Correlation between atherogenic index of plasma and cardiovascular disease risk across Cardiovascular–kidney–metabolic syndrome stages 0–3: a nationwide prospective cohort study

The Cardiovascular–kidney–metabolic (CKM) syndrome, a concept recently proposed by the American Heart Association (AHA), highlights the intricate connection between metabolic, renal, and cardiovascular illnesses. Furthermore, the Atherogenic Index of Plasma (AIP), a useful biomarker for evaluating the risk of Cardiovascular Diseases (CVDs), has been associated with the risk of Adverse Cardiovascular Events (ACEs). Nonetheless, its precise function in populations in CKM syndrome Stages 0–3 remains unknown. This prospective study analyzed the data of 7,708 eligible participants (aged ≥ 45 years) from the Chinese Longitudinal Research of Ageing (CHARLS), particularly the 2011–2012 baseline survey (Wave 1). The primary exposure variable was AIP—a natural logarithm of the ratio of Triglycerides (TGs) to High-Density Lipoprotein Cholesterol (HDL-C). On the other hand, the primary endpoint was CVD incidence, which was determined based on self-reported past diagnoses. The relationship between AIP and CVD risk in the population in CKM syndrome stages 0–3 was examined using a Cox proportional risk model. Subgroup and mediation analyses were performed to further elucidate the interactions among these factors. This study involved 7,708 participants in the CKM syndrome stages 0–3 [Mean age = 58.00 years; Interquartile Range (IQR) = 52.00–65.00 years]. The risk of developing CVD increased significantly with higher AIP levels. Specifically, the risk ratio for each unit increase in AIP was 1.31 (95% CI 1.11–1.55), while the Hazard Ratio (HR) for the group with the highest AIP levels compared to the group with the lowest AIP levels was 1.22 (95% CI 1.08–1.39). Mediation analysis revealed that metabolic syndrome accounted for 12.3% of the association between AIP levels and CVD risk (p = 0.024), highlighting its significance in CVD risk assessment. Herein, AIP levels correlated significantly positively with CVD risk in individuals in CKM stages 0–3, with metabolic syndrome as a key mediating factor. These findings suggest that AIP levels could be valuable not only for CVD risk assessment but also for clinical screening.