SELP genetic polymorphisms may contribute to the pathogenesis of coronary heart disease and myocardial infarction: a meta-analysis

We conducted a meta-analysis of case–control studies to determine whether SELP genetic polymorphisms contribute to the pathogenesis of coronary heart disease (CHD) and myocardial infarction (MI). A range of electronic databases were searched: MEDLINE (1966–2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980–2013), CINAHL (1982–2013), Web of Science (1945–2013) and the Chinese biomedical database (1982–2013) without language restrictions. Meta-analysis was performed with the use of the STATA statistical software. Nine case–control studies with a total of 3,154 CHD patients, 1,608 MI patients and 17,304 healthy controls were involved in this meta-analysis. Six common polymorphisms in the SELE gene were assessed, including ?1969G/A (rs1800805 G > A), ?1817T/C (rs1800808 T > C), ?2123C/G (rs1800807 C > G), Thr715Pro (rs6136 A > C), Leu599Val (rs6133 G > T), and Ser290Asn (rs6131 C > T). Our findings illustrated significantly positive associations of SELE genetic polymorphisms with the development of CHD and MI. The results of subgroup analysis by SNP type indicated that ?1969G/A, ?1817T/C, ?2123C/G, Thr715Pro and Ser290Asn in the SELP gene might be strongly correlated with CHD and MI risk, but no similar results were found in SELP Leu599Val polymorphism. In the subgroup analysis by ethnicity, our results indicated significant relationships between SELE genetic polymorphisms and the pathogenesis of CHD and MI among Asians and Caucasians. However, we observed no significant associations between SELP genetic polymorphisms and the risk of CHD and MI among Africans. Our findings provide empirical evidence that SELE genetic polymorphisms may contribute to the pathogenesis of CHD and MI, especially among Asians and Caucasians. Thus, SELP genetic polymorphisms could be potential and practical biomarkers for early diagnosis of CHD and MI.     

Correlations of SELE genetic polymorphisms with risk of coronary heart disease and myocardial infarction: a meta-analysis

This meta-analysis of case–control studies was conducted to determine whether SELE genetic polymorphisms contribute to the pathogenesis of coronary heart disease (CHD) and myocardial infarction (MI). The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1st, 2013 without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Twenty case–control studies met the inclusion criteria, with a total of 2,292 CHD patients, 901 MI patients and 3,233 healthy controls. Six common polymorphisms in the SELE gene were evaluated, including 554L/F, 98G/T, 128S/R, 2692G/A, 1901C/T, and 1856A/G. The results of our meta-analysis suggest that SELE genetic polymorphisms might be strongly correlated with an increased risk of CHD (allele model: OR 2.08, 95 % CI 1.67–2.58, P < 0.001; dominant model: OR 2.12, 95 % CI 1.68–2.68, P < 0.001; respectively), especially the SELE 554L/F, 98G/T and 128S/R polymorphisms. Furthermore, our findings indicated that SELE genetic polymorphisms were closely linked to the risk of CHD in Asians but not Caucasians. However, our findings reveal no positive correlations between SELE genetic polymorphisms and MI risk (allele model: OR 1.39, 95 % CI 1.00–1.94, P = 0.054; dominant model: OR 1.40, 95 % CI 0.96–2.04, P = 0.081; respectively). The current meta-analysis suggests that SELE genetic polymorphisms may contribute to an increased risk of CHD, especially the SELE 554L/F, 98G/T and 128S/R polymorphisms in Asians. However, SELE genetic polymorphisms may not be important determinants of susceptibility to MI.     

Genetic polymorphisms in the CYP1A1 and CYP1B1 genes and susceptibility to bladder cancer: a meta-analysis

