Bone Abstracts

Purposes: The trabecular bone score (TBS) is an indicator of cancellous bone microstructure obtained from image analysis with lumbar spine dual-energy X-ray absorptiometry (DXA) scans. A decrease in TBS is considered to be a risk factor for vertebral fracture that is independent of BMD. At the same time, it has been reported that, BMD was higher and TBS was lower in women with type 2 diabetes mellitus (DM), and a decreasing TBS is risk factor for fracture. However, the relationships between TBS and glucose metabolism indices in healthy people are unclear, and this study was conducted to elucidate these relationships.

Method: The subjects were 214 healthy postmenopausal women with HbA1c ≤6.2% who underwent an osteoporosis examination. On blood tests, fasting plasma glucose (FPG), HbA1c, Ca, P, Cr, PTH, 25-hydroxy vitamin D [25(OH)D], P1NP, and CTX were measured. Lumbar (L2-4) BMD and femoral neck (FN) BMD were measured with DXA, and TBS (L1-4) was calculated.

Results: The subjects’ mean values were age 63.2±7.5 years, BMI 22.7±3.0 kg/m², FPG 90±8 mg/dl, HbA1c 5.6±0.3%, PTH 45.5±14.5 pg/ml, 25(OH)D 16.3±4.3 ng/ml, BMD (L2-4) 0.846±0.146 g/cm² (Z score 0.3±1.0), and FN 0.620±0.093 g/cm² (Z score 0.1±1.0). TBS was 1.317±0.073. An investigation of the correlation between TBS and each of these factors revealed that TBS was negatively correlated with age, PTH, and HbA1c, and significantly positively correlated with BMD, and 25(OH)D. On multiple regression analysis, HbA1c still showed a significant negative correlation with TBS even after adjusting for age and BMI (r=−0.155, P<0.05).

Conclusion: These results suggest that very mild glucose intolerance, even within the normal range, may be associated with deteriorating cancellous bone microstructure in postmenopausal women.