(PTFS10-06-25) A Higher Complex Carbohydrate Diet in Gestational Diabetes Lowers Daytime Glucose and Associates With Reduced Neonatal Adiposity

Objectives: Dietary approaches to manage maternal glucose in gestational diabetes mellitus (GDM) are debated. Higher 24-hr maternal glucose is associated with increased newborn adiposity (NB%fat), a stronger predictor of childhood obesity than birthweight. The impact of specific glycemic patterns on NB%fat remains unclear. To guide management strategies, we sought to identify whether continuous glucose monitor (CGM) metrics associate with NB%fat during a controlled trial of two diets in GDM.

Methods: After diagnosis, patients with diet-controlled GDM were randomized to a higher-complex carbohydrate (CHO; 60% CHO/25% fat; CHOICE) or a conventional lower carbohydrate (40% CHO/45% fat; LC/CONV) diet. Both diets were eucaloric to reduce excess gestational weight gain. All meals were provided through delivery. A CGM was worn x3d at 30-31 and again at 36-37 wks’. NB%fat was measured by PEA POD at 2 wks’ of life. Deltas were calculated for all CGM metrics (36-37 minus 30-31 wk). Pearson’s and Spearman’s correlations were used to evaluate associations between CGM deltas and NB%fat.

Results: Patients in both groups (n=32; mean±SD; BMI 32±5) were on diet for 4±1 wks between CGM timepoints, met treatment targets, and had improved CGM metrics. There were no differences in CGM metric deltas between diet groups. In CHOICE (~300 g CHO/d CHOICE vs ~200 g CHO/d LC/CONV), decreases in 2-hr postprandial (PP) glucose (-1.72±15 mg/dL; r=.56, p=.036), %time >120 mg/dL (-.008±.11% (~11 min); r=.47, p=.043), mean daytime glucose (-4.24±13 mg/dL; r=.54, p=.016), mean 24-h BG (-1.62±10.38 mg/dL; r_s(19)=.51, p=.025), and daytime area-under-the-curve (AUC) (-5073±26243 mg*min/dL; r_s(19)=.48, p=.040) were positively associated with reduced NB%fat (10.53±4.1%). No changes in CGM metrics were related to NB%fat (10.10±4.5%) in the LC/CONV group.

Conclusions: GDM patients on two diverse diets showed improved glycemia after 4 wks, indicating dietary interventions with options beyond CHO restriction are effective. With CHOICE, even modest reductions in overall daytime glucose may lower NB%fat, suggesting additional dietary mechanisms beyond strict glycemic control influencing NB%fat.

Funding Sources: NIH National Institute of Diabetes and Digestive and Kidney Disease
NIH T32 Research Fellowship