Association between the triglyceride to high-density lipoprotein cholesterol ratio and 90-day post-stroke depression in acute ischemic stroke

Background Post-stroke depression (PSD) commonly complicates acute ischemic stroke (AIS), with insulin resistance (IR)-mediated metabolic disturbances proposed as an underlying pathophysiological link. The triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL)—a validated, cost-effective surrogate for IR—has preliminary associations with depressive symptoms. However, the relationship between TG/HDL and the risk of PSD in patients with AIS remains unclear. Methods A cohort of 519 AIS patients was retrospectively analyzed (October 2023–December 2024). The primary outcome was 90-day PSD, diagnosed via the HAMD-24 (score > 7). Multivariable logistic regression assessed the independent association between admission TG/HDL and PSD. Nonlinear associations were assessed using restricted cubic splines (RCS). Results Thirty-three point nine percent of patients developed PSD. The TG/HDL ratio was an independent predictor of PSD (Model 3: OR = 1.5634, 95% CI: 1.0097–2.4281, P = 0.0452). RCS analysis suggested a potential non-linear relationship, and a two-piecewise logistic regression model identified a candidate inflection point. However, the wide confidence intervals in the higher exposure range indicate substantial uncertainty, and this finding should be regarded as exploratory. Conclusions Admission TG/HDL ratio was independently associated with 90-day PSD, suggesting that it may serve as a convenient metabolic marker for identifying patients at higher risk of developing PSD. The observed non-linear pattern requires cautious interpretation and validation in larger prospective cohorts.