Objectives: Osteoporosis is a disease that increases the fracture rates and it is the major cause of increased mortality and morbidity in the elderly people. To determine which component of body composition is most important to bone health, we analysed the relationship between elements of the body composition and bone mineral density (BMD) in Korean women.
Design: Cross-sectional clinical study.
Patients: Totally 1694 women (mean age 51 years) were selected from subjects who participated in a medical check-up program.
Measurements: Body composition analysis was performed by segmental bioelectric impedance method and lean mass, fat mass and per cent body fat measured. Waist: hip ratio (WHR) was assessed as a marker for visceral fat. Lumbar spine (L-spine) BMD was measured by dual X-ray absorptiometry (DEXA). As menopausal status could not be confirmed in all subjects, we divided the subjects into two groups according to the age > 50 years and < 50 years.
Results: Among the entire population, 599 subjects (35.4%) were osteopaenic and 229 subjects (13.5%) were osteoporotic. The bivariate correlation among the variables showed that weight had the highest correlation with fat mass. Mean lean mass was decreased and the WHR increased as the subjects progressed from normal to osteoporotic status; fat mass was the highest among the osteopaenic subjects. L-spine BMD showed a positive correlation with lean mass, and a negative correlation with WHR by bivariate correlation analysis. However, fat mass had a negative correlation with L-spine BMD only after adjustment for age and weight. Multiple regression analysis with L-spine BMD as the dependent variable showed that age, height, fasting insulin, lean mass and WHR were significant determinants of the L-spine BMD (R(2) = 0.170, P < 0.05).
Conclusion: In this Korean female population, L-spine BMD showed a consistently positive correlation with lean mass and a negative correlation with WHR. Fat mass failed to show any consistent correlation with L-spine BMD in this study population.