The Affect of Lifestyle on Bone Mineral Density and Bone Turnover in Young Women.

INTRODUCTION: This research aimed to evaluate the effect of lifestyle factors such as nutrient intake and physical activity on bone mineral density (BMD) and bone turnover in young women.
MATERIALS AND METHODS: BMD was assessed using Quantitative Ultrasound; lifestyle-related factors such as dietary habits, and physical activity were examined using questionnaires in 194 female college students. The biochemical markers of bone turnover were measured in the Osteopenia (BMD below the Young Adult Mean [YAM] -1.0SD, 16 subjects) and Normal (above the YAM-1.0SD, 31 subjects) groups.
RESULTS: The percentage of osteopenia was 11.9%. Calcium and magnesium intake (p<0.05), and physical activity (p<0.1) were found to be factors influencing BMD. The level of osteocalcin and type 1 procollagen N-terminal propeptide (P1NP) were higher in the Osteopenia group than in the Normal group (p<0.05). There was tendency that showed relationship between the level of undercarboxylated osteocalcin (ucOC) and BMD (p<0.1). The level of bone-specific alkaline phosphatase was significantly higher in the 25OH vitamin D insufficiency group compared to sufficiency group (p<0.05). The levels of OC, tartrate-resistant acid phosphatase-5b and P1NP were lower in the ucOC <4.5 ng/ml group compared to ≥4.5 ng/ml group (p<0.01, p<0.05, p<0.1), respectively.
CONCLUSION: This study showed that BMD in young women is affected by calcium and magnesium intake, physical activity, and vitamin D and K levels. It was suggested that the insufficiency of vitamin D and K might be contributable to low BMD through the change of bone turnover.