CRP–triglyceride–glucose index (CTGI) as a predictor of preeclampsia: a population-based study of risk stratification

BACKGROUND: preeclampsia (PE) remains a leading cause of maternal and perinatal morbidity and mortality worldwide. While metabolic and inflammatory factors are increasingly recognized in its pathogenesis, the clinical utility of composite biomarkers remains underexplored. This study aimed to investigate the association between the C-reactive protein-triglyceride-glucose (CRP-TG-glucose) index (CTGI), a novel marker of metabolic-inflammation stress, and the risk of preeclampsia. METHODS: This retrospective cohort study included 11,916 pregnant women, of whom 486 developed preeclampsia. Maternal baseline characteristics were compared between the PE and non-PE groups. Logistic regression analyses were conducted to identify factors associated with PE. The relationship between CTGI and PE risk was further explored using quartile stratification, restricted cubic spline regression, and threshold effect analyses. Subgroup analyses were also performed to assess interaction effects across maternal and obstetric variables. RESULTS: Women with PE had significantly higher maternal age, body mass index (BMI), in vitro fertilization (IVF) conception, multifetal pregnancies, and elevated CTGI levels compared to non-PE counterparts (all P < .001). Multivariate logistic regression identified CTGI as an independent risk factor for PE (adjusted OR, 1.78; 95% CI, 1.51-2.09; P < .001), alongside BMI, maternal age, IVF, and multifetal gestation. A dose-response relationship was observed across CTGI quartiles, with the highest quartile showing a markedly increased PE risk (adjusted OR, 2.06; 95% CI, 1.52-2.81). Restricted cubic spline models and threshold analysis revealed a nonlinear association with a significant inflection point at CTGI = 2.244. Above this threshold, the risk of PE rose sharply (OR, 3.93; 95% CI, 2.09-7.39; P < .001). Subgroup analyses demonstrated consistent associations across maternal age, BMI, parity, plurality, and IVF status, without significant interaction. CONCLUSIONS: Elevated CTGI in early pregnancy is independently and nonlinearly associated with an increased risk of preeclampsia, particularly above a critical threshold of 2.244. These findings underscore the potential clinical value of CTGI as an early risk stratification biomarker for PE, enabling timely intervention in high-risk pregnancies.