracellular water in the body. This equipment has eight electrodes, four under the feet and four on volunteers’ hands.9,10

The values of ASM (sum of muscle mass of limbs) are useful to diagnose sarcopenia. In this study, we used several adjustments (i.e. by BMI, height squared, weight and non-adjusted data) to verify the best approach in Brazilian older adults. Additional data concerning absolute skeletal muscle was also provided.

Physical function

The walking speed was evaluated in a 10 meters distance. Outside marks of 12 m in length were clearly placed on the ground during the walking test. Another 10-m long delimitation was marked inside the previous one. Participants were asked to walk the entire distance at their usual pace. The time required to complete the inner 10-m distance was assessed.11 Continuous values of walking speed, as well as using 0.8m/s and 1.0m/s cutoffs were also applied. The value 0.8 m/s has been suggested by other studies as representative of slow walking. Also considering the range in walking speed that they found in such studies, and the characteristics of the samples that we studied, 1 m/s was also used.2,3

The TUG has been widely described. The subject has to stand from a chair, to walk three meters in straight line, to surround a cone and to return to the chair and sit.12

The handgrip strength was measured with a digital dynamometer Jamar (Jamar Plus+®; Sammons Preston, Rolyon, Bolingbrook, IL). While seated, the subject held the dynamometer with elbow flexed in 90° without touching his/her body. After preparation, they were instructed to pull the lever at his/her maximum; each hand was tested once and the best value was used in analysis. Subjects were also instructed to avoid the Valsava maneuver or blocked breath while performing the test. Handle position two was set as standard for all subjects as previously recommended.13

Statistical analyses

All analyses were carried out using the Statistical Package for the Social Sciences (version 21.0, SPSS, IBM Inc., Chicago, IL, USA) and the MedCalc Statistical Software version 17.2 (MedCalc Software, Ostend, Belgium). Descriptively, values are presented as

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mean ± standard deviation (SD) for continuous variables and frequency (%) for categorical values.

To compare older adults’ characteristics by gender, unpaired T tests and chi-square tests were used for continuous and categorical variables, respectively. In analyzes by age, subjects were divided into five groups (60 to 64, 65 to 69, 70 to 74, 75 to 79 and 80 + years old). For continuous variables, analysis of variance (ANOVA) was used; when statistical differences were found, Tukey Post Hoc test was applied. For categorical variables, chi-square or Fisher’s Exact Test was used.

In addition, receiver operating characteristic (ROC) curve analyses were used to verify cutoff values for ASM and handgrip strength in association to fear of falling. For this, different adjustments of ASM, and handgrip strength were used; the curves were then compared to verify statistical differences among them. The ROC curve compares true-positive rate (sensitivity) versus false-true-positive rate (1 - specificity) across a range of values for the ability to predict a dichotomous outcome. High sensitivity corresponds to high negative predictive value, while high specificity corresponds to high positive predictive value. Sensitivity and specificity were used to identify the cutoff values for ASM and handgrip strength in this study.14 The area under the curve (AUC) is a measure of test performance and describes the probability that a test will correctly identify individuals who did and did not have a condition and were randomly selected from the cohort. Generally, the closer the AUC is to 1, the better the overall diagnostic performance of the test, and the closer to 0.5, the poorer the test.15,16 Sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and likelihood ratios (positive [LR+] and negative [LR-]) for ASM and handgrip strength according to fear of falling were computed. Predictive values describe the probability of a person having a condition once the results of his or her tests are known. LR+ and LR- indicate how much the odds of a disease increase or decrease when a test is positive and negative, respectively.

The fear of falling was selected as the primary outcome for this study because of its association with psychological and physical aspects, such as falls, loss of confidence, restriction of activities, social withdrawal, which may lead to dependence and disability.17,18 Other variables were considered as outcomes, such as falls and walking speed; however, due to the small number of subjects with positive results or missing data further analyses were not conducted. In all analyses, statistical significance was set at P <0.05.

