Presence and Determinants of Cardiovascular Disease and Mortality in Individuals With Type 1 Diabetes of Long Duration: The FinnDiane 50 Years of Diabetes Study
The aim of this study was to determine the incidence of cardiovascular disease (CVD) and mortality as well as their risk factors in type 1 diabetes (T1D) with more than 50-years duration.
From 5,396 individuals included in the Finnish Diabetic Nephropathy Study, 729 diagnosed in 1967 or earlier survived with T1D for more than 50 years. In this FinnDiane 50-year cohort, cumulative incidence of CVD events was assessed from the diagnosis of diabetes, and the excess CVD risk, compared to matched 12,710 individuals without diabetes, was calculated by Fine and Gray’s method. In addition, at the baseline visit (median duration of diabetes of 39 years) risk factors for different types of CVD (both non-fatal and fatal) and mortality were analyzed and cause-specific hazard ratios were estimated during a median follow-up of 16.6 years from the baseline visit.
In individuals with diabetes duration of more than 50 years, the 60-year cumulative incidence of CVD from the diagnosis of diabetes was 64.3% (62.5-66.0). Compared to individuals without diabetes, the standardized incidence ratio for CVD was 7.4 (6.5-8.3) and was in persons with normoalbuminuria 4.9 (4.0-5.9). Mean HbA1c and HbA1c variability, dyslipidemia, BMI, kidney disease, age and diabetes duration were the variables associated with incident CVD. In particular, HbA1c was associated with peripheral artery disease (PAD). Standardized mortality ratio compared with the Finnish background population was 3.2 (2.8-3.7). The factors, associated with mortality were diabetes duration, increased HbA1c variability, inflammation, insulin resistance, kidney disease and PAD.
Individuals with T1D of very long duration are at a high risk of CVD. In addition, throughout the lifespan, optimal glycemic control remains central to CVD and excess mortality prevention.