The current meta-analysis of case–control studies was conducted to evaluated the relationships of genetic polymorphisms in the CYP1A1 and CYP1B1 genes with the susceptibility to bladder cancer, aiming at determine whether these polymorphisms may contribute to the pathogenesis of bladder cancer. Related articles were determined via searching the following electronic databases without any language restrictions: PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases for relevant articles published before November 1st, 2013. STATA 12.0 software was also selected to deal with statistical data. The relationships were evaluated using the pooled odds ratios (ORs) and their 95 % confidence intervals (CI). Eleven case–control studies with a total of 2,609 bladder cancer patients and 2,634 healthy subjects met the inclusion criteria. The results of our meta-analysis demonstrated that CYP1A1 genetic polymorphisms were associated with increased risks of bladder cancer (allele model: RR = 1.18, 95 % CI 1.07–1.30, P = 0.001; dominant model: RR = 1.15, 95 % CI 1.05–1.27, P = 0.003; respectively), especially among 11599G>C, 2455A>G, 3810T>C, and 113T>C polymorphisms. A subgroup analysis by ethnicity was conducted to investigate its effect on susceptibility to bladder cancer. The subgroup analysis results revealed positive significant correlations between CYP1A1 genetic polymorphisms and bladder cancer risk among Asians (allele model: RR = 1.26, 95 % CI 1.10–1.44, P = 0.001; dominant model: RR = 1.22, 95 % CI 1.08–1.38, P = 0.001), but not among Caucasians (all P < 0.05). Nevertheless, we observed no significant correlations between CYP1B1 genetic polymorphisms and bladder cancer risk (all P > 0.05). Our meta-analysis indicates that CYP1A1 genetic polymorphisms may be involved in the pathogenesis of bladder cancer, especially among 11599G>C, 2455A>G, 3810T>C, and 113T>C polymorphisms. However, CYP1B1 genetic polymorphisms may not be important determinants of bladder cancer susceptibility.     

Relationships of LDLR genetic polymorphisms with cerebral infarction: a meta-analysis

This meta-analysis was undertaken to identify the relationships between genetic polymorphisms in the LDLR gene and the risk of cerebral infarction. The Web of Science (1945–2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966–2013), EMBASE (1980–2013), CINAHL (1982–2013) and the Chinese Biomedical Database (CBM) (1982–2013) were searched for relevant articles without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratios (OR) with their corresponding 95 % confidence interval (CI) were calculated. Eight case–control studies with a total of 4,655 patients with cerebral infarction and 15,920 healthy control subjects were included in our meta-analysis. Five common polymorphisms in the LDLR gene were evaluated, including rs11669576 A > T, rs1433099 C > T, rs5925 C > T, rs688 C > T, rs1122608 T > G in the LDLR gene. The results of this meta-analysis revealed that cerebral infarction patients had a higher frequency of LDLR genetic polymorphisms than that of healthy controls (allele model: OR 1.17, 95 % CI 1.05–1.30, P = 0.004; dominant model: OR 1.18, 95 % CI 1.05–1.33, P = 0.007; homozygous model: OR 1.50, 95 % CI 1.03–2.16, P = 0.032; respectively), especially for the rs11669576 A > T, rs1433099 C > T and rs5925 C > T polymorphisms. Among different ethnic subgroups, the results demonstrated positive correlations between LDLR genetic polymorphisms and an increased risk of cerebral infarction among both Asians and Caucasians under the allele and dominant models (all P < 0.05). Our findings indicate that LDLR genetic polymorphisms may be strongly involved in the pathogenesis of cerebral infarction, especially the rs11669576 A > T, rs1433099 C > T, rs5925 C > T polymorphisms.     

Common genetic variants (rs4779584 and rs10318) at 15q13.3 contributes to colorectal adenoma and colorectal cancer susceptibility: evidence based on 22 studies

Several genome-wide association studies on colorectal cancer (CRC) have reported similar findings of a new susceptibility locus, 15q13.3. After that, a number of studies have reported that the rs4779584 and rs10318 polymorphisms at chromosome 15q13.3 have been implicated in CRC and colorectal adenoma (CRA) risk; however, these studies have yielded inconsistent results. To investigate this inconsistency, we performed a meta-analysis of 22 studies involving a total of 48,468 CRC cases, 4,189 CRA cases, and 85,105 controls for the two polymorphisms to evaluate its effect on genetic susceptibility for CRC/CRA. Potential sources of heterogeneity and publication bias were also systematically explored. Overall, the summary odds ratio (OR) of rs4779584-T variant for CRC was 1.13 (95 % CI 1.09–1.16, P < 10^?5) and 1.15 (95 % CI 1.04–1.28, P = 0.006) for CRA. After stratified by ethnicity, significantly increased CRC risks were found for rs4779584 polymorphism among East Asians and Caucasians, while no significant associations were detected among African American and other ethnic populations. A meta-analysis of studies on the rs10318 polymorphism also showed significant overall association with CRC, yielding a per-allele OR of 1.13 (95 % CI 1.02–1.24, P = 0.02). In the subgroup analysis by ethnicity, significantly increased CRC risks were found in Caucasians; whereas no significant associations were found among East Asians and African Americans. This meta-analysis demonstrated that the rs4779584 and rs10318 polymorphism at 15q13.3 is a risk factor associated with increased CRC/CRA susceptibility, but these associations vary in different ethnic populations.     

