Association of atherogenic index of plasma with cardiovascular disease mortality in patients with type 2 diabetes mellitus and diabetic kidney disease: a cross-sectional study.

OBJECTIVES: Type 2 diabetes mellitus (T2DM) and diabetic kidney disease (DKD) may exacerbate atherosclerosis through mechanisms such as chronic inflammation, oxidative stress, and lipid redistribution. This study aims to investigate the relationship between atherogenic index of plasma (AIP) and cardiovascular disease (CVD) mortality in patients with T2DM and DKD. METHODS: COX regression models and restricted cubic spline (RCS) curves were utilized to analyze the survival outcomes and non-linear associations among patients with T2DM and DKD. Threshold effects were observed in both global and inflection point models, confirming the predictive value of AIP for participants. Subgroup analysis further investigated the interaction of other variables within the AIP index on T2DM and patients with DKD with CVD mortality. RESULTS: A total of 5,108 patients diagnosed with T2DM, along with 1,598 patients suffering from DKD, were included in this study. In patients with DKD, the AIP index has a "U"-shaped association with CVD mortality. The hazard ratio (HR) and 95% confidence interval of the third quartile of CVD mortality in patients with DKD is Model3: 0.76 (0.61-0.96) (P < 0.023). The inflection point of the threshold effect analysis is 0.14. When AIP is less than 0.14, the effect size and 95% confidence interval of CVD mortality risk in patients with DKD is 0.62 (0.40-0.96) (P < 0.033). When AIP is greater than or equal to 0.14, the effect size and 95% confidence interval of CVD mortality risk in patients with DKD is 1.68 (1.15-2.45) (P < 0.008). CONCLUSIONS: The relationship between AIP and CVD mortality in patients with DKD exhibits a "U" shaped curve, with a turning point value of 0.14. When AIP is below 0.14, the risk significantly decreases (HR = 0.62); conversely, when AIP is equal to or exceeds 0.14, the risk markedly increases (HR = 1.68).