Cancer risk in diabetic patients treated with metformin: a systematic review and meta-analysis

Background

A growing body of evidence has suggested that metformin potentially reduces the risk of cancer. Our objective was to enhance the precision of estimates of the effect of metformin on the risk of any-site and site-specific cancers in patients with diabetes.

Methods/Principal Findings

We performed a search of MEDLINE, EMBASE, ISI Web of Science, Cochrane Library, and ClinicalTrials.gov for pertinent articles published as of October 12, 2011, and included them in a systematic review and meta-analysis. We calculated pooled risk ratios (RRs) for overall cancer mortality and cancer incidence. Of the 21,195 diabetic patients reported in 6 studies (4 cohort studies, 2 RCTs), 991 (4.5%) cases of death from cancer were reported. A total of 11,117 (5.3%) cases of incident cancer at any site were reported among 210,892 patients in 10 studies (2 RCTs, 6 cohort studies, 2 case-control studies). The risks of cancer among metformin users were significantly lower than those among non-metformin users: the pooled RRs (95% confidence interval) were 0.66 (0.49–0.88) for cancer mortality, 0.67 (0.53–0.85) for all-cancer incidence, 0.68 (0.53–0.88) for colorectal cancer (n = 6), 0.20 (0.07–0.59) for hepatocellular cancer (n = 4), 0.67 (0.45–0.99) for lung cancer (n = 3).

Conclusion/Significance

The use of metformin in diabetic patients was associated with significantly lower risks of cancer mortality and incidence. However, this analysis is mainly based on observational studies and our findings underscore the more need for long-term RCTs to confirm this potential benefit for individuals with diabetes.     

Hypertension outcomes of adrenalectomy in patients with primary aldosteronism: a systematic review and meta-analysis

Background

The hypertension cure rate of unilateral adrenalectomy in primary aldosteronism (PA) patients varies widely in existing studies.

Methods

We conducted an observational meta-analysis to summarize the pooled hypertension cure rate of unilateral adrenalectomy in PA patients. Comprehensive electronic searches of PubMed, Embase, Cochrane, China National Knowledge Internet (CNKI), WanFang, SinoMed and Chongqing VIP databases were performed from initial state to May 20, 2016. We manually selected eligible studies from references in accordance with the inclusion criteria. The pooled hypertension cure rate of unilateral adrenalectomy in PA patients was calculated using the DerSimonian–Laird method to produce a random-effects model.

Results

Forty-three studies comprising approximately 4000 PA patients were included. The pooled hypertension cure rate was 50.6% (95% CI: 42.9–58.2%) for unilateral adrenalectomy in PA. Subgroup analyses showed that the hypertension cure rate was 61.3% (95% CI: 49.4–73.3%) in Chinese studies and 43.7% (95% CI: 38.0–49.4%) for other countries. Furthermore, the hypertension cure rate at 6-month follow-up was 53.3% (95% CI: 36.0–70.5%) and 49.6% (95% CI: 40.9–58.3%) for follow-up exceeding 6 months. The pooled hypertension cure rate was 50.9% (95% CI: 40.5–61.3%) from 2001 to 2010 and 50.2% (95% CI: 39.0–61.5%) from 2011 to 2016.

Conclusions

The hypertension cure rate for unilateral adrenalectomy in PA is not optimal. Large clinical trials are required to verify the utility of potential preoperative predictors in developing a novel and effective prediction model.

     

Hydroxychloroquine and QTc prolongation in patients with COVID-19: A systematic review and meta-analysis

