Sarcopenia in the elderly: comparative evaluation by anthropometry, bioimpedancometry and bone densitometry

Introdução: A população mundial está envelhecendo, tornando a qualidade de vida do idoso uma demanda de estratégias imediatas sociais, políticas e econômicas. O processo de envelhecimento impõe modificações na composição corporal dos indivíduos, como o declínio gradual da massa e função muscular, definida por sarcopenia, que está associada a incapacidade, dependência e maior vulnerabilidade. A metodologia padrão de medida de índice de massa magra (IMM) é a densitometria (DEXA). Porém necessita de equipamento e treinamento de alta complexidade e custo. Objetivo: avaliar a acurácia das metodologias de mensuração de IMM no idoso, através de bioimpedância (BIA) e cálculos antropométricos comparadas a DEXA. Métodos: Idosos do sexo masculino de um serviço público terciário de geriatria foram submetidos a testes de força de preensão palmar, medidas antropométricas (peso, altura, circunferência de cintura e quadril, prega cutânea tricipital, resistência, reatância e massa apendicular), realização de bioimpedância e DEXA. Os dados obtidos foram aplicados em 3 equações validadas para predição de índice de massa muscular: dados antropométricos para equação de Baumgartner et al; dados da bioimpedância calculados segundo Janssen et al; Delmonico et al para dados de DEXA. Para a estratificação dos participantes em sarcopenicos e não sarcopenicos utilizamos as análises dos dados de IMM por DEXA e preensão palmar segundo seus limites de normalidade. Os dados foram submetidos a tabela de contingência 2x2 para sensibilidade, especificidade, valor preditivos e verossimilhança, ao teste de Bland Altman para análises de dispersão em relação a DEXA e os valores contínuos submetidos ao teste t student. Resultados: O perfil predominante dos 92 idosos que finalizaram todos os testes foi casado, 67% sedentários, 53% portadores de múltiplas morbidades em uso de polifarmácia, média de idade de 72,9±6,6 anos. Ambas metodologias BIA e antropometria mostraram correlação positiva com a DEXA(BIA: r =0,77 e p < 0,0001; antropometria:r=0,81 com p < 0,0001). Evidenciou-se prevalência de 28.2 % (n= 26) de sarcopenia entre os participantes. Os sarcopênicos apresentaram maior idade 76.6± 7,6 anos (p= 0.003), menor força de preensão palmar (24.1±4.7 kgf , p < 0.0001) e pior massa muscular apendicular 17.30 ±1.9 kfg (p=0.0001). A antropometria mostrou 35% (32 indivíduos) de prevalência de baixa massa livre de gordura, apresentando 86% de sensibilidade, Valor Preditivo Positivo (VPP) de 67% e razão de verossimilhança (RVP) de 4,5. Ao analisarmos os dados da BIA, encontramos 93% de sensibilidade, especificidade 70%, VPP de 37% e uma RVP de 3,2. Conclui-se que ambas BIA e antropometria apresentam alta acurácia para estimar IMM. Porém, a utilização de dados antropométricos mostrou ser quase tão sensível e mai específico do que a BIA quando comparados à DEXA. Acrescida a alta acurácia para inferir IMM, o cálculo antropométrico mostrou ser de fácil aplicação e baixo custo,confiável para diagnosticar a sarcopenia, avaliando além da massa magra, também a força muscular, fator determinante para funcionalidadee qualidade de vida do indivíduo idoso vulnerável. Estes resultados sugerem que a antrompometria é o método de escolha para triagem de grandes populações dando suporte às intervenções políticas, socio-econômicas em termos de saude publica e privada, e para acompanhamento de sarcopenia do individuo idoso, exequível em qualquer pais independente do seu nível sócio econômicoIntroduction: The world\'s population is aging, making the elderly\'s quality of life a demand for immediate social, political and economic strategies. The aging process imposes changes in the body composition of individuals, such as the gradual decline of muscle mass and function, defined by sarcopenia, which is associated with incapacity, dependence and greater vulnerability. The standard methodology for measuring lean mass index (LMI) is densitometry (DXA). However, it requires expensive and high complexity equipment and personal training. Objective: to evaluate the accuracy of bioimpedance (BIA) and anthropometric calculations for measuring LMI in the elderly compared to DXA. Methods: Male seniors from a tertiary geriatrics public hospital were submitted to palmar grip strength tests, anthropometric measures (weight, height, waist and hip circumference, triceps skin fold, resistance, reactance and appendicular mass), BIA and DXA. The obtained data were applied in 3 validated equations for prediction of LMI: Baumgartner calculation for anthropometric data; Janssen calculation for bioimpedance data; Delmonico calculation for DXA data. Sarcopeny was defines as LMI by DXA and palmar grip according to their limits of normality. The data were submitted to a 2x2 contingency table for predictive sensitivity, specificity, likelihood values and predictive values; to the Bland Altman test for dispersion in relation to DXA and when continuous values to the student t test. Results: The predominant profile of the 92 elderly subjects who completed all the tests was married, 67% were sedentary, 53% had multiple comorbidities and polypharmacy, mean age was 72,9±6,6 years. Both BIA and anthropometry showed positive correlation with DXA (BIA: r = 0.77 and p < 0.0001; anthropometry: r = 0.81 , p < 0.0001). A prevalence of 28.2% (n = 26) of sarcopenia was observed among the participants. The sarcopenic individuals presented predominance of 76.6± 7,6 years of age (p = 0.10), lower palmar grip strength (24.1±4.7 kgf , p < 0.0001) and worse apendicular Muscle Mass 17.30 ±1.9 kfg (p=0.0001). Anthropometric calculations showed 35% prevalence of low fat free mass, presenting 86% sensitivity, 67% Positive Predictive Value (PPV) and 4,5 likelihood ratio (LR). BIA data presented 93% sensitivity, 70% specificity, 37% PPV, and a LR of 1.3. In conclusion both BIA and anthropometry present high accuracy to estimate LMI. However, anthropometric calculations showed more sensitivity, almost as specific as BIA when compared to DXA. In addition to high accuracy to infer LMI, the anthropometric calculation showed to be easily performed, applicable at low cost and reliable to diagnose sarcopenia. Besides the fat free mass, it also evaluates the muscular strength, a key point for functionability and quality of life of the elderly. These results suggest that anthropometry is the method of choice for screening for sarcopeny in the elderly and that it may support political, socioeconomic interventions in terms of public and private health, and for monitoring sarcopenia of the elderly individual, feasible in any country independent of its socioeconomic statu

