Characteristics of patients with type 1 diabetes and additional autoimmune disease in the DPV registry
Abstract Context Autoimmune diseases affect ~8% of the population. Type 1 diabetes mellitus (T1DM) is linked to other autoimmune diseases (AID) like autoimmune thyroid disease, or Addison’s disease (AD) that may impact diabetes therapy and outcome. Objective To analyze demographic and clinical characteristics of other AID in T1DM from a large standardized registry, the prospective diabetes follow-up (DPV). Methods We searched the registry for T1DM with the additional diagnosis of Hashimoto’s thyroiditis (HT), Graves’ disease (GD), and/or AD. T1DM with other AID (n=6,166, 5.4%) were compared to isolated T1DM (n=107,457). For group comparisons, we used multivariable regression models with age, sex, diabetes duration, migration background, and type of insulin regimen as basic adjustments (microvascular endpoints: additionally adjusted for HbA1c). Results Patients with additional AID were more often female (54.7 vs. 32.0%, p<0.001) and had a longer diabetes duration (7.9 [4.2-12.5] vs. 6.7 [2.7-12.9] years, p<0.001). After adjustment, daily insulin dosage was higher in AD and HT compared to isolated T1DM (0.858±0.032 and 0.813±0.005 vs. 0.793±0.001 IU/kg*d). Retinopathy was less common in HT (1.5%), whereas it was more frequent in GD (3.1%) if compared to isolated T1DM (1.8%). In both GD and HT, microalbuminuria occurred less often (10.6% and 14.3% vs. 15.5%) and neuropathy (2.1% and 1.8% vs. 0.8%) was more common compared to isolated T1DM. Conclusions T1DM with additional AID show heterogeneous differences compared to isolated T1DM. T1DM plus AD or HT requires more insulin. Further, the rate of neuropathy is higher in HD or GD, whereas the rate of microalbuminuria is lower.