Background: Over the last two decades, type 2 diabetes mellitus (T2DM) has increasingly been recognized as a fracture risk factor, despite the occurrence of normal to even increased bone mineral density (BMD) (1). The dual energy X-ray absorptiometry (DXA) derived trabecular bone score (TBS) is considered to be a proxy of bone quality and has been reported to be diminished in diabetic patients (2) and insulin resistant, non-diabetic postmenopausal women (3).
Objective: To assess whether insulin resistance already associates with TBS in young healthy men.
Methods: 999 young healthy men were recruited in the region of Ghent and surrounding communities and were cross sectionally assessed for multiple bone, muscle and metabolic parameters as part of the SIBLOS study. Of 459 participants, aged 35 +/- 5.4 years, data on both TBS and fasting glucose and insulin were available. Insulin resistance was defined by a Homeostatic Model Assessment of Insulin Resistance (HOMA-IR, which is the product of fasting glucose with fasting insulin, divided by a constant) of greater than or equals to 2.17 (4). Statistical significance of DXA-derived parameters between the insulin resistant and insulin sensitive group was assessed using t-tests.
Results: Of the 459 participants, 89 (19.4%) were insulin resistant. Mean TBS +/- standard deviation in this group was 1.42 +/- 0.08, which is slightly lower than the insulin sensitive group: 1.46 +/- 0.08 (P= 0.002). Quantitatively, only total hip BMD tended to be slightly higher in the insulin resistant group (1.09 +/- 0.14 g/cm² vs 1.07 +/- 0.13 g/cm², P= 0.011), while at the level of the femoral neck and the lumbar spine, no statistical significant difference could be noted (0.89 +/- 0.13 g/cm² vs 0.88 +/- 0.13 g/cm², P= 0.220 and 1.06 +/- 0.12 g/cm² vs 1.05 +/- 0.13 g/cm², P= 0.282, respectively).
Conclusion: Despite being years ahead of established T2DM, insulin resistant young men tend to have a lower TBS. However, because of the small order of magnitude, no relevant statements about bone quality on the level of the individual patient can be made based upon TBS alone.
References: 1. Vestergaard P. Discrepancies in bone mineral density and fracture risk in patients with type 1 and type 2 diabetes--a meta-analysis. Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. 2007;18(4):427-44.2. Leslie WD, Aubry-Rozier B, Lamy O, Hans D, Manitoba Bone Density P. TBS (trabecular bone score) and diabetes-related fracture risk. J Clin Endocrinol Metab. 2013;98(2):602-9.3. Campillo-Sanchez F, Usategui-Martin R, Ruiz-de Temino A, Gil J, Ruiz-Mambrilla M, Fernandez-Gomez JM, et al. Relationship between Insulin Resistance (HOMA-IR), Trabecular Bone Score (TBS), and Three-Dimensional Dual-Energy X-ray Absorptiometry (3D-DXA) in Non-Diabetic Postmenopausal Women. J Clin Med. 2020;9(6).4. Ghasemi A, Tohidi M, Derakhshan A, Hasheminia M, Azizi F, Hadaegh F. Cut-off points of homeostasis model assessment of insulin resistance, beta-cell function, and fasting serum insulin to identify future type 2 diabetes: Tehran Lipid and Glucose Study. Acta Diabetol. 2015;52(5):905-15.