Sex and Region-Specific Associations of Bone Mineral Content, Muscle Mass, and Fat Mass with Insulin Resistance

Background:To compare the strengths of the associations between total and region-specific body composition and insulin resistance (IR) considering sex and menopausal status and to compare body composition indicators for discriminating high IR. Materials and Methods:Among 5380 men, 3652 premenopausal women, and 3207 postmenopausal women in the Korean National Health and Nutrition Examination Survey, high IR was defined as the sex-specific highest quintiles of homeostasis model assessment IR and metabolic syndrome. Percentages of bone mineral content (BMC%), muscle mass (MM%), and fat mass (FM%) were measured for the whole body, trunk, and upper/lower extremities by dual-energy X-ray absorptiometry. Results:After adjusting for body mass, age, education, smoking status, alcohol use, and physical activity, one-standard deviation increases in whole-body FM%, MM%, and BMC% were associated with 50%-63%, 19%-26%, and 14%-22% higher odds of high IR in men and pre- and postmenopausal women, 31%-36%, 12%-17%, and 10%-15% lower odds, and 27%-36%, 31%-40%, and 19%-23% lower odds, respectively. Those associations for FM% in men and BMC% in premenopausal women tended to be stronger in the upper body than in lower extremities. In receiver operating characteristic curve analysis, FM% in men and BMC% in women had superior discriminatory abilities for high IR. Conclusions:IR may have a stronger association with FM% in men and BMC% in premenopausal women in upper body, while the association strength in postmenopausal women may be similar across body composition. These findings reveal differences in the strengths of region-, sex, and menopausal status-specific relationships between body composition and IR.