Influence of duration of menopause on bone turnover markers in post-menopausal women

Abstract

Introduction and Aim: Osteoporosis is common among women following 10 years of cessation of menstruation, due to bone loss accelerated by menopause. The study was done to evaluate the effect of duration of menopause on bone turnover markers (BTMs). Materials and Methods: The study involved 100 postmenopausal women; 50 osteoporotic and 50 non-osteoporotic. Comparison and correlation of serum calcium, phosphorus, alkaline phosphatase (ALP), serum osteocalcin (sOC) and urinary hydroxyproline (uHP) were done based on duration of menopause. Comparison of biochemical parameters was done using Independent t-test and ANOVA test for two groups and more than two groups respectively. Correlation was done using Pearson’s correlation test. Statistical significance was considered at p<0.05. Results: The sOC significantly declined and uHP levels increased between quartiles of duration of menopause among study participants. (p<0.001). However, in those without fractures, sOC and uHP were higher in those with <7 years since menopause (YSM) and then plateaued after 8 YSM. The percentage of osteoporotic women having >15 YSM was 82%. Duration of menopause correlated better with sOC (r=-0.633) than uHP (r=0.575) (p<0.001). Conclusion: Osteoporotic fractures were higher in more than 15 YSM. There was no difference in both sOC and uHP in those with fractures, proving non-significance of screening these markers once the fractures have occurred. As sOC correlates better with duration of menopause, monitoring of sOC in early years of menopause is required to prevent osteoporotic fractures and associated burden through prophylactic treatment.