Risk factors for mortality and ischemic heart disease in patients with long-term type 1 diabetes

Abstract 

Aims

The purpose of this study is to evaluate the effect of glycemic regulation, dyslipidemia, and renal dysfunction on mortality (all-cause and cardiovascular) and ischemic heart disease (IHD) in a long-term follow-up of a population-based cohort of Danish type 1 diabetic patients with at least 20 years of diabetes.

Methods

A population-based cohort of type 1 diabetic patients was identified as of July 1, 1973 (n=727). In 1993 to 1996, the cohort was reassessed and baseline data were collected from blood and urine samples in 389 patients. Mean (glycemic regulation and lipids) and highest values (creatinine and albuminuria) of the baseline period were used to predict mortality and IHD between baseline and 2006. Data of mortality and morbidity were provided by the Danish Civil Registration System, the Danish Causes of Death Registry, and the Danish National Patient Registry.

Results

At the follow-up in 2006, 256 patients (65.8%) were still alive. In a statistical model adjusted for age, sex and duration of diabetes, the following parameters were related to all-cause mortality and cardiovascular mortality: glycemic regulation, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (inversely), total cholesterol, creatinine, and macroalbuminuria. Furthermore, all markers except macroalbuminuria were associated with IHD. Microalbuminuria at baseline was not related to any of the endpoints.

Conclusions

Glycemic regulation, dyslipidemia, and renal dysfunction were all related to mortality and IHD in a 13-year follow-up of long-term Danish type 1 diabetic patients. These results underscore the better outcome for tightly regulated type 1 diabetic patients, even in long-term survivors.

Keywords: Type 1 diabetes, Mortality, Ischemic heart disease, Glycemic regulation, Lipids