Objective: To determine coronary heart disease (CHD) incidence among dyslipidemic subjects with non-insulin-dependent diabetes mellitus (NIDDM) and to assess the effect of lipid-modifying treatment on serum and lipoprotein lipids and the CHD incidence in these patients.
Research design and methods: Of the 4081 men participating in the Helsinki Heart Study, a coronary primary prevention trial with gemfibrozil in middle-aged men with high non-high-density lipoprotein (HDL) cholesterol (greater than 5.2 mM; 200 mg/dL), 135 had NIDDM at entry. The incidence of definite myocardial infarction and cardiac death and changes in serum and lipoprotein lipids were determined during the 5-yr trial in the NIDDM patients and compared with those observed in nondiabetic trial participants.
Results: Compared with nondiabetic subjects, NIDDM patients had lower HDL cholesterol (P less than 0.001), higher triglyceride concentration (P less than 0.0001), and greater body mass index (P less than 0.001), there were more hypertensive patients (P less than 0.001) among them. The incidence of myocardial infarction and cardiac death was significantly higher among diabetic than nondiabetic participants (7.4 vs. 3.3%, respectively, P less than 0.02). CHD incidence in the gemfibrozil-treated diabetic men (n = 59) was 3.4% compared with 10.5% in the placebo group (NS). In multivariate analysis, diabetes (P less than 0.05), age (P less than 0.0001), smoking (P less than 0.0001), low HDL cholesterol (P less than 0.05), and high low-density lipoprotein cholesterol (P less than 0.005) were independently related to CHD incidence. Gemfibrozil-induced serum and lipoprotein lipid changes in diabetic patients were similar to those observed in nondiabetic subjects.
Conclusions: Compared with similarly dyslipidemic nondiabetic subjects, patients with NIDDM are at markedly increased risk of CHD. This elevated risk can be somewhat reduced by gemfibrozil.