The association between atherogenic index of plasma and all-cause mortality and cardiovascular disease-specific mortality in hypertension patients: a retrospective cohort study of NHANES.

Background: Atherogenic index of plasma (AIP), a marker of atherosclerosis and cardiovascular disease (CVD), was related to the all-cause mortality and CVD-specific mortality in a U-shape in general population respectively. However, no studies have investigated these associations in hypertensive populations. Herein, this study aims to explore the relationship of AIP and all-cause mortality and CVD-specific mortality in patients with hypertension in order to provide some reference for the risk hierarchical management of hypertension.

Methods: Demographic and clinical data of 17,382 adult patients with hypertension were extracted from the National Health and Nutrition Examination Survey (NHANES) database in 2005-2018 in this retrospective cohort study. We used weighted univariate COX regression analysis to screen the covariates, and that weighted univariate and multivariate COX regression analyses to explore the association between AIP and all-cause mortality and CVD-specific mortality with hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses of age, gender, body mass index (BMI), CVD, diabetes mellitus (DM), antihyperlipidemic agents use, and hypotensive drugs use were also performed for further exploration of these relationships.

Results: The average follow-up time was 97.10 months. A total of 2,844 patients died, and 971 of them died due to CVD. After adjusting for age, race, education level, marital status, poverty-income ratio (PIR), smoking, BMI, physical activity, antihyperlipidemic agents, DM, CVD, hypotensive drugs, estimated glomerular filtration rate (eGFR), and total energy intake, we found that both low [HR = 1.18, 95%CI: (1.07-1.32)] and high [HR = 1.17, 95%CI: (1.03-1.33)] levels of AIP were linked to an increased risk of all-cause mortality, and the U-shape association between AIP and CVD-specific mortality was also found [low AIP level: HR = 1.26, 95%CI: (1.05-1.51); high AIP level: HR = 1.26, 95%CI: (1.06-1.49)]. Furthermore, these relationships were existed in patients whose BMI > 25, were non-Hispanic White, with non-CVD, non-DM, non-antihyperlipidemic agents, and used hypertension drug (all P < 0.05).

Conclusion: AIP was associated with both all-cause mortality and CVD-specific mortality in patients with hypertension, but the specific role of AIP in prognosis in hypertensive populations is needed further exploration.