Dual visual impairment and contrast sensitivity among community-dwelling older adults: a cross-sectional study from the PrevQuedas Brazil trial

OBJECTIVE: To investigate the importance of improving visual assessment for community-dwelling older adult fallers. METHODS: Cross-sectional study with eligible older adults (&gt; 60 years old) living in the community and who suffered at least one fall in the last 12 months from the PrevQuedas Brasil clinical trial. Sociodemographic data, information on previous falls, physical and functional assessment (BOMFAQ and FES-I) were collected. We evaluated impairments in visual acuity and contrast sensitivity using the Snellen E chart and low-contrast visual acuity tests, respectively. Dual visual impairment refers to the presence of both impairments. For statistical analysis we compared the participants in relation to the number of falls (single fallers or recurrent fallers) using Chi-square or Fisher's exact test and the significance level was &lt;0.05 for all analyses. RESULTS: Visual acuity, low contrast sensitivity, and dual visual impairment were associated with recurrent falls (OR 1.85); visual impairment was more prevalent among the oldest old. Approximately 90% of the participants reported using glasses, and 63.80% used multifocal lenses. Dual impairment was identified in 143 (20.30%) participants. In multivariate logistic regression, the predictive variables for recurrent falls were low contrast sensitivity (95%CI 1.15&ndash;2.47), dual visual impairment (95%CI 1.16&ndash;2.83), and self-perceived fall risk (95%CI 1.16&ndash;2.46) which was measured using the Falls Efficacy Scale-International. CONCLUSION: Older adults with dual visual impairment are more likely to suffer recurrent falls. Low contrast sensitivity is crucial for fall risk assessment. Trial registration: ClinicalTrials.gov (NCT01698580).</p