Weight stability masks sarcopenia in elderly men and women

• Published in: American journal of physiology: endocrinology and metabolism Vol. 279; no. 2; pp. E366 - E375
• Main Authors: Gallagher, Dympna, Ruts, Else, Visser, Marjolein, Heshka, Stanley, Baumgartner, Richard N, Wang, Jack, Pierson, Richard N, Pi-Sunyer, F. Xavier, Heymsfield, Steven B
• Format: Journal Article
• Language: English
• Published: United States 01.08.2000
• Subjects: Absorptiometry, Photon; Age Distribution; Aged; Aged, 80 and over; Aging - physiology; Body Composition - physiology; Body Weight - physiology; Bone Density - physiology; Female; Humans; Longitudinal Studies; Male; Middle Aged; Muscle, Skeletal - physiology; Muscular Atrophy - diagnosis; Muscular Atrophy - epidemiology; Muscular Atrophy - physiopathology; Potassium - analysis; Sex Distribution; Whole-Body Counting
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.2000.279.2.e366

1  Department of Medicine, Obesity Research Center, St. Luke's-Roosevelt Hospital, Columbia University, New York, New York 10025; 2  Faculty of Medicine, Institute for Research in Extramural Medicine, 1081 BT Amsterdam, The Netherlands; and 3  Clinical Nutrition Program, Center for Population Health, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131 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. aging; body composition; skeletal muscle mass; longitudinal study