Mendelian randomization study on the association between cheese intake and diabetes

Objective To explore whether there is a causal relationship between cheese intake and diabetes through Mendel randomization (MR). Methods Two samples of MR were used to verify the causal effect of cheese intake on diabetes. The analysis was conducted using inverse variance weighted (IVW), weighted median, and MR-Egger regression methods. We used a meta-analysis of publicly available genome-wide association studies (GWAS) to compile statistical datasets, and cheese intake data as exposure factors were sourced from individuals of European ancestry in the UK biobank (n=451486). At the same time, GWAS's public summary statistical data set is also used for self reporting non cancer disease codes: diabetes data included in the Finnish database (total n=184404; case=1219, control=183185)(http://www.finngen.fi/en)as a result. Result We selected 108 single nucleotide polymorphisms (SNPs) with genome-wide significance as instrumental variables from the GWAS intake of cheese. IVW method results show a causal relationship between cheese intake and diabetes(β=- 1.196, SE=0.3817, P=0.001729). MR Egger regression results show that directed pleiotropy is unlikely to bias the results (intercept=0.015; P=0.58), but there is no causal relationship between cheese intake and diabetes (β=- 2.073, SE=1.621, P=0.206). The results of weighted median method also showed that there was no causal relationship between cheese intake and diabetes(β=- 0.7828, SE=0.5701, P=0.1698). Cochran's Q-test and funnel plot indicate no evidence of heterogeneity and asymmetry, indicating the absence of directed pleiotropy. Conclusion The results of MR analysis support that cheese intake may have a causal relationship with the reduced risk of diabetes. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The author(s) received no specific funding for this work. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Not Applicable The details of the IRB/oversight body that provided approval or exemption for the research described are given below: N/A I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Not Applicable I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Not Applicable I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Not Applicable If the data are held or will be held in a public repository, include URLs, accession numbers or DOIs. If this information will only be available after acceptance, indicate this by ticking the box below. For example: All XXX files are available from the XXX database (accession number(s) XXX, XXX.)