Yu-Hao Zhou

Lipid management in the prevention of stroke: a meta-analysis of fibrates for stroke prevention

BackgroundFibrates has been extensively used to improve plasma lipid levels and prevent adverse cardiovascular outcomes. However, the effect of fibrates on stroke is unclear at the present time. We therefore carried out a comprehensive systematic review and meta-analysis to evaluate the effects of fibrates on stroke.MethodsWe systematically searched Medline, Embase, the Cochrane Central Register of Controlled Trials, reference lists of articles, and proceedings of major meetings to identify studies for our analysis. We included randomized placebo controlled trials which reported the effects of fibrates on stroke. Relative risk (RR) was used to measure the effect of fibrates on the risk of stroke under random effect model. The analysis was further stratified by factors that could affect the treatment effects.ResultsOverall, fibrate therapy was not associated with a significant reduction on the risk of stroke (RR, 1.02, 95% CI, 0.90 to 1.16, P = 0.78). In the subgroup analyses, we observed that gemfibrozil therapy showed a beneficial effect on stroke (RR, 0.72, 95% CI, 0.53 to 0.98, P = 0.04). Similarly, fibrate therapy comparing to placebo had no effect on the incidence of fatal stroke. Subgroup analysis suggested that fibrate therapy showed an effect on fatal stroke when the Jadad score more than 3 (RR, 0.41, 95% CI, 0.17 to 1.00, P = 0.049). Furthermore, a sensitivity analysis indicated that fibrate therapy may play a role in fatal stroke (RR, 0.49, 95% CI, 0.26 to 0.93, P = 0.03) for patients with previous diabetes, cardiovascular disease or stroke.ConclusionsOur study indicated that fibrate therapy might play an important role in reducing the risk of fatal stroke in patients with previous diabetes, cardiovascular disease or stroke. However, it did not have an effect on the incidence of stroke.

Effect of anti-obesity drug on cardiovascular risk factors: a systematic review and meta-analysis of randomized controlled trials.

Background Anti-obesity drugs are widely used to prevent the complications of obesity, however, the effects of anti-obesity drugs on cardiovascular risk factors are unclear at the present time. We carried out a comprehensively systematic review and meta-analysis to assess the effects of anti-obesity drugs on cardiovascular risk factors. Methodology and Principal Findings We systematically searched Medline, EmBase, the Cochrane Central Register of Controlled Trials, reference lists of articles and proceedings of major meetings for relevant literatures. We included randomized placebo-controlled trials that reported the effects of anti-obesity drugs on cardiovascular risk factors compared to placebo. Overall, orlistat produced a reduction of 2.39 kg (95%CI-3.34 to −1.45) for weight, a reduction of 0.27 mmol/L (95%CI: −0.36 to −0.17) for total cholesterol, a reduction of 0.21 mmol/L (95%CI: −0.30 to −0.12) for LDL, a reduction of 0.12 mmol/L (95%CI: −0.20 to −0.04) for fasting glucose, 1.85 mmHg reduction (95%CI: −3.30 to −0.40) for SBP, and a reduction of 1.49 mmHg (95%CI: −2.39 to −0.58) for DBP. Sibutramine only showed effects on weight loss and triglycerides reduction with statistical significances. Rimonabant was associated with statistically significant effects on weight loss, SBP reduction and DBP reduction. No other significantly different effects were identified between anti-obesity therapy and placebo. Conclusion/Significance We identified that anti-obesity therapy was associated with a decrease of weight regardless of the type of the drug. Orlistat and rimonabant could lead to an improvement on cardiovascular risk factors. However, Sibutramine may have a direct effect on cardiovascular risk factors.

