Novel Information Regarding the Treatment of Helicobacter pylori Infection: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

OBJECTIVE: Helicobacter pylori infects at least 50% of the world's human population. The current study aimed to assess and compare the efficacy of triple versus quadruple therapy. METHODS: Randomized clinical trials (RCTs) consisting of triple and quadruple therapy were identified through electronic and manual searches in the national and international online databases (IsI, Magiran, Embase, PubMed, and Scopus). The random-effects model was applied to pool analysis. Funnel plots and the Egger test were used to examine publication bias. RESULTS: After a detailed review of the selected articles, 80 RCTs were included in the meta-analysis; it was based on using triple and quadruple therapy as the first and second-line treatment. The results showed that quadruple therapy in the first-line treatment had a higher eradication rate than triple therapy. Overall, the eradication rate with triple therapy was 74% (95% CI, 71%-77%) for intention-totreat (ITT) analysis and 80% (95% CI, 77%-82%) for per-protocol (PP) analysis. Generally, the eradication rate with quadruple therapy was 82% (95% CI, 78.0%-86.0%) for ITT analysis and 85% (95% CI, 82.0%-89.0%) for PP analysis. The analysis also revealed that quadruple therapy was more effective for 7 or 10 days. CONCLUSION: The current study results demonstrated that quadruple therapy has better effectiveness than triple therapy as the first-line treatment; however, in the second-line treatment, the effectiveness of quadruple and triple regimens is almost similar. The effectiveness of quadruple therapy in the Asian population was found to be slightly higher than that of triple therapy, while this difference was considerably higher in the European population.

Standard Triple Therapy as a Remedy for Treatment of Helicobacter pylori Infection: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

BACKGROUND: H. pylori infection, one of the most prevalent infectious diseases, can cause severe health problems. Therefore, it seems to be crucial to effectively counter the H. pylori infection with a well-tolerated eradication regimen. However, since the discovery of H. pylori, the optimal treatment for this disease is still unclear and remains controversial. OBJECTIVES: The present study aims to estimate the efficacy of standard triple therapy for eradicating H. pylori by systematic review and meta-analysis. METHODS: We identified randomized clinical trials [RCTs] involving triple therapy PPIAC/M [Omeprazole, Amoxicillin, and Clarithromycin/Metronidazole] in the first-line treatment of H. pylori infection and reported eradication rate through electronic and manual searches in PubMed, ISI, EMBASE, the Cochrane Central Register, and Scopus databases. Data were analyzed using the random effect model, and the Cochrane Q test and I2 statistics were used to assess heterogeneity. Statistical analyses were performed using STATA version 12. RESULTS: Forty-seven RCTs [PPIAC: 40 RCTs and PPIAM: 7 RCTs] with 4,938 patients selected as eligible for the final analysis. Per-protocol eradication rate was 80% [95% CI: 74-84] and 80% [95% CI: 73-87] for PPIAC and PPIAM regimens, respectively. The eradication rate for PPIAC and PPIAM regimens was 83% [95% CI: 70%-95%] and 83% [95% CI: 75%-90%] and also 77% [95% CI: 68%- 88%] and 78% [95% CI: 69%-88%], respectively. Based on different treatment durations, the pooled estimates of PP [per-protocol analysis] treatment outcomes were found the highest in 14-day treatment in both regimens. CONCLUSION: Standard triple therapy PPIAC/M is recommended to be an effective and safe regimen, although adequate data are not available to suggest PPIAC/M as the first-line therapy for H. Pylori infection. Interestingly, our analysis demonstrated that PPIAC/M regimens were more effective in Asian than European populations.

A systematic review and meta-analysis on the association of serum and tumor tissue iron and risk of breast cancer.