BackgroundAmong many drugs that hold potential in COVID-19 pandemic, chloroquine (CQ), and its derivative hydroxychloroquine (HCQ) have generated unusual interest. With increasing usage, there has been growing concern about the prolongation of QTc interval and Torsades de Pointes (TdP) with HCQ, especially in combination with azithromycin.AimsThis meta-analysis is planned to study the risk of QTc prolongation and Torsades de pointes (TdP) by a well-defined criterion for HCQ, CQ alone, and in combination with Azithromycin in patients with COVID-19.MethodsA comprehensive literature search was made in two databases (PubMed, Embase). Three outcomes explored in the included studies were frequency of QTc > 500 ms (ms) or ΔQTc > 60 ms (Outcome 1), frequency of QTc > 500 ms (Outcome 2) and frequency of TdP (Outcome 3). Random effects method with inverse variance approach was used for computation of pooled summary and risk ratio.ResultsA total of 13 studies comprising of 2138 patients were included in the final analysis. The pooled prevalence of outcome 1, outcome 2 and outcome 3 for HCQ, CQ with or without Azithromycin were 10.18% (5.59–17.82%, I² – 92%), 10.22% (6.01–16.85%, I² – 79%), and 0.72% (0.34–1.51, I² – 0%) respectively. The prevalence of outcome 2 in subgroup analysis for HCQ and HCQ + Azithromycin was 7.25% (3.22–15.52, I² – 59%) and 8.61% (4.52–15.79, I² – 76%), respectively. The risk ratio (RR) for outcome 1 and outcome 2 between HCQ + Azithromycin and HCQ was 1.22 (0.77–1.93, I² – 0%) & 1.51 (0.79–2.87, I² – 13%), respectively and was not significant. Heterogeneity was noted statistically as well clinically (regimen types, patient numbers, study design, and outcome definition).ConclusionThe use of HCQ/CQ is associated with a high prevalence of QTc prolongation. However, it is not associated with a high risk of TdP.     

Antithrombin III in critically ill patients: systematic review with meta-analysis and trial sequential analysis

Objective To evaluate the benefits and harms of antithrombin III in critically ill patients.Design Systematic review and meta-analysis of randomised trials.Data sources CENTRAL, Medline, Embase, International Web of Science, LILACS, the Chinese Biomedical Literature Database, and CINHAL (to November 2006); hand search of reference lists, contact with authors and experts, and search of registers of ongoing trials.Review methods Two reviewers independently selected parallel group randomised clinical trials comparing antithrombin with placebo or no intervention and extracted data related to study methods, interventions, outcomes, bias risk, and adverse events. Disagreements were resolved by discussion. Trials in any type of critically ill patients in intensive care were eligible. All trials, irrespective of blinding or language status, that compared any antithrombin III regimen with no intervention or placebo were included. Trials were considered to be at low risk of bias if they had adequate randomisation procedure, blinding, and used intention to treat analysis. Risk ratios with 95% confidence intervals were estimated with fixed and random effects models according to heterogeneity. Main outcome measures Mortality, length of stay in intensive care or hospital, quality of life, severity of sepsis, respiratory failure, duration of mechanical ventilation, incidence of surgical intervention, intervention effect among various populations, and adverse events (such as bleeding).Results 20 trials randomly assigning 3458 patients met inclusion criteria. Eight trials had low risk of bias. Compared with placebo or no intervention, antithrombin III did not reduce overall mortality (relative risk 0.96, 95% confidence interval 0.89 to 1.03). No subgroup analyses on risk of bias, populations of patients, or with and without adjuvant heparin yielded significant results. Antithrombin III increased the risk of bleeding events (1.52, 1.30 to 1.78). Heterogeneity was observed in only a few analyses.Conclusion Antithrombin III cannot be recommended for critically ill patients based on the available evidence.     

Assisted reproductive techniques with congenital hypogonadotropic hypogonadism patients: a systematic review and meta-analysis

Background

After hormonal replacement therapy (HRT) including androgen replacement or sequential therapy of estrogen and progesterone, The combination of human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) and pulsatile GnRH, is not sufficient to produce sufficient gametes in some patients with Congenital hypogonadotropic hypogonadism (CHH). A Systematic review and meta-analysis was performed to determine that assisted reproductive techniques (ART) can effectively treat different causes of infertility.

Methods

To determine the effect of ART on fertility of CHH patients and investigate whether outcomes are similar to infertility due to other causes, we conducted a systematic review and meta-analysis of retrospective trials.Clinical trials were systematically searched in Medline, Embase, and the Cochrane central register of controlled trials databases. The keywords and major terms covered “hypogonadotropic hypogonadism”, “kallmann syndrome”, “assisted reproductive techniques”, “intrauterine insemination”, “intracytoplasmic sperm injection”, “testicular sperm extraction”, “in vitro fertilization”, “embryo transplantation” and “intra-Fallopian transfer”.

Results

A total of 388 pregnancies occurred among 709 CHH patients who received ART (effectiveness 46, 95% confidence interval 0.39 to 0.53) in the 20 studies we included. The I² in trials assessing overall pregnancy rate (PR) per embryo transfer (ET) cycle was 73.06%. Similar results were observed in subgroup analysis by different gender. Regression indicates pregnancy rate decreases with increasing age. Fertilization, implantation and live birth rates (72, 36 and 40%) showed no significant differences as compared to infertility due to other causes.

