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

A Comparison of Rosuvastatin Monotherapy and Rosuvastatin Plus Ezetimibe Combination Therapy in Patients With Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Type 2 diabetes mellitus is a metabolic condition where vascular inflammation and oxidative stress contribute to disease progression and associated complications. Although statins are recommended for managing dyslipidemia in diabetes, additional therapies are often required to achieve target lipid levels. This meta-analysis aimed to evaluate the efficacy of rosuvastatin monotherapy versus combination therapy with ezetimibe in patients with type 2 diabetes. A systematic literature search was conducted across multiple databases until April 2024, identifying six randomized controlled trials meeting the inclusion criteria. The meta-analysis revealed that the rosuvastatin plus ezetimibe combination resulted in significantly greater reductions in total cholesterol (mean difference, or MD: 19.49; 95% CI: 13.99 to 24.99), triglycerides (MD: 13.44; 95% CI: 2.04 to 24.85), and low-density lipoprotein cholesterol (MD: -17.68; 95% CI: 12.85 to 22.51) compared to rosuvastatin monotherapy. Conversely, rosuvastatin monotherapy achieved a greater reduction in HbA1c levels (MD: -0.11; 95% CI: -0.17 to -0.04). Subgroup analysis demonstrated that using the same dose of rosuvastatin in both groups led to more significant improvements in lipid parameters with lower heterogeneity. The findings suggest that the rosuvastatin-ezetimibe combination may be a more effective lipid-lowering strategy for patients with type 2 diabetes, though larger studies are needed to assess long-term safety and optimal dosing. Additionally, while rosuvastatin monotherapy provided modest HbA1c reductions, the clinical relevance remains uncertain, and potential risks with high-dose statins should be considered.

Are We Using Ezetimibe As Much As We Should?

Lipid-lowering therapies, particularly non-statin regimens, are underutilized as ~2/3 of patients with atherosclerotic cardiovascular (CV) disease (CVD) are not optimally managed, and do not attain target low-density lipoprotein cholesterol (LDL-C) concentrations, despite statin treatment. Statins have been the mainstay of hypolipidemic therapies; however, they are plagued by adverse effects, which have partly hindered their more widespread use. Ezetimibe is often the first added mode of treatment to attain LDL-C goals as it is efficacious and also allows the use of a smaller dose of statin, while the need for more expensive therapies is obviated. We herein provide a comprehensive review of the effects of ezetimibe in lipid lowering and reducing CV events and improving outcomes. Of the hypolipidemic therapies, oral ezetimibe, in contrast to newer agents, is the most convenient and/or affordable regimen to be utilized as mono- or combined therapy supported by data from CV outcomes studies attesting to its efficacy in reducing CVD risk and events. When combined with a statin, the statin dose could be lower, thus curtailing side-effects, while the hypolipidemic effect is enhanced (by ~20%) as the percentage of patients with target level LDL-C (<70 mg/dL) is higher with combined treatment versus a high-intensity statin. Ezetimibe could also serve as an alternative treatment in cases of statin intolerance. In conclusion, ezetimibe has an excellent safety/tolerability profile; it is the first added treatment to a statin that can attain LDL-C targets. In the combined therapy, the hypolipidemic effect is enhanced while the dose of statin could be lower, thus limiting the occurrence of side-effects. Ezetimibe could also serve as an alternative mode of treatment in cases of statin intolerance.

Elevated small dense low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio is associated with an increased risk of metabolic dysfunction associated fatty liver disease in Chinese patients with type 2 diabetes mellitus

INTRODUCTION

It is demonstrated that elevated small dense low-density lipoprotein cholesterol (sdLDL-C), and reduced high-density lipoprotein cholesterol (HDL-C) is associated with Metabolic dysfunction-associated fatty liver disease (MAFLD). This study aims to explore the relationship between sdLDL-C to HDL-C ratio (SHR) and MAFLD in Chinese patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

A cross-sectional study was performed among 1904 patients with T2DM. Weighted multivariable logistic regression analysis was conducted to explore the relationship between the SHR and the risk of MAFLD. In addition, this study used a two-part linear regression model to identify threshold effects. Subgroup analysis, interaction tests and receiver operating characteristic (ROC) curve analysis were also carried out.

