Subsequent Type 2 Diabetes in Patients with Autoimmune Disease

Immunological data show that type 2 diabetes (T2D) manifests autoimmune features. We wanted to test the association epidemiologically by assessing subsequent diagnosis of T2D following diagnosis of autoimmune disease (AId) and subsequent AId after T2D in the same individuals. Patients were identified from three Swedish health databases. A total of 32 different AId were included. Standardized incidence ratios (SIRs) were calculated for T2D diagnosis in patients with previously diagnosed AId and compared to those without a previous AId. Among a total of 757,368 AId patients, 15,103 were diagnosed with T2D, giving an overall SIR for T2D of 1.66. T2D risks were increased after 27 AIds; the highest SIRs were noted for chorea minor (8.00), lupoid hepatitis (5.75), and Addison disease (2.63). T2D was increased after 27 of 32 AIds but we were unable to control for factors such as obesity and smoking. However, the clearly increased risks for T2D in most types of AId patients, and in reverse order increased risks for AId after T2D, do not support an overall confounding by life-style factors. Mechanistic links shared by T2D, AId and life-style factors such as obesity, perhaps through chronic inflammation, may drive autoimmune activation of T2D and many AIds.