The prognostic significance of stress hyperglycemia ratio for all-cause and cardiovascular mortality in metabolic syndrome patients: prospective cohort study.

Objective: The stress hyperglycemia ratio (SHR) is a new biomarker indicating acute hyperglycemia and predicting adverse outcomes in different conditions. Yet, its impact on metabolic syndrome (MetS) has not been studied. We explored the link between SHR and long-term all-cause and cardiovascular disease (CVD) mortality in MetS patients.

Methods: We conducted a large prospective cohort study involving 9438 participants diagnosed with MetS, drawn from the 1999-2018 NHANES. MetS diagnosis was based on NCEP-ATPIII criteria. Participants were categorized into three groups based on SHR tertiles: T1 (SHR ≤ 0.890), T2 (SHR 0.890-0.992), and T3 (SHR ≥ 0.992). Cox regression and Kaplan-Meier curve analyses assessed the correlation between SHR and mortalities. Non-linear correlations were explored using restricted cubic splines, and stratification analysis was performed.

Results: Out of 9438 MetS patients, 1929 deaths occurred during an average follow-up of 107 ± 64 months, including 541 CVD deaths. All-cause and CVD mortality rates were significantly higher with elevated SHR values (T3) than lower tertiles (23.4% vs. 19.5% and 18.3%, P < 0.001; 6.8% vs. 5.3% and 5.1%, P = 0.007, respectively). A U-shaped relationship was observed between SHR and all-cause and CVD mortality (all P for non-linear < 0.001). Kaplan-Meier analysis indicated higher SHR values associated with increased risk of all-cause and CVD mortality (all log-rank P < 0.001). After adjusting for confounders, multivariate Cox regression showed SHR remained associated with a 1.256-fold and 1.023-fold risk of all-cause and CVD mortality.

Conclusions: SHR independently correlates with all-cause and CVD mortality in MetS patients, displaying a U-shaped relationship with clinical endpoints.