Bone Turnover Markers: An Emerging Tool to Detect Primary Osteoporosis

Abstract

Introduction: Osteoporosis is a global health problem, asymptomatic and noticed only after a fracture. Ten years after the cessation of ovarian function due to hormonal imbalance, women show an accelerated phase of reduction in bone mass known as primary osteoporosis. Determination of Bone Mineral Density (BMD) and Dual Energy X-Ray Absorptiometry (DEXA) are the gold standard diagnostic approaches for osteoporosis. However, they are costly; hence Bone Turnover Markers (BTMs) have been suggested to detect the risk of osteoporotic fractures. Aim: To assess the potential of BTMs as a diagnostic tool for primary osteoporosis in order to reduce the associated morbidity and mortality. Materials and Methods: This study was conducted on 105 women who were divided into Group I with 35 pre-menopausal women, Group II with 35 post-menopausal women without fractures and Group III with 35 post-menopausal women with wrist, spine or hip fractures. Serum osteocalcin (OC), calcium, phosphate, alkaline phosphatase, total protein, albumin and 24 hour urinary hydroxyproline were estimated. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS) Version 16.0. ANOVA test was done to compare variables among the groups. Tukey’s test was applied for intergroup comparison. Student’s t-test was used to compare two groups and correlation studies were done using Pearson’s correlation. Statistical significance was considered as p<0.05. Results: The mean serum OC level in post-menopausal women with fractures was statistically low when compared to the premenopausal and post-menopausal women. The mean urinary hydroxyproline level was statistically higher in post-menopausal women with fractures and a positive correlation of urinary hydroxyproline was seen with age and BMI. The mean OC level was lowest in the spine fractures, when compared to the wrist and hip. Urinary hydroxyproline level had no significant difference among the fracture groups. Conclusion: BTMs can be an inexpensive diagnostic and screening tool for primary osteoporosis. Low serum OC levels and high urinary hydroxyproline levels in post menopausal women could thus predict osteoporosis and its timely intervention could prevent the risk of osteoporotic fractures thereby decreasing the mortality rate.

Keywords

• alkaline phosphatase
• hydroxyproline
• osteocalcin
• pre-menopausal women
• post-menopausal women