Association between interleukin 10 gene -1082 A/G polymorphism and the risk of type 2 diabetes mellitus: a meta-analysis of 4250 subjects.

Increasing evidence suggests that interleukin 10 (IL 10) gene -1082 A/G (rsl800896) polymorphism may be associated with an increased risk of type 2 diabetes mellitus (T2DM). However, the results are inconsistent. The aim of this study is to analyze the association between this variant and the T2DM risk by meta-analysis. PubMed, Embase, Web of Science, and Google Scholar were searched from January 1, 1989 to February 17, 2012, as well as hand searching of the references of identified articles were performed. All the statistical tests were performed using Stata 11.0. Seven case-control studies were identified, covering a total of 1879 T2DM cases and 2371 controls. The results showed evidence of significant association between IL 10 gene -1082 A/G polymorphism and T2DM risk (for G/G+G/A vs. A/A: OR=1.21, 95% CI=1.05-1.40, p=0.010, p=0.040 after Bonferroni testing). In the subgroup analysis by ethnicity, no significant association was found between IL 10 gene -1082 A/G polymorphism and T2DM risk in Europeans. In summary, results from this meta-analysis provide evidence that IL 10 gene -1082 G allele is associated with increased risk of T2DM.

Association between the interleukin-6 gene -572 C/G polymorphism and the risk of type 2 diabetes mellitus: a meta-analysis of 11,681 subjects.

The association between the interleukin-6 (IL-6) gene -572 C/G (rs1800796) polymorphism and type 2 diabetes mellitus (T2DM) risk remains controversial. Thus, we performed this meta-analysis by searching PubMed, Embase, Web of Science, CBMdisc and CNKI databases until January 30, 2012. In addition, hand searching of the references of identified articles was performed. A total of 10 case-control studies including 11,681 subjects were selected to evaluate the possible association. Our results showed evidence for significant association between the IL-6 gene -572 C/G polymorphism and T2DM risk (for G allele vs. C allele: odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.09-1.52, P = 0.002, P = 0.008 after Bonferroni testing; for G/G vs. C/C: OR = 1.89, 95% CI = 1.51-2.37, P < 0.00001, P < 0.00004 after Bonferroni testing; for GG vs. G/C + C/C: OR = 1.75, 95% CI = 1.20-2.56, P = 0.004, P = 0.016 after Bonferroni testing; for G/G + G/C vs. C/C: OR = 1.32, 95% CI = 1.11-1.57, P = 0.001, P = 0.004 after Bonferroni testing). In addition, similar results were obtained in the subgroup analysis based on ethnicity. In summary, the present meta-analysis suggests a significant association between the IL-6 gene -572 G allele and increased risk of T2DM.

Association between interleukin-8 gene -251 T/A polymorphism and the risk of peptic ulcer disease: a meta-analysis.

It remains controversial regarding the association between interleukin-8 (IL-8) gene -251 T/A polymorphism and peptic ulcer disease (PUD) risk. Thus, a large-scale meta-analysis evaluating the precise association between this gene variant and PUD risk is required. We searched the PubMed, Embase, Web of Science, and Google Scholar until April 25, 2012. Additionally, hand searching of the references of identified articles were performed. All the statistical tests were performed using Stata 11.0. A total of eight studies (3105 subjects) were included in this meta-analysis. Overall, no significant association was found between IL-8 gene -251 T/A polymorphism and PUD risk (for A allele vs. T allele: OR = 1.17, 95% CI = 0.97-1.41, p = 0.094; for A/A vs. T/T: OR = 1.33, 95% CI = 0.94-1.90, p = 0.108; for A/A vs. A/T+T/T: OR = 1.22, 95% CI =0.97-1.52, p = 0.083; for A/A+A/T vs. T/T: OR = 1.26, 95% CI = 0.95-1.67, p = 0.113). However, in the subgroup analyses by ethnicity, H. pylori infection and the subtype of PUD, significant associations were found between IL-8 gene -251 T/A polymorphism and PUD risk in Asians, H. pylori+, duodenal ulcer disease (DUD) and gastric ulcer disease (GUD), respectively. In summary, the present meta-analysis suggests that IL-8 gene -251 T/A polymorphism is associated with increased PUD risk among Asians, and especially for the subgroups of H. pylori+, DUD and GUD.