Association of A561C and G98T Polymorphisms in E-Selectin Gene with Coronary Artery Disease: A Meta-Analysis

Objective

E-selectin (SELE) mediates the rolling and adhesion of leukocytes on activated endothelial cells and plays a critial role in the pathogenesis of coronary artery disease (CAD). Associatons between the A561C and G98T polymorphisms of the SELE gene and CAD risk were investigated broadly, but the results were inconsistent. In the present study, we performed a meta-analysis to systematically evaluate the associations between the two polymorphisms and the risk of CAD.

Methods

Comprehensive research was conducted to identify relevant studies. The fixed or random effect model was selected based on the heterogeneity among studies, which was evaluated with Q-test and Ι². Meta-regression was used to explore the potential sources of between-study heterogeneity. Peters''s linear regression test was used to estimate the publication bias.

Results

Overall, 24 articles involving 3694 cases and 3469 controls were included. After excluding articles deviating from Hardy–Weinberg equilibrium in controls and sensitive analysis, our meta-analysis showed a significant association between the A561C ploymprphism and CAD in dominant (OR  = 1.84, 95% CI  = 1.56–2.16) and codominant (OR  = 1.74, 95% CI  = 1.49–2.03) models. As for the G98T polymorphism, significantly increased CAD risk was observed in dominant (OR  = 1.47, 95% CI  = 1.16–1.87) and codominant (OR  = 1.48, 95% CI  = 1.18–1.86) models, but after subgroup analysis, the association was not significant among Caucasians in dominant (OR  = 1.58, 95% CI  = 0.73–3.41) and codominant (OR  = 1.58, 95% CI  = 0.79–3.20) models.

Conclusions

Despite some limitations, our meta-analysis suggested that the SELE gene polymorphisms (A561C, G98T) were significantly associated with increased risk of CAD. However, after subgroup analysis no significant association was found among Caucasians for the G98T polymorphism, which may be due to the small sample size and other confounding factors. Future investigations with multicenter, large-scale, and multi-ethnic groups are needed.     

Slow N-acetyltransferase 2 genotype contributes to anti-tuberculosis drug-induced hepatotoxicity: a meta-analysis

Pathogenesis and genetic factors influencing predisposition to antituberculosis drug-induced hepatotoxicity (ATDH) are not clear. Polymorphism at the genetic locus of a drug and xenobiotic compound metabolizing enzyme, N-acetyltransferase type 2 (NAT2), is reported to be associated with the excess generation of toxic reactive metabolites. To date, many case–control studies have been carried out to investigate the relationship between the NAT2 polymorphisms and ATDH, but the results have been inconsistent. To investigate this inconsistency, a meta-analysis was performed. Databases including PubMed, Web of Science, EMBASE and CNKI were searched to find relevant studies. A total of 26 case–control studies, involving 1,198 cases and 2,921 controls were included. Overall, we found significant association between slow acetylator genotype of NAT2 and ATDH (OR = 3.10, 95 % CI: 2.47–3.88, P < 10^?5). Significant results were also found in East Asians, South Asians, Brazilians and Middle Eastern when stratified by ethnicity. However, no significant associations were found for Caucasians. This meta-analysis demonstrated that the slow acetylator genotype of NAT2 is a risk factor associated with increased ATDH susceptibility, but these associations vary in different ethnic populations.     

Ethnic differences in the association of the glutathione S-transferase T1 (GSTT1) null genotype and risk of gastric carcinoma: a systematic review and meta-analysis