Conclusions

Despite CHH patients usually being difficult to generate gametes, their actual chances of fertility are similar to subjects with other non-obstructive infertility. ART is a suitable option for CHH patients who do not conceive after long-term gonadotropin treatment.

     

Cardiac complications in patients with community-acquired pneumonia: a systematic review and meta-analysis of observational studies

Background

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality. CAP can trigger acute cardiac events. We sought to determine the incidence of major cardiac complications in CAP patients to characterize the magnitude of this problem.

Methods and Findings

Two investigators searched MEDLINE, Scopus, and EMBASE for observational studies of immunocompetent adults with clinical and radiological evidence of CAP that reported any of the following: overall cardiac complications, incident heart failure, acute coronary syndromes (ACS), or incident cardiac arrhythmias occurring within 30 days of CAP diagnosis. At a minimum, studies had to establish enrolment procedures and inclusion and exclusion criteria, enrol their patients sequentially, and report the incidence of cardiac complications as a function of their entire cohorts. Studies with focus on nosocomial or health care–associated pneumonia were not included. Review of 2,176 citations yielded 25 articles that met eligibility and minimum quality criteria. Seventeen articles (68%) reported cohorts of CAP inpatients. In this group, the pooled incidence rates for overall cardiac complications (six cohorts, 2,119 patients), incident heart failure (eights cohorts, 4,215 patients), acute coronary syndromes (six cohorts, 2,657 patients), and incident cardiac arrhythmias (six cohorts, 2,596 patients), were 17.7% (confidence interval [CI] 13.9–22.2), 14.1% (9.3–20.6), 5.3% (3.2–8.6), and 4.7% (2.4–8.9), respectively. One article reported cardiac complications in CAP outpatients, four in low-risk (not severely ill) inpatients, and three in high-risk inpatients. The incidences for all outcomes except overall cardiac complications were lower in the two former groups and higher in the latter. One additional study reported on CAP outpatients and low-risk inpatients without discriminating between these groups. Twelve studies (48%) asserted the evaluation of cardiac complications in their methods but only six (24%) provided a definition for them. Only three studies, all examining ACS, carried out risk factor analysis for these events. No study analyzed the association between cardiac complications and other medical complications or their impact on other CAP outcomes.

Conclusions

Major cardiac complications occur in a substantial proportion of patients with CAP. Physicians and patients need to appreciate the significance of this association for timely recognition and management of these events. Strategies aimed at preventing pneumonia (i.e., influenza and pneumococcal vaccination) in high-risk populations need to be optimized. Further research is needed to understand the mechanisms underlying this association, measure the impact of cardiac complications on other CAP outcomes, identify those patients with CAP at high risk of developing cardiac complications, and design strategies to prevent their occurrence in this population. Please see later in the article for the Editors'' Summary     

Toxocariasis and epilepsy: systematic review and meta-analysis

Objective

Human toxocariasis is a zoonotic infection caused by the larval stages of Toxocara canis (T. canis) and less frequently Toxocara cati (T. cati). A relationship between toxocariasis and epilepsy has been hypothesized. We conducted a systematic review and a meta-analysis of available data to evaluate the strength of association between epilepsy and Toxocara spp. seropositivity and to propose some guidelines for future surveys.

Data Sources

Electronic databases, the database from the Institute of Neuroepidemiology and Tropical Neurology of the University of Limoges (http://www-ient.unilim.fr/) and the reference lists of all relevant papers and books were screened up to October 2011.

Methods

We performed a systematic review of literature on toxocariasis (the exposure) and epilepsy (the outcome). Two authors independently assessed eligibility and study quality and extracted data. A common odds ratio (OR) was estimated using a random-effects meta-analysis model of aggregated published data.

Results

Seven case-control studies met the inclusion criteria, for a total of 1867 participants (850 cases and 1017 controls). The percentage of seropositivity (presence of anti-Toxocara spp. antibodies) was higher among people with epilepsy (PWE) in all the included studies even if the association between epilepsy and Toxocara spp. seropositivity was statistically significant in only 4 studies, with crude ORs ranging 2.04–2.85. Another study bordered statistical significance, while in 2 of the included studies no significant association was found. A significant (p<0.001) common OR of 1.92 [95% confidence interval (CI) 1.50–2.44] was estimated. Similar results were found when meta-analysis was restricted to the studies considering an exclusively juvenile population and to surveys using Western Blot as confirmatory or diagnostic serological assay.

