Lipid and apolipoprotein levels and distribution in patients with hypertriglyceridemia: effect of triglyceride reductions with atorvastatin

Effect of atorvastatin on plasma apoE metabolism in patients with combined hyperlipidemia

Atorvastatin, a synthetic HMG-CoA reductase inhibitor used for the treatment of hyperlipidemia and the prevention of coronary artery disease, significantly lowers plasma cholesterol and low-density lipoprotein cholesterol (LDL-C) levels. It also reduces total plasma triglyceride and apoE concentrations. In view of the direct involvement of apoE in the pathogenesis of atherosclerosis, we have investigated the effect of atorvastatin treatment (40 mg/day) on in vivo rates of plasma apoE production and catabolism in six patients with combined hyperlipidemia using a primed constant infusion of deuterated leucine. Atorvastatin treatment resulted in a significant decrease (i.e., 30-37%) in levels of total triglyceride, cholesterol, LDL-C, and apoB in all six patients. Total plasma apoE concentration was reduced from 7.4 +/- 0.9 to 4.3 +/- 0.2 mg/dl (-38 +/- 8%, P < 0.05), predominantly due to a decrease in VLDL apoE (3.4 +/- 0.8 vs. 1.7 +/- 0.2 mg/dl; -42 +/- 11%) and IDL/LDL apoE (1.9 +/- 0.3 vs. 0.8 +/- 0.1 mg/dl; -57 +/- 6%). Total plasma lipoprotein apoE transport (i.e., production) was significantly reduced from 4.67 +/- 0.39 to 3.04 +/- 0.51 mg/kg/day (-34 +/- 10%, P < 0.05) and VLDL apoE transport was reduced from 3.82 +/- 0.67 to 2.26 +/- 0.42 mg/kg/day (-36 +/- 10%, P = 0.057). Plasma and VLDL apoE residence times and HDL apoE kinetic parameters were not significantly affected by drug treatment. Percentage decreases in VLDL apoE concentration and VLDL apoE production were significantly correlated with drug-induced reductions in VLDL triglyceride concentration (r = 0.99, P < 0.001; r = 0.88, P < 0.05, respectively, n = 6). Our results demonstrate that atorvastatin causes a pronounced decrease in total plasma and VLDL apoE concentrations and a significant decrease in plasma and VLDL apoE rates of production in patients with combined hyperlipidemia.

Atorvastatin and micronized fenofibrate alone and in combination in type 2 diabetes with combined hyperlipidemia

OBJECTIVE

This study evaluated the effect of a atorvastatin-fenofibrate combination on lipid profile, in comparison to each drug alone, in patients with type 2 diabetes and combined hyperlipidemia (CHL).

RESEARCH DESIGN AND METHODS

A total of 120 consecutive patients, who were free of coronary artery disease (CAD) at entry, were studied for a period of 24 weeks. These patients were randomly assigned to atorvastatin (20 mg/day, n = 40), micronized fenofibrate (200 mg/day, n = 40), or a combination of both (atorvastatin 20 mg/day plus fenofibrate 200 mg/day, n = 40). The effect of treatment on LDL cholesterol, triglycerides (TGs), HDL cholesterol, apolipoprotein A-I and B, lipoprotein(a), and plasma fibrinogen (PF) was recorded. Moreover, the percentage of patients that reached the American Diabetes Association treatment goals and the estimated CAD risk status were calculated.

RESULTS

No patient was withdrawn from the study because of side effects. The atorvastatin-fenofibrate combination reduced total cholesterol by 37%, LDL cholesterol by 46%, TGs by 50%, and PF by 20%, whereas it increased HDL cholesterol by 22% (P < 0.0001 for all). These changes were significantly better than those of both monotherapies. Of the patients on drug combination, 97.5% reached the LDL cholesterol treatment goal of <100 mg/dl, 100% reached the desirable TG levels of <200 mg/dl, and 60% reached the optimal HDL cholesterol levels of >45 mg/dl. These rates were significantly higher than those of both monotherapies. Combined treatment reduced the 10-year probability for myocardial infarction from 21.6 to 4.2%.

