Muscle mass is a strong correlation factor of total hip BMD among Korean premenopausal women.

Objectives: This study was to investigate mean Z-score of BMD of Korean premenopausal women and also to investigate the relationship between BMD and body composition, such as skeletal muscle (SM) mass, body fat mass, and abdominal adiposity among healthy Korean premenopausal women in their forties.

Methods: A total of 2711 premenopausal women in her forties (40-49 years) who had taken dual energy X-ray absorptiometry (DXA) for BMD screening and body composition analyser (InBody J10) from 2012 to 2013 at health promotion center of Ewha Womans university Mokdong hospital were analyzed retrospectively. Demographic data such as body mass index (BMI), waist circumference (WC), hip circumference (HC), waist hip ratio (WHR), SM mass, body fat mass, and serum lipid profile were included in this study. The Pearson's correlation coefficient (CC) was used to identify co-efficiency between BMD and other parameters.

Results: The mean age was 44.2 ± 4.44 (years) and mean BMI was 22.43 ± 2.99 (kg/m). Mean Z-score of BMD-lumbar 1-4 (BMD-L) and BMD-femur total hip (BMD-F) was 0.33 ± 1.14 and -0.19 ± 0.85. Mean of BMD-L and BMD-F were 1.18 ± 0.16 (g/cm) and 0.96 ± 0.12 (g/cm). Skeletal muscle mass showed a strong significant correlation coefficient (CC) only with BMD-F (CC = 0.13, p-value = 4.78 × 10). However serum lipid profile, body fat mass, and WHR did not show significant CC with mean Z-score of BMD-F and BMD-L.

Conclusions: Skeletal muscle mass measured by body composition analyzer of BIA method is a strong correlation factor for BMD especially of hip bone among healthy Korean premenopausal women in their forties.