Conclusion

Our results support the existence of a positive association between Toxocara spp. seropositivity and epilepsy. Further studies, possibly including incident cases, should be performed to better investigate the relationship between toxocariasis and epilepsy.     

Short- and long-term outcomes in infective endocarditis patients: a systematic review and meta-analysis

Background

Despite advances in medical knowledge, technology and antimicrobial therapy, infective endocarditis (IE) is still associated with devastating outcomes. No reviews have yet assessed the outcomes of IE patients undergoing short- and long-term outcome evaluation, such as all-cause mortality and IE-related complications. We conducted a systematic review and meta-analysis to examine the short- and long-term mortality, as well as IE-related complications in patients with definite IE.

Methods

A computerized systematic literature search was carried out in PubMed, Scopus and Google Scholar from 2000 to August, 2016. Included studies were published studies in English that assessed short-and long-term mortality for adult IE patients. Pooled estimations with 95% confidence interval (CI) were calculated with DerSimonian-Laird (DL) random-effects model. Sensitivity and subgroup analyses were also performed. Publication bias was evaluated using inspection of funnel plots and statistical tests.

Results

Twenty five observational studies (retrospective, 14; prospective, 11) including 22,382 patients were identified. The overall pooled mortality estimates for IE patients who underwent short- and long-term follow-up were 20% (95% CI: 18.0–23.0, P?<?0.01) and 37% (95% CI: 27.0–48.0, P?<?0.01), respectively. The pooled prevalence of cardiac complications in patients with IE was found to be 39% (95%CI: 32.0–46.0) while septic embolism and renal complications accounted for 25% (95% CI: 20.0–31) and 19% (95% CI: 14.0–25.0) (all P?<?0.01), respectively.

Conclusion

Irrespective of the follow-up period, a significantly higher mortality rate was reported in IE patients, and the burden of IE-related complications were immense. Further research is needed to assess the determinants of overall mortality in IE patients, as well as well-designed observational studies to conform our results.

     

Post-stroke infection: A systematic review and meta-analysis

Background  

stroke is the main cause of disability in high-income countries, and ranks second as a cause of death worldwide. Patients with acute stroke are at risk for infections, but reported post-stroke infection rates vary considerably. We performed a systematic review and meta-analysis to estimate the pooled post-stroke infection rate and its effect on outcome.     

The prognostic value of circulating tumor DNA in patients with melanoma: A systematic review and meta-analysis

BackgroundCirculating tumor DNA (ctDNA) has been investigated as a potential prognostic biomarker to evaluate the therapeutic efficacy and disease progression in melanoma patients, yet results remain inconclusive. The purpose of this study was to illustrate the prognostic value of ctDNA in melanoma.ObjectivesTo describe the clinical prognostic value of ctDNA for melanoma patients.MethodsSearched for eligible articles from Pubmed, Web of Science and Embase. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate the association between ctDNA at baseline or during treatment and overall survival (OS) and progression-free survival (PFS).ResultsA total of 9 articles were obtained, involving 617 melanoma patients. The pooled HRs revealed that compared with baseline undetectable ctDNA patients, detectable ctDNA was highly correlated with poor OS (HR 2.91, 95% CI: 2.22–3.82; p < 0.001) and PFS (HR 2.75, 95% CI: 1.98–3.83; p < 0.001). A meta-analysis of these adjusted HRs was performed and confirmed that ctDNA collected at baseline was associated with poorer OS/PFS (OS: HR 3.00, 95% CI 2.19–4.11, p < 0.001/PFS: HR 2.68, 95% CI 1.77–4.06, p < 0.001). During treatment, a significant association was shown between ctDNA and poorer OS/PFS (OS: HR 6.26, 95% CI 2.48–15.80, p < 0.001; PFS: HR 4.93, 95% CI 2.36–10.33, p < 0.001).ConclusionInvestigation and application of ctDNA will improve "liquid biopsy" and play a role in early prediction, monitoring disease progression and precise adjusting treatment strategies in melanoma patients.     