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RESULTS

In total, 578 older adults (male n=122, female n=456) participated in this study. Their characteristics are descriptively shown in Table 1. The mean age was 70.0 ± 6.7 years for male and 69.4 ± 6.6 for female. Women had lower strength and were more overweight than men. Moreover, more women experienced a fall event in the year prior the research (women 25.3% and men 14.4%) and reported fear of falling (women 65.7% and men 43.7%). Regarding physical function, women had slow walking speed than men (Table 1).

Table 2 and 3 present study data according to gender, divided by age groups.

Higher rates of fear of falling in both groups were shown at the age group 80 years old or more; however, only in men the difference was statistically significant. In older men, the age group 60 to 64 years was stronger than those aged 80 or more when considering absolute values of handgrip strength. Such difference was not verified when data was adjusted by BMI. The age group 60 to 64 years also had higher skeletal muscle (total and adjusted by height squared), and total ASM. Regarding walking speed and the TUG tests, the function also decreased as age increased; a similar trend was observed regarding BMI, but not fat percentage (Table 2).

It was evident that older women had slower walking speed, TUG, and lower muscle strength than younger women, verified by both absolute and relative handgrip strength. Fat percentage, BMI and skeletal muscle (total, adjusted by BMI, height squared, and weight) also decreased with increasing age. Regarding ASM, only the total and the one adjusted by height squared failed to show statistical differences (Table 3).

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Table 1. Older adults’ characteristics

Older adults (n=578) P

Variables Male (n=122) Female (n=456)

Age (y) 70.5 ± 6.7 69.4 ± 6.6 0.11

Handgrip strength (kgf) 37.4 ± 8.1 24.2 ± 4.8 < 0.001

Relative handgrip strength (Adjusted by body mass index)

1.4 ± 0.3 0.8 ± 0.2 < 0.001

Body mass index (kg/m2) 26.8 ± 3.5 28.3 ± 4.9 < 0.001

Fat percentage (%) 26.2 ± 6.1 41.1 ± 6.8 < 0.001

Total skeletal muscle mass (kg) 51.4 ± 6.7 36.2 ± 3.3 < 0.001 Skeletal muscle mass

(Adjusted by body mass index)

1.94 ± 0.2 1.31 ± 0.1 < 0.001

Skeletal muscle mass (kg/m2) (Adjusted by height squared)

18.4 ± 1.4 15.3 ± 0.8 < 0.001

Skeletal muscle mass (Adjusted by weight)

0.7 ± 0.05 0.5 ± 0.06 < 0.001

Total appendicular skeletal muscle (kg) 25.2 ± 4.0 16.4 ± 1.8 < 0.001 Appendicular skeletal muscle

0.95 ± 0.1 0.59 ± 0.08 < 0.001

Appendicular skeletal muscle (kg/m2) (Adjusted by height squared)

9.04 ± 1.0 6.9 ± 0.6 < 0.001

Appendicular skeletal muscle (Adjusted by weight)

0.34 ± 0.03 0.25 ± 0.02 < 0.001

Falls in the year prior research 17 (14.4) 113 (25.3) 0.01

Fear of falling 52 (43.7) 291 (65.7) < 0.001

Waist circumference (cm) 97.5 ± 9.6 95.2 ± 11 0.03

Hip circumference (cm) 100.6 ± 6.3 103.5 ± 9.8 < 0.001

Timed Up and Go (s) 7.6 ± 2.6 8 ± 2.4 0.14

Usual walking speed (m/s) 1.3 ± 0.3 1.2 ± 0.2 0.03

Slow walking speed (by cutoff <0.8 m/s) 6 (5.0) 17 (3.8) 0.56 Slow walking speed (by cutoff <1.0 m/s) 18 (14.9) 62 (13.8) 0.77 Notes. Values are mean ± standard deviation and n (%).

