The Relationship between Bone Mineral Density and Body Composition, Life Styles of Female College Students

The purpose of this study was to investigate the relationship between bone mineral density(BMD), body composition and life styles of female college students. The subjects were 334 students with a mean age of 21.0 years. BMDs of forearm and calcaneus were measured by dual energy X-ray absorptiometry, and body composition was measured by bioelectrical impedence analysis. The means for weight, height, and body mass index(BMI) of the subjects were 55.7 kg, 161.0 cm, 21.5 kg/$m^2$, respectively. Grouping by the BMI, 13.2% of the subjects were classified as overweight, and 11.1% of the subjects as obese group. BMD in the forearm and calcaneus were 0.390 g/$cm^2$, 0.514 g/$cm^2$. In the forearm, 58.1% and 9.6% of the subjects were classified as osteopenia and osteoporosis, respectively, and in the calcaneus, 12.0% and 0.3% of the subjects were classified as osteopenia and osteoporosis, respectively. Body weight, skeletal muscle mass, lean body mass, fat mass and BMI were positively correlated with BMDs in the forearm and calcaneus($r$=0.180~0.495, $p$ <0.01~0.001), and height, % body fat and waist-hip ratio(WHR) were positively correlated with BMDs in the calcaneus($r$=0.213~0.239, $p$ <0.001), but not in the forearm. The factors such as beginning age of cigarette smoking and alcohol drinking and exercise had significant influence on BMD($p$ <0.05; p<0.001), whereas sleeping hours, activity level, frequency of exercise, meal times, frequency of snack and fried food intake, breakfast skipping and amount of meal had not significant influence on BMD. Therefore, the acquisition of balanced body composition is necessary through the increase of fat free mass and muscle mass, not through the increase of fat mass among female college students.

여대생의 골밀도와 신체조성 및 생활습관과의 관계 연구