(P37-25-26) Glucoregulatory and Inflammatory Trajectories During an Antepartum Exercise Intervention in Pregnancies With Obesity: Secondary Analysis of a Randomized Controlled Trial

Objectives: To evaluate the impact of a de novo, moderate-intensity exercise intervention on glucose regulation and inflammatory markers in pregnant women with obesity.

Methods: This study reports secondary and exploratory analyses from the Expecting Study (ClinicalTrials.gov NCT02125149) Sedentary pregnant women (N=264) with a pre-pregnancy BMI ≥ 30 kg/m2 and no baseline metabolic disease were randomized to exercise (EX, N=157) or standard-of-care (SoC, N=107). Fasting glucose, insulin, C-peptide, glucagon, HOMA2 indices, IL-6, TNF-α, and CRP were assessed at 12.14±0.50, 24.19±0.68, and 36.03±0.58 weeks’ gestation. Continuous Glucose Monitoring (CGM) data from a subset of participants (N=18) were summarized into trimester-specific CGM metrics. Linear mixed-effects models evaluated group, trimester, and group-by-trimester effects, adjusting for baseline covariates to improve estimate precision. Cross-sectional associations between CGM metrics and maternal inflammatory markers were explored.

Results: Fasting insulin, C-peptide, HOMA2-IR, estimated β-cell function, IL-6, and TNF-α increased, while estimated insulin sensitivity and CRP decreased from 24 to 36 weeks (all p < 0.001), with no group or interaction effects for any fasting glucoregulatory or inflammatory markers. CGM data was available for >95% of wear time, ≥12-15 day wear per trimester. CGM metrics remained in normoglycemic range for both groups, with modest declines in mean 24-h glucose, nocturnal glucose, and time in range (TIR) in the SoC group only. TIR negatively associated with IL-6 at 24 weeks (-0.23 [95% CI -0.43, 0.02] p = 0.035), whereas mean amplitude of glycemic excursion positively associated with TNF-α at 36 weeks (0.02 [95% CI 0.00, 0.04] p = 0.033).

Conclusions: Structured exercise did not modify mid- to late gestation fasting glucoregulatory or inflammatory profiles in women with obesity with prior sedentary behaviors. High CGM adherence and preliminary indications of sensitivity to subtle shifts in glycemic patterns support the integration of CGM for future antepartum lifestyle interventions.

Funding Sources: USDA, NIH-NIGMS, Maternal, Early Nutrition and Development Research Core,  Arkansas Children's Nutrition Center, Arkansas Children's Research Institute