Despite good compliance, very low fat diet alone does not achieve recommended cholesterol goals in outpatients with coronary heart disease

Abstract

Aim: A low-saturated, low-cholesterol diet is important in the treatment of hypercholesterolaemia in patients with coronary heart disease. The aim of this study was to investigate the efficacy of a very low fat diet to achieve a targeted serum low density lipoprotein (LDL) cholesterol level (</=2.59mmol x l-1) in outpatients with coronary heart disease.

Methods: One hundred and twenty-six male patients (all ex-smokers) with coronary heart disease and a serum LDL cholesterol >3.37mmol x l-1 were investigated 12-14 weeks after an acute coronary event. After overnight fasting each patient had (a) his resting energy expenditure measured (indirect calorimetry using standard protocol) and (b) venous blood sampled from a forearm vein to determine lipid profile. All the patients were randomly allocated to four groups of treatment: Group A on a very low fat diet (resting energy expenditure-fat diet, where fat intake was </=20% resting energy expenditure): Group B on a low fat diet from the National Cholesterol Education program (National Cholesterol Education Program step 2 diet): Group C on resting energy expenditure-fat diet+simvastatin 10mg daily; Group D on National Cholesterol Education Program step 2 diet+simvastatin 10mg daily. For all patients the prescribed energy intakes were equal to their respective resting energy expenditures.

Results: At 6 months, the average decrease in serum LDL cholesterol was not different between Group A and Group B, but the increase in high density lipoprotein cholesterol (HDL) (+29%) observed in Group A led to a reduced LDL cholesterol/HDL cholesterol ratio (P<0.001). As expected, a more important serum lipid improvement was found in the groups supplemented with diet+drug association, but the decrease in LDL cholesterol was higher in Group C than in Group D (-37+/-9.7% vs -24. 5+/-15%;P<0.00001) as well as LDL cholesterol/HDL cholesterol ratio (P<0.001). No patient on diet alone achieved the recommended LDL cholesterol level </=2.59mmol x l-1.

Conclusion: Diet alone does not allow patients with coronary heart disease to achieve the recommended blood cholesterol levels, even if its fat content is highly reduced.