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Table 2. Characteristics according to age in older men (n=122)

Variables 60~64 (n=25) 65~69 (n=35) 70~74 (n=27) 75~79 (n=24) 80+ (n=11) P

Falls in the year prior research 3 (12.5) 5 (14.7) 3 (11.1) 3 (13.0) 3 (30.0) 0.69

Fear of falling 8 (32.0) 13 (38.2) 8 (30.8) 15 (65.2) 8 (72.7) 0.02

Waist circumference (cm) 99.9 ± 8.3 95.4 ± 8.1 99.6 ± 9.7 97.6 ± 11.3 93.4 ± 11.3 0.16

Hip circumference (cm) 102.3 ± 6 100.2 ± 4.6 100.8 ± 6.3 101.0 ± 7.4 96.4 ± 8.8 0.16

Handgrip strength (kgf) 40.4 ± 8.3 39.3 ± 6.5 37.7 ± 8.7 35.6 ± 6.8 28.6 ± 6.9ǂ < 0.001 Relative handgrip strength

1.4 ± 0.2 1.4 ± 0.3 1.4 ± 0.4 1.3 ± 0.2 1.2 ± 0.2 0.13

Usual walking speed (m/s) 1.4 ± 0.2 1.4 ± 0.2 1.3 ± 0.3 1.2 ± 0.3† 1.0 ± 0.3ǂ† < 0.001

Slow walking speed (by cutoff <0.8 m/s) -- -- 1 (3.7) 3 (12.5) 2 (18.2) 0.01

Slow walking speed (by cutoff <1.0 m/s) 1 (4) 1 (2.9) 5 (18.5) 5 (20.8) 6 (54.5) < 0.001

Timed Up and Go (s) 7 ± 1.8 6.6 ± 1.6 7.5 ± 2.10 8.8 ± 3.9† 10 ± 2.4ǂ† < 0.001

Fat percentage (%) 27.5 ± 5.3 25.2 ± 5.9 26.7 ± 6.3 27.1 ± 5.3 22.3 ± 8.9 0.16

Body mass index (kg/m2) 27.8 ± 3.3 26.5 ± 3.2 27.1 ± 3.5 26.9 ± 3.8 23.4 ± 3.1ǂ 0.03 Total skeletal muscle mass (kg) 54.4 ± 6.8 52.4 ± 4.4 50.4 ± 6.5 50.8 ± 7.8 44.0 ± 5.7ǂ 0.001 Skeletal muscle mass

1.9 ± 0.2 1.9 ± 0.2 1.9 ± 0.2 1.9 ± 0.2 1.8 ± 0.2 0.51

18.9 ± 1.2 18.5 ± 1.5 18.4 ± 1.1 18.4 ± 1.5 17.1 ± 1.7ǂ 0.03

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(Adjusted by weight)

Total appendicular skeletal muscle (kg) 26.3 ± 3.9 25.7 ± 2.8 26.6 ± 4.1 25.3 ± 5.0 21.6 ± 3.7ǂ 0.03 Appendicular skeletal muscle

0.9 ± 0.1 0.9 ± 0.1 0.9 ± 0.1 0.9 ± 0.1 0.9 ± 0.1 0.70

9.1 ± 0.8 9.1 ± 0.9 8.9 ± 0.9 9.0 ± 1.1 8.4 ± 1.2 0.34

0.3 ± 0.02 0.3 ± 0.02 0.3 ± 0.03 0.3 ± 0.02 0.3 ± 0.04 0.15

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Table 3. Characteristics according to age in older women (n=455)

Variables 60~64 (n=127) 65~69 (n=123) 70~74 (n=102) 75~79 (n=68) 80+ (n=35) P

Falls in the year prior research 25 (20.2) 30 (25.0) 27 (27.0) 21 (31.3) 9 (26.5) 0.52

Fear of falling 75 (60.5) 73 (60.8) 69 (69.7) 49 (73.1) 24 (75) 0.06

Waist circumference (cm) 95.7 ± 10.9 94.9 ± 10.1 97.2 ± 12.1 92.7 ± 10.8 93.3 ± 10.2 0.07 Hip circumference (cm) 104.7 ± 9 102.7 ± 8.9 105.2 ± 11.7 101.7 ± 9.9 100.7 ± 7.3 0.03 Handgrip strength (kgf) 25.5 ± 5 25.1 ± 4.5 24.5 ± 4.4 21.5 ± 3.8ǂ†‖ 20.9 ± 4.7ǂ†‖ < 0.001 Relative handgrip strength

