The Effects of Cinnamon Supplementation on Plasma Lipid Concentrations: A Systematic Review and Meta-Analysis

Background: Cinnamon is a rich botanical source of polyphenols, whose positive effects on blood lipid concentrations have been hypothesized, but have not been conclusively studied. Objective: To systematically review and evaluate the effect of administration of cinnamon on blood lipid concentrations. Methods: We assessed 13 RCTs with 750 participants investigating the effect of cinnamon supplementation on blood lipid concentrations. A meta-analysis was performed using randomeffect models, with weighted mean differences (with 95% CI) for endpoints calculated using a random-effects model. Results: No statistically significant effect of cinnamon was observed on blood LDL-C (WMD: - 0.16 mmol/L [-6.19 mg/dL], 95% CI: -0.35, 0.03 [-13.53, 1.16], p = 0.10) and HDL-C (WMD: 0.05 mmol/L [1.92 mg/dL], 95% CI: -0.03, 0.12 [-0.03, 4.64], p = 0.21) concentrations. However, a statistically significant reduction in blood triglycerides (WMD: -0.27 mmol/L [- 23.91 mg/dL], 95% CI: -0.39, -0.14 [-34.54, -12.40], p < 0.01) and total cholesterol concentrations (WMD: -0.36 mmol/L [-13.92 mg/dL], 95% CI: -0.63, -0.09 [-24.36, -3.48], p < 0.01) was observed. HDL-C was significantly elevated following the omission of one study (WMD: 0.04 mmol/L [1.54 mg/dL], 95% CI: 0.03, 0.06 [1.16, 2.32], p < 0.01) during our sensitivity analysis. A meta-regression analysis was conducted and no significant association was found between changes in lipid parameters and cinnamon dose. In contrast, changes in blood levels of total cholesterol (slope: 0.09; 95% CI: 0.02, 0.16; p < 0.01), LDL-C (slope: 0.05; 95% CI: 0.001, 0.10; p = 0.05) and triglycerides (slope: 0.06; 95% CI: 0.04, 0.09; p < 0.01) were significantly and positively associated with the duration of supplementation. No statistically significant association was found between blood HDL-C changes and duration of supplementation. Conclusion: Cinnamon supplementation significantly reduced blood triglycerides and total cholesterol concentrations without any significant effect on LDL-C and HDL-C

The Effect of Statins on Cardiovascular Outcomes by Smoking Status: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Smoking is an important risk factor for cardiovascular disease (CVD) morbidity and mortality. The impact of statin therapy on CVD risk by smoking status has not been fully investigated. Therefore we assessed the impact of statin therapy on CVD outcomes by smoking status through a systematic review of the literature and meta-analysis of available randomized controlled trials (RCTs). The literature search included EMBASE, ProQuest, CINAHL and PUBMED databases to 30 January 2016 to identify RCTs that investigated the effect of statin therapy on cumulative incidence of major CVD endpoints (e.g. non-fatal myocardial infarction, revascularization, unstable angina, and stroke). Relative risks (RR) ratios were calculated from the number of events in different treatment groups for both smokers and non-smokers. Finally 11 trials with 89,604 individuals were included. The number of smokers and non-smokers in the statin groups of the analyzed studies was 8826 and 36,090, respectively. The RR for major CV events was 0.73 (95% confidence interval [CI]: 0.67-0.81; p<0.001) in nonsmokers and 0.72 (95%CI: 0.64-0.81; p<0.001) in smokers. Moderate to high heterogeneity was observed both in non-smokers (I2=77.1%, p<0.001) and in smokers (I2=51.6%, p=0.024) groups. Smokers seemed to benefit slightly more from statins than non-smokers according to the number needed to treat (NNT) analysis (23.5 vs 26.8) based on RRs applied to the control event rates. The number of avoided events per 1000 individuals was 42.5 (95%CI: 28.9-54.6) in smokers and 37.3 (95%CI: 27.2-46.4) in non-smokers. In conclusion, this meta-analysis suggests that the effect of statins on CVD is similar for smokers and non-smokers, but in terms of NNTs and number of avoided events, smokers seem to benefit more although non-significantly

