Association Between Type 2 Diabetes Mellitus and Sepsis Outcomes: A Systematic Review and Meta-Analysis

Sepsis is a major cause of morbidity and mortality worldwide. Type 2 diabetes mellitus (T2DM) is common among adults with infection and has been proposed as a potential modifier of sepsis outcomes. This systematic review and meta-analysis aimed to evaluate the association between pre-existing T2DM and mortality among adults with sepsis. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. PubMed, Cochrane CENTRAL, and Google Scholar databases were systematically searched from inception to April 23, 2026. Observational studies comparing outcomes in adult patients with sepsis with and without T2DM were eligible. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. A total of 651 records were identified. Seven studies were included in the qualitative synthesis, and three in the primary quantitative meta-analysis. The pooled analysis showed no statistically significant association between T2DM and sepsis mortality (OR = 0.99; 95% CI = 0.82-1.20). However, substantial heterogeneity was observed across studies (I² = 98.4%). Sensitivity and exploratory analyses yielded similar findings. Narrative evidence suggested that glycemic status, diabetes-related complications, and acute renal dysfunction may be more important determinants of outcomes than the diagnosis of T2DM alone. The current evidence did not demonstrate a statistically significant association between pre-existing T2DM and mortality among adults with sepsis. However, these findings should be interpreted cautiously given the limited number of studies included in the primary meta-analysis, the substantial heterogeneity across studies, and the observational nature of the available evidence. Future prospective, well-adjusted studies should evaluate the impact of glycemic control, diabetes-related complications, organ dysfunction, and antidiabetic treatment exposure on sepsis outcomes.