Meta-Analysis of Case-Control and Family-Based Associations Between the 5-HTTLPR L/S Polymorphism and Susceptibility to ADHD

2015 ◽  
Vol 22 (9) ◽  
pp. 901-908 ◽  
Author(s):  
Young Ho Lee ◽  
Gwan Gyu Song

Objective: The aim of this study was to determine whether the serotonin transporter-linked polymorphic region (5-HTTLPR) L (long)/S (short) polymorphism is associated with susceptibility to ADHD. Method: We conducted a meta-analysis of case-control associations and the transmission disequilibrium test (TDT) between the 5-HTTLPR L/S polymorphism and ADHD. Results: A total of 19 comparison studies were included in this meta-analysis. Our meta-analysis of the case-control studies showed no association between ADHD and the 5-HTTLPR S allele, for all study participants (odds ratio [OR] = 1.075, 95% confidence interval [CI] = [0.990, 1.167], p = .085), or for the European or Asian population. The TDT indicated no association between ADHD and the 5-HTTLPR S allele, for all study participants (OR = 1.078, 95% CI = [0.962, 1.207], p = .196). Conclusion: This meta-analysis of case-control studies and TDT showed a lack of association between the 5-HTTLPR L/S polymorphism and ADHD.

2019 ◽  
Author(s):  
Kamyar Mansori ◽  
Yousef Moradi ◽  
Sara Naderpour ◽  
Roya Rashti ◽  
Ali Baradaran Moghaddam ◽  
...  

Abstract Background Results of previous studies were showed that the association between H. pylori infection and the risk of diabetes is still controversies. Therefore, this systematic review and meta-analysis study was designed and implemented aimed to determine the association between H. pylori infection and the risk of diabetes.Methods All case control articles were searched in international databases, including Medline (PubMed), Web of sciences, Scopus, EMBASE, and CINHAL. Search was done from January 1990 to March 2019 without language limitations. Also, logarithm and standard error logarithm odds ratio (OR) were used for meta-analysis.Results A total of 41 studies were included in this meta-analysis. The range of association with odds ratio in case control studies which published between 1990 to 2019 was 0.21 to 6.08. The pooled estimate of the association between H. pylori infection with diabetes was 1.27 (95% CI 1.11 to 1.45, P = 0.0001, I 2 = 86.6%). The effect of H. pylori infection on diabetes mellitus, type 1 and type 2 diabetes was 1.17 (95% CI 0.94 to 1.45), 1.19 (95% CI 0.98 to 1.45), and 1.43 (95% CI 1.11 to 1.85) respectively. Subgroup analysis by the geographical regions showed in Asian population risk of the effect of H. pylori infection on diabetes was higher than other population, but in the American, this was a protective relationship.Conclusion In conclusion, this systematic review & meta-analysis study suggested that H. pylori infection was associated with the risk of diabetes as compared to non- diabetes individual.


2020 ◽  
Author(s):  
Kamyar Mansori ◽  
Yousef Moradi ◽  
Sara Naderpour ◽  
Roya Rashti ◽  
Ali Baradaran Moghaddam ◽  
...  

Abstract Background There are several studies with varied and mixed results about the possible relationship between H. pylori and diabetes. Therefore, this current meta-analysis performed to determine the association between H. pylori infection and the risk of diabetes mellitus. Methods A systematic literature searches of international databases, including Medline (PubMed), Web of Sciences, Scopus, EMBASE, and CINHAL (January 1990–March 2019) was conducted to identify studies investigating the relationship between H. pylori infection and diabetes mellitus. Only case–control studies were analyzed using odds ratio (OR) with 95 % confidence intervals (CIs). Stratified and subgroup analyses were performed to explore heterogeneity between studies and assess effects of study quality. Logarithm and standard error logarithm odds ratio (OR) were also used for meta-analysis. Results A total of 41 studies involving 9559 individuals (case; 4327 and control; 5232) were analyzed. The pooled estimate of the association between H. pylori infection with diabetes was OR=1.27 (95% CI 1.11 to 1.45, P = 0.0001, I2 = 86.6%). The effect of H. pylori infection on diabetes mellitus (both types), type 1 and type 2 diabetes was 1.17 (95% CI 0.94 to 1.45), 1.19 (95% CI 0.98 to 1.45), and 1.43 (95% CI 1.11 to 1.85) respectively. Subgroup analysis by the geographical regions showed in Asian population risk of the effect of H. pylori infection on diabetes was slightly higher than other population.Conclusion In overall a positive association between H. pyloriinfection and diabetes mellitus was found.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ali Baradaran ◽  
Hojat Dehghanbanadaki ◽  
Sara Naderpour ◽  
Leila Mohammadi Pirkashani ◽  
Abdolhalim Rajabi ◽  
...  

