Bone alkaline phosphatase and urine hydroxyproline assay in pre and postmenopausal women in the state of sikkim and its correlation with bone mineral density

Introduction: Osteoporosis could be viewed as a metabolic disease. The WHO guidelines for diagnosing osteoporosis reflect structural damage only and not the metabolic imbalance that leads to it. Biochemical markers of bone turnover have been shown to provide valuable information for diagnosing and monitoring metabolic bone disease. The present study analyzed bone-specific alkaline phosphatase (BALP) and urinary hydroxyproline in pre- and postmenopausal women and correlated them with changes in bone mineral density (BMD) in the state of Sikkim. The study also intended to know the ethnicity-based disease burden in Sikkim. Materials and Methods: A hospital-based cross-sectional study was done at a tertiary hospital in Sikkim. Blood and 24-h urine samples from 50 premenopausal and 50 postmenopausal women were analyzed for total alkaline phosphatase (ALP), BALP, and Urine Hydroxyproline. BMD was measured using the quantitative ultrasound technique by Achilles densitometer. Results: There was a statistically significant increase in serum calcium (P = 0.01), ALP (P = 0.01), and urine hydroxyproline (P = 0.03) levels in postmenopausal women as compared to premenopausal women. Although ALP was higher in postmenopausal women, BALP isoform was more elevated in premenopausal women (P = 0.001). BMD was significantly lower in postmenopausal women (P < 0.001). It was also noted that there was a significant difference in BMD between tribal and nontribal populations (P = 0.003). Total ALP and BALP as the bone formation marker and urine hydroxyproline as a bone resorption marker added statistically significant r to BMD prediction (P < 0.05). Conclusion: In this study, BALP combined with Urine Hydroxyproline was helpful as a screening biomarker to predict osteoporosis in postmenopausal women.