Abnormal Cortical and Trabecular Bone in Youth With Type 1 Diabetes and Celiac Disease

Abstract

OBJECTIVE This study compared bone health in youth with type 1 diabetes and celiac disease (CD) versus type 1 diabetes alone. RESEARCH DESIGN AND METHODS This was a case-control study of 42 youth with coexisting type 1 diabetes and CD and 40 with type 1 diabetes matched for age, sex, diabetes duration, and HbA1c. Bone mineral density (BMD), bone mineral content (BMC), and BMC-to-lean tissue mass (LTM) ratio were measured using DXA and reported as z-scores for height. Total, trabecular, and cortical bone and muscle parameters were measured using peripheral quantitative computed tomography (pQCT) and reported as z-scores for age. RESULTS Mean age at assessment was 14.3 ± 3.1 years; diabetes duration, 8.0 ± 3.5 years; HbA1c, 8.2 ± 1.5% (66 ± 5 mmol/mol); and 25-hydroxy vitamin D, 71 ± 21 nmol/L. Comparing youth with coexisting CD versus type 1 diabetes alone, DXA showed lower BMC-to-LTM ratio (0.37 ± 1.12 vs. 0.73 ± 2.23, P = 0.007) but no difference in total BMD. Youth with coexisting CD also had lower BMC-to-LTM ratio versus the general population (P = 0.04). Radial pQCT showed lower total BMC (−0.92 ± 1.40 vs. −0.26 ± 1.23, P = 0.03) despite similar bone and muscle cross-sectional area. In multivariable linear regression, lower BMC was associated with higher insulin dose (P = 0.03) but not HbA1c. CONCLUSIONS Youth with both type 1 diabetes and CD have lower BMC relative to LTM and lower BMC, indicating abnormal trabecular and cortical bone development despite similar bone and muscle size. These findings suggest that the two conditions confer a lower bone turnover state. We recommend further examination of bone health in this population; future research should examine early interventions to improve bone health.