BACKGROUND:Niacin and lovastatin are both effective drugs for the treatment of hypercholesterolemia and are among the drugs of first choice recommended by the adult treatment panel. To date, however, no studies have directly compared the lipoprotein-modifying effects and safety of lovastatin and niacin across their usual dosage range in patients with primary hypercholesterolemia.METHODS:The efficacy and safety of lovastatin and niacin were compared in a controlled, randomized, open-label study of 26 weeks' duration that was conducted at five lipid clinics. One hundred thirty-six patients with primary hypercholesterolemia participated in the study. Entry criteria were a low-density lipoprotein (LDL) cholesterol level greater than 4.37 mmol/L (160 mg/dL) with coronary heart disease and/or more than two coronary heart disease risk factors or an LDL cholesterol level greater than 5.19 mmol/L (190 mg/dL) in patients without coronary heart disease or less than two coronary heart disease risk factors. The study consisted of a 4-week diet run-in period after which eligible patients were randomly assigned to receive treatment with either lovastatin (20 mg/d) or niacin (1.5 g/d) for 10 weeks. On the basis of the LDL cholesterol response and patient tolerance, the doses were sequentially increased to 40 and 80 mg/d of lovastatin or 3 and 4.5 g/d of niacin after 10 and 18 weeks of treatment, respectively.RESULTS:In the two patient groups, 66% of patients treated with lovastatin and 54% of patients treated with niacin underwent full dosage titration. At all time points, lovastatin was significantly (P < .01) more effective than niacin in reducing LDL cholesterol levels (26% vs 5% at week 10, 28% vs 16% at week 18, and 32% vs 23% at week 26), whereas niacin was more effective (P < .01) in increasing high-density lipoprotein cholesterol levels (6% vs 20% at week 10, 8% vs 29% at week 18, and 7% vs 33% at week 26). Niacin reduced Lp(a) lipoprotein levels by 35% at week 26, whereas lovastatin had no effect. Cutaneous flushing was the most common side effect during treatment with niacin.CONCLUSIONS:Lovastatin and niacin both exerted favorable dose-dependent changes on the concentrations of plasma lipids and lipoproteins. Lovastatin was more effective in reducing LDL cholesterol concentrations, whereas niacin was more effective in increasing high-density lipoprotein cholesterol concentrations and reducing the Lp(a) lipoprotein level. Lovastatin was better tolerated than niacin, in large part because of the common cutaneous side effects of niacin.

Background: Inhibitors of hydroxymethylglutaryl coenzyme A reductase are widely used to treat hypercholesterolemia. They have a good short- to medium-term safety profile, but long-term safety data are limited.Methods: Seven hundred forty-five patients with severe hypercholesterolemia (mean baseline plasma cholesterol level on diet, 9.3 mmol/L [360 mg/dL]) were treated with lovastatin for a median duration of 5.2 years. Their mean age at baseline was 50 years, 68% were male, 60% had familial hypercholesterolemia, and 42% had a history of coronary heart disease. Seventy-seven percent of patients had titrations of lovastatin to 80 mg/d, and 58% took other lipid-lowering agents, usually bile acid sequestrants, concomitantly.Results: The mean changes at 5 years in total, low-density lipoprotein, and high-density lipoprotein cholesterol were -35%, -44%, and +14%, respectively. Eighty percent of patients completed the study, 13% were unavailable for follow-up, 4% were discontinued due to adverse events unlikely to be related to lovastatin, and 3% (21) were discontinued because of drug-attributable adverse events: marked but asymptomatic increase in aminotransferase values (10 patients), gastrointestinal disturbance (three patients), rash (two patients), myalgia (one patient), myopathy (two patients), arthralgia (one patient), insomnia (one patient), and weight gain (one patient). Sixteen patients died during the study, all of coronary disease. Of these, 14 had coronary heart disease at baseline. There were no deaths attributable to trauma, suicide, or homicide, and there were only 14 cases of cancer (vs 21 expected). There was no evidence for an adverse effect on the lens.Conclusions: Lovastatin is a generally well-tolerated and effective drug during long-term use.

