Endocrine Abstracts

The strong link between bone mass and body composition is widely recognized but only few studies were selectively performed on healthy subjects with body mass index within normal limits. We aimed to evaluate the influence of body composition on bone mass in apparently healthy young non-obese men and women (n=40). To reveal the effect of menopausal transition on the fat mass content, fat mass distribution and fat mass-bone mineral density relationship we compared body composition parameters of young healthy non-obese women to body mass index-matched postmenopausal women (n=20). Despite normal values of body mass index, large variability of the whole-body fat mass content was noted in our study, with limits ranging between 18.6 and 49.7% in women and 22–40.3% in men. Age appeared not to influence significantly the amount of whole-body fat tissue. Fat mass was not related to bone mineral density of the lumbar spine, hip or whole-body; in contrast, bone mineral density at all sites was positively associated to fat-free mass in young non-obese women (L1–L4: r=0.53, P=0.003; femoral neck: r=0.34, P=0.04; hip: r=0.53, P=0.003; total body: r=0.52, P=0.003). Despite a tendency towards higher whole-body and trunk fat mass values in postmenopausal women in comparison to BMI-matched eugonadal young women, the difference between groups reached no statistical significance. Leg fat mass was better represented in young women in comparison to postmenopausal women (P=0.04). To conclude, in subject with normal body mass index, both fat mass content and fat distribution are highly variable. In young, healthy, non-obese women, fat-free mass appears to be the main body composition contributor to bone mass. Menopause was not associated with major changes of whole-body fat and trunk adipose tissue, although we noticed a decrease in peripheral fat mass content and a tendency towards a central distribution of adiposity.