Effect of ezetimibe/simvastatin compared with atorvastatin on lipoprotein subclasses in patients with type 2 diabetes and hypercholesterolaemia

Comparing remnant lipoprotein cholesterol measurement methods to evaluate efficacy of ezetimibe/statin vs statin therapy

BACKGROUND

Elevated remnant lipoprotein cholesterol (RLP-C) levels increase cardiovascular disease risk. However, RLP-C measurement methods are not standardized, leading to variations across studies.

OBJECTIVE

To evaluate the effect of ezetimibe (Eze) + statins vs statin monotherapy on RLP-C using immunoseparation (IM), vertical auto profile (VAP) ultracentrifugation, and calculated RLP-C measurement methods.

METHODS

This post hoc analysis evaluated data pooled from 3 first-line (all-statin [simvastatin 10/20/40/80 mg] vs Eze + statin [Eze 10 mg + simvastatin]) and 2 second-line (statin [atorvastatin uptitrated to 40/80 mg] vs statin + Eze [atorvastatin 20/40 mg + Eze 10 mg]) studies. Similarity of RLP-C methods was evaluated using Pearson correlation coefficients and Bland-Altman plots. RLP-C changes and percent changes from baseline were measured by all 3 methods in first-line and VAP and calculated methods in second-line studies.

RESULTS

Correlations between methods were generally moderate to strong for RLP-C levels, changes, and percent changes across treatment groups (r = 0.29-0.79) but with little evidence of agreement by Bland-Altman plots. Baseline RLP-C levels for Eze + statin vs all-statin groups were lower by IM (14.0 vs 14.0) compared with VAP (36.9 vs 35.9) and calculated (32.8 vs 33.3) methods. RLP-C changes (mg/dL) and percent changes from baseline were significantly greater (P < .01) with Eze + statins vs statins by VAP, calculated, and IM methods (between-treatment differences: -5.0 and -12.0, -2.0 and -5.4, and -1.5 and -12.1, respectively) in first-line, and VAP and calculated methods (between-treatment differences: -5.0 and -19.9 and -2.0 and -7.3) in second-line studies.

CONCLUSION

Although the 3 methods showed little agreement, each supported Eze + statins for achieving greater RLP-C reductions vs statin monotherapy; variability of results reinforces urgent need to standardize RLP-C measurements.

Ezetimibe/statin combination therapy to treat patients with type 2 diabetes

Patients with diabetes represent a population at higher risk for cardiovascular disease. Diabetic dyslipidemia is characterized by the so-called atherogenic lipid triad, consisting of an increase in small dense low density lipoprotein particles and in triglyceride-rich lipoproteins, and a decrease in high-density lipoprotein cholesterol, with an increase in non-HDL cholesterol. Numerous trials have investigated the efficacy of add-on ezetimibe therapy for patients with type 2 diabetes and not controlled by statin therapy. The published data highly suggest that patients with type 2 diabetes may be more likely to benefit from ezetimibe/statin combination therapy. However, evidence specifically addressing hard clinical endpoints and prospective trials addressing differences in response between patients with or without diabetes are still needed.

Influence of metabolic syndrome factors and insulin resistance on the efficacy of ezetimibe/simvastatin and atorvastatin in patients with metabolic syndrome and atherosclerotic coronary heart disease risk

BACKGROUND

Metabolic syndrome (MetS) and insulin resistance (IR) are increasing in prevalence, are associated with higher risk for coronary heart disease (CHD), and may potentially influence the responses to lipid-altering drug therapy. This study evaluated the effects of MetS factors (abdominal obesity, depleted high-density lipoprotein cholesterol [HDL-C], and elevated triglycerides, blood pressure, and fasting glucose) and IR on ezetimibe/simvastatin and atorvastatin treatment efficacy in patients with MetS.

METHODS

This post-hoc analysis of a multicenter, 6-week, double-blind, randomized, parallel group study of 1128 subjects with hypercholesterolemia, MetS, and moderately high/high CHD risk evaluated the effects of baseline MetS factors/IR on percent change from baseline in lipids, apolipoproteins, and high-sensitivity C-reactive protein (hs-CRP), after treatment with the usual starting doses of ezetimibe/simvastatin (10/20 mg) versus atorvastatin (10 mg, 20 mg) and next higher doses (10/40 mg versus 40 mg).

