Relative contribution of aging and menopause to changes in lean and fat mass in segmental regions

Objective: The aim of the study was to investigate the relative contribution of aging and menopause to the changes in lean and fat mass in segmental regions. Materials and methods: Subjects were 365 pre- and 201 postmenopausal Japanese women aged between 20 and 70 years old. Age, height, weight, body mass index (BMI, Wt/Ht(2)), age at menopause, years since menopause (YSM), and menopausal status were recorded. Lean and fat mass of the arms, trunk, legs, total body, and the ratio of trunk fat mass to leg fat mass amount (trunk-leg fat ratio) were measured by dual-energy X-ray absorptiometry (DEXA). Regional (arms, lumbar spine, pelvis, legs, and total body) bone mineral density (BMD) were measured by DEXA. Results: Total body lean mass and regional BMD decreased (P < 0.001), while percentage of body fat, trunk fat mass, and trunk-leg fat ratio increased (P < 0.001) with aging and after menopause. On multiple regression analyses, trunk and total body lean mass were inversely correlated with menopausal status (P < 0.001 and 0.05, respectively) but not with age. Trunk fat mass, trunk-leg fat ratio, and percentage of body fat were positively correlated with age (P < 0.01) but not with menopausal status. Regional BMD were more inversely correlated with menopausal status (P < 0.001) than age. Conclusion: Decrease in lean mass and BMD are more menopause-related, while the shift toward upper body fat distribution and overall adiposity are more age-related. Lean tissue is similar to bone tissue from the viewpoint of more undergoing menopausal effect. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.