Probiotics in Helicobacter pylori eradication therapy: A systematic review and meta-analysis

AIM To summarize the evidence from randomized controlled trials (RCTs) regarding the effect of probiotics by using a meta-analytic approach. METHODS In July 2013, we searched PubMed, EMBASE, Ovid, the Cochrane Library, and three Chinese databases (Chinese Biomedical Literature Database, Chinese Medical Current Content, and Chinese Scientific Journals database) to identify relevant RCTs. We included RCTs investigating the effect of a combination of probiotics and standard therapy (probiotics group) with standard therapy alone (control group). Risk ratios (RRs) were used to measure the effect of probiotics plus standard therapy on Helicobacter pylori (H. pylori) eradication rates, adverse events, and patient compliance using a random-effect model. RESULTS We included data on 6997 participants from 45 RCTs, the overall eradication rates of the probiotic group and the control group were 82.31% and 72.08%, respectively. We noted that the use of probiotics plus standard therapy was associated with an increased eradication rate by per-protocol set analysis (RR = 1.11; 95%CI: 1.08-1.15; P < 0.001) or intention-to-treat analysis (RR = 1.13; 95%CI: 1.10-1.16; P < 0.001). Furthermore, the incidence of adverse events was 21.44% in the probiotics group and 36.27% in the control group, and it was found that the probiotics plus standard therapy significantly reduced the risk of adverse events (RR = 0.59; 95%CI: 0.48-0.71; P < 0.001), which demonstrated a favorable effect of probiotics in reducing adverse events associated with H. pylori eradication therapy. The specific reduction in adverse events ranged from 30% to 59%, and this reduction was statistically significant. Finally, probiotics plus standard therapy had little or no effect on patient compliance (RR = 0.98; 95%CI: 0.68-1.39; P = 0.889). CONCLUSION The use of probiotics plus standard therapy was associated with an increase in the H. pylori eradication rate, and a reduction in adverse events resulting from treatment in the general population. However, this therapy did not improve patient compliance.

Adjuvant Chemotherapy, with or without Taxanes, in Early or Operable Breast Cancer: A Meta-Analysis of 19 Randomized Trials with 30698 Patients

Background Taxanes have been extensively used as adjuvant chemotherapy for the treatment of early or operable breast cancer, particularly in high risk, node-negative breast cancer. Previous studies, however, have reported inconsistent findings regarding their clinical efficacy and safety. We investigated disease-free survival (DFS), overall survival (OS), and drug-related toxicities of taxanes by a systematic review and meta-analysis. Methodology and Principal Findings We systematically searched PubMed, EMBASE, the Cochrane Center Register of Controlled Trials, proceedings of major meetings, and reference lists of articles for studies conducted between January 1980 and April 2011. Randomized controlled trials (RCTs) comparing chemotherapy with and without taxanes in the treatment of patients with early-stage or operable breast cancer were eligible for inclusion in our analysis. The primary endpoint was DFS. Nineteen RCTs including 30698 patients were identified, including 8426 recurrence events and 3803 deaths. Taxanes administration yielded a 17% reduction of hazard ratio (HR) for DFS (HR = 0.83, 95% CI 0.79–0.88, p<0.001) and a 17% reduction of HR for OS (HR = 0.83, 95% CI 0.77–0.90, p<0.001). For high risk, node-negative breast cancer, the pooled HR also favoured the taxane-based treatment arm over the taxane-free treatment arm (HR = 0.82, 95% CI 0.77–0.87, p = 0.022). A significantly increased rate of neutropenia, febrile neutropenia, fatigue, diarrhea, stomatitis, and oedema was observed in the taxane-based treatment arm. Conclusions/Significance Adjuvant chemotherapy with taxanes could reduce the risk of cancer recurrence and death in patients with early or operable breast cancer, although the drug-related toxicities should be balanced. Furthermore, we also demonstrated that patients with high risk, node-negative breast cancer also benefited from taxanes therapy, a result that was not observed in previous studies.

Association between alcohol consumption and the risk of incident type 2 diabetes: a systematic review and dose-response meta-analysis

