Soft tissue composition and the risk of low bone mineral density: the Fourth Korea National Health And Nutrition Examination Survey (KNHANES IV-3), 2009.

The effects of total fat mass (FM) and total lean mass (LM) on total bone mineral density (BMD) were examined using the Fourth Korea National Health and Nutrition Examination Survey, 2009. FM, LM, and BMD were measured by DXA in a population-based sample of 6,762 Koreans, aged 19-93 (1,613 men < 50 years, 1,400 men ≥ 50 years, 2,120 premenopausal women, and 1,629 postmenopausal women). After adjusting for confounders (age, height, education, economic status, physical activity, smoking, alcohol use, serum vitamin D, medical history [diabetes, dyslipidemia, rheumatoid arthritis, and osteoporosis], family history of osteoporosis, multivitamin use, dietary intake [energy, calcium, and sodium], age at menarche, age at menopause, and hormone replacement therapy) and FM, higher LM was associated with a lower odds ratio for being in the group-specific lowest quintile of BMD (low BMD) in all groups. The odds for low BMD increased with higher FM in multivariate-adjusted analyses in men < 50 years, but this was not significant in other groups. Total BMD decreased with a decrease in the LM quintile across all FM subgroups in men of all ages, in the lower two subgroups of FM quintile in premenopausal women, and in the middle subgroup of FM quintile in postmenopausal women. In conclusion, higher LM was associated with a lower risk of low BMD in both genders, while higher FM was associated with a higher risk of low BMD for men < 50 years but not for women and men ≥ 50 years. The combined effects of LM and FM on BMD were gender- and menopause status-specific.