Statin therapy and plasma vitamin E concentrations: A systematic review and meta-analysis of randomized placebo-controlled trials.

Vitamin E is one of the most important natural antioxidants, and its plasma levels are inversely associated with the progression of atherosclerosis. There have been reports suggesting a potential negative effect of statin therapy on plasma vitamin E levels. The aim of this meta-analysis was to determine the impact of statin therapy on plasma vitamin E concentrations. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched to identify randomized placebo-controlled trials evaluating the impact of statins on plasma vitamin E concentrations from inception to February 27, 2015. A systematic assessment of bias in the included studies was performed using the Cochrane criteria. A random-effects model (using DerSimonian-Laird method) and the generic inverse variance method were used to examine the effect of statins on plasma vitamin E concentrations. Heterogeneity was quantitatively assessed using the I(2) index. Sensitivity analysis was conducted using the leave-one-out method. A meta-analysis of data from 8 randomized treatment arms including 504 participants indicated a significant reduction in plasma vitamin E concentrations following statin treatment (WMD: -16.30%, 95% CI: -16.93, -15.98, p < 0.001). However, cholesterol-adjusted vitamin E concentrations (defined as vitamin E:total cholesterol ratio) were found to be improved by statin therapy (WMD: 29.35%, 95% CI: 24.98, 33.72, p < 0.001). Statin therapy was not associated with any significant alteration in LDL vitamin E content (SMD: 0.003, 95% CI: -0.90, 0.90, p = 0.995). Findings of the present study suggest that statin therapy has no negative impact on plasma vitamin E concentrations or LDL vitamin E content.

Sahebkar A ，Simental-Mendía LE ，Ferretti G ，Bacchetti T ，Golledge J ... -  《-》

A PRISMA-compliant systematic review and meta-analysis of randomized controlled trials investigating the effects of statin therapy on plasma lipid concentrations in HIV-infected patients.

Statin therapy may lower plasma lipid concentrations, but the evidence in HIV-infected patients is still unclear. Therefore, we aimed to investigate the impact of statin therapy on plasma lipid concentrations through a systematic review of the literature and meta-analysis of available randomized controlled trials (RCTs). The literature search included PUBMED, SCOPUS, Web of Science and Google Scholar up to October 30, 2015. The meta-analysis was performed using either a fixed-effects or random-effect model according to I(2) statistic. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Two investigators independently reviewed the title or abstract, further reviewed the full-texts and extracted information on study characteristics and study outcomes. Meta-analysis of 12 RCTs with 697 participants suggested significant reductions in plasma concentrations of low density lipoprotein (LDL) cholesterol (WMD: -0.72mmol/L [-27.8mg/dL], 95%CI: -1.04, -0.39, p<0.001; I(2)=85.7%), total cholesterol (WMD: -1.03mmol/L [-39.8mg/dL], 95%CI: -1.42, -0.64, p<0.001; I(2)=94.7%) and non-high density lipoprotein cholesterol (non-HDL-C) (WMD: -0.81mmol/L [-31.3mg/dl], 95%CI: -1.32, -0.30, p=0.002; I(2)=76.5%), and elevations in HDL-C (WMD: 0.072mmol/L [2.8mg/dL], 95%CI: 0.053, 0.092, p<0.001; I(2)=0%) following treatment with statins (mostly of moderate-intensity). No significant alteration in plasma triglycerides (TG) concentrations was found (WMD: -0.16mmol/L [-14.2mg/dL], 95%CI: -0.61, 0.29, p=0.475; I(2)=90.2%). All these effects were robust in sensitivity analysis, suggesting that the computed effect is not driven by any single study. In subgroup analysis, no significant difference was found among different statins in terms of changing plasma concentrations of LDL-C, HDL-C and TG. However, atorvastatin was found to be more efficacious in reducing plasma total cholesterol concentrations (p<0.001). In conclusion, the meta-analysis suggested significant reductions in plasma concentrations of LDL-C, total cholesterol and non-HDL-C, and elevations in HDL-C, but no significant alteration in plasma TG following treatment with statins.

Banach M ，Dinca M ，Ursoniu S ，Serban MC ，Howard G ，Mikhailidis DP ，Nicholls S ，Lip GYH ，Glasser S ，Martin SS ，Muntner P ，Rysz J ，Toth PP ，Sahebkar A ，Lipid Blood Pressure Meta-analysis Collaboration Group ... -  《-》

Effect of statin therapy on plasma proprotein convertase subtilisin kexin 9 (PCSK9) concentrations: a systematic review and meta-analysis of clinical trials.

