Association of metabolic score for insulin resistance and gestational diabetes mellitus: a multicenter cohort study

Qiong Li^1*Ying Zhang²Chenyang Zhao¹Meng Li²Ying Gu³Yangjing Pang⁴Ping Yu³Chaoyan Yue^2*

• ¹The First People's Hospital of Chenzhou, Chenzhou, China
• ²Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
• ³Wuxi Maternity and Child Health Care Hospital, Wuxi, China
• ⁴Jiangnan University Wuxi School of Medicine, Wuxi, China

Background: The metabolic score for insulin resistance (METS-IR) is a novel and effective indicator for assessing insulin resistance. Previous studies have shown that it is positively associated with the risk of type 2 diabetes. However, the association between METS-IR and gestational diabetes mellitus (GDM) has not yet been clearly calrified. This study aims to investigate the association between METS-IR and GDM as well as its related adverse pregnancy outcomes, and to evaluate its predictive value. Methods: A total of 37,770 singleton pregnant women from three hospitals in China between January 2018 and June 2024 were included in the study. METS-IR was calculated using the formula: ln([HDL-C (mg/dL)] × [2 × fasting glucose (mg/dL)] + TG (mg/dL) × BMI (kg/m²)). Participants were divided into four groups according to METS-IR quartiles. Multivariable logistic regression models, smoothed curve fitting, and subgroup analyses were conducted to assess the associations between METS-IR and GDM as well as related adverse pregnancy outcomes. Receiver operating characteristic (ROC) curves were used to evaluate the predictive performance. Results: After adjusting for potential confounders, higher METS-IR levels were significantly associated with increased risk of GDM. Compared with the lowest quartile group (Q1), the risks of GDM in the Q2, Q3, and Q4 groups increased by 13% (OR=1.13, 95% CI: 1.02-1.25), 59% (OR=1.59, 95% CI: 1.44-1.75), and 165% (OR=2.65, 95% CI: 2.42-2.91), respectively. Similar associations were also observed between METS-IR and preterm birth, macrosomia, GDM complicated with preeclampsia (GDM&PE), and pharmacologically treated GDM (GDMA2). Smoothed curve fitting suggested an approximately linear dose-response relationship between METS-IR and GDM. Subgroup analysis indicated that the association between METS-IR and GDM remained consistent across different age groups (interaction P > 0.05), with a higher GDM risk observed among women aged ≥ 35 years. ROC analysis showed that the AUCs of METS-IR for predicting GDM, preterm birth, macrosomia, GDM&PE, and GDMA2 were 0.623, 0.532, 0.640, 0.741, and 0.712, respectively. Conclusion: This study demonstrated that METS-IR is positively associated with GDM risk and its related adverse pregnancy outcomes. METS-IR may serve as a useful tool for risk stratification and early intervention in clinical practice for GDM.