BACKGROUND: Some studies have investigated the effects of iron on breast carcinogenesis and reported different findings about the association between Fe and breast cancer risk. This study was conducted to estimate this effect using meta-analysis method. METHODS: A total of 20 articles published between 1984 and 2017 worldwide were selected through searching PubMed, Scopus, Embase, Web of Science, and Cochrane Library. Keywords such Breast Cancer, Neoplasm, Trace elements, Iron, Breast tissue concentration, Plasma concentration, Scalp hair concentration, toenail concentration and their combination were used in the search. RESULTS: The total number of participants was 4,110 individuals comprising 1,624 patients with breast cancer and 2,486 healthy subjects. Fe concentration was measured in the various subgroups in both case and control groups. There were significant correlations between Fe concentration and breast cancer in breast tissue subgroup (SMD: 0.67 [95% CI: 0.17 to 1.17; P=0.009]). Whereas, there was no meaningful difference in Fe status between women with and without breast cancer related to scalp hair and plasma subgroups; (SMD: -3.74 [95% CI: -7.58 to 0.10; P=0.056] and (SMD:-1.14[95% CI: -2.30 to 0.03; P=0.055], respectively. CONCLUSION: The present meta-analysis indicated a positive and straight association between iron concentrations and risk of breast cancer but because of high heterogeneity we recommend more accurate future studies.

Copper Concentrations in Breast Cancer: A Systematic Review and Meta-Analysis.

Breast cancer is the most common neoplasm, comprising 16% of all women's cancers worldwide. Research of Copper (Cu) concentrations in various body specimens have suggested an association between Cu levels and breast cancer risks. This systematic review and meta-analysis summarize the results of published studies and examine this association. We searched the databases PubMed, Scopus, Web of Science, and Google Scholar and the reference lists of relevant publications. The Standardized Mean Differences (SMDs) between Cu levels in cancer cases and controls and corresponding Confidence Intervals (CIs), as well as I2 statistics, were calculated to examine heterogeneity. Following the specimens used in the original studies, the Cu concentrations were examined in three subgroups: serum or plasma, breast tissue, and scalp hair. We identified 1711 relevant studies published from 1984 to 2017. There was no statistically significant difference between breast cancer cases and controls for Cu levels assayed in any studied specimen; the SMD (95% CI) was -0.01 (-1.06 - 1.03; P = 0.98) for blood or serum, 0.51 (-0.70 - 1.73; P = 0.41) for breast tissue, and -0.88 (-3.42 - 1.65; P = 0.50) for hair samples. However, the heterogeneity between studies was very high (P < 0.001) in all subgroups. We did not find evidence for publication bias (P = 0.91). The results of this meta-analysis do not support an association between Cu levels and breast cancer. However, due to high heterogeneity in the results of original studies, this conclusion needs to be confirmed by well-designed prospective studies.

A meta-analysis of zinc levels in breast cancer.

BACKGROUND: Breast cancer is the most commonly occurring neoplasm in females, comprising 16% of all female cancers worldwide. Various studies indicate some discrepancies regarding zinc (Zn) levels in various samples of breast cancer patients. OBJECTIVE: The present study evaluated by meta-analysed the published data for Zn levels analyzed in breast tissue, plasma, serum, and hair samples and its relationship with breast cancer. METHODS: The present meta-analysis included 36 studies, all of which were published in the years between 1984 to 2017 and selected by searching the databases MEDLINE, EMBASE, Cochrane Library, PubMed, Scopus, and the ISI Web of Knowledge. The articles were analyzed, and I² statistics were used to examine heterogeneity. The objective analysis was performed on data from the 36 studies, with total 1699 study subjects and 2009 controls. RESULTS: Significant statistical differences overall were observed, based on a random effects model (SMD (95 % CI), -0.78[-1.40, -0.16], P = 0.014). Data from 19 of these studies indicated significant statistical differences between cancerous patients and controls with regard to serum and plasma Zn concentration (SMD [(95 %CI): -1.61(-2.43, -0.79)]. There was a significant statistical difference between the breast tissue and hair as regards Zn status (SMD (95%CI): 2.32(1.42, 3.21)) and (SMD (95v%CI): -1.80(-3.41, -0.20), respectively. Zn concentration levels typically decreased in blood and hair samples of patients with breast cancer, whereas it was elevated in tumor tissues. CONCLUSIONS: There is a significant relationship between lowered serum Zn concentrations and risk of breast cancer onset or recurrences in women, but because of high heterogeneity, we recommend other primary studies.