CONCLUSIONS

The atorvastatin-fenofibrate combination has a highly beneficial effect on all lipid parameters and PF in patients with type 2 diabetes and CHL. It improved patients' CAD risk status significantly more than each drug alone.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.

Effect of statin therapy on remnant lipoprotein cholesterol levels in patients with combined hyperlipidemia

Clinical trials with statins have demonstrated significant reductions in cardiovascular events. Remnant lipoproteins are independent predictors of cardiovascular events. Because of the paucity of data on the effect of statins on remnant lipoproteins, we tested the effect of pravastatin, simvastatin, and atorvastatin on remnant lipoprotein cholesterol (RLP-C) levels in a randomized crossover study in patients with combined hyperlipidemia. After a 6-week diet phase, patients (n=22) were randomized to pravastatin (40 mg/d), simvastatin (20 mg/d), or atorvastatin (10 mg/d) for 6 weeks, with a 3-week washout between each drug. All 3 drugs significantly decreased total and low density lipoprotein (LDL) cholesterol (P<0.001). Mean reduction in LDL cholesterol with pravastatin, simvastatin, and atorvastatin was 21%, 29%, and 32%, respectively. None of the drugs affected high density lipoprotein cholesterol levels. Median levels of triglycerides were significantly reduced with simvastatin (26%, P=0.001) and atorvastatin (24%, P=0.0001) but not with pravastatin (9%, P=0.18). Non-high density lipoprotein cholesterol decreased significantly with all 3 statins (20%, 29%, and 32% with pravastatin, simvastatin, and atorvastatin, respectively; P<0.001). Median RLP-C levels were significantly reduced with simvastatin (6%, P<0.05) and atorvastatin (25.9%, P<0.001) but not with pravastatin (2.9%, P=0.58). Thus, atorvastatin and simvastatin, in addition to reducing LDL cholesterol and triglyceride levels, significantly reduced RLP-C levels. This could be another potential mechanism to explain their cardiovascular benefits.

Atorvastatin. A review of its pharmacology and therapeutic potential in the management of hyperlipidaemias

Atorvastatin is a synthetic HMG-CoA reductase inhibitor which lowers plasma cholesterol levels by inhibiting endogenous cholesterol synthesis. It also reduces triglyceride levels through an as yet unproven mechanism. Dose-dependent reductions in total cholesterol, low density lipoprotein (LDL)-cholesterol and triglyceride levels have been observed with atorvastatin in patients with hypercholesterolaemia and in patients with hypertriglyceridaemia. In large trials involving patients with hypercholesterolaemia, atorvastatin produced greater reductions in total cholesterol, LDL-cholesterol, apolipoprotein B and triglyceride levels than lovastatin, pravastatin and simvastatin. In patients with primary hypercholesterolaemia, the combination of atorvastatin and colestipol tended to produce larger reductions in LDL-cholesterol levels and smaller reductions in triglyceride levels than atorvastatin monotherapy. Although atorvastatin induced smaller reductions in triglyceride levels and more modest increases in high density lipoprotein (HDL)-cholesterol levels than either fenofibrate or nicotinic acid in patients with combined hyperlipidaemia, it produced larger reductions in total cholesterol and LDL-cholesterol. As with other HMG-CoA reductase inhibitors, the most frequently reported adverse events associated with atorvastatin are gastrointestinal effects. In comparative trials, atorvastatin had a similar adverse event profile to that of other HMG-CoA reductase inhibitors. Clinical data with atorvastatin are limited at present. However, with its ability to markedly reduce LDL-cholesterol levels, atorvastatin is likely to join other members of its class as a first-line agent for the treatment of patients with hypercholesterolaemia, if changes in lipid levels with atorvastatin convert to reductions in CHD mortality and morbidity. Atorvastatin may be particularly suitable for patients with heterozygous or homozygous familial hypercholesterolaemia because of the marked reductions in LDL-cholesterol experienced with the drug. Additionally, because of its triglyceride-lowering properties, atorvastatin appears to have the potential to become an appropriate treatment for patients with combined hyperlipidaemia or hypertriglyceridaemia.