Prognostic value of survivin in patients with non-small cell lung carcinoma: a systematic review with meta-analysis

Purpose

The potential prognostic value of survivin in resected non-small cell lung carcinoma (NSCLC) is variably reported. The objective of this study was to conduct a systematic review of literatures evaluating survivin expression in resected NSCLC as a prognostic indicator.

Methods

Relevant literatures were identified using PubMed, EMBASE and Chinese Biomedicine Databases. We present the results of a meta-analysis of the association between survivin expression and overall survival (OS) in NSCLC patients. Studies were pooled and summary hazard ratios (HR) were calculated. Subgroup analyses and publication bias were also conducted.

Results

We performed a final analysis of 2703 patients from 28 evaluable studies. Combined HRs suggested that survivin overexpression had an unfavorable impact on NSCLC patients'' survival with no evidence of any significant publication bias (HR = 2.03, 95%CI: 1.78–2.33, Egger''s test, P = 0.24) and no severe heterogeneity between studies (I² = 26.9%). Its effect also appeared significant when stratified according to the studies categorized by histological type, HR estimate, patient race, cutoff point (5%, 10%), detection methods and literature written language except for disease stage. Survivin was identified as a prognostic marker of advanced-stage NSCLC (HR = 1.93, 95%CI: 1.49-2.51), but not early-stage NSCLC (HR = 1.97, 95%CI: 0.76-5.14), in spite of the combined data being relatively small.

Conclusion

This study shows that survivin expression appears to be a pejorative prognostic factor in terms of overall survival in surgically treated NSCLC. Large prospective studies are now needed to confirm the clinical utility of survivin as an independent prognostic marker.     

Periprocedural heparin bridging in patients receiving oral anticoagulation: a systematic review and meta-analysis

Background

Periprocedural heparin bridging therapy aims to reduce the risk of thromboembolic events in patients requiring an interruption in their anticoagulation therapy for the purpose of an elective procedure. The efficacy and safety of heparin bridging therapy has not been well established.

Objectives

To compare through meta-analysis the effects of heparin bridging therapy on the risk of major bleeding and thromboembolic events of clinical significance among patients taking oral anticoagulants.

Methods

We searched PubMed, EMBASE and the Cochrane library from January 2005 to July 2016. Studies were included if they reported clinical outcomes of patients receiving heparin bridging therapy during interruption of oral anticoagulant for operations. Data were pooled using random-effects modeling.

Results

A total of 25 studies, including 6 randomized controlled trials and 19 observational studies, were finally included in this analysis. Among all the 35,944 patients, 10,313 patients were assigned as heparin bridging group, and the other 25,631 patients were non-heparin bridging group. Overall, compared with patients without bridging therapy, heparin bridging therapy increased the risk of major bleeding (OR?=?3.23, 95%CI: 2.06–5.05), minor bleeding (OR?=?1.52, 95%CI: 1.06–2.18) and overall bleeding (OR?=?2.83, 95%CI: 1.86–4.30).While there was no significant difference in thromboembolic events (OR?=?0.99,95%CI: 0.49–2.00), stroke or transient ischemic attack(OR?=?1.45, 95%CI: 0.93–2.26,) or all-cause mortality (OR?=?0.71, 95%CI: 0.31–1.65).

Conclusions

Heparin-bridging therapy increased the risk of major and minor bleeding without decreasing the risk of thromboembolic events and all cause death compared to non-heparin bridging.

     

Zoledronic Acid as an adjuvant therapy in patients with breast cancer: a systematic review and meta-analysis

Background

Zoledronic acid is widely used as adjuvant chemotherapy for the treatment of breast cancer. However, previous trials reported inconsistent findings regarding their clinical efficacy and safety. We carried out a comprehensive systematic review and meta-analysis to evaluate the effects of zoledronic acid on disease-free survival (DFS), overall survival (OS), and drug-related toxicities.

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 with a time limit of Dec. 1, 2011. Randomized controlled trials evaluated the effects of zoledronic acid on OS, DFS, and RFS compared with control were eligible for inclusion in our research. Of 175 identified studies, we collected data from 7 randomized controlled trials of zoledronic acid that had OS, DFS, and RFS reported as one of the endpoint. Overall, we noted that patients receiving zoledronic acid therapy had significant longer OS than the group with non-zoledronic acid therapy (HR, 0.85, 95%CI, 0.73 to 1.00, P = 0.047). Furthermore, zoledronic acid therapy also had a clear effect on frature events (RR, 0.66, 95%CI, 0.52 to 0.84, P<0.001). Subgroup analysis indicated that zoledronic acid therapy showed a great beneficial effect on disease recurrence in patients with early-stage breast cancer, however, it also significantly increased the harm of disease recurrence in patients with advanced breast cancer. Bone pain, neutropenic fever, pyrexia, rash were more frequent in the zoledronic acid therapy group.

