Stress hyperglycemic ratio shows nonlinear link to stroke in older adults with metabolic syndrome

This prospective cohort study enrolled 60,931 participants aged 60 years or older to evaluate whether the stress hyperglycemic ratio (SHR), a composite measure combining fasting blood glucose and glycated hemoglobin, is associated with stroke in older people with metabolic syndrome. Metabolic syndrome was defined as the presence of abdominal obesity, hyperlipidemia, hypertension, and hyperglycemia.

Investigators used Cox proportional hazards models to examine the SHR–stroke association after adjusting for covariates. Restricted cubic spline plots were applied to test for nonlinear relationships, recursive methods identified inflection points, and Kaplan-Meier survival curves characterized stroke risk across SHR levels over time. Subgroup analyses were also performed.

After controlling for all covariates, the authors reported no significant association between SHR and stroke or its subtypes overall. However, restricted cubic spline analysis revealed a nonlinear association specifically for stroke and ischemic stroke, with an inflection point identified at an SHR value of 0.87. The association of SHR with stroke and ischemic stroke was statistically significant both before and after this inflection point, though the abstract characterizes these as opposing directions rather than reporting the effect magnitudes. Subgroup analyses did not reveal significant differences.

Key limitations include the observational cohort design, which precludes causal inference, and the abstract's absence of reported hazard ratios, confidence intervals, p-values, absolute event counts, and follow-up duration. No safety or adverse event data are applicable, as SHR is a laboratory-derived ratio rather than an intervention.

For clinicians, the findings suggest that SHR may have a threshold-dependent rather than linear relationship with stroke risk in older adults with metabolic syndrome, offering a reference point for future investigations into glucose dysregulation and cerebrovascular outcomes, but not a basis for changing current practice.