Recent trends over time in vascular disease in type 1 diabetes: insights from the Pittsburgh Epidemiology of Diabetes Complications study.

aimsTo evaluate recent trends, by diagnosis year, in the cumulative incidence of vascular type 1 diabetes (T1D) complications and their risk factors up to 35 years duration.

methodsParticipants from the Epidemiology of Diabetes Complications study of childhood-onset T1D were categorized into three calendar year onset cohorts: 1965-69, 1970-74, and 1975-80. All-cause, cardiovascular and renal mortality were determined both on the complete cohort (n=440) as well as in the subset with clinical examinations (n=363). Coronary artery disease (CAD, CAD death, myocardial infarction, revascularization, angina and ischemic ECG abnormalities); lower extremity arterial disease (LEAD, abnormal Ankle Brachial Index/amputation/intermittent claudication); distal symmetric polyneuropathy (DSP, clinical exam); cardiac autonomic neuropathy (CAN, abnormal heart rate response to deep breathing); overt nephropathy (ON, albumin excretion rate>200 μg/min) and proliferative retinopathy (PR, fundus photography) were assessed on the subset with clinical examinations.

resultsWhile all-cause, cardiovascular and renal mortality improved with a more recent diagnosis in the overall cohort, no univariate differences were observed for complications requiring examination (CAD, DSP, CAN, ON), although a borderline trend toward improved complication-free survival with a more recent onset was observed for PR (p=0.06). LEAD incidence showed an anomalous pattern, being highest in the 1975-80 and lowest in the 1970-74 cohort (p=0.009). Allowing for risk factors over time did not materially change these results.

conclusionsDespite declines in all-cause, cardiovascular and renal mortality in the total cohort, no improvements were observed in either mortality or complication incidence with a more recent onset in the examined cohort.