Endocrine Abstracts

Introduction: Obesity was thought to be protective against osteoporosis, but studies have shown conflicting results. We analysed the cross-sectional data from the National Health and Nutrition Examination Survey Data (NHANES) survey (2008–2012) to observe the association between BMI (BMI and/or waist circumference) and bone mineral density (BMD) at the femoral neck.

Research methods and design: We categorised the study population (women aged 50 years and above) into three groups based on their BMI- lean (BMI <18.5 kg/m²), normal (BMI between 18.6–24.9 kg/m²), and overweight/obese (BMI >25 kg/m²). We reviewed and tabulated data on the demographics (age, race and other covariates), waist circumference (cm), mean systolic BP (mm/Hg), HOMA insulin resistance, and total cholesterol (mg/dl). We analysed the data on femoral neck BMD (gm/cm²), total femur BMD, femoral neck bone mineral content (BMC in gm) and total femur BMC. We used the one-way ANOVA to test the difference between the groups. We also performed a correlation (non-parametric spearman’s ρ) between BMI and femoral neck BMD and waist circumference and femoral neck BMD.

Results: There were 1071 persons in the cohort. There was no significant difference in BMD or BMC between the groups at the femoral neck (P=0.39, P=0.79 respectively) or total femur (P=0.75, P=0.86 respectively). Systolic blood pressure was higher in obese/overweight women (P <0.01). There was no correlation between femoral neck BMD and BMI (spearman’s ρ −0.07, P=0.25) or femoral neck BMD and waist circumference (spearman ρ −0.09, P=0.14).

Conclusions: Our results shows that BMI and waist circumference are not associated with differences in femoral neck BMD in post-menopausal women.