THE EFFICACY OF INTENSIVE DIETARY THERAPY ALONE OR COMBINED WITH LOVASTATIN IN OUTPATIENTS WITH HYPERCHOLESTEROLEMIA

Background. A diet low in saturated fat and cholesterol is the standar d initial treatment for hypercholesterolemia. However, little quantita tive information is available about the efficacy of dietary therapy in clinical practice or about the combined effects of diet and drug ther apy. Methods. One hundred eleven outpatients with moderate hypercholes terolemia were treated at five lipid clinics with the National Cholest erol Education Program Step 2 diet (which is low in fat and cholestero l) and lovastatin (20 mg once daily), both alone and together. A diet high in fat and cholesterol and a placebo identical in appearance to t he lovastatin were used as the respective controls. Each of the 97 pat ients completing the study (58 men and 39 women) underwent four consec utive nine-week periods of treatment according to a randomized, balanc ed design: a high-fat diet-placebo period, a low-fat diet-placebo peri od, a high-fat diet-lovastatin period, and a low-fat diet-lovastatin p eriod. Results. The level of low-density lipoprotein (LDL) cholesterol was a mean of 5 percent (95 percent confidence interval, 3 to 7 perce nt) lower during the low-fat diet than during the high-fat diet (P<0.0 01). With lovastatin therapy as compared with placebo, the reduction w as 27 percent. Together, the low-fat diet and lovastatin led to a mean reduction of 32 percent in the level of LDL cholesterol. The level of high-density lipoprotein (HDL) cholesterol fell by 6 percent (95 perc ent confidence interval, 4 to 8 percent) during the low-fat diet (P<0. 001) and rose by 4 percent during treatment with lovastatin (P<0.001). The ratio of LDL to HDL cholesterol and the level of total triglyceri des were reduced by lovastatin (P<0.001), but not by the low-fat diet. Conclusions, The effects of the low-fat-low-cholesterol diet and lova statin on lipoprotein levels were independent and additive. However, t he reduction in LDL cholesterol produced by the diet was small, and it s benefit was possibly offset by the accompanying reduction in the lev el of HDL cholesterol.