0.8 ± 0.2 0.9 ± 0.2 0.8 ± 0.2 0.8 ± 0.1† 0.8 ± 0.2 0.01

Usual walking speed (m/s) 1.3 ± 0.2 1.3 ± 0.2 1.2 ± 0.2ǂ 1.2 ± 0.3ǂ† 1 ± 0.3ǂ†‖‡ < 0.001 Slow walking speed (by cutoff <0.8 m/s) -- 3 (2.5) 1 (1.0) 7 (10.4) 6 (17.6) < 0.001 Slow walking speed (by cutoff <1.0 m/s) 8 (6.5) 11 (9.2) 13 (12.7) 15 (22.4) 15 (44.1) < 0.001 Timed Up and Go (s) 7.0 ± 1.4 7.5 ± 1.9 8.2 ± 2.1ǂ 9.0 ± 2.9ǂ† 11.0 ± 3.8ǂ†‖‡ < 0.001 Fat percentage (%) 42.0 ± 6.1 40.9 ± 6.5 42.6 ± 6.7 39.4 ± 6.9‖ 37.3 ± 8.2ǂ†‖ < 0.001 Body mass index (kg/m2) 29.2 ± 5.5 28.1 ± 4.2 29.1 ± 4.9 27.0 ± 4.3ǂ‖ 25.9 ± 4.1ǂ‖ < 0.001 Total skeletal muscle mass (kg) 36.9 ± 3.2 36.5 ± 3.2 35.9 ± 3.3 35.2 ± 3.4ǂ 34.9 ± 3.7ǂ 0.001 Skeletal muscle mass

1.3 ± 0.2 1.3 ± 0.1 1.2 ± 0.1 1.3 ± 0.1 1.3 ± 0.2‖ 0.008

15.4 ± 0.8 15.3 ± 0.8 15.4 ± 0.7 15.1 ± 0.6 14.9 ± 0.8ǂ‖ 0.009

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(Adjusted by weight)

Total appendicular skeletal muscle (kg) 16.4 ± 1.7 16.6 ± 1.8 16.4 ± 1.8 16.1 ± 2.0 16.3 ± 2.1 0.62 Appendicular skeletal muscle

0.5 ± 0.07 0.5 ± 0.07 0.5 ± 0.07 0.6 ± 0.08ǂ 0.6 ± 0.09ǂ‖ < 0.001

6.8 ± 0.6 6.9 ± 0.6 7.1 ± 0.6 6.9 ± 0.6 7.0 ± 0.7 0.15

0.2 ± 0.02 0.2 ± 0.02 0.2 ± 0.02 0.2 ± 0.03ǂ‖ 0.2 ± 0.03ǂ†‖ < 0.001

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The ROC curves and comparisons among them are presented in Figure 1. Regarding ASM, the adjustment by BMI showed the best AUC for the association with fear of falling. Then, cutoff values were identified for both men (0.85; AUC=0.81; confidence interval 95% [CI 95%]: 0.73 – 0.89; P <0.001; sensitivity=33.3% and specificity=93.1%; PPV=73% and NPV=70%; LR+=4.71 and LR-=0.72) and women (0.53; AUC=0.76; CI 95%: 0.71 – 0.81; P <0.001; sensitivity=30.6% and specificity=92.1%; PPV=87% and NPV=41%; LR+=3.75 and LR-=0.76).

Concerning handgrip strength, absolute values showed slight better AUC than relative handgrip strength in men, while the AUC of relative handgrip strength showed better results in women. Considering this, cutoff values for both data will be provided. Thus, in men, the identified cutoffs for absolute handgrip strength were 30.0 kgf (AUC=0.75; CI 95%: 0.66 – 0.84; P <0.001; sensitivity=39.1% and specificity=94.7%; PPV=81% and NPV=71%; LR+=6.5 and LR-=0.64), and for women 21.7 kgf (AUC=0.56; CI 95%: 0.51 – 0.62; P=0.02; sensitivity=29.9% and specificity=73.2%; PPV=67% and NPV=36%; LR+=1.07 and LR-=0.97). Identified cutoffs for relative handgrip strength were 1.07 (AUC=0.74; CI 95%: 0.65 – 0.83; P <0.001; sensitivity=27.9% and specificity=93.2%; PPV=70% and NPV=69%; LR+=3.85 and LR-=0.78), and 0.66 (AUC=0.67; CI 95%: 0.62 – 0.73; P <0.001; sensitivity=22% and specificity=90%; PPV=82% and NPV=39%; LR+=2.2 and LR-=0.86), for men and women, respectively. For computed 2x2 tables, refer to supplementary Tables

