Effects of Ezetimibe Add-on to Statin Therapy on Adipokine Production in Patients With Metabolic Syndrome and Stable Vascular Disease:

Influence of lipid-lowering drugs on inflammation: what is yet to be done?

Atherosclerosis is a chronic inflammatory disease that is associated with risk of cardiovascular events. The best-characterised and well-standardised clinical indicator of inflammation is C-reactive protein. Current evidence-based drug therapies for prevention and treatment of cardiovascular diseases are mainly focused on reduction of low-density lipoprotein cholesterol. However, these drugs do not provide sufficient protection against recurrent cardiovascular events. One of the possible mechanisms behind this recurrence might be the persistence of residual inflammation. For the most commonly used lipid-lowering drugs, the statins, their reduction of cardiovascular events goes beyond lowering of low-density lipoprotein cholesterol. Here, we review the effects of these lipid-lowering drugs on inflammation, considering statins, ezetimibe, fibrates, niacin, proprotein convertase subtilisin/kexin type 9 inhibitors, bempedoic acid, ethyl eicosapentaenoic acid and antisense oligonucleotides. We focus in particular on C-reactive protein, and discuss how the effects of the statins might be related to reduced rates of cardiovascular events.

Effect of ezetimibe on plasma adipokines: a systematic review and meta-analysis

AIMS

Statins are known to influence the status of adipokines, which play a key role in the pathophysiology of cardiometabolic diseases. As the effect of ezetimibe as an add-on to statin therapy on the impact of statins on plasma adipokines levels is currently unclear, the aim of the present study was to investigate this through a meta-analysis of controlled trials.

METHODS

A systematic review was performed, followed by a bibliographic search in PubMed, Medline, SCOPUS, Web of Science and Google Scholar databases. Quantitative data synthesis was performed using a fixed- or random-effects model (based on the level of interstudy heterogeneity) and the generic inverse variance weighting method. Effect sizes were expressed as standardized mean difference (SMD) and 95% confidence interval (CI).

RESULTS

Meta-analysis of 23 controlled trials did not suggest any significant effect of adding ezetimibe on top of statin therapy on plasma concentrations of adiponectin (SMD 0.34, 95% CI -0.28, 0.96; P = 0.288), leptin (SMD -0.75, 95% CI: -2.35, 0.85; P = 0.360), plasminogen activator inhibitor 1 (SMD -1.06, 95% CI: -2.81, 0.69; P = 0.236) and interleukin 6 (SMD 0.30, 95% CI: -0.08, 0.67; P = 0.124). However, significantly greater reductions in plasma concentrations of tumour necrosis factor α (TNF-α) (SMD -0.48, 95% CI -0.87, -0.08; P = 0.018) were achieved with ezetimibe/statin combination therapy.

CONCLUSIONS

The results suggested that ezetimibe add-on to statin therapy is associated with an enhanced TNF-α-lowering effect compared with statin monotherapy. Owing to the emerging role of TNF-α in the pathogenesis of metabolic disorders, further investigations are required to unveil the translational relevance of this TNF-α-lowering effect.

The effect of ezetimibe, administered alone or in combination with simvastatin, on lymphocyte cytokine release in patients with elevated cholesterol levels

OBJECTIVE

Studies assessing the extra-lipid effects of ezetimibe have provided contrasting results. In the present study, we compared the effects of ezetimibe and simvastatin, administered alone or in combination, on the secretory function of human lymphocytes, systemic inflammation and endothelial function in subjects with elevated cholesterol levels.

METHODS

A prospective study involving a group of 178 ambulatory patients with isolated hypercholesterolaemia who were randomly assigned in a double-blind fashion to 90days of treatment with ezetimibe (10mg), simvastatin (40mg), ezetimibe (10mg) plus simvastatin (4mg) or placebo. A total of 170 patients completed the study.

MAIN OUTCOME MEASURES

Lymphocyte cytokine release and plasma levels of high-sensitivity C-reactive protein (hsCRP) and intercellular adhesion molecule 1 (ICAM-1).

RESULTS

Although both drugs reduced lymphocyte release of tumour necrosis factor-α, interferon-γ and interleukin-2 in a lipid-independent manner, only the effect of simvastatin was statistically significant (P<0.001). This lymphocyte-suppressing effect, which was accompanied by a decrease in plasma levels of hsCRP and ICAM-1 (P<0.001), was strongest in patients receiving both simvastatin and ezetimibe. There were no differences in lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects of simvastatin between insulin-resistant and insulin-sensitive subjects, whereas the effects of ezetimibe and the combined treatment were greater in the former group of patients (P<0.01 and P<0.001, respectively).

CONCLUSIONS

The results of this study indicate that simvastatin is superior to ezetimibe in producing lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects in patients with elevated cholesterol levels. Hypercholesterolaemic patients with high cardiovascular risk may receive the greatest benefits from concomitant treatment with a statin and ezetimibe.

Randomised study of ezetimibe, start doses of original statins, and their combination in patients with coronary heart disease and hyperlipidemia Part 2. Therapy effects on the levels of C-reactive protein and proinflammatory cytokines

Aim. To assess the effects of original statins as monotherapy or in combination with ezetimibe on the levels of proinflammatory cytokines and high-sensitive C-reactive protein (hsCRP) in patients with coronary heart disease (CHD) and hyperlipidemia (HLP). Material and methods. The study included 60 male and female patients with CHD, primary polygenic HLP, and the levels of low-density lipoprotein cholesterol (LDL-CH) of 2,9-4,9 mmol/l. Monotherapy with original statins or ezetimibe lasted for 6 months, while the combination therapy lasted for 3 months. In all randomised patients, the levels of hsCRP, interleukin 6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) were measured at baseline, 12 and 24 weeks after the therapy started. Results. At baseline, median hsCRP levels in the groups of Ezetrol, Zocor, Liprimar, and Crestor monotherapy were 0,5-0,88 mg/l, with no significant dynamics after 3 months of the treatment. Baseline IL-6 levels across the monotherapy groups were 1,94-2,54 pg/ml; at 3 months, there was a non-significant reduction by 7-32 %. After 3 months of the therapy, the decrease in MCP-1 levels was not statistically significant (-1,3-7,7 %). The combined therapy did not result in a significant dynamics of hsCRP concentrations, with the exception of the group receiving Ezetrol and Liprimar. Although the combined therapy further reduced MCP-1 levels (by 30-78 pg/ml), these changes were not statistically significant. No significant difference was observed across statin and Ezetrol groups in terms of their effects on IL-6 and MCP-1 levels. Conclusion. The comparison of the three treatment schemes demonstrated similar, but not statistically significant reduction on the levels of hsCRP, IL-6, and MCP-1. No marked benefits were observed for either monotherapy or combination therapy over 12-24 weeks of the follow-up.