Cholestyramine and nicotinic acid in the treatment of familial hyperbetalipoproteinaemia in the homozygous form

The effect of atorvastatin on serum lipids and lipoproteins in patients with homozyous familial hypercholesterolemia undergoing LDL-apheresis therapy

The efficacy of atorvastatin, a new hydroxymethylglutaryl (HMG)-CoA reductase inhibitor, in reducing serum lipid levels, modifying lipoprotein composition, and suppressing cholesterol synthesis was evaluated in patients with homozygous familial hypercholesterolemia (homozygous FH) undergoing LDL-apheresis therapy. Atorvastatin was given in escalating doses (10, 20, and 40 mg/day) to nine patients with homozygous FH. Five of nine patients responded well to atorvastatin; four of these patients were receptor-defective and the remaining one was receptor-negative. The change in LDL-cholesterol in the receptor-defective patients averaged -20.6% compared to the baseline level at the highest dose of atorvastatin. Of five receptor-negative type patients, only one showed good response to atorvastatin therapy with a LDL-cholesterol reduction of 14.9%. Although the other four receptor-negative patients did not show a change in LDL-cholesterol, all of them exhibited a considerable increase in HDL-cholesterol. All patients showed reduced urinary excretion of mevalonic acid, suggesting that atorvastatin decreases LDL-cholesterol by inhibiting cholesterol biosynthesis even where LDL-receptor activity is not present. Atorvastatin also decreased serum triglycerides in both receptor-negative and defective patients, especially in the latter. As cholesterol level rebounds quickly after each apheresis procedure, a combination therapy using atorvastatin and apheresis may increase the efficacy of the apheresis treatment, improving cost-benefit effectiveness by reducing the frequency of the apheresis treatment.

Effects of acipimox and cholestyramine on serum lipoproteins, non-cholesterol sterols and cholesterol absorption and elimination

The hypolipidaemic and metabolic effects of cholestyramine combined with acipimox or placebo have been evaluated in a double-blind ninety-day study in 18 patients with xanthomatous familial hypercholesterolaemia. Serum LDL-cholesterol was reduced by 35% in the cholestyramine group and 39% in the acipimoxcholestyramine group. The latter treatment increased the HDL-cholesterol level. Serum VLDL-cholesterol and triglyceride concentrations were unchanged. Cholesterol absorption efficiency was significantly reduced, and bile acid synthesis and faecal cholesterol elimination in both groups were increased. The metabolic changes were similar in the two treatment groups, but the increase in faecal neutral sterol excretion was significant only when acipimox was added. The serum cholesterol precursor sterol contents were similarly increased during the two treatments, indicating enhancement of endogenous cholesterol synthesis. The decrease in cholesterol absorption and the increase in neutral sterol excretion were more pronounced in subjects with greater than 30% than in those with less than 30% reduction in LDL-cholesterol. The changes in serum total and LDL-cholesterol levels and cholesterol metabolism were not related to apoE phenotype, but the increase in HDL-cholesterol was higher in E4 then in E3 subjects.

Hypercholesterolemia and atherosclerosis: present and future therapy including LDL-apheresis

Atherosclerosis-induced coronary heart disease remains the major cause of death and disability in industrialized countries. Hypercholesterolemia is recognized as a causative factor in the development of atherosclerosis. While the lowering of cholesterol levels as a treatment goal has met with general agreement and acceptance, the preferred methods for doing so are still open to conjecture. This literature review discusses various factors in the hypercholesterolemia-atherosclerosis link and surveys a variety of treatment protocols including diet modification, drug therapy, surgical intervention, and plasmapheresis. Evidence is accumulating to prove that the ideal hypercholesterolemia therapy is one that reduces LDL levels while maintaining or increasing HDL levels. Because LDL-apheresis has this potential, this paper also reviews the various LDL-apheresis methods, including immunoadsorption, chemical affinity, and double-membrane filtration.