RESULTS

Ezetimibe/simvastatin and atorvastatin efficacy was generally consistent across MetS factor/IR subgroups. Ezetimibe/simvastatin produced greater incremental percent reductions in LDL-C, non-HDL-C, apolipoprotein B, total cholesterol, and lipoprotein ratios for all subgroups, and larger percent increases in HDL-C and apolipoprotein AI for all but non-obese and HDL-C ≥ 40 mg/dL subgroups than atorvastatin at the doses compared. Triglycerides, very-LDL-C, and hs-CRP results were more variable but similar between treatment groups.

CONCLUSION

The magnitude of lipid-altering effects produced by each treatment regimen was generally similar across all MetS and IR subgroups. Ezetimibe/simvastatin produced greater percent reductions in most lipid fractions than atorvastatin at the dose comparisons studied, and all treatments were generally well tolerated. (Registered at clinicaltrials.gov: NCT00409773).

Diabetic cardiac autonomic neuropathy: Do we have any treatment perspectives?

Cardiac autonomic neuropathy (CAN) is a serious and common complication of diabetes mellitus (DM). Despite its relationship to an increased risk of cardiovascular mortality and its association with multiple symptoms and impairments, the significance of CAN has not been fully appreciated. CAN among DM patients is characterized review the latest evidence and own data regarding the treatment and the treatment perspectives for diabetic CAN. Lifestyle modification, intensive glycemic control might prevent development or progression of CAN. Pathogenetic treatment of CAN includes: balanced diet and physical activity; optimization of glycemic control; treatment of dyslipoproteinemia; correction of metabolic abnormalities in myocardium; prevention and treatment of thrombosis; use of aldose reductase inhibitors; dihomo-γ-linolenic acid (DGLA), acetyl-L-carnitine, antioxidants, first of all α-lipoic acid (α-LA), use of long-chain ω-3 and ω-6 polyunsaturated fatty acids (ω-3 and ω-6 PUFAs), vasodilators, fat-soluble vitamin B₁, aminoguanidine; substitutive therapy of growth factors, in severe cases-treatment of orthostatic hypotension. The promising methods include research and use of tools that increase blood flow through the vasa vasorum, including prostacyclin analogues, thromboxane A₂ blockers and drugs that contribute into strengthening and/or normalization of Na⁺, K⁺-ATPase (phosphodiesterase inhibitor), α-LA, DGLA, ω-3 PUFAs, and the simultaneous prescription of α-LA, ω-3 PUFA and DGLA.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Effects of lipid-lowering drugs on high-density lipoprotein subclasses in healthy men-a randomized trial

CONTEXT AND OBJECTIVE

Investigating the effects of lipid-lowering drugs on HDL subclasses has shown ambiguous results. This study assessed the effects of ezetimibe, simvastatin, and their combination on HDL subclass distribution.

DESIGN AND PARTICIPANTS

A single-center randomized parallel 3-group open-label study was performed in 72 healthy men free of cardiovascular disease with a baseline LDL-cholesterol of 111±30 mg/dl (2.9±0.8 mmol/l) and a baseline HDL-cholesterol of 64±15 mg/dl (1.7±0.4 mmol/l). They were treated with ezetimibe (10 mg/day, n = 24), simvastatin (40 mg/day, n = 24) or their combination (n = 24) for 14 days. Blood was drawn before and after the treatment period. HDL subclasses were determined using polyacrylamide gel-tube electrophoresis. Multivariate regression models were used to determine the influence of treatment and covariates on changes in HDL subclass composition.

RESULTS

Baseline HDL subclasses consisted of 33±10% large, 48±6% intermediate and 19±8% small HDL. After adjusting for baseline HDL subclass distribution, body mass index, LDL-C and the ratio triglycerides/HDL-C, there was a significant increase in large HDL by about 3.9 percentage points (P<0.05) and a decrease in intermediate HDL by about 3.5 percentage points (P<0.01) in both simvastatin-containing treatment arms in comparison to ezetimibe. The parameters obtained after additional adjustment for the decrease in LDL-C indicated that about one third to one half of these effects could be explained by the extent of LDL-C-lowering.

CONCLUSIONS

In healthy men, treatment with simvastatin leads to favorable effects on HDL subclass composition, which was not be observed with ezetimibe. Part of these differential effects may be due to the stronger LDL-C-lowering effects of simvastatin.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00317993.