The lack of association between interleukin-6 gene -174 G/C polymorphism and the risk of type 1 diabetes mellitus: a meta-analysis of 18,152 subjects.

Epidemiological studies have evaluated the association between interleukin-6 (IL-6) gene -174 G/C polymorphism and type 1 diabetes mellitus (T1DM) risk, but results of different studies have been inconsistent. The present meta-analysis was therefore designed to clarify these controversies. PubMed, Embase and Web of Science were searched from the first available year to March 25, 2012, as well as hand searching of the references of identified articles were performed. All studies investigating the association between IL-6 gene -174 G/C polymorphism and T1DM risk were included. Data analyses were carried out by Review Manager 5.1.2 and Stata 11.0. Seven studies were included in the final meta-analysis, covering a total of 9697 T1DM cases and 8455 controls. The results showed no evidence for significant association between IL-6 gene -174 G/C polymorphism and T1DM risk (for C/C+C/G vs. G/G: OR=1.30, 95% CI=0.84-2.00, p=0.24; for C/C vs. C/G+G/G: OR=1.10, 95% CI=0.75-1.60, p=0.63; for C/C vs. G/G: OR=1.34, 95% CI=0.75-2.42, p=0.33; for C allele vs. G allele: OR=1.16, 95% CI=0.88-1.53, p=0.30). In addition, the similar results were obtained in the subgroup analysis based on ethnicity. In summary, the present meta-analysis suggests that IL-6 gene -174 G/C polymorphism is not associated with T1DM risk. However, due to the small sample size in most of the included studies and the selection bias existed in some studies, the results should be interpreted with caution.

Associations between interleukin-6 gene -174 C/G and -572 C/G polymorphisms and the risk of gastric cancer: a meta-analysis.

BACKGROUND AND OBJECTIVES: Epidemiological studies have evaluated the associations between interleukin-6 (IL-6) gene -174 C/G (rs1800795) and -572 C/G (rs1800796) polymorphisms and gastric cancer (GC) risk, but results and conclusions remain controversial. In order to derive a more precise estimation of the associations, we performed this meta-analysis. METHODS: A meta-analysis was conducted to estimate the associations between IL-6 gene -174 C/G and -572 C/G polymorphisms and GC risk. RESULTS: Nine articles involving 13 studies were included in the final meta-analysis, covering a total of 1,581 GC cases and 2,563 controls. For IL-6 gene -174 C/G polymorphism, nine studies were combined showing no evidence for associations between IL-6 gene -174 C/G polymorphism and GC risk. For IL-6 gene -572 C/G polymorphism, four studies were combined. There was also lack of evidence for significant association between IL-6 gene -572 C/G polymorphism and GC risk. In addition, the similar results were obtained in the subgroup analyses and cumulative meta-analysis. CONCLUSIONS: The present meta-analysis suggests that IL-6 gene -174 C/G and -572 C/G polymorphisms are not associated with GC risk. However, due to the small subjects included in analysis and the selection bias in some studies, the results should be interpreted with caution.

Association between interleukin-10 gene -592 C/A polymorphism and the risk of type 2 diabetes mellitus: a meta-analysis of 5320 subjects.