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Men A

B

AUC ASM (adjusted by BMI): 0.81

ASM (adjusted by height squared): 0.66 ASM (adjusted by weight): 0.74 ASM (non-adjusted): 0.73

AUC Handgrip strength (absolute): 0.75

Relative handgrip strength (adjusted by BMI): 0.74 ASM (non-adjusted) ≠ ASM (adjusted by height squared), p = 0.03 ASM (adjusted by BMI) ≠ ASM (adjusted by height squared), p = 0.02

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Women C

D

Figure 1. ROC curves for appendicular skeletal muscle (ASM) with different adjustments,

and handgrip strength (HGS) (absolute value and adjusted by BMI). Fear of falling was used as outcome variable. Data of men (A-B) and women (C-D) are presented. Statistical difference among or between curves were presented, when they occurred. AUC: area under the curve.

ASM (non-adjusted) ≠ ASM (adjusted by BMI), p<0.001 ASM (adjusted by BMI) ≠ ASM (adjusted by weight), p<0.001 ASM (adjusted by BMI) ≠ ASM (adjusted by height squared), p<0.001 ASM (adjusted by height squared) ≠ ASM (adjusted by weight), p<0.001

Handgrip strength (absolute) ≠ Relative handgrip strength (adjusted by BMI), p<0.001 AUC

ASM (adjusted by BMI): 0.76

ASM (adjusted by height squared): 0.43 ASM (adjusted by weight): 0.70 ASM (non-adjusted): 0.55

AUC Handgrip strength (absolute): 0.56

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DISCUSSION

This study presented reference values of strength, physical function tests, body composition, anthropometric measures, falls, and fear of falling by age in a community-based cohort of older men and women from 60 years old. Moreover, cutoff values for ASM and handgrip strength, useful to verify sarcopenia in older adults, were also presented according to fear of falling.

As extensively reported in the literature, differences by gender concerning ASM, strength, and body composition were observed, as well as decline in physical function with increasing aging in older adults. The tests used in this study have clinical relevance, and reference values of this nature are limited in Brazilian literature, increasing external validity of this study. Even though some of them presented similar values as found in other populations, local values are preferable when available, once regional characteristics can alter results and comparison. This data can be useful for the clinician that needs reference values to compare observed performance at clinical practice and in research, to compare different populations.

Evidence from this study highlights the imminent hazard that surrounds the oldest old group (80 years or more). They showed the highest fear of falling, which might have impacted on their worst physical performance among groups. It is difficult to predict the beginning of such cascade effect; however, for health promoters, it is crucial to implement interventions addressing physical and psychosocial aspects to face these conditions.

The values we found herein for handgrip strength were similar to those shown by Yoshimura et al., 2011; however, the subjects in this study performed better in walking speed. Importantly, in such study subjects were categorized by decades and walking speed was measured in a 6-m path.19 The Asian Working Group for Sarcopenia (AWGS) recommended using the lower 20th percentile of handgrip strength of the study population as the cutoff value for low strength, due to lack of outcome-based cutoff values. Then, they suggest values of <26 kgf for men and <18 kgf for women.2 Similarly, the European Working Group on Sarcopenia in Older People (EWGSOP) suggests <30 kgf for men and <20 kgf for women3 as cutoff values; in this study, we found the cutoffs of 30 kgf for Brazilian men and 21.7 kgf for Brazilian women, when considering absolute handgrip strength values. Despite the fact we could not contribute providing cutoff values for walking speed in Brazilian older

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adults at this time, both studies (AWGS and EWGSOP) recommend the use of <0.8 m/s as the cutoff for slow walking performance.2,3

Concerns have been raised regarding the influence of body mass on the relationships among performance, strength, and muscle mass, especially by the Foundation for the National Institutes of Health (FNIH Sarcopenia Project), a large sample study that used multiple existing data sources to identify criteria for clinically relevant weakness and low lean mass.5,20,21 Then, we performed several analyses to clarify the need to adjust handgrip strength and muscle mass for body mass. In this sense, we found the cutoffs for relative handgrip strength adjusted for BMI of 1.07 for men and 0.66 for women. The values suggested by FNIH Sarcopenia Project were: men with ratio <1.0 and women with a ratio <0.56 defined as weak.21 The necessity of this adjustment will be further discussed.