RESULTS

The overall MAFLD prevalence reached 48.1%. Multiple logistic regression analysis showed that SHR was positively correlated with the risk of MAFLD (OR = 2.37, 95% CI = 1.80-3.12). Subgroup analysis stratified by age, gender, hypertension and BMI showed that there was a consistent positive correlation. A non-linear relationship and saturation effect between SHR and MAFLD risk were identified, with an inverted L shaped curve and an inflection point at 1.02. The area under the curve (AUC) for SHR in the ROC analysis was significantly greater than sdLDL-C and HDL-C, with a sensitivity of 71.2% and a specificity of 62.1%.

CONCLUSIONS

Elevated levels of SHR is independently associated with an increased risk of MAFLD in patients with T2DM. SHR may be taken as practical indicators to assess the risk of MAFLD in T2DM patients.

Insulin Prevents Hypercholesterolemia by Suppressing 12a-Hydroxylated Bile Acid Production

Background: The risk of cardiovascular disease in type 1 diabetes remains extremely high, despite marked advances in blood glucose control and even the widespread use of cholesterol synthesis inhibitors. Thus, a deeper understanding of insulin regulation of cholesterol metabolism, and its disruption in type 1 diabetes, could reveal better treatment strategies. Methods: To define the mechanisms by which insulin controls plasma cholesterol levels, we knocked down the insulin receptor, FoxO1, and the key bile acid synthesis enzyme, CYP8B1. We measured bile acid composition, cholesterol absorption, and plasma cholesterol. In parallel, we measured markers of cholesterol absorption and synthesis in humans with type 1 diabetes treated with ezetimibe and statins in a double-blind crossover study. Results: Mice with hepatic deletion of the insulin receptor showed marked increases in 12α-hydroxylated bile acids (12HBAs), cholesterol absorption, and plasma cholesterol. This phenotype was entirely reversed by hepatic deletion of FoxO1. FoxO1 is inhibited by insulin, and required for the production of 12HBAs, which promote intestinal cholesterol absorption and suppress hepatic cholesterol synthesis. Knockdown of Cyp8b1 normalized 12HBA levels and completely prevented hypercholesterolemia in mice with hepatic deletion of the insulin receptor (n=5-30) as well as mouse models of type 1 diabetes (n=5-22). In parallel, the cholesterol absorption inhibitor, ezetimibe, normalized cholesterol absorption and LDL-cholesterol in patients with type 1 diabetes as well as, or better than, the cholesterol synthesis inhibitor, simvastatin (n=20). Conclusions: Insulin, by inhibiting FoxO1 in the liver, reduces 12HBAs, cholesterol absorption, and plasma cholesterol levels. Thus, type 1 diabetes leads to a unique set of derangements in cholesterol metabolism, with increased absorption rather than synthesis. These derangements are reversed by ezetimibe, but not statins, which are currently the first line of lipid-lowering treatment in type 1 diabetes. Taken together, these data suggest that a personalized approach to lipid lowering in type 1 diabetes may be more effective and highlight the need for further studies specifically in this group of patients.

Main differences between two highly effective lipid-lowering therapies in subclasses of lipoproteins in patients with acute myocardial infarction

Background

Large observational studies have shown that small, dense LDL subfractions are related to atherosclerotic cardiovascular disease. This study assessed the effects of two highly effective lipid-lowering therapies in the atherogenic subclasses of lipoproteins in subjects with ST-segment elevation myocardial infarction (STEMI).

Methods

Patients of both sexes admitted with their first myocardial infarction and submitted to pharmacoinvasive strategy (N = 101) were included and randomized using a central computerized system to receive a daily dose of simvastatin 40 mg plus ezetimibe 10 mg or rosuvastatin 20 mg for 30 days. Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) subfractions were analysed by polyacrylamide gel electrophoresis (Lipoprint System) on the first (D1) and 30th days (D30) of lipid-lowering therapy. Changes in LDL and IDL subfractions between D1 and D30 were compared between the lipid-lowering therapies (Mann-Whitney U test).

Results

The classic lipid profile was similar in both therapy arms at D1 and D30. At D30, the achievement of lipid goals was comparable between lipid-lowering therapies. Cholesterol content in atherogenic subclasses of LDL (p = 0.043) and IDL (p = 0.047) decreased more efficiently with simvastatin plus ezetimibe than with rosuvastatin.

Conclusions

Lipid-lowering therapy with simvastatin plus ezetimibe was associated with a better pattern of lipoprotein subfractions than rosuvastatin monotherapy. This finding was noted despite similar effects in the classic lipid profile and may contribute to residual cardiovascular risk.