OBJECTIVE:To compare the effectiveness of the ternary-drug combination of colestipol, niacin, and lovastatin with binary combinations of those drugs in treating patients with familial hypercholesterolemia.DESIGN:An open sequential study of serum lipoprotein responses in patients receiving diet alone (mean duration, 4 months); colestipol and niacin with diet (mean duration, 9 months); and colestipol, niacin, and lovastatin with diet (mean duration, 15 months).SETTING:Metabolic ward and lipid clinic of a university medical center.PATIENTS:Twenty-two patients with clinical characteristics of familial hypercholesterolemia (low-density-lipoprotein cholesterol, greater than 8.48 mmol/L; 21 of 22 with tendon xanthomas).INTERVENTIONS:Diet: less than 200 mg/d of cholesterol and less than 8% of total calories from saturated fat; colestipol, 30 g/d; lovastatin, 40 to 60 mg/d; and niacin, 1.5 to 7.5 g/d.MEASUREMENTS AND MAIN RESULTS:Mean total serum cholesterol and low-density-lipoprotein cholesterol levels of 4.86 +/- 0.62 mmol/L (188 +/- 24 mg/dL SD) and 2.89 +/- 0.54 mmol/L (112 +/- 21 mg/dL SD), respectively, were significantly lower during ternary-drug treatment than during colestipol-niacin treatment (p less than 0.003) or during treatment in which other possible binary combinations were given. The cholesterol content of very low-density-lipoproteins was lower and high-density-lipoprotein cholesterol levels higher during this phase than during the colestipol-niacin phase.CONCLUSIONS:Colestipol, lovastatin, and niacin are mutually complementary in treating hypercholesterolemia. This regimen produces reductions in serum cholesterol levels similar to those associated with regression of atheromatous plaques in animal studies.

Familial dysbetalipoproteinemia has been reported to be associated uniquely with an apolipoprotein E phenotype (E2/2) that occurs in approximately 1% of all persons. We have observed the typical clinical and biochemical characteristics of this disorder in five members of a family, in all of whom the apolipoprotein E phenotype, as determined by isoelectric focusing electrophoresis, is E3/3. The disorder is present in three generations of the family: the proband, her mother, and three of the proband's five children. The proband's husband, father of all five children, also has apolipoprotein E phenotype E3/3, as do his two unaffected children. As in normal persons with phenotype E3/3, the apolipoprotein E of affected members appears to have a single residue of cysteine. When incorporated with egg lecithin into discoidal complexes, the apolipoprotein E from affected members was taken up normally into perfused livers of estradiol-treated rats, in which a high level of LDL receptors is expressed. When isoelectric focusing electrophoresis was carried out over a narrow range of pH (5-7), each of the apolipoprotein E isoforms of affected members was observed as a doublet, even after reduction of dimers of the protein with 2-mercaptoethanol and treatment with neuraminidase to minimize the content of sialylated forms of the protein. Doublets were also observed in the apolipoprotein E-2 of patients with classical dysbetalipoproteinemia, but only in the affected members of the family with atypical dysbetalipoproteinemia were the components of the doublets equally prominent. As in classical dysbetalipoproteinemia, both apolipoprotein B-100 and B-48 were present in the very low density lipoprotein fraction of plasma obtained in the postabsorptive state, indicating that remnantlike lipoproteins of both hepatic and intestinal origin accumulate. This observation, together with available evidence on the structural and functional heterogeneity of human apolipoprotein E, lead us to suggest that the disorder in this family is caused by one or two structurally abnormal forms of apolipoprotein E that contain a single residue of cysteine.