Regarding the TUG, Bohannon (2006), in a descriptive meta-analysis verified mean values (95% confidence intervals - CI) according to age (60 to 69, 70 to 79 and 80 to 99 years) of 8.1s (95% CI=7.1 – 9.0), 9.2s (95 % CI=8.2 – 10.2) and 11.3s (95% CI=10.0 – 12.7), respectively.12 Indicating that those whose performance exceeds the limits of reported confidence intervals can be considered to have worse than average performance. These values are within the range we found in this study. Furthermore, considering healthy Japanese individuals from 60 years or more, Kamide, Takahashi and Shiba (2011) verified the weighted mean of TUG with maximum effort at 6.60 (95% CI=6.18 – 7.02) seconds, and that at usual pace was 8.86 (95% CI=7.99 – 9.72) seconds;22 certainly, shorter than other populations.

The study data presented the decline of physical performance through specific tests in both genders as age increases, but the changes in skeletal muscle depended on the adjustment applied. The identified ASM (adjusted by BMI) cutoff values for older adults according to gender were 0.85 for men and 0.53 for women. Interestingly, the values proposed by the FNIH sarcopenia project were 0.789 and 0.512, for men and women, respectively.5 We also verified that adjustments by BMI were the best approach in both genders; then, we suggest the use of these cutoffs to screen older adults from both sexes for increasing disability risk, according to fear of falling, being these values a more realistic approach to Brazilian older individuals.

Because of the adjustments of data we conducted herein, our results are not directly comparable to other proposed definitions of low ASM or sarcopenia. Initially, both the EWGSOP and AWGS groups suggested the approach of using – 2 SD of ASM of young individuals as cutoff points of muscle mass.2,3 However, low muscle mass alone is not

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consistently associated with adverse health outcomes5 challenging new approaches. Then, the adopted methodology in this study limits our comparisons, but stimulates other researchers to provide more suitable and comparable data.

Considering the role of body mass, it was different according to gender. In men, the AUC was slightly lower in the relative than absolute handgrip strength. However, in women the relative handgrip strength showed better results. Interestingly, a similar finding was verified by Alley et al. (2014); and even with our small sample size in men’s group and with a different outcome-based variable we verified a similar condition.20 It remains unclear why this occurs, and BMI would be more important for women than for men.

To our knowledge, this is the first study providing reference data and cutoff values adjusted by body mass in Brazilian older adults. We expect that these data will be useful for both clinicians at practice and researchers, which can use national data regarding physical function and muscle mass in older adults.

We provided several adjustments of data, but for consistency, we encourage researchers to use ASM adjusted by BMI and to choose by convenience absolute handgrip strength or relative handgrip strength adjusted by BMI for both men and women, or even different types of indicators for each gender. For walking speed, a cutoff value <0.8 m/s, as previously suggested2,3,5 can be applied to research and clinical practice to identify mobility impairment. Values of physical function tests and other variables can be used as reference by age categories as we presented in this study.

The limitations of this study included: (i) its cross-sectional design that did not permit the determination of a cause-effect relationship between variables; (ii) the small number of older male subjects; (iii) the retrospective nature of data about the occurrence of falls that might be biased; and (iv) the use of fear of falling, and no other disability condition or mortality, as outcome. However, although longitudinal analyses are preferable over cross-sectional designs, it is appropriate for establishing clinical diagnostic cutoff values.5 Moreover, even though mortality or other disability outcomes seems more representatives to sarcopenia, fear of falling was highly associated to sarcopenia in older adults23, as previously verified, certifying its use. We suggest future studies to recruit a higher number of male subjects, to use different sampling fields and alternative methods to verify body composition, such as dual-energy x-ray absorptiometry. In addition, longitudinal studies using disability or mortality as an outcome are necessary to determine optimal cutoffs for ASM, handgrip strength and walking speed.

