Bone Abstracts

Background: Among body composition phenotypes there is no consensus on definition and consequences of sarcopenic obese phenotype. The recommended method to quantify the muscle mass is the dual energy X-ray absorptiometry (DXA), based on measurement of total fat mass and appendicular lean mass. A high BMI may provide a great bone mineral density (BMD) in many individuals, but it does not guarantee optimal bone strength. The aim of our study is to investigate the influence of sarcopenic obesity on hip bone strength indices: femoral strength index (FSI), Cross-Sectional Moment of Inertia (CSMI), cross-sectional area (CSA), section modulus (Z) and buckling ratio (BR).

Methods: In this retrospective case–control study, participants were recruited among patients who were assessed for osteoporosis, using DXA method, from January 2011 to December 2013. Inclusion criteria were: post-menopausal women aged 50 years or older; BMI≥30 kg/m². We classified all the included patients in sarcopenic obeses and non sarcopenic obeses following Newman’s criteria, based on appendicular lean mass adjusted for height and body fat mass (residuals). We performed a hip structural analysis (HSA) from hip DXA images to measure FSI, CSMI, CSA, Z and BR.

Results: We evaluated 127 women mean aged 63.50 years±8.69 S.D. (min. 50 years and max. 84 years) with a mean BMI of 34.27 kg/m²±4.01 S.D. (min. 30.04 and max. 53.97). Forty-five sarcopenic obeses patients (35.43%) had a mean FSI of 1.17±0.33 S.D., a mean CSMI of 9613 mm⁴±2403 S.D., a mean CSA of 134 mm²±23 S.D., a mean Z of 556 mm³±113 S.D. and a mean BR of 9.11±4.23 S.D. Eighty-two non sarcopenic obeses (64.57%) had a mean FSI of 1.30±0.30 S.D., a mean CSMI of 9886 mm⁴±1970 S.D. and a mean CSA of 135 mm²±21 S.D., a mean Z of 571 mm³±102 S.D. and a mean BR of 7.11±2.67 S.D.

Conclusions: In our cohort of post-menopausal women, sarcopenic obeses had worse bone quality and strength.