1532-P: A Low-Glycemic Load Breakfast Improves Glycemia in Women with Gestational Diabetes (GDM): A Randomized Crossover Trial

Introduction and Objective: Medical nutrition therapy underpins GDM management, yet evidence-based guidelines are needed. Greater morning insulin resistance often results in post-breakfast hyperglycemia in GDM. A low glycemic load (GL) diet reduces glucose concentrations and need for pharmacotherapy in GDM, but the impact of targeting breakfast only is unknown. In a randomized cross-over trial, we compared the effects of a low vs high GL breakfast (LGL-B vs HGL-B) on breakfast 1-h postprandial glucose (PPG) and 24-h glycemic variability (GV) (primary outcomes) within GDM women. Methods: Women were provided a LGL-B (245 kcal; carbohydrate: 10.9g) and HGL-B (247 kcal; carbohydrate: 43.4g) for 7d separated by a 7d washout. Fasting blood was drawn on day 1 and 7; a masked continuous glucose monitor was worn. PPG and GV (% coefficient of variation [%CV]) were averaged over 7d. Mixed effect models with Bonferroni corrections were conducted to compare between intervention effects within women. Results: Thirty women with diet managed GDM (median 34.5 yrs, BMI 28.1 kg/m2) were randomized (26 wks’ gestation). Compared to HGL-B, LGL-B decreased 1-h PPG (mean 134 mg/dL [95% CI 129, 140] vs 89 mg/dL [84, 94]) and 24-h %CV (19.5 [18.1, 21.0] vs 16.6 [15.2, 18.1]) (both p<0.001). Triglycerides decreased over 7d on LGL-B and increased on HGL-B (time x intervention; p=0.047). There was no difference in ketones, satiety, or acceptability. Conclusion: Within women with GDM, a LGL-B improves breakfast PPG, GV, and potentially triglycerides. This approach may be a simple dietary recommendation to improve glycemia and reduce need for pharmacotherapy in women with GDM. Disclosure J. Burk: None. G.P. Ross: None. S. Colagiuri: None. G.D. Brinkworth: None. P.J. Taylor: None. E.G. Dunn: None. S. Hagen-Lillevik: None. M. Hivert: None. T.L. Hernandez: None. A. Sweeting: None. Funding Sydney Local Health District, Sydney Institute for Women, Children and their Families Seed Funding Grant 2022