Abstract / Summary
Objective To clarify the association of elevated BMI with short- and long-term mortality in sepsis, and to evaluate this association specifically in patients with a BMI ≥ 40 kg/m 2 . Design Systematic review and meta-analysis. Setting PubMed, Embase, and the Cochrane Library were searched for studies published up to December 2025. Twelve studies met the inclusion criteria. Participants Twelve retrospective studies with 130755 adult sepsis patients. Elevated BMI was defined as ≥30 kg/m 2 ; normal weight as 18.5–25.0 kg/m 2 . Interventions Not applicable. Main variables of interest Exposure: BMI ≥ 30 kg/m 2 . Outcomes: short-term (28-day, 30-day, ICU, in-hospital) and long-term (1-year) mortality. A separate analysis targeted BMI ≥ 40 kg/m 2 . Results An elevated BMI was associated with reduced short-term mortality (8 studies: OR 0.75, 95% CI 0.69–0.81; I 2 = 11.8%), 28-/30-day mortality (5 studies: OR 0.74, 95% CI 0.68–0.81; I 2 = 7.7%), and long-term mortality (2 studies: OR 0.68, 95% CI 0.60–0.77; I 2 = 0.0%). This inverse association persisted in patients with BMI ≥ 40 kg/m 2 (4 studies: OR 0.70, 95% CI 0.62–0.79; I 2 = 26.3%). Sensitivity analyses confirmed robustness. Conclusions Elevated BMI is associated with lower short- and long-term mortality in sepsis, consistent with the obesity paradox. The inverse association also persisted in patients with a BMI ≥ 40 kg/m 2 .