scholarly journals Evaluation of Mobile Phone and Cordless Phone Use and Glioma Risk Using the Bradford Hill Viewpoints from 1965 on Association or Causation

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Michael Carlberg ◽  
Lennart Hardell
Keyword(s):  
Animal Studies ◽  
Meta Analysis ◽  
Low Frequency ◽  
Cumulative Exposure ◽  
Malignant Schwannoma ◽  
Case Control Studies ◽  
Cordless Phone ◽  
Increased Risk ◽  
Wireless Phones ◽  
Glioma Risk

Objective.Bradford Hill’s viewpoints from 1965 on association or causation were used on glioma risk and use of mobile or cordless phones.Methods.All nine viewpoints were evaluated based on epidemiology and laboratory studies.Results.Strength: meta-analysis of case-control studies gave odds ratio (OR) = 1.90, 95% confidence interval (CI) = 1.31–2.76 with highest cumulative exposure. Consistency: the risk increased with latency, meta-analysis gave in the 10+ years’ latency group OR = 1.62, 95% CI = 1.20–2.19. Specificity: increased risk for glioma was in the temporal lobe. Using meningioma cases as comparison group still increased the risk. Temporality: highest risk was in the 20+ years’ latency group, OR = 2.01, 95% CI =1.41–2.88, for wireless phones. Biological gradient: cumulative use of wireless phones increased the risk. Plausibility: animal studies showed an increased incidence of glioma and malignant schwannoma in rats exposed to radiofrequency (RF) radiation. There is increased production of reactive oxygen species (ROS) from RF radiation. Coherence: there is a change in the natural history of glioma and increasing incidence. Experiment: antioxidants reduced ROS production from RF radiation. Analogy: there is an increased risk in subjects exposed to extremely low-frequency electromagnetic fields.Conclusion.RF radiation should be regarded as a human carcinogen causing glioma.

scholarly journals Case-Control Study on Occupational Exposure to Extremely Low-Frequency Electromagnetic Fields and the Association with Meningioma

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Michael Carlberg ◽  
Tarmo Koppel ◽  
Mikko Ahonen ◽  
Lennart Hardell
Keyword(s):  
Electromagnetic Fields ◽  
Childhood Leukemia ◽  
Linear Trend ◽  
Low Frequency ◽  
Case Control ◽  
Cumulative Exposure ◽  
International Agency ◽  
Case Control Studies ◽  
Extremely Low Frequency ◽  
Increased Risk

Objective. Exposure to extremely low-frequency electromagnetic fields (ELF-EMF) was in 2002 classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO based on an increased risk for childhood leukemia. In case-control studies on brain tumors during 1997–2003 and 2007–2009 we assessed lifetime occupations in addition to exposure to different agents. The INTEROCC ELF-EMF Job-Exposure Matrix was used for associating occupations with ELF-EMF exposure (μT) with meningioma. Cumulative exposure (μT-years), average exposure (μT), and maximum exposed job (μT) were calculated. Results. No increased risk for meningioma was found in any category. For cumulative exposure in the highest exposure category 8.52+ μT years odds ratio (OR) = 0.9, 95% confidence interval (CI) = 0.7–1.2, and p linear trend = 0.45 were calculated. No statistically significant risks were found in different time windows. Conclusion. In conclusion occupational ELF-EMF was not associated with an increased risk for meningioma.

scholarly journals Association between early bronchiolitis and the development of childhood asthma: a meta-analysis

BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e043956
Author(s):  
Guizuo Wang ◽  
Dong Han ◽  
Zhengdong Jiang ◽  
Manxiang Li ◽  
Shumei Yang ◽  
...  
Keyword(s):  
Early Life ◽  
Fixed Effects ◽  
Late Onset ◽  
Meta Analysis ◽  
Later Life ◽  
Analysis Data ◽  
Fixed Effects Model ◽  
Case Control Studies ◽  
Increased Risk ◽  
Registration Number