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In summary, we have identified age-related decline in physical function, changes in body composition and anthropometrical measures. Moreover, cutoff values of handgrip strength (absolute: men <30 kgf; women <21.7 kgf; and relative: men <1.07; women <0.66) and ASM (ASM adjusted by BMI: men <0.85; women <0.53) in association with fear of falling in Brazilian older adults were also provided. Further analyses also suggested that adjustment for BMI may influence how data can be interpreted. Value of walking speed was established at <0.8 m/s as previously recommended. In future studies, we intend to evaluate the capacity of these cutoff values to discriminate those in vulnerable conditions, especially regarding low quality of life and frailty.

CONCLUSION

The values of physical function tests and the other variables presented by age groups highlights the hazard surrounding the oldest old. Such data are useful references for both clinicians at practice and researchers. Moreover, ASM adjusted by BMI was the best approach, while adjustment of handgrip strength varied by gender. We recommend the use of ASM adjusted by BMI and to choose over absolute handgrip strength or relative handgrip strength (adjusted by BMI) for both men and women according to study needs.

REFERENCES

1. Diz JB, Leopoldino AA, Moreira BS, et al. Prevalence of sarcopenia in older Brazilian: A systematic review and meta-analysis. Geriatr Gerontol Int. 2017;17(1):5-16.

2. Chen L-K, Liu LK, Woo J, et al. Sarcopenia in Asia: Consensus Report of the Asian Working Group for Sarcopenia. J Am Med Dir Assoc. 2014;15(2):95-101.

3. Cruz-Jentoft AJ, Baeyens JP, Bauer JM, et al. Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People. Age and ageing. 2010;39(4):412-23.

4. Morley JE, Abbatecola AM, Argiles JM, et al. Sarcopenia with Limited Mobility: An International Consensus. J Am Med Dir Assoc. 2011;12:403-9.

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5. Studenski SA, Peters KW, Alley DE, et al. The FNIH Sarcopenia Project: Rationale, study, description, conference recommendations, and final estimates. J Gerontol A Biol Sci Med Sci. 2014;69(5):547-58.

6. Goodpaster BH, Park SW, Harris TB, et al. The loss of skeletal muscle strength, mass, and quality in older adults: the health, aging and body composition study. J Gerontol A Biol Sci Med Sci. 2006;61:1059-64.

7. Auyeung TW, Lee SW, Leung J, Kwok T, Woo J. Age-associated decline of muscle mass, grip strength and gait speed: a 4-year longitudinal study of 3018 community dwelling older Chinese. Geriatr Gerontol Int. 2014;14(Suppl 1):76–84.

8. Morley JE, CAO L. Rapid screening for sarcopenia. Journal of Cachexia, Sarcopenia and Muscle. 2015;6:312-4.

9. TANITA CORPORATION Website. TANITA Bioimpedance Analyzer BC-108 (In Japanese). Available from: http://www.tanita.co.jp/shop/g/_BC10800001/. Accessed in 2017 (Apr 25).

10. Pietrobelli A, Rubiano F, St-Onge M-P, Heymsfield SB. New bioimpedance analysis system: improved phenotyping with whole-body analysis. European Journal of Clinical Nutrition. 2004;58(11):1479-84.

11. Sampaio RAC, Sewo Sampaio PY, Uchida MC, et al. Walking speed and balance performance are associated with Short-Form 8 bodily pain domain in Brazilian older female. Journal of Clinical Gerontology & Geriatrics. 2015;6:89-94.

12. Bohannon RW. Reference values for the timed up and go test: a descriptive meta-analysis. J Geriatr Phys Ther. 2006;29(2):64-8.

13. Trampisch US, Franke J, Jedamzik N, Hinrichs T, Platen P. Optimal Jamar dynamometer handle position to assess maximal isometric hand grip strength in epidemiological studies. J Hand Surg. 2012;37(11):2368-73.