Selective removal of low density lipoprotein by plasmapheresis in familial hypercholesterolemia

Plasma lipoproteins were selectively removed from familial hypercholesterolemic patients by using two types of plasmapheresis: double-membrane filtration and selective adsorption of very low density lipoproteins (VLDL) and low density lipoproteins (LDL). In both techniques, plasma was separated from blood cells by using hollow-fiber filters, and 100% of the VLDL and LDL was recovered in the filtrate. In double-membrane filtration, the second hollow-fiber filter trapped 84% of LDL + VLDL, 48% of high density lipoprotein (HDL), 24% of albumin, and 46% of the remaining plasma protein. By treating 3 liters of plasma from a patient weighing 60 kg, 60% of the LDL and 30% to 40% of the HDL were removed as a result of an exponential decay of each component with the respective trapping coefficients. When dextran sulfate-cellulose was used as a LDL sorbent, there was only loss of LDL and VLDL, and no loss of any other major plasma component or of HDL. The sorbent column (400 ml) was saturated with 7.5 g of LDL cholesterol by treatment with 3.5 liters of plasma; the maximum reduction of LDL cholesterol was thus about 300 mg/dl for the patient weighing 60 kg. No serious side effects were observed during the long-term trials (19 to 27 months for four patients on double-membrane filtration and 10 months for the two patients on dextran sulfate-cellulose treatment.

Effects of probucol on homozygous cases of familial hypercholesterolemia

A marked reduction of serum cholesterol was obtained by treatment with probucol in heterozygous as well as in homozygous cases of familial hypercholesterolemia. A strict dietary regimen (low-fat, low-calories) intensified the hypocholesterolemic effect of the drug. The drug was also useful in diminishing the rebound of serum cholesterol after plasma exchange. Probucol reduced serum triglycerides in heterozygous cases of familial hypercholesterolemia, but there was a slight increase in triglycerides in homozygous cases. Treatment with probucol resulted in the regression of cutaneous and tendon xanthomas. Although it caused a decrease in HDL, it seems to be very effective in the treatment of familial hypercholesterolemia.

Treatment of homozygous familial hypercholesterolaemia with portacaval shunt

Thirteen patients with homozygous familial hypercholesterolaemia (HFH) were treated with portacaval shunt operations. One patient died postoperatively and the others were followed for 2-6 years. The main beneficial effects were regression of xanthomas and sustained falls in serum total and LDL cholesterol levels of about 18% in the majority of cases, sustained rises in HDL cholesterol values in most patients, and the long period of survival after the operation without further deaths or serious cardiac complications. Other favourable effects were improvement of angina pectoris, ejection systolic múrmurs or electrocardiograms in some cases. Growth and development of patients after the operation were normal and there were no clinical or biochemical signs of liver damage or portal systemic encephalopathy. Apart from the patient who died, negative or adverse effects of the operation included shunt closure causing portal hypertension and bleeding varices in 1 case, unsatisfactory clinical responses in half the patients, small or unsustained falls in serum total cholesterol in one third of cases, and failure of total cholesterol to fall below 12.0 mmol/l in any patient. Enlargement of the spleen appeared to be an invariable consequence of the operation and possible reasons for this are discussed. Finally the place of portacaval shunts in the management of HFH is reviewed.

Normalization of low-density-lipoprotein levels in heterozygous familial hypercholesterolemia with a combined drug regimen

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.

The effects of plasma exchange on cholesterol metabolism

Four patients heterozygous for familial hypercholesterolaemia were treated by repeated plasma exchange with or without lipid-lowering drugs. Repeated plasma exchange without drug therapy in 3 patients was associated with a significant 18--28% decrement in plasma cholesterol level, comparing control with plateau values observed 3 weeks after exchange. Further decrements in plateau values followed the addition of lipid-lowering drugs used in combination, clofibrate--nicotinic acid or clofibrate--nicotinic acid--cholestyramine (range of total decrement 39--50%). Plasma exchange was associated with an increased excretion of endogenous faecal steroids, but this increase was completely abolished by the subsequent administration of clofibrate--nicotinic acid. This therapy prevented any increase in bile acid excretion with concomitant use of cholestyramine resin. Plasma exchange with drug therapy was associated with a sustained rise in plasma cholesterol specific radioactivity. In a fourth patient, clofibrate--nicotinic acid was administered prior to plasma exchange and led to a 24% fall in plasma cholesterol. Subsequent plasma exchange in this patient produced no sustained change in plasma cholesterol plateau level. In two patients, withdrawal of drugs allowed plasma cholesterol to return to pre-exchange control levels. These observations suggest that plasma exchange probably produced an increase in endogenous cholesterol synthesis and a mobilisation of tissue cholesterol. In relation to plateau cholesterol values 3 weeks after an exchange, the data suggested that the reduction in plasma cholesterol level with plasma exchange and drug therapy could have been achieved by intensive drug therapy alone.

