The Effect of Single Nucleotide Polymorphisms on Depression in Combination With Coronary Diseases: Protocol for a Systematic Review and Meta-analysis

Abstract Background: Depression and coronary heart disease (CHD) have common risk mechanisms. Common single nucleotide polymorphisms (SNPs) may be associated with the risk of depression combined with coronary heart disease. Methods: This protocol was designed according to the PRISMA-P guidelines. CENTRAL in the Cochrane Library, MEDLINE Ovid, Embase Ovid, Web of Science, CNKI, CQVIP, SinoMed, Wanfang Data, and ChiCTR will be systematically searched. We will include case-control studies and cohort studies investigating the relationship between gene SNPs and depression and coronary heart disease comorbidities. The Newcastle-Ottawa Scale (NOS) will be used to assess the risk of bias. When measuring dichotomous outcomes, we will use the risk ratio (RR) and 95% confidence interval (95%CIs) in a cohort study and use the odds ratio (OR) and 95% confidence interval (95%CIs) in a case-control study. Five genetic models (allele model, homozygous model, heterozygous model, dominant model, and recessive model) will be evaluated for each included study. Subgroup analysis by ethnicity will be performed. If necessary, post hoc analysis will be made according to different types. Discussion: The purpose of this meta-analysis is to comprehensively study the current evidence and assess the association between single nucleotide polymorphisms and susceptibility of depression in combination with coronary heart disease. Systematic review registration: This protocol was prospectively registered in the PROSPERO (registration number CRD42021229371).