Trial registration

ClinicalTrials.gov, NCT02428374, registered on 28/09/2014.

Small dense low-density lipoprotein-lowering agents

Metabolic disorders, including obesity, diabetes, and hyperlipidemia, as well as cardiovascular diseases (CVD), particularly atherosclerosis, are still leading causes of death worldwide. Plasma levels of low-density lipoprotein (LDL) are currently being considered as a critical risk factor for the diseases mentioned above, especially atherosclerosis. Because of the heterogeneous nature of LDL, many studies have already been conducted on its subclasses, especially small dense LDL (sdLDL). According to available evidence, sdLDL levels can be considered as an ideal alternative to LDL levels for monitoring CVD and early diagnosis of atherosclerosis. Recently, several researchers have focused on factors that are able to decrease sdLDL levels and improve health quality. Therefore, the purpose of this study is to describe the production process of sdLDL particles and review the effects of pharmaceutical and dietary agents as well as lifestyle on sdLDL plasma levels. In brief, their mechanisms of action are discussed. Apparently, cholesterol and LDL-lowering compounds are also effective in the reduction of sdLDL levels. In addition, improving lipid profile, especially the reduction of triglyceride levels, appropriate regimen, and lifestyle can decrease sdLDL levels. Therefore, all the aforementioned parameters should be taken into consideration simultaneously in sdLDL levels reducing strategies.

Markers of cholesterol synthesis are elevated in adolescents and young adults with type 2 diabetes

BACKGROUND

Changes in cholesterol absorption and cholesterol synthesis may promote dyslipidemia and cardiovascular disease in individuals with type 2 diabetes mellitus (T2DM).

OBJECTIVE

To assess cholesterol synthesis and absorption in lean individuals, obese individuals, and individuals with T2DM.

METHODS

We measured lathosterol and lanosterol (markers of cholesterol synthesis) as well as campesterol and β-sitosterol (markers of cholesterol absorption) in the serum of 15 to 26 years old individuals with T2DM (n = 95), as well as their lean (n = 98) and obese (n = 92) controls.

RESULTS

Individuals with T2DM showed a 51% increase in lathosterol and a 65% increase in lanosterol compared to lean controls. Similarly, obese individuals showed a 31% increase in lathosterol compared to lean controls. Lathosterol and lanosterol were positively correlated with body mass index, fasting insulin and glucose, serum triglycerides, and C-reactive protein, and negatively correlated with HDL-cholesterol. In contrast, campesterol and β-sitosterol were not altered in individuals with T2DM. Moreover, campesterol and β-sitosterol were negatively correlated with body mass index, fasting insulin, and C-reactive protein and were positively correlated with HDL-cholesterol.

CONCLUSIONS

Adolescents and young adults with T2DM show evidence of increased cholesterol synthesis compared to non-diabetic lean controls. These findings suggest that T2DM may promote cardiovascular disease by increasing cholesterol synthesis, and provide additional rationale for the use of cholesterol synthesis inhibitors in this group.

Type 1 diabetes is associated with an increase in cholesterol absorption markers but a decrease in cholesterol synthesis markers in a young adult population

BACKGROUND

To optimize treatment and prevent cardiovascular disease in subjects with type 1 diabetes, it is important to determine how cholesterol metabolism changes with type 1 diabetes.

OBJECTIVE

The objective of the study was to compare plasma levels of campesterol and β-sitosterol, markers of cholesterol absorption, as well as lathosterol, a marker of cholesterol synthesis, in youth with and without type 1 diabetes.

METHODS

Serum samples were obtained from adolescent subjects with type 1 diabetes (n = 175, mean age 15.2 years, mean duration of diabetes 8.2 years) and without diabetes (n = 74, mean age 15.4 years). Campesterol, β-sitosterol, and lathosterol, were measured using targeted liquid chromatography tandem mass spectrometry, compared between groups, and correlated with the available cardiometabolic variables.

RESULTS

Campesterol and β-sitosterol levels were 30% higher in subjects with type 1 diabetes and positively correlated with hemoglobin A1c levels. In contrast, lathosterol levels were 20% lower in subjects with type 1 diabetes and positively correlated with triglycerides, body mass index, and systolic blood pressure.

CONCLUSION

Plasma markers suggest that cholesterol absorption is increased, whereas cholesterol synthesis is decreased in adolescent subjects with type 1 diabetes. Further studies to address the impact of these changes on the relative efficacy of cholesterol absorption and synthesis inhibitors in subjects with type 1 diabetes are urgently needed.