Abstract Introduction The relationship between H. pylori infection and obesity development has remained controversial among various studies. The aim of this study was to clarify the pooled effect of H. pylori infection on the development of obesity and vice versa. Methods We searched international databases including Medline (PubMed), Web of sciences, Scopus, EMBASE, Cochrane, Ovid, and CINHAL to retrieve all case–control studies reporting the effect of H. pylori on obesity and vice versa, which had been published in English between January 1990 and June 2019. The quality of included studies was assessed by the Modified Newcastle–Ottawa Scale for Case–Control studies. The logarithm of the odds ratio (OR) and its standard error was used for the meta-analysis. Results Eight case–control studies with 25,519 participants were included for qualitative and quantitative analyses. The pooled analysis showed that obese participants had a higher risk of H. pylori infection than lean participants with an odds ratio of 1.46 (95%CI: 1.26, 1.68). Also, the pooled analysis revealed that participants infected by H. pylori had a higher risk of obesity than non-infected participants with an odds ratio of 1.01 (95%CI: 1.01, 1.02). Conclusion The results of this meta-analysis showed that there was a positive correlation between the risk of H. pylori infection and the prevalence of obesity development. Thus, H. pylori positive patients were more likely to be obese, and obese individuals had higher risks of H. pylori infection.


2018 ◽  
Vol 64 (10) ◽  
pp. 942-951 ◽  
Author(s):  
Mohammad Zare ◽  
Jamal Jafari-Nedooshan ◽  
Mohammadali Jafari ◽  
Hossein Neamatzadeh ◽  
Seyed Mojtaba Abolbaghaei ◽  
...  

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.


2021 ◽  
Author(s):  
Mobin Azami ◽  
Hamid Reza Baradaran ◽  
Parisa Kohnepoushi ◽  
Lotfolah Saed ◽  
Asra Moradkhani ◽  
...  

Abstract Background Conflicting results of recent studies on the association between Helicobacter pylori (H. pylori) infection and the risk of insulin resistance and metabolic syndrome explored the need for updated meta-analysis on this issue. Therefore, this systematic review aimed to estimate the pooled effect of H. pylori infection on the risk of insulin resistance and metabolic syndrome. Methods To identify case-control studies and cohort studies evaluating the association of H. pylori infection with insulin resistance and metabolic syndrome, a comprehensive literature search was performed from international databases including Medline (PubMed), Web of Sciences, Scopus, EMBASE, and CINHAL from January 1990 until January 2021. We used odds ratio with its 95% confidence interval (95%CI) to quantify the effect of case-control studies and risk ratio with its 95%CI for the effect of cohort studies. Results 22 studies with 206911 participants were included for meta-analysis. The pooled estimate of odds ratio between H. pylori infection and metabolic syndrome in case-control studies was 1.19 (95%CI: 1.05, 1.35; I2 = 0%), and in cohort studies, the pooled risk ratio was 1.31 (95%CI: 1.13, 1.51; I2 = 0%). Besides, case-control studies showed the pooled odds ratio of 1.54 (95%CI: 1.19, 1.98; I2 = 6.88%) for the association between H. pylori infection and insulin resistance. Conclusion A positive association was found between H. pylori infection and insulin resistance as well as metabolic syndrome, so planning to eliminate or eradicate H. pylori infection could be an effective solution to improve metabolic syndrome or insulin resistance, and vice versa.


Gene ◽  
2018 ◽  
Vol 678 ◽  
pp. 370-376 ◽  
Author(s):  
Abdolkarim Moazeni-Roodi ◽  
Gholamreza Bahari ◽  
Mohsen Taheri ◽  
Hossein Ansari ◽  
Mohammad Hashemi

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 471
Author(s):  
B. Krishna ◽  
Samir Jana ◽  
Aditya Panda ◽  
David Horne ◽  
Sanjay Awasthi ◽  
...  

Reports on the association of TGF-β1 polymorphisms with breast cancer (BC) have been conflicting, inconsistent, inconclusive, and controversial. PubMed, EMBASE, and Google Scholar were used to identify studies on TGF-β1 polymorphisms and BC risk. Data were extracted independently, and of the initial 3043 studies, 39 case-control studies were eligible for inclusion in the meta-analysis. Information from these studies was extracted, and the overall associations of three TGF-β1 polymorphisms (TGF-β1 29>T/C, TGF-β1-509 C/T, and TGF-β1*6A) with BC risk were analyzed using overall allele, homozygous, heterozygous, recessive, and dominant models. None of the three TGF-β1 polymorphisms studied had a significant influence on the development of BC. However, stratified analysis revealed a positive correlation between the TGF-β1 29T>C polymorphism and BC risk according to a heterozygous model of the Asian population (odds ratio (OR) = 1.115, 95% confidence interval (CI) = 1.006–1.237, p = 0.039). Interestingly, this polymorphism was associated with lower odds of BC according to a heterozygous model of the Middle Eastern population (OR = 0.602, 95% CI = 0.375–0.966, p = 0.035). Thus, our analysis of large datasets indicates that the TGF-β1 29T>C polymorphism is significantly associated with BC risk in the Asian population. In contrast, the TGF-β1*6A and TGF-β1-509 C/T polymorphisms failed to show an association with BC.