We performed a systematic review and meta-analysis of the association between the glutathione S-transferase T1 (GSTT1) deletion polymorphism and gastric cancer risk in populations from different ethnic backgrounds, based on a comprehensive literature search of the MEDLINE, EMBASE, and COCHRANE libraries. Thirty-six individual case–control studies comprising 7,689 gastric cancer cases and 12,445 controls were included in our meta-analysis. Overall, the GSTT1 null genotype appeared to increase gastric cancer risk (OR 1.17, 95 % CI 1.06–1.31, p = 0.003). While Caucasian populations showed an association between the GSTT1 deletion polymorphism and gastric cancer risk (OR 1.27, 95 % CI 1.05–1.52, p = 0.01), Asian populations did not show such an association (p = 0.11). When stratified by quality assessment scores, a significant association between the GSTT1 deletion polymorphism and gastric cancer risk was observed only in the Caucasian high quality subgroup (OR 1.27 95 % CI 1.01–1.60, p = 0.05). Null genotypes for both GSTT1 and GSTM1 deletion polymorphisms also increased gastric cancer risk (OR 1.37, 95 % CI 1.04–1.80, p = 0.03). Our study suggests that the GSTT1 null genotype is associated with a significant increase in gastric cancer risk in Caucasians, but not in Asians. Further well-designed studies are required to confirm the association between GSTT1 polymorphisms and gastric cancer risk in relation to various clinicopathological factors in different ethnic groups, especially Caucasians.     

Genetic association studies of endothelial nitric oxide synthase gene polymorphisms in women with unexplained recurrent pregnancy loss: a systematic and meta-analysis

Recurrent pregnancy loss (RPL) is a multifactorial disorder, both genetic and environmental factors contribute to the development of RPL. Recently, the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and unexplained recurrent pregnancy loss (URPL) has been reported, and the results were inconsistent. Hence, we performed the meta-analysis to drive a more precise estimation of association between eNOS polymorphisms and URPL. Odds ratio (OR) and its 95 % confidence interval were calculated under co-dominant (AA vs. BB, TT vs. GG) and additive (A vs. B, T vs. G) genetic models. Studies of eNOS intron 4 VNTR and Glu298Asp were separated by ethnicities. 13 studies included 1,769 URPL cases and 1,376 healthy controls on eNOS intron 4 VNTR polymorphism, and 11 studies were involved in Glu298Asp polymorphism with 1,498 URPL cases and 1,123 healthy controls. The integrated results showed that eNOS Glu298Asp polymorphism was associated with URPL [ORs were 1.91 (1.42–2.56), P < 0.001; 1.67 (1.36–2.04), P < 0.001, respectively]. When analyses were separated by ethnic subgroups, the association between eNOS Glu298Asp polymorphism and URPL was only observed in East Asians [OR = 1.88 (1.52–2.33), P < 0.001 under additive model], and there was no association between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians. The results indicated a significant association between eNOS Glu298Asp polymorphism and URPL in East Asians. No association was observed between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians.     

The association between CD14 gene C-260T polymorphism and coronary heart disease risk: a meta-analysis

Monocyte differentiation antigen CD14 is considered an important cell-activating mediator of inflammatory responses that may result in atherosclerosis, coronary heart disease (CHD), thrombus formation, and myocardial infarction (MI). A common C-260T polymorphism in the promoter of the CD14 gene, the trans-membrane receptor of lipopolysaccharides, has been inconsistently associated with CHD. To investigate this inconsistency, we performed a meta-analysis of 28 studies involving a total of 13,335 CHD cases and 7,979 controls for C-260T of the CD14 gene to evaluate the effect of CD14 on genetic susceptibility for CHD. An overall random effects odds ratio of 1.24 (95 % CI: 1.12–1.36, P < 10^?5) was found for T allele. Significant results were also observed using dominant (OR = 1.34, 95 % CI: 1.17–1.54, P < 10^?4) or recessive genetic model (OR = 1.25, 95 % CI: 1.10–1.41, P = 0.0004). There was strong evidence of heterogeneity (P < 10^?5), which largely disappeared after stratification by ethnicity. After stratified by ethnicity, significant results were found in East Asians; whereas no significant associations were found among Caucasians and other ethnic populations in all genetic models. In the stratified analysis according to sample size, CHD endpoints, and HWE status, significantly increased risks for the polymorphism were found in all genetic models. In conclusion, our results indicate that the CD14 C-260T polymorphism is a risk factor of CHD, especially in East Asians. However, additional very large-scale studies are warranted to confirm our results.     

