Endocrine Abstracts

Introduction: Central obesity and the consequent metabolic syndrome have global devastating effect on the health system due to their strong association with type 2 diabetes mellitus and cardiovascular disorder. There are contradictory results about the influence of insulin resistance and visceral adipose tissue on bone phenotype. The study was designed to evaluate the association between bone quality and bone mineral density (BMD) with bone marrow adipose tissue (MAT) as well as with insulin resistance-related parameters (i.e. HOMA-IR, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and intrahepatic lipids (IHL).

Material and Methods: The study comprised 56 subjects (36F/20M), which were submitted to biochemical exams of (glucose, HbA1C, calcium, phosphorus, alkaline phosphatase, insulin, PTH, 25-OHD, osteocalcin, telopeptide carboxiterminal of collagen type 1), dual X-ray absorptiometry for the assessment of BMD [lumbar spine, femoral neck, and total hip BMD, as well as lumbar spine trabecular bone score (TBS)]. In addition, all subjects underwent to Magnetic resonance exams for the evaluation of MAT (¹H spectroscopy), SAT, VAT and IHL.

Results: No subject had diabetes mellitus based on fasting glucose and HbA1c determinations. The group showed: age=47±14 years, weight=67.8±10.9 Kg, height=1.65±0.10 m; and BMI=24.8±3.9 Kg/m² (17.5–33.6 Kg/m²). The mean of L3 TBS was 1.4±0.1 (1.17–1.77) and MAT was 32±11% (10.6–69.1). There was a negative association between VAT, SAT, IHL with TBS (R²=0.29; P<0.0001 and R²=0.23; P<0.005; R²=0.14; P<0.05, respectively). In addition, there was a negative association between TBS with MAT and HOMA-IR, respectively, R²=0.16; P=0.001 and R²=0.23, P=0.0002, which was maintained after adjustment age and BMI. There was no association between BMD with SAT, VAT, IHL and HOMA-IR.

Conclusion: The present study shows for the first time that MAT affects bone quantity and quality, while insulin resistance parameters (VAT, IHL and HOMA-IR) are only associated with bone quality (TBS). The present results encourage further studies to verify if TBS may serve as tool for BMD-independent fracture risk assessment in metabolic syndrome.