Background:The relationship between lean mass (LM), fat mass (FM) and bone mineral density (BMD) remains controversial. Some population studies have emphasized the positive association between them, while others have found an inverse relationship. RA patients are characterized by a decrease in muscle mass and an increase in fat mass. Such changes in body composition may be associated with low BMD.Objectives:To study the relationship between BMD, LM and FM in postmenopausal women with RA.Methods:68 postmenopausal women with RA (median age 59 [54; 63] years) were included in the study. BMD and body composition were evaluated using two-energy X-ray absorptiometry. Correlation analysis between body composition parameters and BMD was performed with the Spearman method, correlation coefficients R for p<0.05 are presented.Results:The average L1-L4 BMD was 0,92±0,16 g/cm2, total hip BMD - 0,84±0,15 g/cm2 and femoral neck - 0,73±0,13 g/cm2. 33 (48.5%) women had osteopenia, and 17 (25.0%) - osteoporosis (OP). Low appendicular LM was found in 5 (7.4%) and low appendicular muscle index (appendicular LM/height2, AMI) – in 10 (14.7%) patients. Overfat was revealed in 47 (69.1%) women, but only 20 (29.4%) women had BMI corresponding to obesity. The positive correlations between BMD in L1-L4, total hip and femoral neck regions and body weight (R=0.46, R=0.56 and R=0.50, respectively), trunk fat (R=0.4, R=0.51 and R=0.37, respectively), total FM (R=0.27, R=0.43 and R=0.34, respectively), trunk LM (R=0.55, R=0.54 and R=0.51, respectively), total LM (R=0.51, R=0.50 and R=0.52, respectively), appendicular LM (R=0.31, R=0.29 and R=0.37, respectively) and AMI (R=0.26, R=0.33 and R=0.51, respectively) were found out. In the multivariate linear regression analysis total LM was associated with BMD of lumbar spine (β=0.638, p=0.001) and total hip (β=0.473, p=0.008), and AMI - with femoral neck BMD (β=0.360; p=0.014). We found that FM hadn’t a significant effect on BMD in any region.Conclusion:73.5% of patients with RA had a reduced BMD, and 14.7% women – low AMI. LM was positively associated with BMDs in different regions of interest, but FM had no effect on BMD. Further researches are needed to identify associations between body composition, inflammatory activity and bone health in patients with RA.Disclosure of Interests:None declared
An investigation into the relationship between soft tissue body composition and bone mineral density in a young adult twin sample