Relationship of Body Mass Index, Bone Turnover Marker and Bone Mineral Density in Postmenopausal Women

Abstract

Objective:To observe the correlation of body mass index (BMI) with bone mineral density(BMD) and bone turnover marker (NTX) in postmenopausal women Materials and Methods: This observational cross sectional study was carried outfrom January 2014 to December 2014. In this study 85 postmenopausal women were included from Orthopedics and Gynecology outpatient departments of a tertiary care hospital of Karachi.Their BMI in Kg/m2 and BMD by DEXA scan (femur and lumbar spine) were measured.Seruml evels of bone turn over marker, N-telopeptide of type I collagen (NTX) was assayed by ELISA.To evaluate the relationship between BMI, bone mass and NTX, Pearson Correlation co-efficient was computed (P-value significancewas <0.05). Results:The correlation between BMI and BMD at both femur(r = 0.060, P = 0.586) and lumbar spine(r =0.093, P=.0.398)was weak and found to be non-significant. The correlation between serum NTX & BMI was negative but also found to be nonsignificant( r = -0.14, P=0.203). Conclusion:Both bone mass and bone turnover marker (NTX) are not correlated to an index of obesity, BMI in postmenopausal women in our clinical set up.