Endocrine Abstracts

Background: Body composition parameters might be determinants of bone strength and we aimed to investigate the relationship between body composition variables and surrogate parameters of spine and hip bone quality.

Patients and methods: 235 patients with overweight or obesity (mean age= 50.12±14.2 years, mean BMI =35.04 ± 6.65 kg/m²) were included. DXA whole-body scans were conducted, using a DEXA Prodigy®, GE machine. Measurements included total and regional fat and lean mass, total and lumbar BMD. Trabecular bone score (TBS) measurements were performed using TBS iNsight. Proximal hip DEA scans were analysed for bone geometry by use of the HSA programme and cross-sectional area (CSA), section modulus (SM), and cross-sectional moment of inertia (CSMI) were included in the analysis.

Results: There was no significant difference in TBS values between men and women, but men showed higher values of CSA, CSMI and SM. In univariate analysis, TBS negatively correlated with age (r = -0.421, P < 0.001) and positively correlated with BMI, total bone mass (r = 0.394, P < 0.001), total fat (r = 0.210, P < 0.001) and total lean mass (r = 0.188, P = 0.004). In a linear regression model, age and total fat mass, but not total lean mass remained independently associated with TBS. Hip geometry parameters showed no association with BMI but positively correlated with total BMD (P < 0.001 for all), total lean mass (r = 0.583 for CSMI,0.615 for CSA, 0.683 for SM, P < 0.001 for all)and negatively correlated with t%at mass (r = -0.317 for CSMI, -0.262 for CSA, -0.382 for SM, P < 0.001 for all). In regression models, lean mass retained its positive association with all HSA parameters, while %fat mass remained negatively correlated.

Conclusions: Bone quality surrogate parameters show a different pattern of association with body composition variables; while total fat mass was an important determinant of TBS, lean mass proved to be the strongest factor associated with hip strength parameters.