Null genotype of GSTT1 contributes to increased Parkinson’s disease risk in Caucasians: evidence from a meta-analysis

Conflicting results in previous case–control studies on the association between Glutathione S-transferase T1 (GSTT1) gene polymorphism and Parkinson’s disease (PD) risk have been reported, so we conducted this meta-analysis. We searched and extracted data from 3 Chinese and 3 English web-based electronic databases to evaluate the associations by odds ratio (OR) and its 95 % confidence interval (CI) under the recessive genetic comparison model (null genotype vs. present genotype). We also conducted subgroup analyses by ethnicity and adjusted status of OR, respectively. Meta-analyses and subgroup analyses of larger studies (sample size ≥300) were also reanalyzed. When 18 eligible studies (3,963 PD cases and 5,472 controls) were pooled to analyze the association, we found no statistically significant result (OR 1.24, 95 % CI 0.96–1.60). In the subgroup analyses by ethnicity, there was statistically significant association between the null genotype of GSTT1 and PD risk among Caucasians, while the associations were not found among Asians and Latinos. In the subgroup analyses by adjusted status of OR, there were no significant associations both in studies with crude OR and adjusted OR. Meta-analyses and subgroup analyses of larger studies (sample size ≥300) were also confirmed the associations mentioned above. Power analysis indicated only meta-analysis of Caucasians had enough evidence to claim the association. In conclusion, the meta-analysis suggests that the null genotype of GSTT1 contributes to PD risk in Caucasians, and no association in Asians is needed more studies to confirm.     

VEGF +936C/T and +460C/T gene polymorphisms and oral cancer risk: a meta-analysis

Many studies have examined the association between the VEGF +936C/T (rs833061) and +460C/T (rs3025039) gene polymorphisms and oral cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, we performed a meta-analysis. The PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases were searched for case–control studies that were published up to January 2013. Data were extracted and pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated. Ultimately, six studies were included, comprising 1006 oral cancer cases and 1016 controls. Overall, the pooled OR for VEGF +936 T allele carriers (TC + TT) versus the wild-type homozygotes (CC) was 1.28 (95 % CI 1.04–1.58; P = 0.228 for heterogeneity), the pooled OR for TT versus CC was 1.64 (95 % CI 1.34–1.98; P = 0.315 for heterogeneity), and the pooled OR for the T allele versus the C allele was 1.42 (95 % CI 1.22–1.76; P = 0.286 for heterogeneity). In the stratified analysis by ethnicity, significant risks were found among Caucasians but not Asians. However, there were no associations between VEGF +460C/T and oral cancer risk in only two of the included studies. In conclusion, this meta-analysis demonstrates that the VEGF +936 T allele may be associated with an increased risk of oral cancer, especially among Caucasian populations.     

Role of methylenetetrahydrofolate reductase 677C→T polymorphism in the development of myocardial infarction: evidence from an original study and updated meta-analysis

The methylenetetrahydrofolate reductase (MTHFR) gene variant 677C→T is considered a risk factor for myocardial infarction (MI) in Caucasians, but it remains unclear whether this applies to Chinese or other Asian populations. A total of 551 controls and 304 age-matched Chinese MI patients were recruited. MTHFR genotypes were determined. A subsequent meta-analysis was performed to determine the association between MTHFR and MI in Asia. Conventional risk factors such as hypertension, diabetes mellitus and low-density lipoprotein exhibited no significant differences between the two groups. Genotype frequencies among cases and controls were compatible with Hardy–Weinberg equilibrium. The frequencies of CC, CT and TT genotypes were 28, 46 and 26 % for patients with MI and 31, 52 and 17 % for the matched control group (p = 0.006). T-allele frequency in MI patients was higher than in controls (49 vs. 43 %, odds ratio = 0.785, 95 % confidence interval = 0.644–0.958, p = 0.017). A total of 16 studies including ours were identified, involving 4053 patients and 6791 controls. A recessive genotype model of MTHFR 677C→T polymorphism, but not a dominant genotype model, was significantly associated with greater MI risk in Asians. MI risk increased 48, 37 and 47 % for the TT homozygote compared with the CC wild type, CT heterozygote and the combination of CT and CC. Thus, we conclude that the MTHFR gene variant 677C→T is a risk factor for MI in the Chinese population and the TT genotype is associated with a significant increase in MI risk in Asia.     

