scholarly journals The association of MTHFR C677T variant with increased risk of ischemic stroke in the elderly population: a meta-analysis of observational studies

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Guilin Chang ◽  
Zheng Kuai ◽  
Jia Wang ◽  
Jiayu Wu ◽  
Kan Xu ◽  
...  

Abstract Background C677T point mutation in methylenetetrahydrofolate reductase (MTHFR) gene have been found to be associated with ischemic stroke in general population, while the results seem inconsistent. We aim to assess the association between variant MTHFR C677T variant and increased risk of ischemic stroke and focus on the elderly population. Methods We searched PubMed, Embase, Cochrane Library, and Web of Science for eligible studies. Odds ratios (ORs) were calculated with the two-tailed 95% confidence intervals (CIs) by using a random effects model to evaluate any possible association. Among the Chinese and non-Chinese populations, we conducted a subgroup analysis. Results The electronic database search yielded 1,358 citations as of December 2017; finally, nine case-control studies involving 3,337 subjects fulfilled our eligibility criteria for inclusion in the study. The pooled results showed that MTHFR C677T variant increased the risk of ischemic stroke (OR = 1.23, 95%CI 1.06–1.43, P = 0.0067 for CT + TT vs. CC; OR = 1.18, 95%CI 1.01–1.38, P = 0.0333 for CT vs. CC; OR = 1.41, 95%CI 1.14–1.75, P = 0.0016 for TT vs. CC; OR = 1.27, 95%CI 1.05–1.54, P = 0.0145 for TT vs. CC + CT; OR = 1.18, 95%CI 1.06–1.31, P = 0.0023 for T-allele vs. C-allele). Further subgroup analyses in the Chinese population indicated that MTHFR C677T variant was associated with a higher risk of ischemic stroke. Conclusion Our findings showed that T-allele increases risk for stroke in the pooled sample. This association was statistically significant in the Chinese cohorts and showed a similar trend in the non-Chinese cohorts. (Word count: 237).

2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Meng ◽  
Shaoyan Huang ◽  
Yali Yang ◽  
Xiaofeng He ◽  
Liping Fei ◽  
...  

Background: Since the 1990s, there have been a lot of research on single-nucleotide polymorphism (SNP) and different diseases, including many studies on 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism and essential hypertension (EH). Nevertheless, their conclusions were controversial. So far, six previous meta-analyses discussed the internal relationship between the MTHFR polymorphism and EH, respectively. However, they did not evaluate the credibility of the positive associations. To build on previous meta-analyses, we updated the literature by including previously included papers as well as nine new articles, improved the inclusion criteria by also considering the quality of the papers, and applied new statistical techniques to assess the observed associations. Objectives: This study aims to explore the degree of risk correlation between two MTHFR polymorphisms and EH. Methods: PubMed, EMBASE, the Cochrane Library, CNKI, and Wan Fang electronic databases were searched to identify relevant studies. We evaluated the relation between the MTHFR C677T (rs1801133) and A1298C (rs1801131) polymorphisms and EH by calculating the odds ratios (OR) as well as 95% confidence intervals (CI). Here we used subgroup analysis, sensitivity analysis, cumulative meta-analysis, assessment of publication bias, meta-regression meta, False-positive report probability (FPRP), Bayesian false discovery probability (BFDP), and Venice criterion. Results: Overall, harboring the variant of MTHFR C677T was associated with an increased risk of EH in the overall populations, East Asians, Southeast Asians, South Asians, Caucasians/Europeans, and Africans. After the sensitivity analysis, positive results were found only in the overall population (TT vs. CC: OR = 1.14, 95% CI: 1.00–1.30, Ph = 0.032, I2 = 39.8%; TT + TC vs. CC: OR = 1.15, 95% CI: 1.01–1.29, Ph = 0.040, I2 = 38.1%; T vs. C: OR = 1.14, 95% CI: 1.04–1.25, Ph = 0.005, I2 = 50.2%) and Asian population (TC vs. CC: OR = 1.14, 95% CI: 1.01–1.28, Ph = 0.265, I2 = 16.8%; TT + TC vs. CC: OR = 1.17, 95% CI: 1.04–1.30, Ph = 0.105, I2 = 32.9%; T vs. C: OR = 1.10, 95% CI: 1.02–1.19, Ph = 0.018, I2 = 48.6%). However, after further statistical assessment by FPRP, BFDP, and Venice criteria, the positive associations reported here could be deemed to be false-positives and present only weak evidence for a causal relationship. In addition, when we performed pooled analysis and sensitivity analysis on MTHFR A1298C; all the results were negative. Conclusion: The positive relationships between MTHFR C677T and A1298C polymorphisms with the susceptibility to present with hypertension were not robust enough to withstand statistical interrogation by FPRP, BFDP, and Venice criteria. Therefore, these SNPs are probably not important in EH etiology.