Continuous flow plasma exchange in the treatment of homozygous familial hypercholesterolemia

We report the clinical and laboratory effects of continuous-flow plasma exchange in two patients suffering from homozygous familial hypercholesterolemia. In one (Case 1) plasmapheresis was performed at fortnightly intervals over a period of 18 months; in the other (Case 2) the necessity for surgical relief of an associated supravalvular aortic stenosis resulted in premature termination of the trial. The plasma cholesterol levels in both patients fell by 35 per cent from the mean before study in the course of treatment. In Case 1 this was associated with marked regression of the patient's xanthomas, disappearance of the S-T segment depression seen on effort electrocardiograms obtained prior to the introduction of plasmapheresis, possible widening of the stenosis present at the origin of the left anterior descending coronary artery, and a marked increase in exercise tolerance and diminished frequency of anginal attacks. Cessation of cholestyramine and clofibrate administration during this study did not in any way reverse the reduction of plasma cholesterol achieved by means of plasmapheresis combined with drug therapy. We conclude that plasmapheresis has a role to play in the management of patients with homozygous familial hypercholesterolemia.

An automated method for the analysis of nicotinic acid in serum

Rational antihyperlipemic therapy based on the use of nicotinic acid and its derivatives and/or combinations demands a rapid and reliable method for monitoring nicotinic acid blood levels. To this end, an automated colorimetric method for the analysis of nicotinic acid in serum has been elaborated. For serum from rats, dogs and man given p.o. nicotinic acid or 3-pyridine methanol, the method is greater than 90% specific for nicotinic acid. The limit detection for nicotinic acid is 2 microgram/ml based on 0.15 ml of serum or 0.3 microgram/ml based on 1.5 ml of serum.

[Drug treatment of primary hyperlipoproteinemia (author's transl)]

Cardiovascular disease has become the major cause of death in the Western countries. There is strong evidence that elevations of serum lipids contribute to the pathogenesis of premature atherosclerosis. The classification of the hyperlipoproteinemias has been most beneficial as a guide to development of dietary and pharmacological regimens for lowering serum lipid concentrations. The results of dietary and drug prevention trials are discussed. Insight into the mechanisms involved in lipoprotein metabolism as well as the mode of action and of side-effects of hypolipidemic drugs is reviewed. Using present knowledge of heart disease research, it is reasonable to suggest dietary and drug treatments for the high risk patient.

A comparison of cholestyramine and nicotinic acid in the treatment of familial type II hyperlipoproteinaemia

1 The effects of cholestyramine and nicotinic acid on plasma lipid concentration have been compared in patients with type IIa hyperlipoproteinaemia. 2 During a 3-month period, cholestyramine resulted in a mean decrease in cholesterol levels of 26%. Triglyceride levels rose in eight of the ten patients during treatment with this drug but in the majority of patients remained within the normal range. 3 During nicotinic acid therapy, cholesterol fell by a mean of 21% and triglyceride by a mean of 23%. 4 The slow release preparation of nicotinic acid used was acceptable to the majority of the patients studied and the results therefore suggest that this drug may be a useful alternative to the more widely used agent, cholestyramine.

Prevention of induced atherosclerosis by diversion of bile or blockade of intestinal lymphatics in dogs

The prevention of induced hypercholesterolemia and atherosclerosis was studied by means of intestinal lymphatic blockade and of bile diversion in the dog. Hypercholesterolemia and atherosclerosis were produced by high cholesterol feeding after induction of hypothyroidism with radio-iodine plus thiouracil. Complete diversion of bile, by shunting all bile into the urinary bladder, effectively prevented hypercholesterolemia and atherosclerosis; in contrast, blockade of the intestinal lymphatics failed to prevent the consequences of the atherogenic regimen, because of the development of collateral lymphatic channels.