Efficacy of Statin Therapy in Pulmonary Arterial Hypertension : a Systematic Review and Meta-Analysis

Since the evidence regarding statin therapy in PAH has not been conclusive, we assessed the impact of statin therapy in PAH through a systematic review and meta-analysis of available studies. We searched selected databases up to August 1, 2015 to identify the studies investigating the effect of statin administration on PAH. Meta-analysis was performed using either a fixed-effects or random-effect model according to I 2 statistic. Meta-analysis of 8 studies with 665 patients did not suggest any significant improvement in 6-min walking distance (6MWD) by statin therapy (weighed mean difference [WMD]:-6.08 m, 95% confidence interval [CI]:-25.66, 13.50, p = 0.543; Q = 8.41, I 2 = 28.64%). Likewise, none of the other indices including pulmonary arterial pressure (WMD:-0.97 mmHg, 95%CI:-4.39, 2.44, p = 0.577; Q = 14.64, I 2 = 79.51%), right atrial pressure (WMD: 1.01 mmHg, 95%CI:-0.93, 2.96, p = 0.307; Q = 44.88, I2 = 95.54%), cardiac index (WMD: 0.05 L/min/m2, 95%CI:-0.05, 0.15, p = 0.323; Q = 3.82, I 2 = 21.42%), and pulmonary vascular resistance (WMD:-1.42 dyn 17s/cm5, 95%CI:-72.11, 69.27, p = 0.969; Q = 0.69, I2 = 0%) was significantly altered by statin therapy. In conclusion, the results of the meta-analysis did not show a statistically significant effect of statin therapy in the improvement of 6MWD, pulmonary arterial pressure, right atrial pressure, cardiac index and pulmonary vascular resistance

The Effects of Tamoxifen on Plasma Lipoprotein(a) Concentrations: Systematic Review and Meta-Analysis

Introduction: Tamoxifen is a selective estrogen receptor modulator widely used in the treatment of breast cancer. Tamoxifen therapy is associated with reduced circulating low-density lipoprotein cholesterol and increased triglycerides, but its effects on other lipids are less-well studied. Aims: We aimed to investigate the effect of tamoxifen on circulating concentrations of lipoprotein(a) (Lp(a)) through systematic review and meta-analysis of available randomized controlled trials (RCTs) and observational studies. Methods: This study was registered in the PROSPERO database (CRD42016036890). Scopus, Medline and EMBASE were searched from inception until 22nd March 2016 to identify studies investigating the effect of tamoxifen on Lp(a) values in humans. Results: Meta-analysis of 5 studies with 284 participants suggested a significant reduction of Lp(a) levels following tamoxifen treatment (weighted mean difference [WMD]: -3.53 mg/dL, 95% confidence interval [CI]: -6.53, -0.53, p=0.021). When studies were categorized according tamoxifen dose, there was a significant effect in the subset of studies with administered doses ≥20 mg/day (WMD: -5.05 mg/dL, 95% CI: -7.86, -2.23, p<0.001), but not in the subset with doses <20 mg/day (WMD: -1.41 mg/dL, 95% CI: -5.13, 2.31, p=0.458). With respect to duration of treatment, a greater effect was observed in subgroup of studies administering tamoxifen for <12 weeks (WMD: -4.01 mg/dL, 95% CI: -7.84, -0.18, p=0.04) versus the subgroup of studies lasting ≥12 weeks (WMD: -2.48 mg/dL, 95% CI: -5.50, 0.53, p=0.107). Conclusions: Meta-analysis suggested a significant reduction of Lp(a) levels following tamoxifen treatment. Further well-designed trials are required to validate these results

