Iranian Journal of

Background: Evidences exist that abdominal obesity is a difference in terms of body mass index (BMI) and these two factors have different effects on bone density. This study examined the association between body mass index, obesity, the history of fracture and bone mineral density in Iranian population. There exist evidences on the effects of body mass index (BMI) and abdominal obesity, and the role of this two factor on bone density. This study examined the association between body mass index, abdominal obesity, and the frequency of fracture with bone mineral density in Iranian population Methods: The Study was done as a cross-sectional, population-based retrospective study. People over 18 years were included in the third part of the IMOS project (National comprehensive plan for the prevention, diagnosis and treatment of osteoporosis). Abdominal obesity was calculated based on waist to hip ratio that was considered positive > 0.95 in men and 0.85 in women. The linear regression test was used to examine the relationship between BMI and abdominal obesity with bone densitometry. Results: A total 2019 cases (717 men, 1302 women) with 41.85 ± 13.95 years enrolled in this study. Almost, 36% of men and women were obese based on waist circumference. Correlation coefficients of BMI with bone density were equal 0.236 for Hip, 0.133 for femoral neck, 0.138 for lumbar spine. Waist to hip ratio was inversely associated with bone density. Bone densities in the hip and lumbar spine, in individuals with a positive history of wrist fracture were significantly lower than those with a negative history of fracture. Conclusion: contrary to the total body fat, abdominal obesity based on waist to hip ratio is inversely associated with bone density. In other words, abdominal obesity increases the risk of fractures by reducing the bone density without creating protective shield of adipose tissue in vulnerable areas.