Comparison of the lipid-modifying efficacy and safety profiles of ezetimibe coadministered with simvastatin in older versus younger patients with primary hypercholesterolemia: A post Hoc analysis of subpopulations from three pooled clinical trials

Impact of ezetimibe on markers of inflammation in patients treated with statins: a systematic review

Statins are the primary pharmacological intervention to reduce LDL cholesterol; they significantly reduce inflammatory markers. Ezetimibe also reduces LDL cholesterol and reduces cardiovascular events when given on top of statin therapy. Whether ezetimibe, like statins, reduces markers of inflammation is less clear. We, therefore, conducted a systematic literature research addressing the impact of ezetimibe on CRP, TNFα and IL-6 when given on top of statin therapy. Our work indicates that overall ezetimibe reduces inflammation on top of statin treatment. However, available data are limited for CRP and even more so for TNFα and IL-6.

Effects of ezetimibe, simvastatin and ezetimibe/simvastatin on correlations between apolipoprotein B, LDL cholesterol and non-HDL cholesterol in patients with primary hypercholesterolemia

BACKGROUND/SYNOPSIS

Apolipoprotein (apo) B is highly predictive of coronary risk, especially in patients with high triglycerides (TG). This post hoc analysis evaluated the effects of lipid-lowering therapy on correlations between apoB and low-density lipoprotein cholesterol (apoB:LDL-C) and non-high-density lipoprotein cholesterol (apoB:non-HDL-C) in patients with TG< and ≥ 200 mg/dL.

METHODS

This analysis used data from 3 randomized clinical trials in patients with primary hypercholesterolemia receiving placebo, ezetimibe (EZE), simvastatin (SIMVA) or EZE/SIMVA for 12 weeks. Simple linear regression analyses predicted LDL-C and non-HDL-C levels corresponding to apoB values (80 mg/dL) at baseline and Week 12.

RESULTS

ApoB correlated with LDL-C (r ≥ 0.76) and non-HDL-C (r ≥ 0.86) at baseline. The correlations were strengthened with SIMVA and EZE/SIMVA at Week 12 (r ≥ 0.88 for LDL-C and r ≥ 0.94 for non-HDL-C). The predicted LDL-C and non-HDL-C values were lower following treatment with SIMVA or EZE/SIMVA than for placebo and EZE. For SIMVA and EZE/SIMVA, the predicted LDL-C and non-HDL-C values were closer to more aggressive LDL-C and non-HDL-C levels (i.e., 70 and 100 mg/dL, respectively). The apoB:LDL-C and apoB:non-HDL-C correlations were weaker and the predicted LDL-C values were generally lower in high TG patients than in low TG patients both at baseline and Week 12. In contrast, the predicted non-HDL-C values were generally higher in high versus low TG patients at baseline but less so at Week 12.

CONCLUSION

After treatment with EZE, SIMVA, or EZE/SIMVA, a given apoB value corresponds to lower LDL-C and non-HDL-C levels than those obtained from untreated patients.

Dietary cholesterol reverses resistance to diet-induced weight gain in mice lacking Niemann-Pick C1-Like 1

Niemann-Pick C1-Like 1 (NPC1L1) mediates intestinal cholesterol absorption. NPC1L1 knockout (L1-KO) mice were recently shown to be resistant to high-fat diet (HFD)-induced obesity in one study, which was contrary to several other studies. Careful comparison of dietary compositions in these studies implies a potential role of dietary cholesterol in regulating weight gain. To examine this potential, wild-type (WT) and L1-KO mice were fed one of three sets of diets for various durations: (1) a HFD without added cholesterol for 5 weeks; (2) a high-carbohydrate diet with or without added cholesterol for 5 weeks; or (3) a synthetic HFD with or without added cholesterol for 18 weeks. We found that L1-KO mice were protected against diet-induced weight gain only on a diet without added cholesterol but not on a diet containing 0.16% or 0.2% (w/w) cholesterol, an amount similar to a typical Western diet, regardless of the major energy source of the diet. Food intake and intestinal fat absorption were similar between the two genotypes. Intestinal cholesterol absorption was blocked, and fecal cholesterol excretion increased in L1-KO mice. Under all diets, L1-KO mice were protected from hepatosteatosis. In conclusion, increasing dietary cholesterol restores diet-induced weight gain in mice deficient in NPC1L1-dependent cholesterol absorption.

Lipid-lowering therapy does not affect the postprandial drop in high density lipoprotein-cholesterol (HDL-c) plasma levels in obese men with metabolic syndrome: a randomized double blind crossover trial

INTRODUCTION

The postprandial lipid metabolism in metabolic syndrome patients is disturbed and may add to the increased cardiovascular risk in these patients. It is not known whether postprandial high density lipoprotein-cholesterol (HDL-c) metabolism is also affected and whether this can be influenced by statin and/or ezetimibe treatment.

