Type 1 diabetes mellitus and associated risk factors in patients with or without CHD: a case-control study.

BACKGROUND: Approximately 1% of children are born with CHD, and 90-95% reach adulthood. Increased exposure to infections and stress-strain can contribute to an increased risk of developing type 1 diabetes mellitus. CHD may increase the risk of more serious infections, stress-strain, and increased risk of developing type 1 diabetes mellitus.

METHODS: We analysed the onset of and the risk of mortality and morbidity associated with concurrent CHD in patients with type 1 diabetes mellitus compared with patients with type 1 diabetes mellitus without CHD. The study combined data from the National Diabetes Register and the National Patient Register.

RESULTS: A total of 104 patients with CHD and type 1 diabetes mellitus were matched with 520 controls. Patients with CHD and type 1 diabetes mellitus had an earlier onset of diabetes (13.9 versus 17.4 years, p<0.001), longer duration of diabetes (22.4 versus 18.1 years, p<0.001), higher prevalence of retinopathy (64.0 versus 43.0%, p=0.003), higher creatinine levels (83.5 versus 74.1 µmol/L, p=0.03), higher mortality (16 versus 5%, p=0.002), and after onset of type 1 diabetes mellitus higher rates of co-morbidity (5.28 versus 3.18, p⩽0.01), heart failure (9 versus 2%, p=0.02), and stroke (6 versus 2%, p=0.048) compared with controls.

CONCLUSIONS: From a nationwide register of patients with type 1 diabetes mellitus, the coexistence of CHD and type 1 diabetes mellitus was associated with an earlier onset, a higher frequency of microvascular complications, co-morbidity, and mortality.