Impact of statin therapy on coronary plaque composition: a systematic review and meta-analysis of virtual histology intravascular ultrasound studies

textabstractBackground: Virtual histology intravascular ultrasound (VH-IVUS) imaging is an innovative tool for the morphological evaluation of coronary atherosclerosis. Evidence for the effects of statin therapy on VH-IVUS parameters have been inconclusive. Consequently, we performed a systematic review and meta-analysis to investigate the impact of statin therapy on plaque volume and its composition using VH-IVUS. Methods: The search included PubMed, Cochrane Library, Scopus and Embase (through 30 November 2014) to identify prospective studies investigating the effects of statin therapy on plaque volume and its composition using VH-IVUS. Results: We identified nine studies with 16 statin treatment arms and 830 participants. There was a significant effect of statin therapy in reducing plaque volume (standardized mean difference (SMD): -0.137, 95 % confidence interval (CI): -0.255, -0.019; P = 0.023), external elastic membrane volume (SMD: -0.097, 95 % CI: -0.183, -0.011; P = 0.027) but not lumen volume (SMD: -0.025, 95 % CI: -0.110, +0.061; P = 0.574). There was a significant reduction in fibrous plaque volume (SMD: -0.129, 95 % CI: -0.255, -0.003; P = 0.045) and an increase of dense calcium volume (SMD: +0.229, 95 % CI: +0.008, +0.450; P = 0.043), while changes in fibro-fatty (SMD: -0.247, 95 % CI: -0.592, +0.098; P = 0.16) and necrotic core (SMD: +0.011, 95 % CI: -0.144, +0.165; P = 0.892) tissue volumes were not statistically significant. Conclusions: This meta-analysis indicates a significant effect of statin therapy on plaque and external elastic membrane volumes and fibrous and dense calcium volumes. There was no effect on lumen volume, fibro-fatty and necrotic tissue volumes

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.Maciej Banach, Madalina Dinca, Sorin Ursoniu, Maria-Corina Serban, George Howard, Dimitri P. Mikhailidis, Stephen Nicholls, Gregory Y.H. Lip, Stephen Glasser, Seth S. Martin, Paul Muntner, Jacek Rysz, Peter P. Toth, Amirhossein Sahebkar (Lipid Blood Pressure Meta-analysis Collaboration Group

Impact of statin therapy on coronary plaque composition: a systematic review and meta-analysis of virtual histology intravascular ultrasound studies

Background: Virtual histology intravascular ultrasound (VH-IVUS) imaging is an innovative tool for the morphological evaluation of coronary atherosclerosis. Evidence for the effects of statin therapy on VH-IVUS parameters have been inconclusive. Consequently, we performed a systematic review and meta-analysis to investigate the impact of statin therapy on plaque volume and its composition using VH-IVUS. Methods: The search included PubMed, Cochrane Library, Scopus and Embase (through 30 November 2014) to identify prospective studies investigating the effects of statin therapy on plaque volume and its composition using VH-IVUS. Results: We identified nine studies with 16 statin treatment arms and 830 participants. There was a significant effect of statin therapy in reducing plaque volume (standardized mean difference (SMD): -0.137, 95 % confidence interval (CI): -0.255, -0.019; P = 0.023), external elastic membrane volume (SMD: -0.097, 95 % CI: -0.183, -0.011; P = 0.027) but not lumen volume (SMD: -0.025, 95 % CI: -0.110, +0.061; P = 0.574). There was a significant reduction in fibrous plaque volume (SMD: -0.129, 95 % CI: -0.255, -0.003; P = 0.045) and an increase of dense calcium volume (SMD: +0.229, 95 % CI: +0.008, +0.450; P = 0.043), while changes in fibro-fatty (SMD: -0.247, 95 % CI: -0.592, +0.098; P = 0.16) and necrotic core (SMD: +0.011, 95 % CI: -0.144, +0.165; P = 0.892) tissue volumes were not statistically significant. Conclusions: This meta-analysis indicates a significant effect of statin therapy on plaque and external elastic membrane volumes and fibrous and dense calcium volumes. There was no effect on lumen volume, fibro-fatty and necrotic tissue volumes