Cardiovascular and Renal Disease Burden in Type 1 Compared With Type 2 Diabetes: A Two-Country Nationwide Observational Study

OBJECTIVE Type 1 diabetes (T1D) and type 2 diabetes (T2D) increase risks of cardiovascular (CV) and renal disease (CVRD) compared with diabetes-free populations. Direct comparisons between T1D and T2D are scarce. We examined this by pooling full-population cohorts in Sweden and Norway. RESEARCH DESIGN AND METHODS A total of 59,331 patients with T1D and 484,241 patients with T2D, aged 18–84 years, were followed over a mean period of 2.6 years from 31 December 2013. Patients were identified in nationwide prescribed drug and hospital registries in Norway and Sweden. Prevalence and event rates of myocardial infarction (MI), heart failure (HF), stroke, chronic kidney disease (CKD), all-cause death, and CV death were assessed following age stratification in 5-year intervals. Cox regression analyses were used to estimate risk. RESULTS The prevalence of CV disease was similar in T1D and T2D across age strata, whereas CKD was more common in T1D. Age-adjusted event rates comparing T1D versus T2D showed that HF risk was increased between ages 65 and 79 years, MI between 55 and 79 years, and stroke between 40 and 54 years (1.3–1.4-fold, 1.3–1.8-fold, and 1.4–1.7-fold, respectively). CKD risk was 1.4–3.0-fold higher in T1D at all ages. The all-cause death risk was 1.2–1.5-fold higher in T1D at age >50 years, with a similar trend for CV death. CONCLUSIONS Adult patients with T1D compared with those with T2D had an overall greater risk of cardiorenal disease (HF and CKD) across ages, MI and all-cause death at middle-older ages, and stroke at younger ages. The total age-adjusted CVRD burden and risks were greater among patients with T1D compared with those with T2D, highlighting their need for improved prevention strategies.