Association between body composition and bone mineral density assessed by whole body dual-energy X-ray absorptiometry

Abstract

Introduction: Despite the observation that higher body weight has protective effect against the development of osteoporosis, accumulating evidence suggest presence of negative impact of obesity on bone function associated with the low-grade inflammation and production of proinflammatory cytokines from dysfunctional adipose tissue in obese individuals. These data stimulate the interest and suggest need for clarifying studies about the association between the body composition and bone mineral density.
 The aim of the study: The aim of the current study was to evaluate the association between body mass index (BMI), body composition (fat mass and lean body mass) and the bone mineral density of the lumbar spine and femoral neck assessed by whole body scan using DXA (dual-energy x-ray absorptiometry).
 Materials and methods: A retrospective study was performed with analysis of patient data who have undergone whole body scan in Medical Center “Avis Medica” Pleven, device Lunar prodigy. The values of T-score of the lumbar spine and femoral neck were analyzed and their associations with body composition and BMI.
 Results and discussion: 111 women at mean age 59±8 years were included in the study. In the patients with T-score values ​​≤ /-2.5/ of the lumbar spine and femoral neck BMI was significantly lower. In the group of patients with T-score values of the lumbar spine ≤ /-2.5/ (n=27), significantly lower fat mass was found (2239.90±607.63 grams) in comparison with the cases with T-score > /-2.5/ (n=84) (fat mass 2510.41±570.68 grams; p=0.037). The lean body mass in the patients with T-score ≤ /-2.5/ of the lumbar spine (4025.30±862.58 grams) was also significantly lower vs the group with T-score > /-2.5/ (4760.09±607.63 grams; p=0.000). A significant difference of body lean mass was also found between the groups with different T-score of femoral neck (4110.60±832.01 grams in patients with T-score of femoral neck ≤2.5, n=15; 4802.01±862.87 grams in those with T-score>2.5, n=96, p=0.004). Regarding the fat mass and fat percentage in the groups with different T-score of the femoral neck, they were lower in the patients with osteoporosis with T-score < /-2.5/, but the difference reached statistical significance only for the fat percentage (31 vs 38%, p=006) but not for the fat mass (p=0.081).
 Conclusion: The results of the current study confirm the protective effect of the higher lean and fat mass against the development of osteoporosis with possible leading role of the lean mass.