Prevalence of vancomycin resistance among isolates of enterococci in Iran: a systematic review and meta-analysis.

INTRODUCTION: Enterococcus is responsible for 10% of hospital-acquired infections. The purpose of this review was to evaluate the prevalence of vancomycin-resistant Enterococcus (VRE) isolates in Iran using a meta-analysis method. MATERIALS AND METHODS: Iranian databases, including Magiran and IranDoc, and international databases, including PubMed and MedLib, were examined carefully, and a total of 20 articles published between 2000 and 2011 were extracted. The data were subjected to meta-analysis and random-effects models. In addition, heterogeneous studies were assessed using the I 2 index. Finally, the data were analyzed using R and STATA software. RESULTS: The results showed that the strain of Enterococcus faecalis had been more common than Enterococcus faecium in clinical infection (69% vs 28%). However, resistance to vancomycin was higher among strains of E. faecium compared with strains of E. faecalis (33% vs 3%). The complete resistance, intermediate resistance, and sensitivity to vancomycin among Enterococcus isolates were 14% (95% CI: 11, 18), 14% (95% CI: 5, 23), and 74% (95% CI: 65, 83), respectively. The resistance patterns, depending on the sample type, did not show a significant difference. In addition, the resistance of isolated strains to vancomycin in outpatients was significantly higher than that in inpatients (16% vs 1%). Moreover, 80%-86% of resistant strains were genotype van A and 14%-20% of resistant strains were genotype van B. CONCLUSION: The findings of the present review show that there is a high frequency of resistant Enterococcus in Iran. Therefore, consideration of the prevalence and frequency of subjected resistant strains can be helpful for decision makers to implement proper health policies in this direction.

Prevalence of Anaerobic Bacteria (P.gingivalis) as Major Microbial Agent in the Incidence Periodontal Diseases by Meta-analysis.

STATEMENT OF THE PROBLEM: Periodontal diseases are complex oral diseases characterized by bacterial-induced inflammatory destruction of tooth-supporting tissues. Porphyromonas gingivalis (P. gingivalis) is a common gram-negative anaerobic oral bacteria strongly associated with periodontal disease. PURPOSE: The present study was conducted to estimate prevalence of P. gingivalis in patients with periodontal diseases by using meta-analysis method. MARTIALS AND METHOD: Different databases including PubMed, EmBase, Scopus, the Institute for Scientific Information (ISI) Web of Science, and the Cochrane Library were searched to identify original English-language studies addressing prevalence of P. gingivalis in periodontal diseases up to December 2014. The random effects model was applied in the meta-analysis and the heterogeneity between studies was assessed using a Cochran test and the I2 index. Funnel plots and Egger test were used to examine publication bias. Statistical analyses were performed using STATA version 12. RESULTS: Forty-two eligible studies published during 1993- 2016 were selected for meta-analysis. Considering all the included studies, the total sample size was 5,884 individuals containing 2,576 healthy people with a mean age of 37.21±7.45 years and 3,308 periodontal patients with a mean age of 44.16±8.35 years. Overall, the prevalence of P. gingivalis was 78% [95% CI: 74-81] in periodontal diseases group and 34% [95% CI: 26-41] in healthy individuals. There was a significantly higher prevalence of P.gingivalis in individuals with periodontal diseases compared to healthy subjects [78% versus 34%, respectively]. CONCLUSION: This study indicates that P. gingivalis is highly present in subjects with periodontal diseases and it also appears in periodontally healthy people, although to a lesser extent. Thus, the presence of P. gingivalis increases the chance of periodontal disease and it can be considered as a main potential risk factor.