Changes in lipoprotein particle number with ezetimibe/simvastatin coadministered with extended-release niacin in hyperlipidemic patients

Background

Combination therapy with ezetimibe/simvastatin (E/S) and extended‐release niacin (N) has been reported to be safe and efficacious in concomitantly reducing low‐density lipoprotein cholesterol and increasing high‐density lipoprotein cholesterol in hyperlipidemic patients at high risk for atherosclerotic cardiovascular events. This analysis evaluated the effect of E/S coadministered with N on low‐density lipoprotein particle number (LDL‐P) and high‐density lipoprotein particle number (HDL‐P) as assessed by nuclear magnetic resonance (NMR) spectroscopy in patients with type IIa or IIb hyperlipidemia.

Methods and Results

This was an analysis of a previously reported 24‐week randomized, double‐blind study in type IIa/IIb hyperlipidemic patients randomized to treatment with E/S (10/20 mg/day)+N (titrated to 2 g/day) or N (titrated to 2 g/day) or E/S (10/20 mg/day). Samples from a subset of patients (577 of 1220) were available for post hoc analysis of LDL‐P and HDL‐P by NMR spectroscopy. Increases in HDL‐P (+16.2%) and decreases in LDL‐P (−47.7%) were significantly greater with E/S+N compared with N (+9.8% for HDL‐P and −21.5% for LDL‐P) and E/S (+12.8% for HDL‐P and −36.8% for LDL‐P). In tertile analyses, those with the lowest baseline HDL‐P had the greatest percent increase in HDL‐P (N, 18.4/7.9/2.1; E/S, 19.3/12.2/5.3; and E/S+N, 26.9/13.8/6.9; all P<0.001). Individuals in the highest tertile of LDL‐P had the greatest percent reduction in LDL‐P (N, 18.3/23.1/24.6; E/S, 29.7/38.3/41.8; and E/S+N, 44.3/49.0/50.5; all P<0.001).

Conclusions

These results suggest that E/S+N improves lipoprotein particle number, consistent with its lipid‐modifying benefits in type IIa or IIb hyperlipidemia patients and may exert the greatest effect in those with high LDL‐P and low HDL‐P at baseline.

Clinical Trial Registration

URL: Clinicaltrials.gov Identifier: NCT00271817

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.

A comparison of the efficacy of combined ezetimibe and statin therapy with doubling of statin dose in patients with remnant lipoproteinemia on previous statin therapy

BACKGROUND AND PURPOSE

It remains undetermined whether the addition of ezetimibe to ongoing statin therapy is more effective than increasing the dose of statin for reducing remnant lipoprotein levels in patients with remnant lipoproteinemia on previous statin treatment. This study examined whether combined ezetimibe and statin therapy resulted in a greater improvement in remnant lipoprotein levels and endothelial function than with the dose of statin in patients with remnant lipoproteinemia on previous statin treatment.

METHODS AND RESULTS

A total of 63 patients with stable coronary artery disease and high levels of remnant-like lipoprotein particle cholesterol (RLP-C) (≥5.0 mg/dL) on statin treatment were assigned randomly to two groups and treated with either addition of ezetimibe (10mg/day, n=32) or doubling of statin dose (n=31). The lipid profiles and flow-mediated dilation (FMD) of the brachial artery were measured at enrollment and after 6 months of treatment. Statin and ezetimibe combined therapy reduced RLP-C and improved FMD to a greater extent than doubling the statin dose (% reduction in RLP-C, 48 ± 18% vs. 33 ± 24%, respectively, p=0.01; % improvement in FMD, 47 ± 48% vs. 24 ± 23%, respectively, p=0.02).

CONCLUSIONS

The addition of ezetimibe to ongoing statin treatment reduced RLP-C levels and improved endothelial dysfunction to a greater extent than doubling the statin dose in patients with high RLP-C levels on previous statin treatment. The present results are preliminary and should be confirmed by further studies on a larger number of study patients.

Ezetimibe alone and in combination lowers the concentration of small, dense low-density lipoproteins in type 2 diabetes mellitus

OBJECTIVE

The effectiveness of the cholesterol absorption inhibitor ezetimibe on LDL subfractions and ultimately on the atherosclerotic risk profile remains controversial. We thus determined the concentration of atherogenic small, dense LDL (sdLDL) in patients with type 2 diabetes and an elevated cardiovascular risk profile.

RESEARCH DESIGN AND METHODS

Multicenter, randomized, open-label 6-week study investigating the effect of ezetimibe 10mg (E), simvastatin 20mg (S) and the combination of ezetimibe-/simvastatin 10/20mg (C) on the concentration of sdLDL separated from fresh plasma by gradient ultracentrifugation in patients with type 2 diabetes (NCT01384058).