Cholesterol esterification, cholesteryl ester transfer between lipoproteins, and cholesterol transport between lipoproteins and cultured cells have been measured in the plasma of 22 patients with primary hyperlipidemia and 10 normolipidemic subjects. In hyperbetalipoproteinemia, increase in plasma low density lipoprotein levels was associated with a reduction of cholesteryl ester transfer rates, and with a reversal of the normal direction of sterol transport between fibroblasts and their plasma culture medium. Instead of net transport from cells to medium there was a net uptake of sterol from plasma by the cells, despite a level of plasma lecithin/cholesterol acyltransferase activity that was within the normal range. In dysbetalipoproteinemia, esterification rates were increased above normal levels, but cholesteryl ester transfer was reduced and the direction of sterol transport between the cells and plasma medium was reversed, as in the hyperbetalipoproteinemic group. In hypertriglyceridemia, those subjects with cardiovascular disease showed a metabolic pattern similar to the hyperbetalipoproteinemic group. The subjects in this group without symptoms of cardiovascular disease showed a normal direction of sterol transport, normal or raised rates of cholesteryl ester transfer between lipoproteins, and an increased rate of sterol esterification in plasma that decreased towards normal levels as plasma triglyceride levels decreased. Despite their quite distinct metabolic patterns there was no consistent difference between the two hypertriglyceridemic groups in triglyceride or cholesterol levels, very low density lipoprotein composition, or electrophoretic or isoelectric focussing patterns. All hypertriglyceridemic subjects with documented cardiovascular disease showed reversed cell-plasma sterol transport and all subjects without such disease showed a normal direction of cell-plasma sterol transport. The results of this study indicate major and reproducible abnormalities in plasma cholesterol metabolism in several groups of subjects with genetically distinct hyperlipidemias, who are at risk for atherosclerotic vascular disease. The possible predictive value of sterol metabolic measurements in the analysis of cardiovascular disease is discussed.

We studied the effect of th bite acid sequestrant colestipol, alone and in combination with clofibrate or niacin, in patients with heterozygous familial hypercholesterolemia who were given a diet low in cholesterol and saturated fat. With colestipol alone, mean cholesterol levels in serum decreased 16 to 25 per cent. The addition of clofibrate produced a total mean decrement of only 28 per cent. In contrast, serum cholesterol levels fell 45 per cent when colestipol as combined with niacin. Low-density-lipoprotein (LDL) cholesterol decreased 55 per cent with colestipol and niacin, whereas high-density-lipoprotein (HDL) cholesterol increased. Mean LDL cholesterol was lower in patients given this regimen than in matched normal controls eating an unrestricted diet. Tendinous xanthomas, measured by quantitative xeroradiography, were significantly reduced (P < 0.01), indicating that this regimen mobilized cholesterol from tissue pools with slow turnover. Colestipol plus niacin promises to be useful in the treatment of patients at high risk from elevated levels of LDL.

A radioimmunoassay for apolipoprotein E in human blood serum has been developed that measures equally the major polymorphic species of the protein (apolipoproteins E-1, E-2, E-3, and E-4) and the apo E in the dimer of apolipoproteins E and A-II. The assay is specific and yields values for apolipoprotein E in very low density lipoproteins that agree closely with those obtained by a quantitative electrophoretic method. Apolipoprotein E is also present in at least one species of high density lipoprotein, but the content of apolipoprotein E in the lipoprotein fractions of plasma is uncertain owing to dissociation during ultracentrifugation. The concentration of apolipoprotein E is higher in serum of normolipidemic, premenopausal women than in men of comparable age and is a direct function of the serum triglyceride level. Apolipoprotein E levels are increased out of proportion to triglyceride levels in hyperlipidemic patients with familial dysbetalipoproteinemia (homozygotes for lack of apolipoprotein E-3). Heterozygous relatives of homozygotes have significantly higher apolipoprotein E levels in serum than unaffected relatives. The concentration of partially degraded (remnant) triglyceride-rich lipoproteins also appears to be increased in heterozygotes, who comprise about 15% of the population.

The monogenic disorder familial hypercholesterolemia (FH) is associated with a high risk of premature coronary arteriosclerosis, largely attributable to a 2-3 fold increase in levels of low density lipoproteins (LDL) in serum. Heretofore, no regimen of drug therapy or surgical intervention has been reported which is capable of lowering levels of low density lipoproteins consistently to normal in FH heterozygotes. Regimens employing bile acid binding resins, nicotinic acid, neomycin and paraaminosalicylic acid individually have achieved reductions of serum cholesterol of only 25-30%, nearly comparable to the effect of partial ileal bypass, (33%) (Miettinen and Lempinen 1977). Combinations of clof ibrate with bile acid resins or neomycin are only slightly more effective than these agents given individually.