Increasing evidence suggests that interleukin-10 (IL-10) gene -592 C/A polymorphism may be associated with an increased risk of type 2 diabetes mellitus (T2DM). To provide a quantitative assessment of the association between this variant and risk of T2DM, we performed this meta-analysis. Systematic searches of electronic databases PubMed, Embase, Web of Science, CBMdisc and CNKI, as well as hand searching of the references of identified articles were performed. A total of 2698 T2DM cases and 2622 controls in seven case-control studies were included in this meta-analysis. The results showed no evidence for significant association between IL-10 gene -592 C/A polymorphism and T2DM risk (for A allele vs. C allele: OR=0.94, 95% CI=0.69-1.29, p=0.69; for A/A vs. C/C: OR=0.88, 95% CI=0.39-1.98, p=0.75; for A/A vs. A/C+C/C: OR=1.04, 95% CI=0.59-1.82, p=0.89; for A/A+A/C vs. C/C: OR=1.11, 95% CI=0.73-1.69, p=0.61). In addition, the similar results were obtained in the subgroup analysis based on the ethnicity. In summary, results from this meta-analysis suggest that the IL-10 gene -592 C/A polymorphism is not associated with T2DM risk.

Association between interleukin-6 gene -174 G/C polymorphism and the risk of coronary heart disease: a meta-analysis of 20 studies including 9619 cases and 10,919 controls.

Interleukin-6 (IL-6) gene -174 G/C polymorphism has been reported to be associated with coronary heart disease (CHD), but the results remain inconclusive. The present meta-analysis was therefore designed to clarify these controversies. This meta-analysis was performed by searching PubMed, Embase and Web of Science databases. A total of 20 studies including 9619 CHD cases and 10,919 controls were combined showing no evidence of association between IL-6 gene -174 G/C polymorphism and CHD risk (for C/C+C/G vs. G/G: OR=1.10, 95% CI=0.99-1.22, p=0.07; for C/C vs. C/G+G/G: OR=1.08, 95% CI=0.93-1.24, p=0.33; for C/C vs. G/G: OR=1.16, 95% CI=0.97-1.39, p=0.11; for C allele vs. G allele: OR=1.10, 95% CI=1.00-1.21, p=0.06). Moreover, we also did not find significant association between IL-6 gene -174 G/C polymorphism and myocardial infarction (MI) risk. However, in the subgroup analysis by ethnicity, significant association was found among Asians (for C/C+C/G vs. G/G: OR=1.35, 95% CI=1.05-1.63, p=0.02). In summary, the present meta-analysis suggests that IL-6 gene -174 G/C polymorphism is associated with increased CHD risk among Asians. However, due to the small subjects included in the subgroup analysis of Asians, the results should be interpreted with caution.

Association between tumor necrosis factor-alpha gene -308A/G polymorphism and the risk of acute pancreatitis: a meta-analysis.

BACKGROUND: Epidemiologic studies have evaluated the association between tumor necrosis factor-alpha (TNF-α) gene -308A/G polymorphism and the risk of acute pancreatitis (AP), but the results are inconsistent. In order to derive a more precise estimation of the associations, a meta-analysis was performed. MATERIALS AND METHODS: Systematic searches of electronic databases PubMed, Embase, and Web of Science, as well as hand searching of the references of identified articles, were performed. All case-control studies investigating the association between TNF-α gene -308A/G polymorphism and AP risk were included. The association was assessed by odds ratio (OR) with 95% confidence intervals (CIs). Publication bias was analyzed by Begg's funnel plot and Egger's regression test. RESULTS: The initial search revealed 818 potentially eligible studies. Having read the title, abstract, or full text, we included six relevant studies in the final meta-analysis, which contained 1,006 AP cases and 782 controls. Overall, no significant association was found between TNF-α gene -308A/G polymorphism and AP risk when all studies were pooled into the meta-analysis (for A/A+A/G versus G/G: OR = 1.03, 95% CI = 0.83-1.28, P = 0.79; for A/A versus A/G+G/G: OR = 0.97, 95% CI = 0.65-1.45, P = 0.87; for A/A versus G/G: OR = 1.23, 95% CI = 0.79-1.91, P = 0.37; for A allele versus G allele: OR = 0.99, 95% CI = 0.83-1.18, P = 0.90). In addition, the similar results were obtained in the subgroup analysis based on the ethnicity and subtype of AP. CONCLUSIONS: The present meta-analysis reveals that the TNF-α gene -308A/G polymorphism is not associated with AP risk. However, due to the small number of subjects included in analysis and the selection bias in some studies, the results should be interpreted with caution.