Association of Bone Mineral Density with Lean Mass and Fat Mass

Abstract

Obese individuals hold an increased risk of chronic diseases such as CVD. We reported that a relationship exists between BMI and indices of CVD risk in postmenopausal women. To investigate the relationship between BMI and chronic diseases, we measured CRP level, a marker of inflammation, in 132 postmenopausal women. Participants were divided into three groups based on their BMI values: 1) normal (18.5–24.9); 2) overweight (25–29.9); and 3) obese (>30). BMI was positively correlated with CRP. In addition, overweight and obese individuals had higher serum levels of CRP compared to individuals with normal BMI. In contrast to existing relationship of higher BMI and higher incidence of chronic diseases, studies have shown that osteoporosis is the only chronic disease that has negative correlation with BMI. To investigate this relation, we evaluated the correlation between BMI and BMD in this population. BMI was positively correlated with BMD which means a negative correlation with osteoporosis; however, when we examined the correlation between BMD and components of body composition including fat mass and lean mass; BMD was highly correlated with lean mass but not with fat mass. Although these data supports the notion that individuals with higher BMI have lower risk of osteoporosis, break down of body composition clearly demonstrate that the credit for this correlation should be given to lean mass and not fat mass. Grant Funding Source: USDA