Background: Non-insulin-dependent diabetes mellitus dialysis patients have the highest cardiovascular mortality known in any group of patients. Mixed dyslipidemia with moderately elevated low-density lipoprotein (LDL) cholesterol and high levels of triglyceride-rich lipoproteins is common in this condition. It is not known, however, whether patients with type 2 diabetes on dialysis with this form of dyslipidemia derive benefit from lipid-lowering therapy. Recently, drugs have become available that potently lower triglyceride-rich, apoB-containing lipoproteins and thus permit testing of this issue. This is the first trial to address specifically the issue of whether the excessive cardiovascular mortality of patients with type 2 diabetes on dialysis can be lowered by statins.
Methods: The Die Deutsche Diabetes Dialyse Studie is a prospective randomized placebo-controlled trial that tests the hypothesis that atorvastatin, a hydroxymethyl-glutaryl coenzyme A reductase inhibitor, decreases the rate of cardiovascular mortality and of nonfatal myocardial infarction in patients with type 2 diabetes who have been on hemodialysis treatment for no more than two years. The primary endpoint, cardiovascular mortality, includes fatal myocardial infarction, sudden death, death during coronary intervention, death from heart failure, and other coronary causes. Secondary endpoints comprise overall mortality, nonfatal cardiovascular events, fatal and nonfatal cerebrovascular disease, and the mean percentage change in lipid profile from baseline. The trial enrolls 1200 men and women on hemodialysis for less than two years and with type 2 diabetes at 150 centers throughout Germany. Inclusion criteria are age of 18 to 80 years, low-density cholesterol of 80 to 190 mg/dl (2.1 to 4.9 mmol/liter), and triglyceride levels of less than 1000 mg/dl (11.4 mmol/liter). Patients are randomized to cither inactive (placebo) or active (atorvastatin, 20 mg/day) drug therapy. The average duration of follow-up is more than 2.5 years. To protect against a lower than expected rate of events, the trial will be continued until a predetermined fixed number of endpoints occurs in the entire cohort so that the predefined power of the trial will be guaranteed.
Conclusions: This trial was designed to demonstrate that lipid lowering with atorvastatin will improve life expectancy and quality of life in type 2 diabetics on hemodialysis. The resolution of this question is important because the genesis of vascular lesions in this condition is multifactorial and the precise role of dyslipidemia has not been defined.