Prevalence of Hypercholesterolemia, High LDL, and Low HDL in Iran: A Systematic Review and Meta-Analysis.

BACKGROUND: Chronic and abnormal increase of different types of dyslipidemia leads to some important diseases, such as constriction and abstraction of vessels in various parts of the body, especially in the heart. High lipid profile, such as increased total cholesterol and LDL as well as decreased HDL are recognized as cardiovascular disease risk factors. The present study aimed to estimate the prevalence of different types of dyslipidemia in Iran by a meta-analysis method. METHODS: A literature search for studies published during 1998-2015 was carried out using both Persian and English databases (SID, Magiran, IranMedex, MedLib, PubMed, and Scopus). Keywords such as lipid, dyslipidemia, CVD, cardiovascular risk factors, hypercholesterolemia, high LDL-C, low HDL-C, and prevalence were used in the search. Random-effects model was used for the analysis using STATA (version 11.2). RESULTS: In total, 163 articles were identified of which 49 articles fulfilled the inclusion criteria. The estimated prevalence (95% confidence interval) of eligible articles for high cholesterol ≥200 mg/dl and ≥240 mg/dl was 42% (95% CI: 38-45) and 17% (95% CI: 14-20), respectively. Moreover, the prevalence (95% confidence interval) for high LDL-C ≥130 mg/dl and ≥160 mg/dl was 40% (95% CI: 32-48) and 19% (95% CI: 16-23), respectively. The pooled prevalence estimate for low HDL-C (<40 among males, <50 among females) was 43% (95% CI: 33-53) in both sexes of the Iranian people. All types of lipid component abnormalities (hypercholesterolemia, high LDL-C, and low HDL-C) were more prevalent in women. CONCLUSION: The results indicate that the prevalence of different types of dyslipidemia in Iran is substantial. Given the risk of complications (e.g. cardiovascular disease and control of different types of dyslipidemia) in Iranian people, it is important to reduce the burden of cardiovascular diseases.

Prevalence, causes, and complications of cesarean delivery in Iran: A systematic review and meta-analysis.

BACKGROUND: Uncontrolled increase of C-section is one of the major problems in Iranian health system, such that C-section is the most common surgical procedure in the entire country's hospitals in Obstetrics and Gynecology sections. A variety of complications also come along with cesarean. OBJECTIVE: The aim of this study was to evaluate the prevalence, causes, and complications of cesarean in Iran. MATERIALS AND METHODS: forty-one articles were considered with respect to certain criteria and were included in a systematic review to perform a meta-analysis study. The systematic review's search was conducted on SID, Iranmedx, Magiran, Medlib, PubMed, and Science Direct databases published between1999-2016. The weight of each included study was calculated according to its sample size and the reported prevalence of binomial distribution. A random-effects model using R and STATA (Version 11.2) software was utilized for analyzing data. RESULTS: The total number of the sample was 197514 pregnant women with a mean age of 26.72 yr. The prevalence of cesarean in Iran was estimated at 48%. The main reasons for the prevalence of cesarean in this study were mothers' higher education, previous cesarean, and doctor recommendation. The most frequent complication in women undergoing cesarean was the muscular pain, and the most common fetal complications in newborns by caesarean delivery was transient tachypnea. CONCLUSION: The prevalence of C-section in Iran is much higher than what WHO recommends. It is essential, to decrease such a phenomenon, making the mothers aware of the risks of cesarean delivery, and establishing counselling sessions as well to eliminate the mothers' fear of vaginal delivery.

Toxic elements as biomarkers for breast cancer: a meta-analysis study.