Conclusion/Significance

Treatment with zoledronic acid had a clear effect on fracture events, and it might contribute an important role for overall survival.     

Clinicopathological and prognostic significance of osteopontin expression in patients with prostate cancer: a systematic review and meta-analysis

Background: Evaluation of the feasibility for osteopontin (OPN) to serve as a biomarker in the prognosis and clinical-pathological features of prostate cancer (PCA) patients.Methods: The original publications related to OPN and PCA were comprehensively searched in the online databases, including PubMed, Embase, Cochrane Library, Web of Science, Medline, Wanfang and China National Knowledge Infrastructure up to August 2019. Results were analyzed by Revman 5.3 and Stata 12.0.Results: A total of 21 studies were included in the analysis and the result showed that the positive OPN expression group had a lower overall survival than the negative expression group (univariate: hazards ratio (HR) = 2.32, 95% confidence interval (95% CI) [1.74, 3.10], multivariate: HR = 2.41, 95% CI [1.63, 3.57]) and a lower biochemical relapse-free survival than the negative group (univariate: HR = 1.42, 95% CI [0.92, 2.17], multivariate: HR = 1.61, 95% CI [1.39, 1.87]). In addition, there was a higher expression level of OPN in PCA tissues than in normal prostate tissues (OR = 46.55, 95% CI [12.85, 168.59], P<0.00001) and benign prostatic hyperplasia (BPH) tissues (OR = 11.07, 95% CI [3.43, 35.75], P<0.0001). Moreover, OPN positive expression was also related to high Gleason score (OR = 2.64, 95% CI [1.49, 4.70], P=0.0009), high TNM stage (OR = 3.15, 95% CI [1.60, 6.20, P=0.0009), high Whitmore–Jewett stage (OR = 2.53, 95% CI [1.06, 6.03], P=0.04), high lymph node (OR = 3.69, 95% CI [1.88, 7.23], P=0.0001), and distant metastasis (OR = 8.10, 95% CI [2.94, 22.35], P=0.01). There was no difference observed in the differentiation of PCA (OR = 1.79, 95% CI [0.39, 8.33], P=0.46).Conclusion: OPN could be recognized as a promising diagnostic and prognostic biomarker for PCA patients.     

Association of mycoplasma with prostate cancer: A systematic review and meta-analysis

Mycoplasmas are emerging sexually transmitted pathogens usually associated with male urinary tract infection, non-gonococcal urethritis (NGU), infertility, and prostate cancer. In this study, we review the evidence linking mycoplasma infection and prostate cancer. We conducted a systematic review and meta-analysis based on PRISMA guidelines. Four electronic databases were reviewed through January 31, 2021. Studies were eligible for inclusion if odds ratio for prevalence or incidence of colonization and/or infection were provided or calculable. All included studies were evaluated independently by three reviewers. The quality of the included studies was assessed using the Newcastle-Ottawa Scale for Case-Control Studies. Statistical analysis was done using Review Manager Version 5.4. A total of 183/744 (24.6 %) patients with prostate cancer compared to 87/495 (17.58 %) patients with benign prostatic hyperplasia (BPH) tested positive for Mycoplasma spp., while 86/666 (12.91 %) and 11/388 (2.84 %) prostate cancer patients and BPH patients, respectively, had Ureaplasma spp. infections. This meta-analysis showed that prostate cancer patients had 2.24 times higher odds (p = 0.0005) of being colonized with any species of Mycoplasma spp. and 3.6 times increased odds (p = 0.008) of being colonized with any species of Ureaplasma spp. In conclusion, patients with prostate cancer were more likely to be colonized with Mycoplasma spp. or Ureaplasma spp. compared to patients with BPH, which highlights the potential association between chronic infection and cancer. However, more studies are needed to determine the specific role that mycoplasma plays in the pathogenesis of prostate cancer.     

