Association Between the Lifestyle Inflammation Score and Gestational Diabetes Mellitus and Postpartum Glucose Metabolism Alterations

<b>Background/Objectives:</b> This study aimed to assess the associations between the Lifestyle Inflammation Score (LIS) and gestational diabetes mellitus (GDM), and glucose metabolism alterations (GMA) postpartum. <b>Methods:</b> A secondary analysis was conducted on 378 pregnant women at the end of pregnancy. Anthropometric, clinical, biochemical, and dietary parameters were evaluated. Postpartum reclassification was based on fasting serum glucose (>100 mg/dL), HbA1c (>5.7%), and/or a 2-h oral glucose tolerance test (>140 mg/dL). The LIS was calculated using a proxy index including smoking status, physical activity, and pregestational BMI, applying the beta coefficient from the original LIS model. Tertiles were created, with T3 indicating the highest level of proinflammatory exposure. Statistical analyses included Kruskal-Wallis, one-way ANOVA, linear-by-linear association, and multivariate logistic regression, adjusted for family history, gestational weight gain, carbonylated proteins, and adiponectin to evaluate associations between LIS and GDM, and adjusted for pharmacological treatment, gestational weight gain, and breastfeeding for LIS and GMA. <b>Results:</b> Higher LIS values were more common among women with GDM (T1 = 45.9%, T2 = 62.2%, T3 = 74.8%, <i>p</i> < 0.001) and among those with GMA (T1 = 34.4%, T2 = 45.6%, T3 = 53.7%, <i>p</i> = 0.019). Compared with the lowest tertile, the highest tertile of LIS was associated with greater odds of GDM (OR 3.72; 95% CI: 1.19-11.64, <i>p</i> = 0.024) and GMA (OR 2.69; 95% CI: 1.25-5.76, <i>p</i> = 0.011). <b>Conclusions:</b> A more proinflammatory lifestyle, as reflected by a higher LIS, increases the risk of progression to GDM and later to GMA.