BACKGROUND Previous cohort studies have shown that moderate alcohol consumption was associated with a lower risk of type 2 diabetes (T2D). However, whether these associations differ according to the characteristics of patients with T2D remains controversial. OBJECTIVE The purpose of this study was to explore and summarize the evidence on the strength of the association between alcohol consumption and the subsequent risk of T2D by using a dose-response meta-analytic approach. DESIGN We identified potential studies by searching the PubMed, Embase, and Cochrane Library databases up to 24 March 2015. Prospective observational studies that evaluated the relation between alcohol consumption and the risk of T2D and reported its effect estimates with 95% CIs were included. RESULTS Analyses were based on 706,716 individuals (275,711 men and 431,005 women) from 26 studies with 31,621 T2D cases. We detected a nonlinear relation between alcohol consumption and the risk of T2D, which was identified in all cohorts (P-trend < 0.001, P-nonlinearity < 0.001), in men (P-trend < 0.001, P-nonlinearity < 0.001), and in women (P-trend < 0.001, P-nonlinearity < 0.001). Compared with the minimal category of alcohol consumption, light (RR: 0.83; 95% CI: 0.73, 0.95; P = 0.005) and moderate (RR: 0.74; 95% CI: 0.67, 0.82; P < 0.001) alcohol consumption was associated with a lower risk of T2D. However, heavy alcohol consumption had little or no effect on subsequent T2D risk. Furthermore, the summary RR ratio (RRR; male to female) of the comparison between moderate alcohol consumption and the minimal alcohol categories for T2D was significantly higher, and the pooled RRR (current smoker to never smoker) of light alcohol consumption was significantly reduced. CONCLUSIONS Light and moderate alcohol consumption was associated with a lower risk of T2D, whereas heavy alcohol consumption was not related to the risk of T2D.

Sleep duration and breast cancer risk: A meta-analysis of observational studies

Studies on the association of short or long sleep duration with breast cancer risk have reported inconsistent results. We quantitatively assessed this association by conducting a meta‐analysis based on the evidence from observational studies. In April 2013, we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify studies examining the effect of sleep duration on breast cancer incidence. The odds ratio (OR) was used to measure any such association in a random‐effects model. The analysis was further stratified by confounding factors that could bias the results. A total of six studies (two case–control and four cohort studies) involving 159,837 individuals were included in our meta‐analysis. Our study did not show an association between either short or long sleep duration and breast cancer risk (short sleep duration data: pooled OR = 1.01, 95% confidence interval (CI) = 0.90–1.14, p = 0.853; long sleep duration data: pooled OR = 0.95, 95% CI = 0.86–1.04, p = 0.251). Moreover, we did not identify any statistically significant association between sleep duration and breast cancer risk in all the subgroup analyses. In conclusion, our findings indicate that sleep duration has no effect on breast cancer risk.

Tea consumption and the incidence of cancer: a systematic review and meta-analysis of prospective observational studies

The aim of this study was to summarize the current evidence on the strength of associations between tea consumption and the incidence of cancer at different sites. We searched PubMed, Embase and the Cochrane Library for relevant articles published before October 2013. Prospective studies that reported effect estimates of cancer incidence, with 95% confidence intervals (CIs), for more than two categories of tea consumption were included. We analysed 87 datasets (57 articles), which included a total of 49 812 incident cases. Overall, high tea consumption had no significant effect on the risk of gastric, rectal, colon, lung, pancreatic, liver, breast, prostate, ovarian, bladder cancers or gliomas. However, high tea consumption was associated with a reduced risk of oral cancer (risk ratio 0.72; 95% CI 0.54–0.95; P=0.021). A dose–response meta-analysis suggested that an increase in tea consumption by one cup per day was associated with a reduced risk of oral cancer (risk ratio 0.89; 95% CI 0.80–0.98; P=0.022), but had little effect on the incidence of other cancers. Subgroup analysis indicated that an increase in the consumption of black tea by one cup per day was associated with an increased risk of breast cancer. Moreover, in western countries, we found that an increase in the consumption of tea by one cup per day was associated with a reduced risk of bladder cancer. Increased tea consumption has no significant effect on the risk of common malignancies. For some cancer types, associations differ according to sex, ethnicity and tea type.