METHODS

Prospective, randomized, double blind, crossover trial comparing simvastatin 80 mg with simvastatin/ezetimibe 10 mg/10 mg treatment for 6 weeks on postprandial HDL-c metabolism in 15, nonsmoking, male, obese metabolic syndrome patients (Adult Treatment Panel III, ATPIII). Only study medication was allowed. HDL-c concentrations, cholesteryl ester transfer (CET), CET protein (CETP) mass and adiponectin were measured before and after oral fat loading. ClinicalTrials.gov NCT00189085.

RESULTS

Plasma HDL-c levels remained stable during continuous fasting following an overnight fast. Pre-fat load HDL-c concentrations without treatment, after simvastatin and simvastatin/ezetimibe treatment were 1.15 +/- 0.04, 1.16 +/- 0.05 and 1.11 +/- 0.04 mmol/l. Fat load induced a 11% drop in HDL-c plasma levels; 1.02 +/- 0.05 mmol/l (P < 0.001) which was not affected by either therapy. Triglyceride levels during fat load were similar after both treatments. Total CET increased from 9.73 +/- 0.70 to 12.20 +/- 0.67 nmol/ml/h (P = 0.004). Four hours after fat loading CETP mass was increased while adiponectin levels were decreased, irrespective of treatment.

DISCUSSION

HDL-c levels decrease as CET increases after fat loading in obese metabolic syndrome patients. This is not influenced by either simvastatin or simvastatin/ezetimibe treatment. After fat loading, CETP mass and CET increased, and adiponectin decreased pointing towards a potential role for intra-abdominal fat. Decreased postprandial HDL-c levels may contribute to the increased cardiovascular risk in metabolic syndrome patients on top of already low HDL-c levels.

Hyperlipidemia in the elderly

People are now living longer, largely because of a combination of falling rates of fertility and mortality, thus producing a greater proportion of older people in society. Thirty times more centenarians were alive in 2000 than in 1900, and the population growth in the elderly segment of society is expected to continue at an exponential rate. Vascular disease is responsible for more than a quarter of all deaths worldwide. More than 80% of individuals who die of coronary heart disease are older than 65 years. Although a myocardial infarction may be perceived as fatal, heart attacks do not always lead to death but to conditions such as congestive heart failure, ischemic cardiomyopathy, and angina, which greatly impact quality of life. These issues are only a few that must be contemplated when considering the clinical and economic effects of preventive therapies in the elderly population.

Meta-analysis of the cholesterol-lowering effect of ezetimibe added to ongoing statin therapy

OBJECTIVE

To review and analyse the evidence for the cholesterol-lowering effect of ezetimibe in adult patients with hypercholesterolaemia who are not at low-density lipoprotein cholesterol (LDL-C) goal on statin monotherapy.

RESEARCH DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE and EMBASE were searched to identify ezetimibe randomised controlled trials (RCTs) published between January 1993 and December 2005. The meta-analysis combined data from RCTs, with a minimum treatment duration of 6 weeks, that compared treatment with ezetimibe 10 mg/day or placebo added to current statin therapy. The difference between treatments was analysed for four co-primary outcomes: mean percentage change from baseline in total cholesterol (TC), LDL-C, and high-density lipoprotein cholesterol (HDL-C), and number of patients achieving LDL-C treatment goal. Meta-analysis results are presented for a modified version of the inverse variance random effects model.

RESULTS

Five RCTs involving a total of 5039 patients were included in the meta-analysis. The weighted mean difference (WMD) between treatments significantly favoured the ezetimibe/statin combination over placebo/statin for TC (-16.1% (-17.3, -14.8); p < 0.0001), LDL-C (-23.6% (-25.6, -21.7); p < 0.0001) and HDL-C (1.7% (0.9, 2.5); p < 0.0001). The relative risk of reaching the LDL-C treatment goal was significantly higher for patients on ezetimibe/statin relative to those on placebo/statin (3.4 (2.0, 5.6); p < 0.0001). In pre-defined sub-group analyses of studies in patients with coronary heart disease, the WMD between treatments remained significantly in favour of ezetimibe/statin (p < 0.0001) for TC and LDL-C but was no longer significant for HDL-C. Elevations in creatine kinase, alanine aminotransferase or aspartate aminotransferase that were considered as an adverse effect did not differ significantly between treatments.

CONCLUSIONS

The meta-analysis we performed included only five studies and was restricted to analysis of the changes in cholesterol levels relative to baseline. However, the results suggest that ezetimibe co-administered with ongoing statin therapy provides significant additional lipid-lowering in patients not at LDL-C goal on statin therapy alone, allowing more patients to reach their LDL-C goal.

Ezetimibe: an update on the mechanism of action, pharmacokinetics and recent clinical trials

Elevated serum cholesterol is a known risk factor for the development of coronary artery disease. Circulating cholesterol is a product of both cholesterol absorption from the gut and cellular cholesterol production. Ezetimibe is a novel cholesterol-lowering drug that acts at the brush border of the small intestine. Recent studies have further identified the molecular target as the Niemann-Pick C1-like transporter. Ezetimibe blocks the absorption of dietary and biliary cholesterol and plant sterols resulting in intracellular cholesterol depletion. Clinical studies have demonstrated beneficial improvements in the lipid profile with ezetimibe as monotherapy, but dramatic effects are seen when ezetimibe is combined with other lipid-lowering drugs, particularly 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Combination studies of ezetimibe with statins, bile acid sequestrants, fenofibrate and niacin all demonstrate significant total and low density lipoprotein cholesterol lowering. An excellent safety and tolerability profile combined with once-daily dosing make this attractive adjunct therapy for the treatment of hypercholesterolemia.

