Association between atherogenic index of plasma and stroke risk: A cross-sectional analysis of NHANES data

While metabolic and inflammatory factors have long been associated with stroke, emerging lipid-based markers such as the atherogenic index of plasma (AIP) may offer additional predictive value. This study aimed to evaluate the association between AIP and stroke incidence using a nationally representative dataset. A cross-sectional analysis was performed using data from the 2005 to 2018 National Health and Nutrition Examination Survey (NHANES), focusing on adults with complete records for AIP and stroke diagnosis. AIP was defined as the base-10 logarithm of the triglyceride-to-high-density lipoprotein cholesterol cholesterol ratio, measured in mmol/L. We applied weighted multivariable logistic regression models and generalized additive models to assess linear and nonlinear associations between AIP and stroke prevalence. Threshold effects were explored via 2-piecewise linear regression. We further examined interactions across subgroups to test for effect modification. Among 16,834 eligible participants, 510 (3.03%) had a history of stroke. Stroke prevalence increased progressively across ascending AIP tertiles (Q1: 39.05%, Q2: 44.95%, Q3: 53.45%; P < .0001). Adjusted analyses revealed a statistically significant positive association between AIP and stroke. Specifically, each 1-unit increase in AIP was associated with a 38% increase in stroke risk (model III: odds ratio = 1.38; 95% confidence interval: 1.04-1.83). No significant interactions were observed across major demographic or clinical subgroups (P for interaction > .05). Higher AIP values are independently associated with increased odds of stroke. These findings suggest that AIP could serve as a useful marker in evaluating cerebrovascular risk profiles in the general population.