Association between B Vitamins Supplementation and Risk of Cardiovascular Outcomes: A Cumulative Meta-Analysis of Randomized Controlled Trials

Background Observational studies suggest that B vitamin supplementation reduces cardiovascular risk in adults, but this association remains controversial. This study aimed to summarize the evidence from randomized controlled trials (RCTs) investigating B vitamin supplementation for the primary or secondary prevention of major adverse cardiovascular outcomes and to perform a cumulative meta-analysis to determine the evidence base. Methodology and Principal Findings In April 2013, we searched PubMed, Embase, and the Cochrane Library to identify relevant RCTs. We included RCTs investigating the effect of B vitamin supplementation on cardiovascular outcome. Relative risk (RR) was used to measure the effect using a random-effect model. Statistical heterogeneity scores were assessed using the Q statistic. We included data on 57,952 individuals from 24 RCTs: 12 primary prevention trials and 12 secondary prevention trials. In 23 of these trials, 10,917 major adverse cardiovascular events (MACE) occurred; in 20 trials, 7,203 deaths occurred; in 15 trials, 3,422 cardiac deaths occurred; in 19 trials, 3,623 myocardial infarctions (MI) occurred; and in 18 trials, 2,465 strokes occurred. B vitamin supplementation had little or no effect on the incidence of MACE (RR, 0.98; 95% confidence interval [CI]: 0.93–1.03; P = 0.37), total mortality (RR, 1.01; 95% CI: 0.97–1.05; P = 0.77), cardiac death (RR, 0.96; 95% CI: 0.90–1.02; P = 0.21), MI (RR, 0.99; 95% CI: 0.93–1.06; P = 0.82), or stroke (RR, 0.94; 95% CI: 0.85–1.03; P = 0.18). Conclusion/Significance B vitamin supplementation, when used for primary or secondary prevention, is not associated with a reduction in MACE, total mortality, cardiac death, MI, or stroke.

Effect of omega-3 fatty acid supplementation on cancer incidence, non-vascular death, and total mortality: a meta-analysis of randomized controlled trials

BackgroundOmega-3 fatty acids are known to prevent cardiac death. However, previous observational studies have suggested that omega-3 fatty acids are associated with cancer risk in adults. We conducted a meta-analysis based on randomized controlled trials to evaluate the effect of omega-3 fatty acids on the risk of cancer incidence, nonvascular death, and total mortality.MethodsIn February 2013, we performed electronic searches in PubMed, EmBase, and the Cochrane Library to identify randomized controlled trials on cancer incidence, nonvascular death, and total mortality. Relative risk (RR) was used to measure the effect of omega-3 fatty acid supplementation on the risk of cancer incidence, nonvascular death, and total mortality using a random-effect model. The analysis was further stratified by factors that could affect the treatment effects.ResultsOf the 8,746 identified articles, we included 19 trials reporting data on 68,954 individuals. These studies reported 1,039 events of cancer, 2,439 events of nonvascular death, and 7,025 events of total mortality. Omega-3 fatty acid supplementation had no effect on cancer incidence (RR, 1.10; 95% CI: 0.97–1.24; P = 0.12), nonvascular death (RR, 1.00; 95% CI: 0.93–1.08; P = 1.00), or total mortality (RR, 0.95; 95% CI: 0.88–1.03; P = 0.24) when compared to a placebo. Subgroup analysis indicated that omega-3 fatty acid supplementation was associated with a reduction in total mortality risk if the proportion of men in the study population was more than 80%, or participants received alpha-linolenic acid.ConclusionsOmega-3 fatty acid supplementation does not have an effect on cancer incidence, nonvascular death, or total mortality.

Association between folate intake and the risk of lung cancer: a dose-response meta-analysis of prospective studies.

Background Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach. Methodology and Principal Findings In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer. Only prospective cohort studies that reported the effect estimates about the incidence of lung cancer with 95% confidence intervals (CIs) for more than 2 categories of folate intake were included. Overall, we examined 9 cohort studies reporting the data of 566,921 individuals. High folate intake had little effect on the risk of lung cancer (risk ratio [RR], 0.92; 95% CI, 0.84–1.01; P = 0.076). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of lung cancer (RR, 0.99; 95% CI, 0.97–1.01; P = 0.318). Subgroup analysis suggested that the potential protective effect of low folate intake (100–299 µg/day) was more evident in women than men, while the opposite was true of high folate intake (>400 µg/day). Finally, subgroup analyses of a 100 µg/day increment in folate intake indicated that its potential protective effect was more evident in men than in women. Conclusion/Significance Our study revealed that folate intake had little or no effect on the risk of lung cancer. Subgroup analyses indicated that an increased folate intake was associated with a reduced risk of lung cancer in men. Furthermore, low folate intake may be a protective factor for women, and high folate intake for men.