Socioeconomic Inequalities and Type 2 Diabetes Comorbidities: A Systematic Review and Meta-Analysis on Observational Studies.

Abstract

<h4>Background</h4>Previous studies have reported inconsistent findings regarding the relationship between socioeconomic status (SES) inequalities and comorbidities in patients with diabetes mellitus (DM). This systematic review and meta-analysis aims to evaluate, for the first time, the association between SES inequalities and comorbidities in individuals with DM.<h4>Methods</h4>Two independent investigators searched the PubMed, Embase, Scopus, Web of Science and Google Scholar databases using MeSH terms to identify studies that investigated the association between SES and DM comorbidities up to 15 December 2025. This systematic review followed the PRISMA 2020 checklist. Heterogeneity among studies was assessed using Cochran's Q and I² statistics. Meta-regression was used to control for heterogeneity; Egger's test assessed publication bias.<h4>Results</h4>Thirteen studies involving 757,599 DM patients were included. A pooled estimate of 13 studies showed that low SES, compared with moderate or high SES, was significantly associated with an increased probability of DM comorbidities (OR: 1.43; 95% CI: 1.30, 1.59; I²: 92.7, p: 0.01). Subgroup analysis of 12 studies showed that the probability of DM comorbidities was different in men (OR: 1.30; 95% CI: 1.28, 1.32) and women (OR: 1.39; 95% CI: 1.36, 1.42).<h4>Conclusion</h4>The chance of developing type 2 diabetes comorbidities in patients with T2DM of low SES, especially in women, may be higher than in patients with middle and high SES. Improvements in healthcare systems and interventions to reduce inequalities in SES in patients with type 2 diabetes, especially in patients with low SES, are recommended.