Poor Glycemic Control Predicts Coronary Heart Disease Events in Patients With Type 1 Diabetes Without Nephropathy

Abstract

—Patients with type 1 diabetes mellitus, especially those with nephropathy, are at increased risk for coronary heart disease (CHD). However, information on the predictive value of cardiovascular risk factors and the degree of hyperglycemia with respect to CHD events in patients with type 1 diabetes without nephropathy is still incomplete. Therefore, we performed a prospective study on risk factors for CHD in patients with type 1 diabetes free of clinical nephropathy. At baseline examination, cardiovascular risk factor levels of CHD were determined in 177 patients with type 1 diabetes (87 men and 90 women), age 45 to 64 years at baseline and ≥30 years at the time of diagnosis of diabetes. These patients were followed up to 7 years with respect to CHD events. Altogether, 20 patients with type 1 diabetes (13 men [7.3%] and 7 women [3.9%]) died of CHD and 28 patients with type 1 diabetes (17 men [9.6%] and 11 women [6.2%]) had a serious CHD event (death from CHD or nonfatal myocardial infarction). In multivariate Cox regression analysis, a previous history of myocardial infarction (hazard ratio [HR] and its 95% confidence interval, 8.0 [3.1 to 21.0], P 10.4%, the highest tertile, HR 5.4 [1.4 to 20.4], P =0.013), and the duration of diabetes (>16 years, the highest tertile, HR 4.2 [1.3 to 12.9], P =0.013) were the only variables associated with CHD death even after adjustment for other cardiovascular risk factors. These variables also predicted the incidence of all CHD events. Our results indicate that poor metabolic control is a strong predictor of CHD events in patients with late-onset type 1 diabetes without nephropathy, independently of other cardiovascular risk factors.