Effects of loneliness and isolation on cardiovascular diseases:a two sample Mendelian Randomization Study

BACKGROUND Loneliness and isolation are associated with multiple cardiovascular diseases(CVDs),but there is a lack of research on whether they were causally linked.We conducted a Mendelian Randomization(MR)study to explore causal relationships between loneliness and isolation and multiple CVDs.METHODS Single nucleotide polymorphisms associated with loneliness and isolation were identified from a genome-wide association study(GWAS)of 455,364 individuals of European ancestry in the IEU GWAS database.Summary data for 15 CVDs were also obtained from the IEU GWAS database.We used three MR methods including inverse variance weighting,MR-Egger,and weighted median estimation to assess the causal effect of exposure on outcomes.Cochran's Q test and MR-Egger intercept test were used to evaluate the heterogeneity and pleiotropy.RESULTS MR analysis showed that loneliness and isolation were significantly associated with essential hypertension(OR=1.07,95%CI:1.03-1.12),atherosclerotic heart disease(OR=1.04;95%CI:1.02-1.06),myocardial infarction(OR=1.02;95%CI:1-1.04)and angina(OR=1.04;95%CI=1.02-1.06).No heterogeneity and pleiotropy effects were found in this study.CONCLUSIONS Causal relationship of loneliness and isolation with CVDs were found in this study.

Helicobacter pylori infection and esophageal cancer risk:An updated meta-analysis

AIM:To clarify the association between Helicobacter pylori(H.pylori)infection and the risk of esophageal carcinoma through a meta-analysis of published data.METHODS:Studies which reported the association between H.pylori infection and esophageal cancer published up to June 2013 were included.The odds ratios(ORs)and corresponding 95%CIs of H.pyloriinfection on esophageal cancer with respect to health control groups were evaluated.Data were extracted independently by two investigators and discrepancies were resolved by discussion with a third investigator.The statistical software,STATA(version 12.0),was applied to investigate heterogeneity among individual studies and to summarize the studies.A meta-analysis was performed using a fixed-effect or random-effect method,depending on the absence or presence of significant heterogeneity.RESULTS:No significant association between H.pylori infection and esophageal squamous cell carcinoma(ESCC)risk was found in the pooled overall population(OR=0.97,95%CI:0.76-1.24).However,significant associations between H.pylori infection and ESCC risk were found in Eastern subjects(OR=0.66,95%CI:0.43-0.89).Similarly,cytotoxin-associated gene-A(CagA)positive strains of infection may decrease the risk of ESCC in Eastern subjects(OR=0.77,95%CI:0.65-0.92),however,these associations were not statistically significant in Western subjects(OR=1.26,95%CI:0.97-1.63).For esophageal adenocarcinoma(EAC)the summary OR for H.pylori infection and CagA positive strains of infection were 0.59(95%CI:0.51-0.68)and 0.56(95%CI:0.45-0.70),respectively.CONCLUSION:H.pylori infection is associated with a decreased risk of ESCC in Eastern populations and a decreased risk of EAC in the overall population.