January - 7 - 2010
Findings from the Health, Aging and Body Composition study, conducted in well-functioning, community-dwelling older adults aged 70-79 years, have revealed the influence of type 2 diabetes on skeletal muscle mass. Using dual-energy X-ray absorptiometry, researchers examined body composition in a sample of 2,675 older adults over a 6-year period. Annual decline in total body mass was significantly higher in persons with undiagnosed or diagnosed diabetes than in those without diabetes (-435 vs -293 vs -193 g/year, respectively, P < 0.01)after adjusting for age, race, sex, clinic site, body mass index and weight loss intention. Total lean mass, particularly in the extremities (appendicular lean mass) mostly contributed to total body mass decrease. Diabetes, either diagnosed or undiagnosed, was also associated with a marked reduction in total fat mass, especially trunk fat mass, while it was unchanged in nondiabetic individuals. Declines in thigh muscle cross-sectional area (CSA) were generally more profound in men than women regardless of their glycemic status. However, women with diabetes (diagnosed or undiagnosed) exhibited a 2-fold greater loss of thigh muscle CSA than nondiabetic women (-11.1 vs. -11.7 vs. -5.1 cm2, P < 0.001), even when adjusting for differences in body size, weight changes and inflammatory cytokines (Park, S.W. et al. Diabetes Care 2009, 32(11): 1993).