Midarm muscle circumference, physical performance and mortality: results from the aging and longevity study in the Sirente geographic area (ilSIRENTE study).

Background & Aims: Sarcopenia has been indicated as a reliable marker of frailty and poor prognosis among the oldest individuals. We evaluated the relationship between midarm muscle circumference (MAMC) and physical performance, muscle strength, functional status and survival in persons aged 80 years or older.
Methods: Data are from the baseline evaluation of the Aging and Longevity Study in the Sirente Geographic Area (ilSIRENTE Study) (n = 357). MAMC was calculated taking into account the mid upper arm circumference and the triceps skinfold thickness of the right arm. Physical performance was assessed using the physical performance battery score, which is based on three timed tests: 4-m walking speed test, the balance test and the chair stand test. Analyses of covariance were performed to evaluate the relationship between different MAMC levels and physical function. Cox proportional regression models were used to estimate crude and adjusted hazard ratios and 95% confidence intervals of death by MAMC levels.
Results: After adjustment for potential confounders - which included age, gender, living alone, sensory impairments (hearing and vision), body mass index, albumin and cholesterol - physical performance and function (which were measured using the 4-m walking speed test, the Short Physical Performance Battery score, the hand grip strength), improved significantly as MAMC increased. Compared with those in the low MAMC tertile, subjects in the high MAMC tertile had a lower risk of death (adjusted hazard ratio (HR) 0.45; 95% Confidence Interval (CI) 0.23-0.87).
Conclusions: The present study suggests that among community-dwelling old-old subjects muscle mass may be positively related to functional performance and survival.
(Copyright 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)