Association of Osteoporosis with Anthropometric Measures in a Representative Sample of Iranian Adults: The Iranian Multicenter Osteoporosis Study

Background: Osteoporosis and obesity are two major public health problems worldwide. Considering the conflicting results about the association between anthropometric measurement and bone mineral density (BMD) and also differences between various races, this study was designed to examine the relationship between anthropometric measurements and BMD in a sample of Iranian adults. Methods: This cross-sectional population-based study was conducted on 2625 Iranian adults aged 18 and above who were selected using multistage, cluster sampling method from Sanandaj and Arak (two cities of Iran). The evaluated variables included age, sex, height, weight, body mass index (BMI), BMD, and waist and hip circumferences. The correlations between anthropometric measures and BMD in three bone areas (total hip, femoral neck, and spine) were observed in four sex/age groups (men <50 years, men ≥50 years, and pre‑ and postmenopausal women). Results: Of all the 2625 participants in the Iranian Multicenter Osteoporosis Study, 2022 (1303 women and 719 men) entered into our survey and were stratified into four sex/age groups. According to the results, increasing BMI was directly associated with BMD increase, while an inverse association was observed between waist-to-hip ratio (WHR) and total hip BMD. In a similar analysis on the femoral neck and WHR, the correlation coefficients in premenopausal women and men ≥50 years were reported as being the highest and the lowest, respectively, among the four groups. Conclusions: Our results showed that high BMI is a protective factor (positive correlation), and high WHR is a risk factor for osteoporosis, although it should be reminded that we could not specifically define which factors including lean tissue mass, fat mass, and total weight are really affecting BMD increase in the overweight/obese participants.