14. Florkowski CM. Sensitivity, specificity, receiver-operating characteristic (ROC) curves and likelihood ratios: communicating the performance of diagnostic tests. Clin Biochem Rev. 2008;29 Suppl 1:S83-7.

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15. Akobeng AK. Understanding diagnostic tests 1: sensitivity, specificity and predictive values. Acta Paediatrica. 2006;96(3):338-41.

16. Akobeng AK. Understanding diagnostic tests 3: receiver operating characteristic curves. Acta Paediatrica. 2007;96(5):644-7.

17. Denkinger MD, Lukas A, Nikolaus T, Hauer K. Factors associated with fear of falling and associated activity restriction in community-dwelling older adults: a systematic review. Am J Geriatr Psychiatry. 2015;23:73-86.

18. Trombetti A, Reid KF, Hars M, et al. Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life. Osteoporos Int. 2016;27(2):463-71.

19. Yoshimura N, Oka H, Muraki S, et al. Reference values for hand grip strength, muscle mass, walking time, and one-leg standing as indices for locomotive syndrome and associated disability: the second survey of the ROAD study. J Orthop Sci. 2011;16:768-77.

20. Alley DE, Shardell MD, Peters KW, et al. Grip strength cutpoints for the identification of clinically relevant weakness. J Gerontol A Biol Sci Med Sci. 2014;69(5):559-66.

21. Cawthon PM, Peters KW, Shardell MD, et al. Cutpoints for low appendicular lean mass that identify older adults with clinically significant weakness. J Gerontol A Biol Sci Med Sci. 2014;69(5):567-75.

22. Kamide N, Takahashi K, Shiba Y. Reference values for the Timed Up and Go in healthy Japanese elderly people: Determination using the methodology of meta-analysis. Geriatr Gerontol Int. 2011;11:445-51.

23. Yamada M, Nishiguchi S, Fukutani N, et al. Prevalence of sarcopenia in community-dwelling Japanese older adults. JAMDA. 2013;14(12):911-5.

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Supplementary tables

Table S1. Appendicular skeletal muscle adjusted by body mass index vs. fear of falling

(Men).

Fear of falling Total

Had fear of falling No fear of falling

ASM(BMI) < 0.85 14 5 19

ASM(BMI) > 0.85 28 67 95

Total 42 72 114

Pearson Chi-square P<0.001. ASM(BMI)= Appendicular skeletal muscle adjusted by body mass index.

Sensitivity: {14/(14+28)}=0.33=33% Specificity: {67/(5+67)}=0.93=93%

Positive predictive value (PPV): {14/(14+5)}=0.73=73% Negative predictive value (NPV): {67/(28+67)}=0.70=70% Positive likelihood ratio (LR+): sensitivity/(1-specificity)=4.71 Negative likelihood ratio (LR-): (1-sensitivity)/specificity=0.72

Table S2. Absolute handgrip strength vs. fear of falling (Men).

Absolute HGS < 30 kgf 18 4 22

Absolute HGS > 30 kgf 28 71 99

Total 46 75 121

Pearson Chi-square P<0.001. HGS= Handgrip strength. Sensitivity: {18/(18+28)}=0.39=39%

Specificity: {71/(4+71)}=0.94=94%

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Table S3. Relative handgrip strength vs. fear of falling (Men).

HGS(BMI) < 1.07 12 5 17

HGS(BMI) > 1.07 31 69 100

Total 43 74 117

Pearson Chi-square P=0.002. HGS(BMI)= Handgrip strength adjusted by body mass index. Sensitivity: {12/(12+31)}=0.27=27%

Specificity: {69/(5+69)}=0.93=93%

Table S4. Appendicular skeletal muscle adjusted by body mass index vs. fear of falling

(Women).

ASM(BMI) < 0.53 84 12 96

ASM(BMI) > 0.53 194 140 334

Total 278 152 430

Pearson Chi-square P<0.001. ASM(BMI)= Appendicular skeletal muscle adjusted by body mass index.

Sensitivity: {84/(84+194)}=0.30=30% Specificity: {140/(12+140)}=0.92=92%