Rationale:

• Treating dyslipidemia aggressively decreases the risk of macrovascular disease. Although no large trials of patients exclusively with type 1 diabetes have been done, subgroup analysis from large clinical trials has found that the use of HMG CoA-reductase inhibitors is effective for the primary and secondary prevention of acute MI.

Evidence:

• In the Air Force/Texas Coronary Atherosclerosis Prevention Study, a subgroup of diabetes patients with average total and LDL cholesterol levels were randomized to receive lovastatin (20 to 40 mg/d) or placebo in addition to a low-saturated fat, low-cholesterol diet. After an average follow-up of 5.2 years, lovastatin reduced the incidence of first acute major coronary events, MI, unstable angina, coronary revascularization procedures, and cardiovascular events (108).
• In the Heart Protection Study, patients with diabetes randomized to simvastatin had a 22% reduction in cardiovascular events. This reduction was independent of baseline cholesterol levels and was also observed in patients with baseline LDL cholesterol <116 mg/dL (109).
• The Helsinki Heart Study showed that compared with similarly dyslipidemic nondiabetic subjects, patients with type 2 diabetes have a markedly increased risk for CAD. This elevated risk can be somewhat reduced by gemfibrozil. Of the 4081 participants in this trial, 135 had type 2 diabetes at entry. Compared with nondiabetic subjects, patients with type 2 diabetes had lower HDL cholesterol levels, higher triglyceride concentrations, greater BMI, and more hypertension (110; 111).
• A post hoc analysis was done on data from 202 diabetic patients and 4242 nondiabetic patients who participated in the Scandinavian Simvastatin Survival Study (4S), in which participants were randomly assigned to placebo or to double-blind treatment with simvastatin, 20 mg/d, and blinded dosage titration up to 40 mg/d. This analysis showed that over the 5.4-year median follow-up period, simvastatin treatment improved the prognosis of diabetic patients with CAD. The absolute clinical benefit achieved by cholesterol lowering may be greater in diabetic than in nondiabetic patients with CAD because diabetic patients have a higher absolute risk of recurrent CAD events and other atherosclerotic events (112).
• The Cholesterol and Recurrent Events (CARE) trial, a 5-year trial that compared the effect of pravastatin and placebo, included 586 patients (14.1%) with clinical diagnoses of diabetes. The study showed that patients with diabetes are at high risk for recurrent coronary events that can be reduced substantially by pravastatin treatment. Pravastatin treatment reduced the AR for coronary events for diabetes patients by 8.1% and the RR by 25% (P = 0.05). Pravastatin also reduced the relative risk for revascularization procedures by 32% (P = 0.04) in the diabetes patients (113; 114).

Comments:

• None.