# Association between the atherogenic index of plasma and prehypertension or hypertension among adults in Fujian, China: a population-based cross-sectional study

## TL;DR

This study finds that higher atherogenic index of plasma (AIP) is linked to increased risks of prehypertension and hypertension in Chinese adults.

## Contribution

The study provides new evidence on the association between AIP and prehypertension/hypertension risks in a Chinese population.

## Key findings

- AIP was significantly positively associated with prehypertension and hypertension risks.
- White blood cell count mediated a portion of the AIP's effect on blood pressure risks.
- AIP showed clinical predictive value for hypertension with an AUC of 0.721.

## Abstract

Elevated blood pressure may share a similar pathophysiology with cardiovascular disease (CVD). Although the atherogenic index of plasma (AIP) has been associated with hypertension and CVD, evidence on the association between the AIP and prehypertension risk remains limited. This study aims to explore the relationship of the AIP with the risks of prehypertension and hypertension in a Chinese population.

This study was based on a population-based cross-sectional survey data of Fujian province and was conducted between August 2020 and April 2021. The association between the AIP and prehypertension/hypertension risk was assessed through multivariate logistic regression. Four-knot restricted cubic splines (RCS) were performed to examine the potential dose–response relationships. Subgroup analyses were used to assess the heterogeneity of the associations across different population subgroups, and an receiver operating characteristic (ROC) curve analysis was used to determine the cutoff values for predicting prehypertension/hypertension. The mediating roles of the two types of inflammatory indicators were analyzed through mediation analysis. Several sensitivity analyses were also conducted to further assess the robustness of the results.

A total of 9,473 adults were included in the final analysis, including 3,273 diagnosed with prehypertension and 3,248 with hypertension. Overall, participants with elevated AIP levels demonstrated higher prehypertension detection rates and hypertension prevalence (all P < 0.05). The multivariate logistic regression model showed that the AIP was significantly positively associated with prehypertension [per 0.1-unit increment in the AIP: odds ratio (OR), 1.05, 95% confidence interval (CI): 1.03–1.07] and hypertension (per 0.1-unit increment in the AIP: OR, 1.11, 95% CI: 1.09–1.14), respectively. Compared with the lowest quartile of the AIP, participants in the highest quartile had a higher risk of prehypertension [OR: 1.58 (1.32, 1.90)] and hypertension [OR: 2.30 (1.86, 2.84)]. No evidence of a non-linear association was observed between the AIP and the risk of prehypertension (Pnon-linear = 0.178) or hypertension (Pnon-linear = 0.087). There were significant interactions between the AIP and both residential location and educational level regarding the risk of blood pressure classification (Pinteraction < 0.05). Furthermore, an ROC analysis indicated a higher clinical predictive value of the AIP for hypertension (AUC = 0.721, 95% CI: 0.708–0.734). White blood cell count mediated 10.91% and 15.52% of the total effect of the AIP on prehypertension and hypertension, respectively.

The AIP is positively associated with the risk of prehypertension and hypertension among participants ≥ 18 years of age in China, with white blood cell count potentially mediating a part of this association, which indicates that monitoring and maintaining optimal AIP levels may help prevent the deterioration of blood pressure categories.