AIMS AND BACKGROUND: Breast cancer (BC) is responsible for a large proportion of incidence of cancer in the world. Identifying the risk factors contributing to the incidence of BC is crucial to find efficient preventive and management strategies for this disease. Several studies have examined Arsenic (As), Cadmium (Cd), and Nickel (Ni) as risk factors for BC. The present study aimed at studying the link between As, Cd, and Ni concentrations and BC by using a meta-analysis. MATERIALS AND METHODS: All case-control studies addressing the relationship between As, Cd, and Ni concentrations with BC were identified through electronic search databases (Scopus, ISI Web of Science, PubMed, EmBase, and Cochrane Library). The relevant data obtained from these papers were analyzed by a random-effects model. The heterogeneity of studies was secured by using I2 index. Funnel plots and Egger's test were used to examine publication bias. RESULTS: In the present study, due to different measurement methods used for measuring As, Cd, and Ni, the concentration of these elements was measured in various subgroups (1: plasma, 2: breast tissue, and 3: scalp hair and nail) of individuals with BC and healthy subjects. The overall integration of data from the 3 groups led to the conclusion that there was a significant difference in Cd and Ni statuses between healthy and BC patients; the standard mean difference was 2.65 (95% CI: 1.57-3.73; P=0.000) and 2.06 (95% CI: 1.20-3.32; P=0.000), respectively. Whereas, there was no significant statistical difference in As status between healthy subjects and BC patients; the standard mean difference between them being 0.52 (95% CI: -0.12-1.16; P=0.114). CONCLUSION: The present study indicates that there is a direct and positive association between Cd and Ni concentrations and BC risk. It is a warning to health care providers and policy makers to find viable solutions and take requisite measures to reduce BC risk in the society.

Prevalence of metabolic syndrome in Iran: A meta-analysis.

BACKGROUND: Metabolic syndrome) MetS( is a complex risk factor which increases the risk of cardiovascular diseases and type 2 diabetes. There are many studies with various populations and results about the prevalence of MetS in Iran; in order to authenticate these studies and have an overall estimation of its prevalence in Iran, performing a meta-analysis seems to be necessary. OBJECTIVE: This study aimed to investigate the prevalence of MetS and its components in Iran via meta-analysis method. METHODS: All associated published papers in national and international journals of PubMed, Scopus, Web of Science, Magiran, Iranmedex, Science Direct, Medlib, and SID databases were searched from January, 2000 to October, 2016. All types of studies, including local and national surveys that reported the prevalence of MetS among healthy populations in Iran were reviewed. The effects of age, sample size and publication date as possible sources of heterogeneity among the study findings was examined by meta-regression. P-values less than 0.05 were considered as significant in heterogeneity tests. All analysis was done by R Ver. 3.2.1 and STATA (version 10). RESULTS: Seventy eligible studies were selected for meta-analysis. The overall estimation of MetS prevalence was 25% (95% CI: 22-29%) based on the Adult Treatment Panel III (ATP III) criteria, 30% (95% CI: 25-36%) according to the International Diabetes Federation (IDF), and 39% (95% CI: 26-52%) based on the Joint Interim Societies (JIS) criteria. The prevalence of MetS was lower in men than in women (26.9% versus 35.7%). The prevalence of various MetS components including High TG (triglyceride), Low HDL-C, High BP and High FBS (fasting blood sugar) was 43%, 54%, 38% and 22% among the adult population. CONCLUSION: Findings from the present meta-analyses study displayed a high prevalence of metabolic syndrome in Iran, especially in women, which increases with age in both sexes. It alerts health care providers and policy makers to find solutions in order to take action to reduce MetS risk in society.

Study of Porphyromonas gingivalis in periodontal diseases: A systematic review and meta-analysis.