2009 ◽  
Vol 27 (33) ◽  
pp. 5565-5572 ◽  
Author(s):  
Seung-Kwon Myung ◽  
Woong Ju ◽  
Diana D. McDonnell ◽  
Yeon Ji Lee ◽  
Gene Kazinets ◽  
...  

Purpose Case-control studies have reported inconsistent findings regarding the association between mobile phone use and tumor risk. We investigated these associations using a meta-analysis. Methods We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library in August 2008. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. Results Of 465 articles meeting our initial criteria, 23 case-control studies, which involved 37,916 participants (12,344 patient cases and 25,572 controls), were included in the final analyses. Compared with never or rarely having used a mobile phone, the odds ratio for overall use was 0.98 for malignant and benign tumors (95% CI, 0.89 to 1.07) in a random-effects meta-analysis of all 23 studies. However, a significant positive association (harmful effect) was observed in a random-effects meta-analysis of eight studies using blinding, whereas a significant negative association (protective effect) was observed in a fixed-effects meta-analysis of 15 studies not using blinding. Mobile phone use of 10 years or longer was associated with a risk of tumors in 13 studies reporting this association (odds ratio = 1.18; 95% CI, 1.04 to 1.34). Further, these findings were also observed in the subgroup analyses by methodologic quality of study. Blinding and methodologic quality of study were strongly associated with the research group. Conclusion The current study found that there is possible evidence linking mobile phone use to an increased risk of tumors from a meta-analysis of low-biased case-control studies. Prospective cohort studies providing a higher level of evidence are needed.


Author(s):  
Sharon A. Warren ◽  
Susan Armijo Olivo ◽  
Jorge Fuentes Contreras ◽  
Karen V. L. Turpin ◽  
Douglas P. Gross ◽  
...  

A systematic review/meta-analysis of literature addressing a possible association between traumatic injury and onset of multiple sclerosis was conducted. Medline, Embase, Cochrane DSR, Ovid HealthStar, CINAHL, ISI Web of Science and Scopus were searched for analytical studies from 1950 to 2011. Two investigators independently reviewed articles for inclusion, assessing their quality using the Newcastle-Ottawa Scale. Of the 13 case-control studies included, 8 were moderate quality and 5 low; of the 3 cohort studies 2 were high and 1 moderate. Meta-analysis including moderate and low quality case-control studies produced a modest but significant odds ratio: 1.41 (95% confidence interval: 1.03, 1.93). However, when low quality studies were excluded, the resulting odds ratio was non-significant. Cohort studies produced a non-significant standardized incidence ratio of 1.00 (95% confidence interval: 0.86, 1.16). These findings support the conclusion that there is no association between traumatic injury and multiple sclerosis onset; more high quality cohort studies would help to confirm this observation.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yuen-Fann Ng ◽  
Ebonne Ng ◽  
Ee-Wei Lim ◽  
Kumar M. Prakash ◽  
Louis C. S. Tan ◽  
...  

AbstractWe evaluate the association of hypertension with PD in an Asian population and performed a meta-analysis on similar studies to address the effect of hypertension on PD risk. A matched case-control study involving 1342 Chinese subjects (671 PD and 671 age and gender-matched controls (with a mean age of 63.9 ± 9.7 and 63.5 ± 9.8 years, and identical proportion of gender distribution) was conducted. Hypertension increases PD risk by 1.9 times [OR 1.86 (1.46–2.38)]. The literature search identified 618 studies initially; however, only three matched case-control studies (all in Caucasians) met the inclusion criteria for meta-analysis. Overall analysis showed that hypertension decreases PD risk by 0.2 times [OR 0.80 (0.66–0.96)]. Hypertension increases PD risk by 1.9 times in our Asian population. However, a meta-analysis comprising of Caucasian populations showed a protective effect of hypertension suggesting that ethnic differences or other genetic or environmental factors may contribute to the divergent observation. Early diagnosis and treatment of hypertension may potentially reduce the risk of PD, at least in our population.


Sign in / Sign up

Export Citation Format

Share Document