U-shaped association of the stress hyperglycemia ratio with all-cause mortality and premature death in patients with cardiovascular disease: a cohort study.

Background: The stress hyperglycemia ratio (SHR) is recognized as a significant indicator of relative hyperglycemia that has demonstrated to correlate with poor outcomes, including elevated mortality rates in individuals facing severe acute conditions. However, the connection between SHR and all-cause mortality and premature death in individuals with cardiovascular disease (CVD) remains insufficiently investigated. This research intended to investigate the relationship between SHR and all-cause mortality and premature death among individuals with CVD.

Methods: This cohort study involved data extracted from 2,714 follow-up cohorts sourced from the National Health and Nutrition Examination Survey (NHANES). Participants were categorized based on SHR quartiles. The relationship between SHR and all-cause mortality and premature death in CVD patients was analyzed using Kaplan-Meier survival curves, restricted cubic splines (RCS), Cox proportional hazards models, threshold effect analysis, and subgroup analyses.

Results: Over an average follow-up duration of 88.38 months, 1,201 deaths were documented, of which 351 were classified as premature. The Kaplan-Meier curves illustrated that individuals in quartile 2 of SHR exhibited highest survival probability compared to other quartiles. Cox proportional hazards regression revealed a positive association between SHR (for continuous) and all-cause mortality (HR 1.57, 95% CI 1.12-2.19) as well as premature death (HR 1.96, 95% CI 1.10-3.49). Compared with the second quartile, both lower and higher SHR values were significantly correlated with elevated risk of all-cause mortality and premature death (HR > 1, P-value < 0.05). The RCS analysis elucidated a U-shaped association of SHR with risk of all-cause mortality and premature death. Furthermore, the threshold effect analysis pinpointed the inflection points for SHR relative to all-cause mortality and premature death at 0.86 and 0.87, respectively. E-value indicated that the model demonstrated robust stability concerning potential unknown confounding variables.

Conclusion: An independent association of SHR with all-cause mortality and premature death was observed among individuals with CVD. Maintaining SHR within a moderate range might improve their prognosis.