Biochemical and Dietary Indicators of Bone Health in Rural Adolescent Girls from Konkan Region of Maharashtra, India (DERVAN-5)

Abstract

Adolescent period is marked by bone modeling and remodeling and leads to accrual of peak bone mass. Ideal peak bone mass depends on diet, hormones, genetic influence and environment and has consequences on bone health in adulthood. We measured biochemical indicators of bone health in rural adolescent girls. Methods: Five hundred fifty adolescent girls from longitudinal DERVAN cohort study from Indian state of Maharashtra underwent anthropometry. Biochemical parameters (intact parathyroid hormone, vitamin D, calcium, phosphorus and alkaline phosphatase) were measured. Results: Prevalence of underweight & stunting was 28.8%, 30.7% respectively. More than 56% were thin & only 5% were obese. Median body fat% & bone mass measured by bio-impedance were 23.3 and 1.6 Kg respectively. More than 80% were vitamin D deficient and 12.0% were calcium deficient. Median dietary calcium intake was 158.5mg/day which was far below recommended 850 mg/day. Median parathyroid hormone concentration was 8.49pmol/L and 66.7% had elevated concentrations (> 6.89pmol/L). Elevated phosphorus and alkaline phosphatase were observed in 23.3% and 23.0%. Parathyroid hormone was inversely associated with age (p<0.001) and vitamin D (p<0.001) and directly with phosphorus and alkaline phosphatase (p<0.05) for both. On multivariate analysis elevated parathyroid hormone was associated with low vitamin D (p<0.001). Conclusion: The adolescent girls of KONKAN are undernourished and vitamin D deficient. Despite poor dietary calcium intake the serum calcium levels were maintained at the cost of elevated parathyroid hormone. Thus parathyroid hormone may be used as a marker of bone health. This could be useful in planning early interventions to improve bone health.