Nonlinear association between stress hyperglycemia ratio and short-term and long-term mortality in sepsis patients with atrial fibrillation: a cohort study.

OBJECTIVE: The stress hyperglycemia ratio (SHR) demonstrates mortality associations across various populations; however, its nonlinear relationship with mortality in the specific subgroup of sepsis with atrial fibrillation (AF) remains insufficiently characterized. METHODS: Retrospective cohort of sepsis patients with AF from Medical Information Mart for Intensive Care (MIMIC) -IV version 3.1 database. SHR was calculated as the ratio of admission glucose to estimated average glucose derived from hemoglobin A1c (HbA1c). Nonlinear associations between SHR and 30-day/365-day mortality were assessed using restricted cubic spline (RCS) and threshold effect analyses with multivariable adjustment and entropy balancing weighting. RESULTS: Among 2,297 participants (median age 73.64 years, 63.2% male), 337 (14.67%) and 629 (27.38%) experienced 30-day and 365-day mortality. Nonlinear associations were identified between SHR and mortality, with inflection points at 0.70 (30-day) and 0.89 (365-day). Below thresholds, SHR was inversely associated with 30-day (HR = 0.10, 95% CI: 0.02-0.47, P = 0.003) and 365-day mortality (HR = 0.40, 95% CI: 0.20-0.78, P = 0.008). Above thresholds, mortality risk increased (30-day HR = 3.24, 95% CI: 2.19-4.80, P < 0.001; 365-day HR = 2.60, 95% CI: 1.80-3.76, P < 0.001). Entropy balancing weighting confirmed these threshold effects. CONCLUSION: A nonlinear relationship exists between SHR and mortality in sepsis patients with AF, where both extremely low and high SHR values may increase mortality risk.