Endothelial nitric oxide (eNOS) gene G894T and VNTR polymorphisms are closely associated with the risk of ischemic stroke development for Asians: meta-analysis of epidemiological studies

Although the relationships between endothelial nitric oxide synthase (eNOS) gene polymorphisms (including G894T, VNTR and T786C) and risk of ischemic stroke (IS) have been extensively studied, controversial results have been reported. The aim of this study was to assess the relationships between them by using a meta-analysis. Literatures were retrieved through the following databases: Medline, Embase and Wangfang (updated to January 1st, 2013). Fixed- or random-effects model was used to calculate pooled odds ratio and 95 % confidence interval (OR and 95 % CI). A total of 31 case–control studies including 8,547 patients and 9,117 controls were included in this meta-analysis eventually. For eNOS G894T polymorphism, the results indicated that TT genotype was significantly associated with increased risk of IS incidence compared to G allele (OR and 95 % CI 1.25 (1.09–1.42) for TT vs. GT+GG, P < 0.001). When subgroup analysis was conducted according to ethnicities, T allele was significantly associated with risk of IS for Asians rather than for Caucasians. For eNOS VNTR polymorphism, 4aa genotype was significantly associated with risk of IS incidence compared to 4bb genotype (OR (95 % CI) 2.22 (1.66–2.97) for aa vs. bb, P < 0.001). Similarly, when subgroup analyses were conducted, 4aa was closely associated with increased risk of IS for Asians rather than for Caucasians. For eNOS T786C polymorphism, it was not associated with risk of IS incidence. In conclusion, this study indicated that eNOS 894T and VNTR 4a allele was significantly associated with risk of IS incidence for Asians. However, eNOS T786C polymorphism was not a likely risk factor for IS incidence.     

Steroid 5-alpha-reductase type 2 (SRD5A2) V89L and A49T polymorphisms and sporadic prostate cancer risk: a meta-analysis

Steroid 5-α-reductase type 2 (SRD5A2) V89L and A49T polymorphisms are thought to play a crucial role in the androgen synthesis and metabolic pathway, but their associations with prostate cancer risk remain controversial. To provide a more precise estimation of the associations between V89L and A49T polymorphisms and prostate cancer risk, we performed a meta-analysis using all published case–control studies of prostate cancer since January 1995. We used odds ratio (OR) and its 95 % confidence interval (CI) to assess the strength of the association under various genetic models in both overall and stratified analyses. We also calculated the false-positive report probability, the power of the current study, and the observed P value for significant findings. This analysis included 45 eligible studies of a total of 15,562 cases and 15,385 controls, in which no significant associations were found for the V89L polymorphisms under all genetic models. However, small excess prostate cancer risk was associated with the 49T allele in mixed populations compared with the 49A allele (OR = 1.24, 95 % CI = 1.02–1.50), and similar results were observed in Caucasians (OR = 1.24, 95 % CI = 1.01–1.53). The sensitivity analysis further strengthened the validity of these findings without publication bias. Although there was no overall association between V89L and prostate cancer risk, A49T might play a role in the etiology of prostate cancer among Caucasians. Additional large and well-designed studies are warranted to validate these findings.     

The association between the Lys751Gln polymorphism in the XPD gene and the risk of bladder cancer

The Lys751Gln polymorphism in the XPD gene have been suggested as a risk factor for bladder cancer, however the results were inconclusive. The aim of the current study is to assess the association by meta-analysis. A total of 15 case–control studies concerning the association between the XPD Lys751Gln polymorphism and bladder cancer risk were included in the meta-analysis. The results suggested that the Lys751Gln polymorphism was not associated with an increased risk of bladder cancer in the dominant model (OR = 1.03, 95 % CI 0.95–1.11, P = 0.53 for Lys/Gln+Gln/Gln vs. Lys/Lys) in overall analysis. In the subgroup analysis by ethnicity, no significant association was found in Caucasians or Asians. Other comparatives suggested a slight significant association between the polymorphism with the risk of bladder cancer in the recessive comparative (OR = 1.14, 95 % CI 1.02–1.29, P = 0.03). The current meta-analysis indicated that the Lys751Gln polymorphism in the XPD gene might be a risk factor for bladder cancer. In the future, more large-scale case–control studies are needed to validate our results.     

A meta-analysis of the relationship between glutathione S-transferase T1 null/presence gene polymorphism and the risk of lung cancer including 31802 subjects

The relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on July 1, 2012, and eligible investigations were included and synthesized using meta-analysis method. 51 reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations (OR = 1.15, 95 % CI 1.04–1.27, P = 0.007). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.47, 95 % CI 1.23–1.76, P < 0.0001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.     

