Body composition and muscular strength as predictors of bone mineral density in African American women with metabolic syndrome.

Our cross-sectional study investigated the relationships between regional bone mineral density (BMD) and body composition variables, including total body lean mass (LM) and fat mass (FM), as well as muscular strength in overweight and obese African-American (AA) women with metabolic syndrome (MetS). Forty-four women ranging in age from 39 to 61 years participated. Upper and lower body strength measurements were assessed using chest press and leg extension exercises, respectively. Body composition and BMD of the total body, spine (L2-L4), hip, and radius were measured by dual-energy X-ray absorptiometry. LM was positively correlated with total body, spine, hip, and radius BMD (r = .338-.603, all P < .05), and FM was positively correlated with total body BMD (r = .343, P < .05). In multiple linear regression analyses after controlling for age, height, total energy, and calcium intake, LM was a significant positive determinant of BMD at various skeletal sites (P < .05), while FM was negatively related to BMD of total hip (P < .05). Our results indicate that LM is an independent predictor of total body, spine, hip, and total radius BMD. In contrast, FM is a negative predictor of total body and hip BMD in overweight or obese AA women with MetS (P < .05). Upper and lower body muscular strength measures were not associated with BMD at any skeletal sites. These results suggest an important role for LM in preventing the development of osteopenia and osteoporosis.