Bone mineral density in patients with longstanding type 1 diabetes: Results from the Canadian study of longevity in type 1 diabetes

Abstract Aim It is currently unclear if longstanding type 1 diabetes (T1D) affects bone mineral density (BMD). Methods BMD measured by dual-energy X-ray absorptiometry and history of fragility fracture was determined in 75 T1D participants with ≥50 years of diabetes duration and 75 age- and sex-matched non-diabetic controls. BMD T-scores were determined for the lumbar spine (LS), total hip (TH) and femoral neck (FN). Results T1D participants had median diabetes duration of 54[52,58]y, 41(55%) were females, and mean A 1c was 7.3 ± 0.8%. T1D females had higher LS T-scores compared to female controls (−0.3 ± 1.2 vs. -1.1 ± 1.4, p  = 0.014), lower FN T-scores (−1.5 ± 1.0 vs. -1.2 ± 0.9, p  = 0.042) and more fragility fractures (7(17%) vs. 1(2%), p  = 0.021). In T1D, higher A1c was associated with higher adjusted odds of fragility fracture ( p  = 0.006). T1D males and controls showed no difference in BMD or fractures. Conclusions There were no substantial differences in T-score between T1D and matched controls; however, T1D females showed higher BMD at the LS and possibly paradoxically higher fragility fractures compared to matched controls. These findings suggest that lower T-scores may not be associated with a history of fragility fracture in females with longstanding T1D and that other factors should be investigated.