ObjectiveEarly life bronchiolitis has been hypothesised to be associated with the subsequent risk of persistent wheezing or asthma. However, the link remains controversial. The objective of our study was to evaluate the association between bronchiolitis before 2 years of age and the late-onset wheezing/asthma.DesignSystematic review and meta-analysis.MethodsPubMed, Embase and Web of Science databases were systematically searched for studies published between 1955 and January 2020. Meanwhile, we also checked through the reference lists of relevant articles to see whether these references included reports of other studies that might be eligible for the review. Cohort and case–control studies assessing the association between early-life bronchiolitis and late-onset wheezing/asthma were included in this meta-analysis. Data were extracted by two independent reviewers. Results were pooled using a random-effects model or fixed-effects model according to the heterogeneity among studies.Results32 original articles with 292 844 participants, which met the criteria, were included in this meta-analysis. Bronchiolitis before 2 years of age was associated with an increased risk of subsequent wheezing/asthma (relative risk=2.46, 95% CI 2.14 to 2.82, p<0.001). After categorising studies into different groups based on age at the end of follow-up, geographical region and study quality, the association still remained significant.ConclusionsThe meta-analysis indicates an association between bronchiolitis before 2 years of age and the wheezing/asthma in later life. Well-designed and highly standardised prospective studies that better address bias due to potential confounding factors are needed to validate the risk identified in our meta-analysis.PROSPERO registration numberCRD42018089453.

scholarly journals Association of dyslipidemia with the severity and mortality of coronavirus disease 2019 (COVID-19): a meta-analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yanli Liu ◽  
Yilong Pan ◽  
Yuyao Yin ◽  
Wenhao Chen ◽  
Xiaodong Li
Keyword(s):  
Fixed Effects ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Case Control Studies ◽  
Risk Of Death ◽  
Potential Association ◽  
Increased Risk ◽  
Language Restriction ◽  
Newcastle Ottawa Scale

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.

scholarly journals Associations of CTLA4 Gene Polymorphisms with Graves’ Ophthalmopathy: A Meta-Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Pengfei Du ◽  
Xiaojie Ma ◽  
Changjiang Wang
Keyword(s):  
Genetic Model ◽  
Meta Analysis ◽  
Case Control Studies ◽  
Graves Ophthalmopathy ◽  
Increased Risk ◽  
Exon 1 ◽  
Ctla4 Gene ◽  
Relationship Of ◽  
The Relationship ◽  
Susceptible Gene

Many studies have established that T-lymphocyte antigen-4 (CTLA4) is a susceptible gene for Graves’ disease (GD). Also many studies showed the association between the CTLA4 exon-1 49A/G polymorphism and the risk of developing Graves’ ophthalmopathy (GO) in GD patients. But those results were inconsistent. In recent years many new studies were published which helped to shed light on the relationship of CTLA4 SNP49 with GO. So we performed the meta-analysis to explore the association between the SNP49 and GO susceptibility in GD patients. Studies up to February 29, 2012, were searched by using PubMed. The odds ratio was used to evaluate the strength of the association. Altogether 12 case-control studies involving 2,505 participants were included in the meta-analysis. Results showed that the G allele was related to the increased risk of GO compared with the A allele under allelic genetic model (OR = 1.14, 95% CI: 1.14–1.72,P=0.001) in European subgroup. No publication bias was detected. Our results showed that the SNP49 polymorphism of CTLA4 gene was related to increased risk of GO.

scholarly journals Relevance of hMLH1 -93G>A, 655A>G and 1151T>A polymorphisms with colorectal cancer susceptibility: a meta-analysis based on 38 case-control studies

2018 ◽  
Vol 64 (10) ◽  
pp. 942-951 ◽  
Author(s):  
Mohammad Zare ◽  
Jamal Jafari-Nedooshan ◽  
Mohammadali Jafari ◽  
Hossein Neamatzadeh ◽  
Seyed Mojtaba Abolbaghaei ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Susceptibility ◽  
Meta Analysis ◽  
Asian Population ◽  
Case Control ◽  
Biomedical Literature ◽  
Case Control Studies ◽  
Increased Risk ◽  
Comprehensive Search ◽  
Meta Analyses

