Long-term cholesterol-lowering effects of 4 fat-restricted diets in hypercholesterolemic and combined hyperlipidemic men. The Dietary Alternatives Study.

CONTEXT: The long-term effect of aggressively vs moderately fat-restricted diets has not been studied extensively in free-living subjects with different types of hyperlipidemia. OBJECTIVE: To compare the cholesterol-lowering effects of 4 levels of dietary fat intake restriction after 1 year. DESIGN: Randomized, parallel, comparison trial. SETTING: Male employees of a large industry. PARTICIPANTS: A total of 444 men had low-density lipoprotein cholesterol (LDL-C) levels above the 75th age-specific percentile. Subjects with triglyceride (TG) levels less than the 75th age-specific percentile were defined as hypercholesterolemic (HC) and those with TG levels at or above the 75th age-specific percentile were defined as combined hyperlipidemic (CHL). INTERVENTIONS: Hypercholesterolemic subjects were randomized to diets 1, 2, 3, and 4 taught to contain 30%, 26%, 22%, and 18% fat, and the CHL subjects were randomized to diets 1, 2, and 3. All 4 diets were taught to subjects and spouses or partners in 8 weekly 2-hour classes. MAIN OUTCOME MEASURES: Plasma lipoprotein levels after 1 year. RESULTS: Fat intake after 1 year declined from a mean of 34% to 36% of energy to 27%, 26%, 25%, and 22% in the 4 HC diet groups and 28%, 26%, and 25% in the 3 CHL diet groups. Mean+/-SD percent LDL-C reductions were 5.3%+/-16.2%, 13.4%+/-12.6%, 8.4%+/-11.2%, and 13.0%+/-15.7% in the HC diet groups and 7.0%+/-16.2%, 2.8%+/-15.8%, and 4.6%+/-13.5% in the CHL diet groups (P<.01 in all but 1 instance). Apoprotein B levels decreased 8.6%, 10.7%, 4.3%, and 5.3% in the HC groups and 14.6%, 11.4%, and 9.9% in the CHL groups (P<.05-.01 in each instance). Triglyceride levels increased significantly in subjects following HC diets 3 and 4, 21.7% and 38.7% (P<.05 and .01), but not in any CHL subjects. High-density lipoprotein cholesterol decreased 2.8% and 3.2% in subjects on HC diets 3 and 4, respectively (P<.05 in both cases). CONCLUSIONS: After 1 year, moderate restriction of dietary fat intake attains meaningful and sustained LDL-C reductions in HC subjects and apoprotein B reductions in both HC and CHL subjects. More extreme restriction of fat intake offers little further advantage in HC or CHL subjects and potentially undesirable effects in HC subjects.

Improvement in exertional left ventricular dysfunction after revascularization.

The case is reported of a 63-year-old white man with mild angina pectoris, whose systolic pressure fell 30 mmHg (4-0 kPa) with maximal exercise, without chest pain but with accompanying dizziness. Grafting the internal mammary arteries into the mid left anterior descending and obtuse marginal arteries improved regional myocardial perfusion and increased maximal cardiac output 24 per cent and maximal systolic pressure 32 per cent.

Quinidine plasma concentration and exertional arrhythmia.

Quinidine gluconate was used to treat arrhythmia induced with maximal exercise testing. Twenty-nine subjects who had previously developed frequent premature contractions on testing were selected for further study. After a control maximal exercise test, quinidine (10 mg. per kilogram) in solution was given orally in a single dose, and two hours later the same test was repeated. Recurrence of premature contractions was completely prevented in five of the 19 subjects tested; suppression was better than the mean value in three others, and in 11 subjects it was below the mean value. The plasma concentration at two hours was 1.68 plus or minus 0.31 ug per milliliter, which is a therapeutic level. Raising the dose to 15 mg. per kilogram eliminated the premautre contractions in six subjects whose response to 10 mg. per kilogram had not been complete, but not in two others. Lowering the dose to 5mg. per kilogram lowered the plasma level to below the therapeutic level. No differences between the responses to the drug of the otherwise healthy subject and those with symptomatic heart disease could be found. Compared with the responses to the control tests, there were small but significant changes in the second test in heart rates, blood pressure, and duration of exercise. Aerobic working capacity estimated by Vo2max was unchanged. Mild toxic effects manifested by malaise and diarrhea were a common finding with both 10mg per kilogram and 15mg per kilogram of quinidine, but not with 5mg per kilogram.