Effect of ezetimibe in patients who cannot tolerate statins or cannot get to the low density lipoprotein cholesterol target despite taking a statin

BACKGROUND

Recent guidelines underline the need for high-risk patients to reach strict low density lipoprotein cholesterol (LDL-C) targets (1.8-2.6 mmol/L; 70-100 mg/dL), and specifically mention the possible use of combination therapy (e.g.statin + ezetimibe) to achieve these goals.

METHODS

A retrospective case-note audit was carried out to assess the response to administering ezetimibe in patients unable to tolerate statins (Group 1), or high dose of statins (Group 2) and patients who cannot achieve the LDL-C target (2.6 mmol/L; 100 mg/dL) despite taking a statin (Group 3).

RESULTS

Ezetimibe lowered LDL-C levels by 20-29% across the 3 patient groups after 2-3 months of treatment. High density lipoprotein cholesterol (HDL-C) levels tended to remain unchanged, although there was a consistent trend for a fall if baseline values were 'high'. However, the LDL-C/HDL-C ratio changed significantly and favourably in all groups. The fall in fasting triglyceride levels in all groups was greater (reaching 19-25%) when baseline levels were > or = 1.5 or 1.7 mmol/L (136-150 mg/dL). There were no marked abnormalities in liver function tests or creatine kinase activity. In Group 3 there was a significant trend for a fall in serum creatinine levels across the tertiles of baseline creatinine values. Limitations of the present study include the small sample size (especially in Groups 1 and 2), its short-term duration and the absence of event-based end-points. Therefore, the results are hypothesis-generating rather than conclusive.

CONCLUSIONS

When used alone or added to a statin, ezetimibe favourably altered the LDL-C/HDL-C ratio and lowered triglyceride levels. Ezetimibe was well tolerated in patients with statin intolerance and was associated with a 26% fall in LDL-C. An additional action may be some degree of improved renal function. Further studies are needed to confirm these findings.

Dual cholesterol inhibition with ezetimibe/simvastatin in pre-treated hypercholesterolaemic patients with coronary heart disease or diabetes mellitus: prospective observational cohort studies in clinical practice

OBJECTIVE

Patients with primary hypercholesterolaemia and concomitant coronary heart disease (CHD) and/or diabetes mellitus (DM), who are at particularly high risk of cardiovascular events such as stroke or myocardial infarction, benefit from aggressive lipid lowering strategies. The present studies investigated the incremental efficacy and safety of dual cholesterol inhibition with ezetimibe/simvastatin in such high-risk patients pre-treated with statins but not reaching the 100 mg/dL (2.6 mmol/L) low density cholesterol (LDL-C) cholesterol threshold in the primary care setting.

METHODS

Two open-label, prospective, non-randomised, observational studies (study 1 with n = 19 194 patients, predominantly with CHD; study 2 with n = 19 484 patients, predominantly with DM). Patients received--almost all after statin pre-treatment--ezetimibe 10 mg plus simvastatin 10 mg (study 1: 15%, study 2: 16%), 20 mg (in 68% each), 40 mg (12%/10%) or 80 mg (1%/1%) as fixed dose combinations over 3 months (dosage at investigator's discretion).

RESULTS

Mean LDL-C was reduced by 28%/27% (study 1/ study 2) compared with baseline values (on statin monotherapy). Mean total cholesterol was decreased by 22% in each study, mean triglycerides by 16/17%, and mean high density cholesterol (HDL-C) was increased by 9/10%. Adverse events were reported in 0.3% and 0.2% of patients, respectively.

CONCLUSION

Dual cholesterol inhibition with ezetimibe/simvastatin was effective and well tolerated under real practice conditions in high-risk patients with CHD and/or DM.

Non-low-density lipoprotein cholesterol-associated actions of ezetimibe: an overview

Ezetimibe, an intestinal cholesterol absorption inhibitor, lowers circulating low-density lipoprotein cholesterol (LDL-C) levels both when administered as monotherapy and in combination with other hypolipidaemic drugs, mostly statins. This review focuses on the effects of ezetimibe on non-LDL-C-associated variables. In most studies, ezetimibe effectively reduced triglyceride and increased high density lipoprotein cholesterol levels. The authors also consider the effect of ezetimibe on other variables such as C-reactive protein levels, insulin sensitivity and endothelial function. Ezetimibe is useful in patients with sitosterolaemia (a rare inherited disorder) as it significantly reduces plasma phytosterol concentrations. Ezetimibe fulfils two of the three essential characteristics of any drug (efficacy and safety). However, clinical studies are required to provide evidence of its ability to reduce vascular events.