SUMMARY OBJECTIVE: There has been increasing interest in the study of the association between human mutL homolog 1 (hMLH1) gene polymorphisms and risk of colorectal cancer (CRC). However, results from previous studies are inconclusive. Thus, a meta-analysis was conducted to derive a more precise estimation of the effects of this gene. METHODS: A comprehensive search was conducted in the PubMed, EMBASE, Chinese Biomedical Literature databases until January 1, 2018. Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the association. RESULTS: Finally, 38 case-control studies in 32 publications were identified met our inclusion criteria. There were 14 studies with 20668 cases and 19533 controls on hMLH1 −93G>A, 11 studies with 5,786 cases and 8,867 controls on 655A>G and 5 studies with 1409 cases and 1637 controls on 1151T>A polymorphism. The combined results showed that 655A>G and 1151T>A polymorphisms were significantly associated with CRC risk, whereas −93G>A polymorphism was not significantly associated with CRC risk. As for ethnicity, −93G>A and 655A>G polymorphisms were associated with increased risk of CRC among Asians, but not among Caucasians. More interestingly, subgroup analysis indicated that 655A>G might raise CRC risk in PCR-RFLP and HB subgroups. CONCLUSION: Inconsistent with previous meta-analyses, this meta-analysis shows that the hMLH1 655A>G and 1151T>A polymorphisms might be risk factors for CRC. Moreover, the −93G>A polymorphism is associated with the susceptibility of CRC in Asian population.

scholarly journals Oral Contraceptive Use and Breast Cancer Risk Assessment: A Systematic Review and Meta-Analysis of Case-Control Studies, 2009–2020

Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5654
Author(s):  
Agnieszka Barańska ◽  
Agata Błaszczuk ◽  
Wiesław Kanadys ◽  
Maria Malm ◽  
Katarzyna Drop ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Oral Contraceptive ◽  
Cancer Risk ◽  
Meta Analysis ◽  
Case Control ◽  
Cochrane Library ◽  
Control Group ◽  
Case Control Studies ◽  
Increased Risk ◽  
Breast Cancer Risk Assessment

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.

scholarly journals Association of XPC Polymorphisms with Cutaneous Malignant Melanoma Risk: Evidence from a Meta-Analysis

2020 ◽  
Vol 63 (3) ◽  
pp. 101-112
Author(s):  
Fatemeh Asadian ◽  
Seyed Mohammadreza Niktabar ◽  
Yaser Ghelmani ◽  
Shadi Kargar ◽  
Elahe Akbarian ◽  
...  
Keyword(s):  
Malignant Melanoma ◽  
Meta Analysis ◽  
Complementation Group ◽  
Cutaneous Malignant Melanoma ◽  
Case Control Studies ◽  
Melanoma Risk ◽  
Pooled Data ◽  
Increased Risk ◽  
Pcr Rflp ◽  
Rflp Assay

Background: A number of studies have reported that the xeroderma pigmentosum complementation group C (XPC) polymorphisms are associated with cutaneous malignant melanoma (CMM) susceptibility. But the results of those studies were inconsistent. Here, we performed a study to obtain a more conclusive result on the association of XPC polymorphisms with risk of CMM. Methods: The XPC Lys939Gln and Ala499Val polymorphisms were genotyped in 150 CMM cases and 150 controls by PCR-RFLP assay. Subsequently, all published relevant studies were identified through a comprehensive literature search in PubMed, Web of Science, and CNKI databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of correlation. Results: There was no significant association between XPC Lys939Gln and Ala499Val polymorphisms and CMM risk in our population. A total of 15 case-control studies including ten studies with 5,990 cases and 7,697 controls on XPC Lys939Gln and five studies with 3,139 cases and 3,721 controls on XPC Ala499Val polymorphism were selected. Pooled data revealed that XPC Lys939Gln (C vs. A: OR = 1.108, 95% CI 1.008– 1.217; P = 0.033) and Ala499Val (C vs. A: OR = 0.918, 95% CI 0.850–0.992; p = 0.031; CC+CA vs. AA: OR = 0.904, 95% CI 0.819–0.997; p = 0.043) polymorphisms were significantly associated with an increased risk of CMM. Moreover, stratified analyses by ethnicity revealed that the XPC Ala499Val and Lys939Gln polymorphisms were significantly associated with risk of CMM in Caucasians and mixed populations, respectively. Conclusions: This meta-analysis result suggested that XPC Lys939Gln and Ala499Val polymorphisms were significantly associated with risk of CMM.

scholarly journals ASSOCIATION OF IL-8 -251T>A (RS4073) POLYMORPHISM WITH SUSCEPTIBILITY TO GASTRIC CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS BASED ON 33 CASE-CONTROL STUDIES