Effect of ezetimibe on glycemic control: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Given the increased risk of incident diabetes and the side effects on glycemic control with statin treatment, statin and ezetimibe combination therapy has been widely used. However, whether the same concern exists in ezetimibe remains uncertain. This meta-analysis aimed to investigate the influence of ezetimibe treatment on glycemic control.

METHODS

Articles were searched from PubMed, EMBASE, and Cochrane Library. Randomized controlled trials (RCTs) were included if they compared the effects of ezetimibe with placebo, ezetimibe plus statin with the same statin, or low-dose stain plus ezetimibe with high-dose statin on FBG and glycosylated hemoglobin A1c (HbA1c).

RESULTS

Of the 2440 articles retrieved, 16 RCTs were included. Ezetimibe did not cause side effects on FBG (WMD -0.62, 95% CI: -3.13 to 1.90) and HbA1c (WMD 0.07, 95% CI: -0.07 to 0.20%). No significant changes in FBG (WMD -1.78, 95% CI: -6.33 to 2.77%) and HbA1c (WMD -0.05, 95% CI: -0.14 to 0.05%) were observed in ezetimibe plus low-dose statin treatment compared with high-dose statin. According to subgroup analysis, in comparison with high-dose statin, ezetimibe plus low-dose statin taken for more than 3 months showed a significant decrease in FBG (WMD -7.12, 95% CI: -13.86 to -0.38%) compared with that taken for less than 3 months (WMD 0.90, 95% CI: -2.91 to 4.71%). Nevertheless, this difference was invalid when the study conducted by Dagli et al. was removed.

CONCLUSIONS

Compared with high-dose statin therapy, ezetimibe with low-dose statin for more than 3 months may have a beneficial tendency of effects on glycemic control.

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).

Ezetimibe and simvastatin modulate gut microbiota and expression of genes related to cholesterol metabolism

AIMS

Hypolipidemic drugs are prescribed in the most of cases for the treatment of cardiovascular diseases. Several studies have showed that the gut microbiota is able to regulate the host cholesterol metabolism. This study aimed to investigate the potential impact of hypolipidemic drugs on the gut microbiota in mice, and to correlate it to the regulation of cholesterol metabolism.

MAIN METHODS

Male C57Bl/6J mice were divided into four groups fed either a control diet alone (CT), or supplemented with simvastatin (0.1% w/w, Zocor®, MSD), or ezetimibe (0.021% w/w, Ezetrol®, MSD) or a combination of simvastatin and ezetimibe (0.1% and 0.021%, respectively) for one week.

KEY FINDINGS

The combination of ezetimibe and simvastatin is required to observe a drop in cholesterolemia, linked to a huge activation of hepatic SREBP-2 and the consequent increased expression of genes involved in LDL cholesterol uptake and cholesterol synthesis. The gut microbiota analysis revealed no change in total bacteria, and in major Gram positive and Gram negative bacteria, but a selective significant increase in Lactobacillus spp. in mice treated with the ezetimibe and a decrease by the combination. The changes in lactobacilli level observed in ezetimibe or combination treated-mice are negatively correlated to expression of genes related to cholesterol metabolism.

SIGNIFICANCE

The present study showed that ezetimibe taken alone is able to modify the composition of gut microbiota in favor of Lactobacillus spp. These results suggest that members of the genus Lactobacillus play an important role in cholesterol metabolism, even in normocholesterolemic mouse model.

Prevalence of plasma small dense LDL is increased in obesity in a Thai population

BACKGROUND

Plasma low density lipoprotein (LDL) particles vary in size, density, electrical charge and chemical composition. An increased presence of small dense LDL (sdLDL), along with raised triglyceride concentrations and decreased high density lipoprotein (HDL) cholesterol concentrations is commonly known as the atherogenic triad and has been observed in some cases of obesity, principally in Europe and America. This study examines the prevalence of sdLDL in the plasma of an obese (BMI≥25 kg/m2) Thai population.

METHODS

Plasma from fasted obese (n=48) and non-obese (n=16) Thai participants was subjected to density gradient ultracentrifugation in iodixanol to separate lipoproteins. Gradients were unloaded top-to-bottom into 20 fractions which were assayed for cholesterol, triglyceride, apo B and apo A-1 to identify lipoprotein types and subtypes.

