The endothelial nitric oxide synthase (eNOS) gene plays an important role in regulating vascular tone and blood pressure. Recently, the eNOS G894T and T-786C single nucleotide polymorphisms (SNPs) were intensively studied with regard to their associations with hypertension. However, the results of these studies were inconsistent. Therefore, we conducted the so far largest meta-analysis to better assess the correlations between eNOS SNPs and hypertension. Eligible articles were searched in PubMed, Medline, Embase, Scopus, and CNKI up to April 2016. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to detect any potential associations between eNOS SNPs and the risk of hypertension. A total of 95 case-control studies involving 29,308 hypertension cases and 33,950 healthy controls were analyzed. The overall meta-analysis results showed that eNOS G894T and T-786C SNPs were both significantly associated with the risk of hypertension, the T allele of G894T SNP (G versus T, P < 0.00001, OR = 0.82, 95% CI 0.76-0.89) and C allele of T-786C SNP (T versus C, P = 0.004, OR = 0.92, 95% CI 0.87-0.97) conferred an increased susceptibility to hypertension. Further subgroup analyses yielded similar positive results for G894T SNP in essential hypertension, gestational hypertension, and Asian ethnicity, and that for T-786C SNP in essential hypertension and Asian population. Overall, our findings suggest that eNOS G894T and T-786C SNPs were both significantly correlated with hypertension. Additionally, the T allele of G894T SNP and C allele of T-786C SNP may serve as potential biological markers for hypertension susceptibility in Asians.

Background Telomeres and telomerase play key roles in the chromosomal maintenance and stability. Recent epidemiological studies have shown that longer telomeres are associated with increased risk of several cancer types. However, epidemiological data for telomere length and risk of breast cancer are sparse. Methods We prospectively studied the association between telomere length and risk of breast cancer in 14,305 middle-aged or older Chinese women of the Singapore Chinese Health Study including 442 incident breast cancer cases after 12.3 years of follow-up. Relative telomere length in peripheral blood leukocytes was quantified using a validated monochrome multiple quantitative polymerase chain reaction method. The Cox proportional hazard regression method was used to estimate hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for breast cancer associated with longer telomeres after adjustment for potential confounders. Results Longer telomeres were significantly associated with higher risk of breast cancer in a dose-dependent manner ( P trend = 0.006); the highest quartile of telomere length was associated with a statistically significant 47% higher risk of breast cancer compared with the lowest quartile of telomere length after the adjustment for age and other known risk factors for breast cancer (HR Q4 vs Q1 = 1.47, 95% CI = 1.11, 1.94). Conclusions The findings of the present study support the hypothesis that longer telomeres may be a risk factor for breast cancer. Telomere length in peripheral blood leukocytes may be developed as a biomarker for breast cancer risk prediction. Electronic supplementary material The online version of this article (10.1186/s13058-019-1133-0) contains supplementary material, which is available to authorized users.

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The association between microRNA polymorphisms (miR polymorphisms) and coronary heart disease (CHD) risk has been studied intensively, but the results have been conflicting. Therefore, we conducted the present meta-analysis to obtain a more conclusive answer. We searched for eligible articles in PubMed, MEDLINE, EMBASE, Scopus, and CNKI. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to identify any potential associations. Ten case-control studies including 5,292 CHD patients and 5,446 control subjects were analyzed. The overall meta-analysis results showed that the miR-146a rs2910164 polymorphism, the miR-196a2 rs11614913 polymorphism, and the miR-499 rs3746444 polymorphism were all significantly associated with CHD risk in certain genetic models. Besides, the C allele of the miR-146a rs2910164 and miR-499 rs3746444 polymorphisms conferred increased susceptibility to CHD (C versus G, p < 0.0001, OR = 1.14, 95% CI = 1.07-1.21; p = 0.003, OR = 1.14, 95% CI = 1.05-1.25). Overall, our findings suggest that the miR-146a rs2910164, miR-196a2 rs11614913, and miR-499 rs3746444 polymorphisms may be correlated with the risk of CHD.

The NKX2-5 gene is a vital regulator of cardiac formation and development. Recently, the roles of NKX2-5 63A>G polymorphism and 606G>C polymorphism in congenital heart disease (CHD) have been extensively studied, with conflicting results. The aim of the present study was to better elucidate the associations between NKX2-5 genetic polymorphisms and CHD risk through a meta-analysis. Eligible articles were searched in PubMed, MEDLINE, EMBASE, Google Scholar and CNKI up to December 2015. Odds ratios (ORs) and 95 % confidence intervals were used to detect any potential associations between NKX2-5 genetic polymorphisms and CHD risk. Heterogeneity between studies was assessed with Q test and I (2) statistic. Subgroup analysis and sensitivity analysis were performed to test the reliability and stability of the results, and funnel plots were applied to estimate publication bias. A total of 13 case-control studies including 2245 CHD patients and 1953 healthy controls were analyzed. The overall meta-analysis results showed that NKX2-5 63A>G polymorphism and 606G>C polymorphism were not significantly associated with CHD risk. Subgroup analysis was further performed for NKX2-5 63A>G polymorphism based on types of CHD and ethnicity of study population, and similar negative results were found in all subgroups. Our findings suggested that NKX2-5 63A>G polymorphism and 606G>C polymorphism may not be implicated in the pathogenesis of CHD.