2020 ◽  
Vol 57 (1) ◽  
pp. 91-99
Author(s):  
Mansour MOGHIMI ◽  
Seyed Alireza DASTGHEIB ◽  
Naeimeh HEIRANIZADEH ◽  
Mohammad ZARE ◽  
Elnaz SHEIKHPOUR ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Meta Analysis ◽  
Random Effect ◽  
Random Effect Model ◽  
Case Control ◽  
Case Control Studies ◽  
Effect Model ◽  
Increased Risk ◽  
Mixed Populations ◽  
Stratified Analysis

ABSTRACT BACKGROUND: The role of -251A>T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene in gastric cancer was intensively evaluated, but the results of these studies were inconsistent. OBJECTIVE: Therefore, we performed a meta-analysis to provide a comprehensive data on the association of IL-8 -251T>A polymorphism with gastric cancer. METHODS: All eligible studies were identified in PubMed, Web of Science, EMBASE, Wanfang and CNKI databases before September 01, 2019. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. RESULTS: A total of 33 case-control studies with 6,192 cases and 9,567 controls were selected. Overall, pooled data showed that IL-8 -251T>A polymorphism was significantly associated with an increased risk of gastric cancer under all five genetic models, i.e., allele (A vs T: OR=1.189, 95% CI 1.027-1.378, P=0.021), homozygote (AA vs TT: OR=1.307, 95% CI 1.111-1.536, P=0.001), heterozygote (AT vs TT: OR=1.188, 95% CI 1.061-1.330, P=0.003), dominant (AA+AT vs TT: OR=1.337, 95% CI 1.115-1.602, P=0.002) and recessive (AA vs AT+TT: OR=1.241, 95% CI 1.045-1.474, P=0.014). The stratified analysis by ethnicity revealed an increased risk of gastric cancer in Asians and mixed populations, but not in Caucasians. Moreover, stratified by country found a significant association in Chinese, Korean and Brazilian, but not among Japanese. CONCLUSION: This meta-analysis suggests that the IL-8 -251T>A polymorphism is associated with an increased risk of gastric cancer, especially by ethnicity (Asian and mixed populations) and country (Chinese, Korean and Brazilian).

scholarly journals Hypertension and the risk of endometrial cancer: a systematic review and meta-analysis of case-control and cohort studies

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Dagfinn Aune ◽  
Abhijit Sen ◽  
Lars J. Vatten
Keyword(s):  
Systematic Review ◽  
Endometrial Cancer ◽  
Cohort Studies ◽  
Contraceptive Use ◽  
Meta Analysis ◽  
Case Control ◽  
Adjusted Relative Risk ◽  
Case Control Studies ◽  
Relative Risks ◽  
Increased Risk

Abstract A history of hypertension has been associated with increased risk of endometrial cancer in several studies, but the results have not been consistent. We conducted a systematic review and meta-analysis of case-control and cohort studies to clarify the association between hypertension and endometrial cancer risk. PubMed and Embase databases were searched up to 27th of February 2016. Prospective and case-control studies which reported adjusted relative risk estimates and 95% confidence intervals of endometrial cancer associated with a hypertension diagnosis were included. Summary relative risks were estimated using a random effects model. Nineteen case-control studies and 6 cohort studies were included. The summary RR was 1.61 (95% CI: 1.41–1.85, I2 = 86%) for all studies, 1.73 (95% CI: 1.45–2.06, I2 = 89%) for case-control studies and 1.32 (95% CI: 1.12–1.56, I2 = 47%) for cohort studies. The association between hypertension and endometrial cancer was weaker, but still significant, among studies with adjustment for smoking, BMI, oral contraceptive use, and parity, compared to studies without such adjustment. This meta-analysis suggest an increased risk of endometrial cancer among patients with hypertension, however, further studies with more comprehensive adjustments for confounders are warranted to clarify the association.

scholarly journals The correlation between methylenetetrahydrofolate reductase gene 677C > T polymorphism and fetal congenital defects: A meta-analysis

Pteridines ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 9-17
Author(s):  
Dexia Li ◽  
Enxia Wang ◽  
Xia Gao ◽  
Ping Li
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Publication Bias ◽  
Methylenetetrahydrofolate Reductase ◽  
Meta Analysis ◽  
Random Effect ◽  
Congenital Defects ◽  
Nucleotide Polymorphism ◽  
Case Control Studies ◽  
Single Nucleotide ◽  
Increased Risk

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.

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