BMJ Open ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. e016582 ◽  
Author(s):  
Mengjuan Long ◽  
Zhenming Fu ◽  
Ping Li ◽  
Zhihua Nie

ObjectiveThe role of cigarette smoking as an independent risk factor for patients with nasopharyngeal carcinoma (NPC) is controversial. We attempted to provide evidence of a reliable association between cigarette smoking and the risk of NPC.DesignMeta-analysis.Data sourcesPubMed online and the Cochrane Library of relevant studies published up to February 2016.Eligibility criteriaAll studies had to evaluate the relationship between NPC and cigarette smoking with never smokers as the reference group.OutcomesThe primary outcome was the adjusted OR, RR or HR of NPC patients comparing smoking with never-smoking; the second was the crude OR, RR or HR.ResultsWe identified 17 case–control studies and 4 cohort studies including 5960 NPC cases and 429 464 subjects. Compared with never smokers, current smokers and ever smokers had a 59% and a 56% greater risk of NPC, respectively. A dose–response relationship was identified in that the risk estimate rose by 15% (p<0.001) with every additional 10 pack-years of smoking, and risk increased with intensity of cigarette smoking (>30 cigarettes per day). Significantly increased risk was only found among male smokers (OR, 1.36; 95% CI 1.15 to 1.60), not among female smokers (OR, 1.58; 95% CI 0.99 to 2.53). Significantly increased risk also existed in the differentiated (OR, 2.34; 95% CI 1.77 to 3.09) and the undifferentiated type of NPC (OR, 1.15; 95% CI 0.90 to 1.46). Moreover, people who started smoking at younger age (<18 years) had a greater risk than those starting later for developing NPC (OR, 1.78; 95% CI 1.41 to 2.25).ConclusionsCigarette smoking was associated with increased risk of NPC, especially for young smokers. However, we did not find statistical significant risks of NPC in women and in undifferentiated type, which might warrant further researches.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yanli Liu ◽  
Yilong Pan ◽  
Yuyao Yin ◽  
Wenhao Chen ◽  
Xiaodong Li

Abstract Background The numbers of confirmed cases of coronavirus disease 2019 (COVID-19) and COVID-19 related deaths are still increasing, so it is very important to determine the risk factors of COVID-19. Dyslipidemia is a common complication in patients with COVID-19, but the association of dyslipidemia with the severity and mortality of COVID-19 is still unclear. The aim of this study is to analyze the potential association of dyslipidemia with the severity and mortality of COVID-19. Methods We searched the PubMed, Embase, MEDLINE, and Cochrane Library databases for all relevant studies up to August 24, 2020. All the articles published were retrieved without language restriction. All analysis was performed using Stata 13.1 software and Mantel–Haenszel formula with fixed effects models was used to compare the differences between studies. The Newcastle Ottawa scale was used to assess the quality of the included studies. Results Twenty-eight studies involving 12,995 COVID-19 patients were included in the meta-analysis, which was consisted of 26 cohort studies and 2 case–control studies. Dyslipidemia was associated with the severity of COVID-19 (odds ratio [OR] = 1.27, 95% confidence interval [CI] 1.11–1.44, P = 0.038, I2 = 39.8%). Further, patients with dyslipidemia had a 2.13-fold increased risk of death compared to patients without dyslipidemia (95% CI 1.84–2.47, P = 0.001, I2 = 66.4%). Conclusions The results proved that dyslipidemia is associated with increased severity and mortality of COVID-19. Therefore, we should monitor blood lipids and administer active treatments in COVID-19 patients with dyslipidemia to reduce the severity and mortality.


Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5654
Author(s):  
Agnieszka Barańska ◽  
Agata Błaszczuk ◽  
Wiesław Kanadys ◽  
Maria Malm ◽  
Katarzyna Drop ◽  
...  

To perform a meta-analysis of case-control studies that addressed the association between oral contraceptive pills (OC) use and breast cancer (BrCa), PubMED (MEDLINE), Embase, and the Cochrane Library were searched to identify case-control studies of OC and BrCa published between 2009 and 2020. We used the DerSimonian–Laird method to compute pooled odds ratios (ORs) and confidence intervals (CIs), and the Mantel–Haenszel test to assess the association between OC use and cancer. Forty-two studies were identified that met the inclusion criteria and we included a total of 110,580 women (30,778 into the BrCa group and 79,802 into the control group, of which 15,722 and 38,334 were using OC, respectively). The conducted meta-analysis showed that the use of OC was associated with a significantly increased risk of BrCa in general, OR = 1.15, 95% CI: 1.01 to 1.31, p = 0.0358. Regarding other risk factors for BrCa, we found that increased risk was associated significantly with early menarche, nulliparous, non-breastfeeding, older age at first parity, postmenopause, obesity, smoking, and family history of BrCa. Despite our conclusion that birth control pills increase the cancer risk being supported by extensive previous studies and meta-analyzes, further confirmation is required.


2018 ◽  
Vol 45 (5-6) ◽  
pp. 279-287 ◽  
Author(s):  
Frans Kauw ◽  
Richard A.P. Takx ◽  
Hugo W.A.M. de Jong ◽  
Birgitta K. Velthuis ◽  
L. Jaap Kappelle ◽  
...  

Background: Predictors of recurrent ischemic stroke are less well known in patients with a recent ischemic stroke than in patients with transient ischemic attack (TIA). We identified clinical and radiological factors for predicting recurrent ischemic stroke in patients with recent ischemic stroke. Methods: A systematic search in PubMed, Embase, Cochrane Library, and CINAHL was performed with the terms “ischemic stroke,” “predictors/determinants,” and “recurrence.” Quality assessment of the articles was performed and the level of evidence was graded for the articles included for the meta-analysis. Pooled risk ratios (RR) and heterogeneity (I2) were calculated using inverse variance random effects models. Results: Ten articles with high-quality results were identified for meta-analysis. Past medical history of stroke or TIA was a predictor of recurrent ischemic stroke (pooled RR 2.5, 95% CI 2.1–3.1). Small vessel strokes were associated with a lower risk of recurrence than large vessel strokes (pooled RR 0.3, 95% CI 0.1–0.7). Patients with stroke of an undetermined cause had a lower risk of recurrence than patients with large artery atherosclerosis (pooled RR 0.5, 95% CI 0.2–1.1). We found no studies using CT or ultrasound for the prediction of recurrent ischemic stroke. The following MRI findings were predictors of recurrent ischemic stroke: multiple lesions (pooled RR 1.7, 95% CI 1.5–2.0), multiple stage lesions (pooled RR 4.1, 95% CI 3.1–5.5), multiple territory lesions (pooled RR 2.9, 95% CI 2.0–4.2), chronic infarcts (pooled RR 1.5, 95% CI 1.2–1.9), and isolated cortical lesions (pooled RR 2.2, 95% CI 1.5–3.2). Conclusions: In patients with a recent ischemic stroke, a history of stroke or TIA and the subtype large artery atherosclerosis are associated with an increased risk of recurrent ischemic stroke. Predictors evaluated with MRI include multiple ischemic changes and isolated cortical lesions. Predictors of recurrent ischemic stroke concerning CT or ultrasound have not been published.


BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e039303
Author(s):  
Shiwen Jing ◽  
Chang Chen ◽  
Yuexin Gan ◽  
Joshua Vogel ◽  
Jun Zhang

ObjectivesTo update the WHO estimate of preterm birth rate in China in 1990–2016 and to further explore variations by geographic regions and years of occurrence.DesignSystematic review and meta-analysis.Data sourcesPubmed, Embase, Cochrane Library and Sinomed databases were searched from 1990 to 2018.Eligibility criteriaStudies were included if they provided preterm birth data with at least 500 total births. Reviews, case–control studies, intervention studies and studies with insufficient information or published before 1990 were excluded. We estimated pooled incidence of preterm birth by a random effects model, and preterm birth rate in different year, region and by livebirths or all births in subgroup analyses.ResultsOur search identified 3945 records. After the removal of duplicates and screening of titles and abstracts, we reviewed 254 studies in full text and excluded 182, leaving 72 new studies. They were combined with the 82 studies included in the WHO report (154 studies, 187 data sets in total for the meta-analysis), including 24 039 084 births from 1990 to 2016. The pooled incidence of preterm birth in China was 6.09% (95% CI 5.86% to 6.31%) but has been steadily increasing from 5.36% (95% CI 4.89% to 5.84%) in 1990–1994 to 7.04% (95% CI 6.09% to 7.99%) in 2015–2016. The annual rate of increase was about 1.05% (95% CI 0.85% to 1.21%). Northwest China appeared to have the highest preterm birth rate (7.3%, 95% CI 4.92% to 9.68% from 1990 to 2016).ConclusionsThe incidence of preterm birth in China has been rising gradually in the past three decades. It was 7% in 2016. Preterm birth rate varied by region with the West having the highest occurrence.


Pteridines ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 9-17
Author(s):  
Dexia Li ◽  
Enxia Wang ◽  
Xia Gao ◽  
Ping Li

AbstractObjective To investigate the correlation between the methylenetetrahydrofolate reductase (MTHFR) gene 677C> T polymorphism and fetal congenital defects.Method Original studies relevant to the MTHFR gene 677C>T single nucleotide polymorphism and fetal congenital defects were systematically searched in the electronic databases of Medline, EMBSE and China National Knowledge Infrastructure (CNKI). All relevant publications were screened for inclusion in the present work. The correlation between the MTHFR gene 677C > T single nucleotide polymorphism and the occurrence of fetal congenital defects was expressed as an odds ratio (OR) and its 95% confidence interval (95% CI). Publication bias was assessed by Begg’s funnel plot and Egger’s line regression test.Results Nineteen case-control studies were ultimately included in the present meta-analysis. The pooled results indicated that the general risk of fetal congenital defects was significantly elevated in subjects with the 677T allele of the MTHFR gene in dominant (OR=1.07,95%CI:1.03-1.12, P<0.05), homozygous (OR=1.17,95%CI:1.06-1.30, P<0.05) and recessive genetic models (OR=1.16,95%CI:1.03-1.31, P<0.05) through the random effect method. However, significant publication bias was identified upon pooling the individual data and evaluating the correlation.Conclusion According to the present evidence, the MTHFR gene 677C>T single nucleotide polymorphism is correlated with poor pregnancy outcomes, and subjects with the T allele have an increased risk of developing general fetal congenital defects.


2010 ◽  
Vol 103 (04) ◽  
pp. 749-756 ◽  
Author(s):  
Francesca Cesari ◽  
Rosanna Abbate ◽  
Franco Gensini ◽  
George Broze ◽  
Sandra Fedi ◽  
...  

SummaryThe relationship between protein Z levels and thrombosis is controversial. We performed a systematic review and meta-analysis of the available studies to assess the association between protein Z and vascular thrombotic diseases. We conducted an electronic literature search through MedLine, Embase, Google Scholar, Web of Science, The Cochrane Library, bibliographies of retrieved articles and abstracts of congresses up to October, 2009. Studies were included if they analysed protein Z levels in patients with vascular thrombotic diseases. After the review process, 28 case-control studies (33 patient cohorts), including 4,218 patients with thrombotic diseases and 4,778 controls, were selected for analysis. The overall analysis using a random-effects model showed that low protein Z levels were associated with an increased risk of thrombosis (odds ratio [OR] 2.90, 95% confidence interval [CI] 2.05–4.12; p<0.00001). On subgroup analysis, a significant association was found between low protein Z levels and arterial vascular diseases (OR 2.67, 95%CI 1.60–4.48; p=0.0002), pregnancy complications (OR 4.17, 95%CI 2.31–7.52; p<0.00001), and venous thromboembolic diseases (OR 2.18, 95%CI 1.19–4.00; p=0.01). The results of this meta-analysis are consistent with a role for protein Z deficiency in thrombotic diseases, including arterial thrombosis, pregnancy complications and venous thromboembolism.