Metformin in polycystic ovary syndrome: systematic review and meta-analysis

Objective To assess the effectiveness of metformin in improving clinical and biochemical features of polycystic ovary syndrome.Design Systematic review and meta-analysis.Data sources Randomised controlled trials that investigated the effect of metformin compared with either placebo or no treatment, or compared with an ovulation induction agent.Selection of studies 13 trials were included for analysis, including 543 women with polycystic ovary syndrome that was defined by using biochemical or ultrasound evidence.Main outcome measure Pregnancy and ovulation rates. Secondary outcomes of clinical and biochemical features of polycystic ovary syndrome.Results Meta-analysis showed that metformin is effective in achieving ovulation in women with polycystic ovary syndrome, with odds ratios of 3.88 (95% confidence interval 2.25 to 6.69) for metformin compared with placebo and 4.41 (2.37 to 8.22) for metformin and clomifene compared with clomifene alone. An analysis of pregnancy rates shows a significant treatment effect for metformin and clomifene (odds ratio 4.40, 1.96 to 9.85). Metformin has an effect in reducing fasting insulin concentrations, blood pressure, and low density lipoprotein cholesterol. We found no evidence of any effect on body mass index or waist:hip ratio. Metformin was associated with a higher incidence of nausea, vomiting, and other gastrointestinal disturbance.Conclusions Metformin is an effective treatment for anovulation in women with polycystic ovary syndrome. Its choice as a first line agent seems justified, and there is some evidence of benefit on variables of the metabolic syndrome. No data are available regarding the safety of metformin in long term use in young women and only limited data on its safety in early pregnancy. It should be used as an adjuvant to general lifestyle improvements and not as a replacement for increased exercise and improved diet.     

The height premium: A systematic review and meta-analysis

The taller people are, the more money they tend to earn. This phenomenon is widely known as the height premium. However, it is not yet known whether the height premium is universal, or whether it varies by context. To that end, a systematic review of the literature was performed. Five databases were searched until August 2020. Ultimately, a list of 42 studies were included in a narrative synthesis, and 17 studies were included in a meta-analysis. Based on the meta-analysis, we found evidence that the height premium varied by context: the height premium was smaller in the U.S. and Australia, and larger in Latin America and Asia. Within geographies, there appeared to be a larger height premium for men than for women. Cultural factors, labor market structures and biology may play a role in determining the strength of the height premium.     

Prevalence of Leishmania RNA virus in Leishmania parasites in patients with tegumentary leishmaniasis: A systematic review and meta-analysis

BackgroundCutaneous leishmaniasis is caused by different protozoan parasites of the genus Leishmania. Leishmania RNA virus (LRV) was identified as the first Leishmania infecting virus in 1998. Different studies showed the presence and role of the LRV in Leishmania parasites causing cutaneous leishmaniasis (CL). However, there is limited data on the pooled prevalence of LRV in Leishmania parasites causing CL. Therefore, the aim of this systematic review and meta-analysis was to determine the pooled prevalence of LRV in Leishmania parasite isolates and/or lesion biopsies in patients with CL from the available literature globally.MethodologyWe retrieved the studies from different electronic databases. The studies were screened and identified based on the inclusion and exclusion criteria. We excluded studies exclusively done in experimental animals and in vitro studies. The review was conducted in line with PRISMA guidelines. The meta-analysis was performed with Stata software version 14 with metan command. The forest plot with random-effect model was used to estimate the pooled prevalence with 95% confidence interval. Inverse variance index (I²) was used to assess the heterogeneity among the included articles.Principal findingsA total of 1215 samples from 25 studies were included. Of these, 40.1% (487/1215) were positive for LRV. The overall pooled prevalence of LRV globally was 37.22% (95% CI: 27.54% - 46.90%). The pooled prevalence of LRV in the New World (NW) and Old World (OW) regions was 34.18% and 45.77%, respectively. Leishmania guyanensis, L. braziliensis, L. major, and L. tropica were the most studied species for the detection of LRV. The prevalence of LRV from Leishmania isolates and lesion biopsies was 42.9% (349/813) and 34.3% (138/402), respectively.ConclusionThis systematic study revealed that there is high prevalence of LRV in Leishmania parasites isolated from patients with CL. More comprehensive studies would be required to investigate the presence of the LRV in other Leishmania species such as L. aethiopica to fully understand the role of LRV in different clinical manifestations and disease pathology presented in CL patients.