RESULTS

LDL cholesterol was subfractionated into LDL I+II (fractions 3-6, ρ=1.021-1.033 g/ml) which was considered to represent large buoyant LDL (lbLDL), LDL III (fractions 7-9, ρ=1.036-1.039 g/ml) which was considered to represent sdLDL, and, LDL IV (fractions 10-12, ρ=1.044-1.051 g/ml) which was considered to represent very sdLDL. Concentrations of LDL III and IV were increased by 15-20% in obese participants whilst that of LDL I+II was concomitantly decreased by 10%. This was accompanied by a 50% increase in plasma triglyceride concentrations and 15% decrease in HDL cholesterol concentrations. Only 3/16 (19%) non-obese participants had a pattern B LDL cholesterol profile (peak density of >1.033 g/ml), whilst 28/48 (58%) obese participants were pattern B. When expressed as a fraction of the LDL concentration, total sdLDL (i.e. LDL III+IV) showed highly significant correlations to plasma triglyceride concentrations and the triglyceride/HDL cholesterol ratio.

CONCLUSIONS

The prevalence of sdLDL is increased in obesity in a Thai population such that they demonstrate a similar atherogenic triad to that previously observed in European and American populations.

LDL-migration index (LDL-MI), an indicator of small dense low-density lipoprotein (sdLDL), is higher in non-alcoholic steatohepatitis than in non-alcoholic fatty liver: a multicenter cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is associated with increased risks of atherosclerotic diseases, including cardiovascular disease. However, the difference in risk between patients with non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) has not yet been determined. Accumulating evidence has shown that high amounts of small dense low-density lipoprotein (sdLDL) are closely associated with atherosclerotic diseases. This study investigated differences in risk factors for atherosclerotic diseases, especially LDL-migration index (LDL-MI), an indicator of sdLDL, between patients with NAFL and NASH.

Methods

LDL-MI was analyzed in a primary cohort of 156 patients with NAFLD, including 53 with NAFL and 103 with NASH, and a validation cohort of 69 patients with NAFLD, including 25 with NAFL and 44 with NASH.

Results

In the primary cohort, NASH was associated with elevated LDL-MI (p = 0.039). Multiple regression analysis showed that NASH and the non-use of lipid lowering medications were independently correlated with higher LDL-MI in all patients with NAFLD. Among patients not on lipid lowering medications, those with NASH had significantly higher LDL-MI than those with NAFL (p = 0.001). These findings were confirmed in a validation cohort, in that LDL-MI was significantly higher in patients with NASH than with NAFL (p = 0.043).

Conclusion

This study is the first to show that LDL-MI, an indicator of sdLDL, was higher in patients with NASH than with NAFL, suggesting that the risk of atherosclerotic diseases may be higher in NASH than NAFL. Patients with NASH should be followed closely, especially for the progression of liver pathology and atherosclerotic diseases.

Trial Registration

UMIN000009614

Add-on ezetimibe reduces small dense low-density lipoprotein cholesterol levels without affecting absorption of eicosapentaenoic acid in patients with coronary artery disease: a pilot study

BACKGROUND

Residual risk of cardiovascular disease from increased small dense low-density lipoprotein (sdLDL)-cholesterol levels and low n-3 polyunsaturated fatty acid (PUFA) levels is a considerable therapeutic issue. The purpose of this study was to evaluate the effect of ezetimibe as an add-on to statins and supplemental eicosapentaenoic acid (EPA) on sdLDL cholesterol and absorption of EPA in patients with coronary artery disease.

METHODS

The study population consisted of ten male patients who were concurrently receiving statins and EPA 1,800 mg/day. Serum lipids and PUFAs, including EPA and arachidonic acid, were measured in blood samples collected before ezetimibe (baseline), 4 weeks after starting 10-mg/day ezetimibe, and 4 weeks after discontinuing ezetimibe.

RESULTS

Ezetimibe significantly decreased sdLDL-cholesterol levels after 4 weeks of treatment (baseline 35 ± 13 mg/dl; treatment 27 ± 9 mg/dl), but the levels returned to baseline after discontinuation of ezetimibe (37 ± 13 mg/dl). The concentration of EPA did not significantly change during the study.

CONCLUSION

Ezetimibe shows great promise as an add-on therapy to statins to reduce sdLDL-cholesterol-related residual risk of cardiovascular disease without affecting absorption of supplemental EPA in patients with coronary artery disease.