2019 ◽  
Vol 105 (6) ◽  
pp. 2068-2080 ◽  
Author(s):  
Tou-Yuan Tsai ◽  
Yu-Kang Tu ◽  
Kashif M Munir ◽  
Shu-Man Lin ◽  
Rachel Huai-En Chang ◽  
...  

Abstract Context The evidence of whether hypothyroidism increases mortality in the elderly population is currently inconsistent and conflicting. Objective The objective of this meta-analysis is to determine the impact of hypothyroidism on mortality in the elderly population. Data Sources PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases were searched from inception until May 10, 2019. Study Selection Studies evaluating the association between hypothyroidism and all-cause and/or cardiovascular mortality in the elderly population (ages ≥ 60 years) were eligible. Data Extraction Two reviewers independently extracted data and assessed the quality of the studies. Relative risk (RR) was retrieved for synthesis. A random-effects model for meta-analyses was used. Data Synthesis A total of 27 cohort studies with 1 114 638 participants met the inclusion criteria. Overall, patients with hypothyroidism experienced a higher risk of all-cause mortality than those with euthyroidism (pooled RR = 1.26, 95% CI: 1.15-1.37); meanwhile, no significant difference in cardiovascular mortality was found between patients with hypothyroidism and those with euthyroidism (pooled RR = 1.10, 95% CI: 0.84-1.43). Subgroup analyses revealed that overt hypothyroidism (pooled RR = 1.10, 95% CI: 1.01-1.20) rather than subclinical hypothyroidism (pooled RR = 1.14, 95% CI: 0.92-1.41) was associated with increased all-cause mortality. The heterogeneity primarily originated from different study designs (prospective and retrospective) and geographic locations (Europe, North America, Asia, and Oceania). Conclusions Based on the current evidence, hypothyroidism is significantly associated with increased all-cause mortality instead of cardiovascular mortality among the elderly. We observed considerable heterogeneity, so caution is needed when interpreting the results. Further prospective, large-scale, high-quality studies are warranted to confirm these findings.


2020 ◽  
Vol 34 (11) ◽  
pp. 4727-4740 ◽  
Author(s):  
Sivesh K. Kamarajah ◽  
Santhosh Karri ◽  
James R. Bundred ◽  
Richard P. T. Evans ◽  
Aaron Lin ◽  
...  

Abstract Background Laparoscopic cholecystectomy is increasingly performed in an ever ageing population; however, the risks are poorly quantified. The study aims to review the current evidence to quantify further the postoperative risk of cholecystectomy in the elderly population compared to younger patients. Method A systematic literature search of PubMed, EMBASE and the Cochrane Library databases were conducted including studies reporting laparoscopic cholecystectomy in the elderly population. A meta-analysis was reported in accordance with the recommendations of the Cochrane Library and PRISMA guidelines. Primary outcome was overall complications and secondary outcomes were conversion to open surgery, bile leaks, postoperative mortality and length of stay. Results This review identified 99 studies incorporating 326,517 patients. Increasing age was significantly associated with increased rates of overall complications (OR 2.37, CI95% 2.00–2.78), major complication (OR 1.79, CI95% 1.45–2.20), risk of conversion to open cholecystectomy (OR 2.17, CI95% 1.84–2.55), risk of bile leaks (OR 1.50, CI95% 1.07–2.10), risk of postoperative mortality (OR 7.20, CI95% 4.41–11.73) and was significantly associated with increased length of stay (MD 2.21 days, CI95% 1.24–3.18). Conclusion Postoperative outcomes such as overall and major complications appear to be significantly higher in all age cut-offs in this meta-analysis. This study demonstrated there is a sevenfold increase in perioperative mortality which increases by tenfold in patients > 80 years old. This study appears to confirm preconceived suspicions of higher risks in elderly patients undergoing cholecystectomy and may aid treatment planning and informed consent.


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