Undiagnosed coronary artery disease in long-term type 1 diabetes. The Dialong study.

AIMS: We studied the total prevalence of obstructive coronary artery disease (CAD), undiagnosed CAD and absent CAD in persons with ≥45-year duration of type 1 diabetes (T1D) versus controls, and associations with mean HbA1c, LDL-cholesterol and blood pressure over 2-3 decades.

METHODS

We included 76% (n = 103) of all persons with T1D diagnosed ≤1970 attending a diabetes center and 63 controls without diabetes. We collected 20-30 years of HbA1c, LDL-cholesterol and blood pressure measurements. Participants without previously diagnosed coronary heart disease (CHD) underwent Computed Tomography Coronary Angiography (CTCA). Undiagnosed obstructive CAD was defined as any coronary stenosis >50% on CTCA, absent CAD as no detected plaque, and total obstructive CAD as either obstructive CAD on CTCA or previous CHD diagnosis.

RESULTS

The prevalence of undiagnosed, absent and obstructive CAD was 24% (21/88), 16% (14/88) and 35% (36/103) in T1D versus 10% (6/60), 50% (30/60) and 14% (9/63) in controls (all p < 0.05). Mean HbA1c was associated with undiagnosed obstructive CAD (OR 2.30 95% C.I. 1.13-4.69), while mean LDL-cholesterol was inversely associated with absent CAD (0.12, 0.04-0.43).

CONCLUSIONS

The prevalence of undiagnosed obstructive CAD was high (24%) in this cohort of long-term survivors with T1D. Mean LDL-cholesterol and HbA1c were associated with CAD.