Association between polymorphism of MTHFR c.677C>T and risk of cardiovascular disease in Turkish population: a meta-analysis for 2.780 cases and 3.022 controls

Cardiovascular diseases (CVDs) remain the main cause of morbidity and mortality around the world. A common polymorphism c.677C>T has been identified in the gene coding for methylenetetrahydrofolate reductase (MTHFR), which is involved in the remethylation of homocysteine, and may predispose to CVDs. A meta-analysis was performed to estimate the risk of CVDs associated with MTHFR c.677C>T in Turkish population. Published studies were retrieved from PubMed, Science Citation Index/Expanded, Google Scholar, Turkish Medline, and the Turkish Council of Higher Education Theses Database. For each study, we calculated odds ratios and 95 % confidence intervals (CI), assuming frequency of allele and homozygote comparison, dominant and recessive genetic models. Thirty-one separate studies were included and 2.780 cases/3.022 controls were involved in the current meta-analysis. Significant association was found between c.677C>T polymorphism and risk of CVD when all studies pooled with random-effects model for T versus C (OR 1.33; 95 % CI 1.11–1.59; p = 0.002), TT vs. CC (OR 1.87; 95 % CI 1.35–2.60; p = 3.53E?04), TT+CT vs. CC (OR 1.32; 95 % CI 1.06–1.64; p = 0.014) and TT vs. CT+CC (OR 1.75; 95 % CI 1.29–2.37; p = 6.57E?04). Further analysis indicated the significant association between methylenetetrahydrofolate reductase (MTHFR) TT genotype and groups with venous thrombosis, peripheral arterial thrombosis, acute MI/MI. No publication bias was observed in any comparison model. Our results of meta-analysis suggest that MTHFR c.677C>T polymorphism is associated with the CVDs in Turkish population.     

Association between the receptor for advanced glycation end products gene polymorphisms and coronary artery disease

Receptor for advanced glycation end products (RAGE) is a cell-surface molecule member of the immunoglobulin superfamily and thought to play a critical role in diabetic atherosclerosis. A growing body of studies has been conducted to determine the extent to which the variants of RAGE gene influence the risk of coronary artery disease (CAD). However, these have reported conflicting results. To investigate this inconsistency, we performed a comprehensive meta-analysis on the associations between the RAGE ?374T/A, ?429T/C, and Gly82Ser polymorphisms and the risk of CAD. A total of 4,402 cases and 6,081 controls from 17 published case–control studies were included. The overall odds ratio (OR) of CAD was 0.99 (95 % CI 0.87–1.13), 1.06 (95 % CI 0.95–1.18) and 1.12 (95 % CI 0.90–1.39) for ?374A, ?429C, and the minor S allele of the Gly82Ser polymorphism, respectively. Similarly, no significant results were observed for these polymorphisms using dominant model. However, when stratified by diabetic/non-diabetic status of the CAD patients, we found significant association among Caucasian type two diabetic CAD patients with the ?374A allele [OR 1.39, 95 % CI 1.10–1.76, P(Z) = 0.006], while no association was detected between the ?374T/A polymorphism and non-diabetic CAD in Caucasians [OR 0.79, 95 % CI 0.58–1.07, P(Z) = 0.13]. In conclusion, this meta-analysis suggested that possession of the ?374A allele may be a risk factor in CAD among Caucasian patients with type two diabetes.     

Endothelial nitric oxide synthase gene polymorphisms and the risk of acute myocardial infarction in a South Indian population

Myocardial infarction (MI) is a complex multi-factorial, polygenic disorder which results from an interaction between a person’s genetic makeup and various environmental factors. Nitric oxide (NO), a potent vasodilator produced by endothelial cells, plays an important role in the regulation of blood pressure, regional blood flow and also inhibits platelet aggregation, vascular smooth muscle cell proliferation and leukocyte adhesion to vascular endothelium. Our aim was to analyze the association of NOS3 (endothelial nitric oxide synthase 3) 894G>T and ?786T>C gene polymorphisms and MI risk in the South Indian population. A total of 287 MI patients, 279 risk control patients and 321 healthy controls were recruited for the retrospective study. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). There was no significant association observed between NOS3 894G>T, ?786T>C polymorphisms and MI. A significant difference was observed in the distribution of GT genotype of the NOS3 894G>T polymorphism between the cases and the risk controls (p = 0.05) but the odds ratio (0.6) did not show risk for MI. The present study showed lack of association between NOS3 gene polymorphisms and MI in South Indian population.