Endocrine Abstracts

Introduction: Adults with Type 1 Diabetes Mellitus (T1DM) are at risk of premature osteoporosis and fractures. The onset of T1DM typically starts during childhood and adolescence thus the effects of diabetes on the skeleton may be established in this period. Studies in children primarily use DXA to evaluate the effects of T1DM on bone with conflicting results. We present the first study in children assessing the impact of T1DM on skeletal microstructure and strength, using HRpQCT (High Resolution peripheral Quantitative Computed Tomography).

Methods: We recruited 22 patients aged 12–16 years with T1DM who were matched by age and gender with healthy controls. Recruits underwent a standard medical and fracture history; diabetic therapy and control was assessed in T1DM patients. Paired t-tests were applied to assess differences in total body and lumbar DXA parameters, cortical and trabecular microstructural parameters (assessed by HRpQCT) and skeletal strength assessed by microfinite element analysis.

Results: There was no significant difference in the total body and lumbar spine bone mineral density between T1DM and control pairs. Tibial trabecular thickness was lower in T1DM patients (−0.005 mm; CI −0.01,−0.001, P=0.029). There was a reduction in trabecular loading at the radius (Tb.F/TF distal: −6.2; CI −12.4, −0.03, P=0.049) and tibia (Tb.F/TF distal: −5.2; CI −9.2, −1.2, P=0.013), (Tb.F/TF proximal: −5.0; CI −9.8, −0.1, P=0.047). Regression models demonstrated a reduction in tibial stiffness (kN.mm, P=0.03) and tibial failure load (kN, P=0.03) with higher HbA1C before and after adjusting for age and gender.

Conclusion: Alteration of tibial trabecular microarchitecture is associated with an alteration in tibial loading properties. Similar loading alterations at the radius also appear to emerge in children with T1DM. Poor diabetic control may contribute to reduced tibial bone strength. Larger patient cohorts are required to determine if T1DM results in changes in skeletal integrity driven by duration and control of T1DM in childhood.