Long-term effects of colestipol (U-26,597 A) on plasma lipids in familial type II hyperbetalipoproteinaemia

Results related to long term treatment with Colestipol (a new resin sequestering bile acids) in 23 subjects with familial hypercholesterolaemia, 12 with Type IIA, 8 with Type IIB and 3 homozygotes are reported. Patients were given 15 g/day active drug for a period of 12 months and a double dose (30 g/day) for a successive period of 4 months along with a low cholesterol, low saturated fat, polyunsaturated fat-rich diet. Mean cholesterol decrease was --42 +/- 18 mg/dl (P less than 0.05) after 12 months of 15 g/day Colestipol and --69 +/- 17 mg/dl (P less than 0.01) after the following 4 months of 30 g/day Colestipol. The difference between the two periods of treatment (15 g and 30 g/day was not statistically significant. A slight but not significant increase in triglyceride levels was observed. Serum uric acid showed a significant increase throughout the entire period of treatment. No malabsorption syndrome or signs of toxicity were seen. Most frequent side effects were constipation, nausea, and metheorism which, with the exception of 4 cases which were withdrawn from the study, were reported as being transitory and mild.

Homozygous familial hypercholesterolemia. A possible biochemical explanation of clinical heterogeneity

Patients with homozygous familial hypercholesterolemia fall into two groups: one responds to diet and drug therapy; the other does not. Fibroblasts from patients in each group were compared for low-density lipoprotein suppression of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and low-density lipoprotein binding. In fibroblasts from four therapy-responsive patients, low-density lipoprotein (100 mug per milliliter) suppressed 3-hydroxy-3-methylglutaryl coenzyme A reductase activity to 41 +/- 12 per cent of control (without low-density lipoprotein) whereas fibroblast enzyme activity from two therapy-unresponsive patients was not suppressed (P less than 0.001). Low-density lipoprotein binding to fibroblasts from both groups was defective as compared to normal controls. Fibroblasts from two therapy-responsive patients had specific binding of low-density lipoprotein of 27 +/- 4 per cent of normal -- greater than the 12 +/- 2 per cent (P less than 0.005) binding to fibroblasts from one therapy-unresponsive patient. These biochemical differences may help explain the variable response to therapy in homozygous familial hypercholesterolemia.

Plasma exchange in the management of homozygous familial hypercholesterolaemia

Two young women with homozygous familial hypercholesterolaemia and coronary and aortic atheroma were treated by repeated plasma exchange, using a continuous-flow blood-cell separator, for 4 and 8 months. A pronounced reduction in plasma cholesterol and low-density lipoprotein (L.D.L.) concentrations was achieved by exchanging each patient's plasma with cholesterol-free plasma protein fraction (B.P.), at 3-weekly intervals on an outpatient basis. By pre-labelling the patients' cholesterol with 14-C and comparing the specific activity of the cholesterol in adipose tissue with that in plasma, evidence was obtained of an influx of tissue cholesterol into plasma after each exchange. There was no side-effects and both patients lost their angina. Plasma exchange offers a new and practical approach to the long-term management of this lethal disorder and may also provide information about the possible reversibility of human atheroma.

Portacaval shunt in four patients with homozygous hypercholesterolaemia

Four patients with homozygous hyperbetalipoproteinaemia who had proved resistant to intensive medical therapy have undergone portacaval shunt. During 3 weeks of total parenteral alimentation before the operation, the serum-cholesterol decreased significantly in each of the four patients. During the fat-emulsion phase of hyperalimentation, one patient experienced a rise in cholesterol. Postoperatively, the size of xanthomas decreased in all cases; serum-cholesterol levels rose above those achieved during hyperalimentation, and this rise continued for as long as 3 months before a further reduction was recorded. In patients with angina, this improved considerably; and in most cases bruits decreased in itensity. The results at this stage do not, however, suggest portacaval shunt for all patients with homozygous hypercholesterolaemia.