To evaluate the magnitude of the effect of statin therapy on plasma proprotein convertase subtilisin kexin 9 (PCSK9) levels through a systematic review and meta-analysis of clinical trials. A random-effects model (using DerSimonian-Laird method) and the generic inverse variance method were used for quantitative data synthesis. Heterogeneity was quantitatively assessed using the I(2) index. Sensitivity analyses were conducted using the one-study remove approach. Random-effects meta-regression was performed using an unrestricted maximum likelihood method to evaluate the association between statin-induced elevation of plasma PCSK9 concentrations with duration of treatment and magnitude of LDL cholesterol reduction. A total of 15 clinical trials examining the effects of statin therapy on plasma PCSK9 levels were included. Meta-analysis of data from single-arm statin treatment arms [weighted mean difference (WMD) 40.72 ng/ml, 95% confidence interval (CI) 34.79, 46.65; p < 0.001] and randomized placebo-controlled trials (WMD 22.98 ng/ml, 95% CI 17.95, 28.01; p < 0.001) showed a significant increase in plasma PCSK9 concentrations after statin therapy, irrespective of the type of statin administered in either of the analyses (single-arm or randomized placebo-controlled trial). There was no significant elevation of plasma PCSK9 levels with statin/ezetimibe combination therapy compared with statin monotherapy (WMD 23.14 ng/ml, 95% CI -1.97, 48.25; p = 0.071); however, removal of one study in the meta-analysis yielded a significant result in the sensitivity analysis (WMD 31.41 ng/ml, 95% CI 7.86, 54.97; p = 0.009). This meta-analysis suggests that statin therapy causes a significant increase in plasma PCSK9 concentrations.

Sahebkar A ，Simental-Mendía LE ，Guerrero-Romero F ，Golledge J ，Watts GF ... -  《-》

Statin therapy reduces plasma endothelin-1 concentrations: A meta-analysis of 15 randomized controlled trials.

Raised plasma endothelin-1 (ET-1) levels may be a risk factor for vascular dysfunction and cardiovascular (CV) disease. This meta-analysis assessed the effect of statins on circulating ET-1 concentrations. The search included PUBMED, Cochrane Library, Web of Science, Scopus, and EMBASE up to September 30, 2014 to identify randomized controlled trials (RCTs) with ET-1 measurement during statin therapy. Quantitative data synthesis was performed using a random-effects model, with weighed mean difference (WMD) and 95% confidence interval (CI) as summary statistics. Data from 15 RCTs showed that statin therapy significantly reduces plasma ET-1 concentrations (WMD: -0.30 pg/mL, 95%CI: -0.47, -0.13; p < 0.01). This effect was robust in sensitivity analysis, and not largely affected by the duration of statin therapy (<12 weeks - WMD: -0.51 pg/mL, 95%CI: -0.89, -0.14, p < 0.01; >12 week -WMD: -0.19 pg/mL, 95%CI: -0.36, -0.02; p < 0.05) or by dose of statins (<40 mg/day - WMD: -0.27 pg/mL, 95%CI: -0.49, -0.05; p = 0.01; >40 mg/day - WMD: -0.38 pg/mL, 95%CI: -0.68, -0.08; p = 0.01). Lipophilic (atorvastatin, simvastatin, fluvastatin, and cerivastatin - WMD: -0.34 pg/mL, 95%CI: -0.55, -0.13; p < 0.01), but not a hydrophilic statin (pravastatin - WMD: -0.18 pg/mL, 95%CI: -0.44 -0.08; p > 0.05) had a significant effect in promoting ET-1 reduction. Statin therapy significantly reduces circulating ET-1 concentrations, regardless of treatment duration or dose of statins. This effect of statins may be influenced by statin lipophilicity. There is a need to establish whether lowering ET-1 levels has a beneficial effect on CV events.

Sahebkar A ，Kotani K ，Serban C ，Ursoniu S ，Mikhailidis DP ，Jones SR ，Ray KK ，Blaha MJ ，Rysz J ，Toth PP ，Muntner P ，Lip GY ，Banach M ，Lipid and Blood Pressure Meta-analysis Collaboration (LBPMC) Group ... -  《-》

Impact of statin therapy on plasma resistin and visfatin concentrations: A systematic review and meta-analysis of controlled clinical trials.

The beneficial effects of statin therapy in reducing cardiovascular morbidity and mortality is not merely explained by the lipid-modulating effects. Although adipokines levels have been associated with cardiometabolic disorders, a few studies have explored the effect of statin on resistin and visfatin. We aimed to evaluate the impact of statin therapy on levels of resistin and visfatin through a meta-analysis of published studies. A systematic literature search in Medline and SCOPUS databases was conducted up to January 2015 to identify controlled trials assessing changes in plasma concentrations of visfatin and resistin during treatment with statins. Quantitative data synthesis was performed using a random-effects model, with weighed mean difference (WMD) and 95% confidence interval (CI) as summary statistics. 12 eligible studies with 14 treatment arms were included. Overall, 844 participants were studied. No significant change in plasma resistin concentrations was observed following statin therapy (WMD: -0.11ng/mL, CI: -1.94,1.73, p=0.909). This effect was robust and not affected by statin type, treatment duration and LDL-cholesterol concentrations. With respect to visfatin concentrations, there was a marginally significant reduction following statin therapy (WMD: -2.40ng/mL, CI: -4.79,-0.002, p=0.050). However, this effect size was weak and sensitive to three of the trials included in the analysis. This meta-analysis did not suggest any effect of statin therapy on plasma resistin levels, while a slight reduction in visfatin levels was found. The effect of statins on visfatin levels may represent a novel pleiotropic characteristic of these drugs.

Sahebkar A ，Giorgini P ，Ludovici V ，Pedone C ，Ferretti G ，Bacchetti T ，Grassi D ，Di Giosia P ，Ferri C ... -  《-》