Atherogenic index of plasma and cognitive impairment risk among hypertensive adults: evidence from a nationwide cohort study

BACKGROUND: Cognitive impairment is a major complication in individuals with hypertension. Emerging evidence suggests that metabolic abnormalities may contribute to its pathogenesis. This study examined the association between the atherogenic index of plasma (AIP) and risk of cognitive impairment in middle-aged and older adults with hypertension. METHODS: Data were from the 2011 baseline and 2018 follow-up waves of the China Health and Retirement Longitudinal Study (CHARLS). Multivariable logistic regression was used to assess the association between baseline AIP and subsequent cognitive impairment. Dose-response patterns were explored using restricted cubic spline (RCS) models, and subgroup analyses evaluated effect modification. Predictive performance of AIP versus traditional lipids was assessed by receiver operating characteristic (ROC) curves. RESULTS: Among 3,739 hypertensive participants (mean age: 60.5 ± 9.1 years; 50.0% female), 43.0% developed cognitive impairment. Compared with quartile 1 (Q1), higher AIP quartiles were significantly associated with increased risk of cognitive impairment: Q2 (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.15-1.80), Q3 (OR, 1.76; 95% CI, 1.40-2.20), and Q4 (OR, 1.85; 95% CI, 1.45-2.37). RCS indicated a linear dose-response (P for nonlinearity = 0.061). Subgroup analyses showed consistent associations across age, gender, body mass index, residence, and diabetes, with no significant interactions detected. AIP outperformed traditional lipid markers in predicting cognitive impairment. CONCLUSION: Elevated AIP was independently associated with an increased risk of cognitive impairment among middle-aged and older adults with hypertension, suggesting its potential as a practical biomarker for early identification of cognitive risk in this high-risk population.