Background: The mouth cavity hosts various types of anaerobic bacteria including Porphyromonas gingivalis, which causes periodontal inflammatory diseases. P. gingivalis is a gram-negative oral anaerobe and is considered as a main etiological factor in periodontal diseases. Several studies have reported a relationship between P. gingivalis in individuals with periodontal diseases and a critical role of this bacterium in the pathogenesis of periodontal diseases. The present study aimed at estimating this probability using a meta-analysis. Methods: We searched several databases including PubMed, Scopus, Google Scholar, and Web of Science to identify case-control studies addressing the relationship between P. gingivalis with periodontal diseases. A total of 49 reports published from different countries from 1993 to 2014 were included in this study. I² (heterogeneity index) statistics were calculated to examine heterogeneity. Data were analyzed using STATA Version 11. Results: After a detailed analysis of the selected articles, 49 case-control studies with 5924 individuals fulfilled the inclusion criteria for the meta-analysis. The healthy controls included 2600 healthy individuals with a Mean±SD age of 36.56±7.45 years. The periodontal diseases group included 3356 patients with a mean age of 43.62±8.35 years. There was a statistically significant difference between P. gingivalis in periodontal patients and healthy controls; 9.24 (95% CI: 5.78 to 14.77; P = 0.000). In the other word, there was a significant relationship between the presence of P. gingivalis and periodontal diseases. Conclusion: Analyzing the results of the present study, we found a strong association between the presence of P. gingivalis and periodontal diseases. This result suggests that another research is needed to further assess this subject.

Prevalence of polycystic ovary syndrome and its associated complications in Iranian women: A meta-analysis.

BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and is the most common cause of infertility due to anovulation. There is no single criterion for the diagnosis of this syndrome. OBJECTIVE: The purpose of this study was to investigate the prevalence of PCOS and its associated complications in Iranian women using meta-analysis method. MATERIALS AND METHODS: Prevalence of PCOS was investigated from the SID, Goggle scholar, PubMed, Magiran, Irandoc, and Iranmedex, and weighting of each study was calculated according to sample size and prevalence of the binomial distribution. Data were analyzed using a random-effects model meta-analysis (Random effects model) and the software R and Stata Version 11.2. RESULTS: 30 studies conducted between the years 2006 to 2011 were entered into meta-analysis. The total sample size was 19, 226 women aged between 10-45 years. The prevalence of PCOS based on National institute of child health and human disease of the U.S was, 6.8% (95 % CI: 4.11-8.5), based on Rotterdam was 19.5% (95 % CI: 2.24-8.14), and based on ultrasound was 4.41% (95% CI: 5.68-4.14). Also, the prevalence of hirsutism was estimated to be 13%, acne 26%, androgenic alopecia 9%, menstrual disorders 28%, overweight 21%, obesity 19%, and infertility 8%. CONCLUSION: The prevalence of PCOS in Iran is not high. However, given the risk of complications such as heart disease - cardiovascular and infertility, prevention of PCOS is important; we suggest that health officials must submit plans for the community in this respect.

Prevalence of cagA and vacA among Helicobacter pylori-infected patients in Iran: a systematic review and meta-analysis.

The varieties of infections caused by Helicobacter pylori may be due to differences in bacterial genotypes and virulence factors as well as environmental and host-related factors. This study aimed to investigate the prevalence of cagA and vacA genes among H. pylori-infected patients in Iran and analyze their relevance to the disease status between two clinical groups via a meta-analysis method. Different databases including PubMed, ISI, Scopus, SID, Magiran, Science Direct, and Medlib were investigated, and 23 relevant articles from the period between 2001 and 2012 were finally analyzed. The relevant data obtained from these papers were analyzed by a random-effects model. Data were analyzed using R software and STATA. The prevalence of cagA and vacA genes among H. pylori-infected patients was 70% (95% CI, 64-75) and 41% (95% CI, 24.3-57.7), respectively. The prevalence of duodenal ulcers, peptic ulcers, and gastritis among cagA+ individuals was 53% (95% CI, 20-86), 65% (95% CI, 34-97), and 71% (95% CI, 59-84), respectively. Odds ratio (OR) between cagA-positive compared with cagA-negative patients showed a 1.89 (95% CI, 1.38-2.57) risk of ulcers. In conclusion, the frequency of cagA gene among H. pylori strains is elevated in Iran and it seems to be more frequently associated with gastritis. Therefore, any information about cagA and vacA prevalence among different H. pylori-infected clinical groups in the country can help public health authorities to plan preventive policies to reduce the prevalence of diseases associated with H. pylori infection.