Associations between dimensions of the social environment and cardiometabolic health outcomes: a systematic review and meta-analysis

Objectives The social environment (SE), that is, the social relationships and social context in which groups of people live and interact, is an understudied element of the broader living environment which impacts health. We aim to summarise the available evidence on the associations between SE and cardiometabolic disease (CMD) outcomes. Design Systematic review and meta-analysis. Data sources PubMed, Scopus and Web of Science Core Collection were searched from inception to 28 February 2024. Eligibility criteria We included studies for which determinants were SE factors such as area-level deprivation and social network characteristics and outcomes were type 2 diabetes mellitus and cardiovascular diseases incidence and prevalence. Data extraction and synthesis Titles and abstracts and full text were screened in duplicate. Data appraisal and extraction were based on the study protocol published in PROSPERO. Methodological quality was assessed with the Newcastle-Ottawa Scale. We synthesised the data through vote counting and meta-analyses. Results From 10 143 records screened, 281 studies reporting 1108 relevant associations are included in this review. Of the 384 associations included in vote counting, 271 (71%) suggested that a worse SE is associated with a higher risk of CMD. 14 meta-analyses based on 180 associations indicated that worse SE was associated with increased odds of CMD outcomes, with 4 of them being statistically significant. For example, more economic and social disadvantage was associated with higher heart failure risk (OR 1.58, 95% CI 1.08 to 1.61; n=18; I-2=95%). With the exception of two meta-analyses for men, meta-analysed sex-specific associations consistently showed results in the same direction as the overall meta-analyses. Conclusion Worse SE seems to be associated with increased odds of CMD outcomes, although certain SE dimensions are underexplored in relation to CMD.