Effects of two lipid lowering therapies on immune responses in hyperlipidemic subjects

AIMS

To compare the effects of two of the most effective lipid-lowering therapies with similar LDL-cholesterol reduction capacity on the innate and adaptive immune responses through the evaluation of autoantibodies anti-oxidized LDL (anti-oxLDL Abs) and electronegative LDL [LDL(-)] levels.

MAIN METHODS

We performed a prospective, randomized, open label study, with parallel arms and blinded endpoints. One hundred and twelve subjects completed the study protocol and received rosuvastatin 40 mg or ezetimibe/simvastatin 10/40 mg for 12 weeks. Lipids, apolipoproteins, LDL(-), and anti-oxLDL Abs (IgG) were assayed at baseline and end of study.

KEY FINDINGS

Main clinical and laboratory characteristics were comparable at baseline. Lipid modifications were similar in both treatment arms, however, a significant raise in anti-oxLDL Abs levels was observed in subjects treated with rosuvastatin (p=0.026 vs. baseline), but not in those receiving simvastatin/ezetimibe. (p=0.233 vs. baseline), thus suggesting modulation of adaptive immunity by a potent statin. Titers of LDL(-) were not modified by the treatments.

SIGNIFICANCE

Considering atherosclerosis as an immune disease, this study adds new information, showing that under similar LDL-cholesterol reduction, the choice of lipid-lowering therapy can differently modulate adaptive immune responses.

Efficacy of combination of Ezetimibe 10 mg and rosuvastatin 2.5 mg versus rosuvastatin 5 mg monotherapy for hypercholesterolemia in patients with type 2 diabetes

BACKGROUND

Statins are used to treat hypercholesterolemia in patients with type 2 diabetes mellitus, but many of these patients fail to achieve the target LDL-C level. Recent reports have suggested that a synergistic effect can be obtained by concomitant administration of the cholesterol absorption inhibitor ezetimibe and a statin. However, in patients with type 2 diabetes who are already being treated with satins, it remains unclear whether it is more effective to add ezetimibe or to increase the statin dose. Therefore, this study was performed to examine the effects of these two regimens on LDL-C and lipoproteins.

METHODS

The subjects were type 2 diabetic patients under treatment with rosuvastatin (2.5 mg daily), who had LDL-C levels ≥80 mg/dL. They were randomly allocated to a group that received add-on therapy with ezetimibe at 10 mg/day (combination group, n = 40) or an increase of the rosuvastatin dose to 5 mg/day (dose escalation group, n = 39). These two groups were compared at baseline and after 12 weeks of treatment.

RESULTS

The percent change of LDL-C was -31% in the combination group and -12% in the dose escalation group. Both groups showed a significant decrease, but the decrease was greater in the combination group. In both groups, there was a significant decrease in the levels of small dense LDL-C, oxidized LDL and remnant-like lipoprotein cholesterol. For all of these parameters, the percent changes were greater in the combination group. Only the combination group showed a significant decrease of triglycerides. Multivariate analysis was performed to identify factors associated with reaching an LDL-C level <80 mg/dL. As a result, add-on therapy with ezetimibe was extracted as a factor related to improvement of LDL-C.

CONCLUSIONS

Compared with increasing the dose of rosuvastatin, the combination of rosuvastatin and ezetimibe not only achieves quantitative but also qualitative improvement of serum lipid levels in type 2 diabetic patients, suggesting that this combination could suppress the progression of atherosclerosis.

TRIAL REGISTRATION

UMIN000011005.

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

Ezetimibe therapy: mechanism of action and clinical update

The lowering of low-density lipoprotein cholesterol (LDL-C) is the primary target of therapy in the primary and secondary prevention of cardiovascular events. Although statin therapy is the mainstay for LDL-C lowering, a significant percentage of patients prescribed these agents either do not achieve targets with statin therapy alone or have partial or complete intolerance to them. For such patients, the use of adjuvant therapy capable of providing incremental LDL-C reduction is advised. One such agent is ezetimibe, a cholesterol absorption inhibitor that targets uptake at the jejunal enterocyte brush border. Its primary target of action is the cholesterol transport protein Nieman Pick C1 like 1 protein. Ezetimibe is an effective LDL-C lowering agent and is safe and well tolerated. In response to significant controversy surrounding the use and therapeutic effectiveness of this drug, we provide an update on the biochemical mechanism of action for ezetimibe, its safety and efficacy, as well as the results of recent randomized studies that support its use in a variety of clinical scenarios.