Serum Inflammatory Indices and Preeclampsia Risk: A Matched Case-control Study

Abstract

Background: While numerous studies have linked individual serum inflammatory biomarkers to preeclampsia (PE) risk, few have evaluated how composite inflammatory indices correlate with the condition. Methods: A hospital-based 1:1 matched case-control study including 440 PE cases and 440 controls was conducted. Sociodemographic and lifestyle data were collected through structured questionnaires. Peripheral blood platelet, neutrophil, monocyte, and lymphocyte counts were measured using a fully automated analyzer (Cobas 8000, modules C701/C702/C502), and the corresponding inflammatory indices were subsequently calculated. Results: Multivariable-adjusted regression revealed an inverse risk trend across quartiles for all six evaluated metrics. In the highest-versus-lowest quartile comparison, the most pronounced reduction in odds was observed for PLR (OR = 0.08, 95% CI: 0.05–0.15), followed sequentially by AISI (OR = 0.13, 0.08–0.22), SIRI (OR = 0.23, 0.14–0.37), SII (OR = 0.41, 0.30–0.55), and LMR (OR = 0.53, 0.39–0.71), all presenting a P -trend < 0.001. A similar significant trend was noted for NLR (OR = 0.63, 0.48–0.83, P -trend < 0.01). Among the individual indicators, PLR showed a relatively higher AUC, while the combined model yielded a slightly higher area under the curve (AUC) overall. Conclusion: Lower levels of SII, LMR, NLR, SIRI, AISI, and PLR were associated with an increased risk of PE, while combining these inflammatory indices provided the best discriminative performance.