Weight stability masks sarcopenia in elderly men and women

TLDR

Cross‑sectional studies suggest sarcopenia in aging, but longitudinal evidence in elderly has been lacking. We followed 24 men and 54 women aged 60+ for an average of 4.7 years, measuring regional skeletal muscle mass and other lean components to track changes. Total skeletal muscle declined in both sexes—men lost 0.8 kg (leg 0.7 kg) and women 0.4 kg (leg 0.3 kg)—with men showing faster leg loss, stable body weight, and increased fat, indicating progressive sarcopenia even without weight loss.

Abstract

Skeletal muscle loss or sarcopenia in aging has been suggested in cross-sectional studies but has not been shown in elderly subjects using appropriate measurement techniques combined with a longitudinal study design. Longitudinal skeletal muscle mass changes after age 60 yr were investigated in independently living, healthy men ( n = 24) and women ( n = 54; mean age 73 yr) with a mean ± SD follow-up time of 4.7 ± 2.3 yr. Measurements included regional skeletal muscle mass, four additional lean components (fat-free body mass, body cell mass, total body water, and bone mineral), and total body fat. Total appendicular skeletal muscle (TSM) mass decreased in men (−0.8 ± 1.2 kg, P = 0.002), consisting of leg skeletal muscle (LSM) loss (−0.7 ± 0.8 kg, P = 0.001) and a trend toward loss of arm skeletal muscle (ASM; −0.2 ± 0.4 kg, P = 0.06). In women, TSM mass decreased (−0.4 ± 1.2 kg, P = 0.006) and consisted of LSM loss (−0.3 ± 0.8 kg, P = 0.005) and a tendency for a loss of ASM (−0.1 ± 0.6 kg, P = 0.20). Multiple regression modeling indicates greater rates of LSM loss in men. Body weight in men at follow-up did not change significantly (−0.5 ± 3.0 kg, P = 0.44) and fat mass increased (+1.2 ± 2.4 kg, P = 0.03). Body weight and fat mass in women were nonsignificantly reduced (−0.8 ± 3.9 kg, P= 0.15 and −0.8 ± 3.5 kg, P = 0.12). These observations suggest that sarcopenia is a progressive process, particularly in elderly men, and occurs even in healthy independently living older adults who may not manifest weight loss.