RESULTS

Fifty-six patients were screened for sdLDL, 41 were randomized, and 40 patients (12 E, 14 S and 14 C) completed the study. Total and LDL cholesterol fell by 14% (p=0.004) and 15% (p=0.006) with E, 22% (p<0.001) and 32% (p<0.001) with S, and 32% (p<0.001) and 44% (p<0.001) with C, respectively. E reduced the concentration of sdLDL by 20% (p=0.043) whereas S and C reduced sdLDL by 24% (p=0.020) and 33% (p=0.003), respectively, and non-sdLDL by 28% (p=0.004) and 42% (p<0.001), respectively. However, the further drop in sdLDL by adding E to S was not significant.

CONCLUSION

Ezetimibe alone and in combination with simvastatin reduced the concentration of atherogenic sdLDL in patients with type 2 diabetes.

Plasma lipid profiling across species for the identification of optimal animal models of human dyslipidemia

In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profiles in 24 models. These included five mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profiles, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study.

Ezetimibe and low density lipoprotein subfractions: an ongoing debate

There is evidence that small dense low density lipoprotein (sdLDL) subfractions are more atherogenic than buoyant LDL. Therefore, it is relevant to assess the effect of lipid lowering drugs on LDL subfractions. In this editorial we discuss the effect of ezetimibe (EZE; a cholesterol transport inhibitor) alone or in combination with a statin, on sdLDL levels. We conclude that, based on currently available evidence, more studies are needed before a definitive answer can be provided regarding the effect of EZE on sdLDL levels.

Are post-treatment low-density lipoprotein subclass pattern analyses potentially misleading?

BACKGROUND

Some patients administered cholesterol-lowering therapies may experience an increase in the proportion of small LDL particles, which may be misinterpreted as a worsening of atherosclerotic coronary heart disease risk. This study assessed the lipid effects of adding ezetimibe to atorvastatin or doubling the atorvastatin dose on low-density lipoprotein cholesterol (LDL-C) levels (and the cholesterol content of LDL subclasses), LDL particle number (approximated by apolipoprotein B), and LDL particle size. This was a multicenter, double-blind, randomized, parallel-group study of hypercholesterolemic, high atherosclerotic coronary heart disease risk patients. After stabilization of atorvastatin 40 mg, 579 patients with LDL-C >70 mg/dL were randomized to 6 weeks of ezetimibe + atorvastatin 40 mg or atorvastatin 80 mg. Efficacy parameters included changes from baseline in LDL-C, apolipoprotein B, non-high-density lipoprotein cholesterol (non-HDL-C), and lipoprotein subclasses (Vertical Auto Profile II) and pattern for the overall population, as well as patient subgroups with baseline triglyceride levels <150 mg/dL or ≥150 mg/dL.

RESULTS

Both treatments significantly reduced LDL-C (and the cholesterol content of most LDL subfractions [LDL1-4]) apolipoprotein B, non-HDL-C levels, but did not reduce the proportion of smaller, more dense LDL particles; in fact, the proportion of Pattern B was numerically increased. Results were generally similar in patients with triglyceride levels <150 or ≥150 mg/dL.

CONCLUSIONS

When assessing the effects of escalating cholesterol-lowering therapy, effects upon Pattern B alone to assess coronary heart disease risk may be misleading when interpreted without considerations of other lipid effects, such as reductions in LDL-C, atherogenic lipoprotein particle concentration, and non-HDL-C levels.

TRIAL REGISTRATION

(Registered at clinicaltrials.gov: Clinical trial # NCT00276484).

Ezetimibe in diabetes: more than cholesterol lowering?

Ezetimibe, an inhibitor of cholesterol intestinal absorption, is a lipid lowering agent with potential pleiotropic actions. Ezetimibe in combination with a statin is effective in decreasing low density lipoprotein cholesterol(LDL-C), lowering triglyceride and raising high density lipoprotein cholesterol levels. Ezetimibe plus statin achieve LDL-C targets in a greater proportion of patients than statin monotherapy. Ezetimibe also seems to improve renal function, insulin resistance and inflammatory markers. These actions are useful in patients with diabetes. Ezetimibe is a well-tolerated and effective (in terms of achieving LDL-C targets) option inpatients with hyperlipidemia with or without diabetes. This editorial will discuss several properties of ezetimibe, with special reference to diabetes.