Body composition and development of diabetes: a 15-year follow-up study in a Japanese population

Background/objectives Few longitudinal studies have examined the association between diabetes risk and body composition in Asians. The aim of this prospective cohort study was to determine the role of body composition, estimated by whole-body dual-energy X-ray absorptiometry, in the development of diabetes and to examine the impact of body composition on diabetes risk in normal weight (body mass index (BMI) < 23 kg/m(2)) and overweight/obese groups (>= 23 kg/m(2)). Subjects/methods We measured the body composition for 1532 diabetes-free subjects (463 men and 1069 women), aged 48-79 years, at the baseline examination period from 1994-96 and followed-up to detect new cases of diabetes over the next 15 years (median 13.4 years). Results After being adjusted for BMI and other potential confounding factors, body fat distribution was associated with diabetes risk. Percentage of trunk fat was positively associated with the development of diabetes (hazards ratio (HR) per 1 SD (95% confidential interval (CI)), 1.58 (1.10-2.28) in men, and 1.34 (0.99-1.83) in women), and percentage of leg fat was negatively associated with the development of diabetes (HR per 1 SD (95% CI), 0.68 (0.50-0.91) in men and 0.68 (0.55-0.85) in women). The estimated HRs of % trunk and leg fat on the development of diabetes differed little between normal weight and overweight/obese subjects. Appendicular lean mass was also negatively associated with diabetes risk only in normal weight men. Conclusions Opposite associations of trunk fat and leg fat with diabetes risk were observed. Assessment of body composition might help in the evaluation of diabetes risk.