Acute Caffeine Ingestion and Glucose Tolerance in Women With or Without Gestational Diabetes Mellitus

Abstract

ObjectiveRecent work showing that caffeine impairs glucose tolerance may be of particular concern in pregnancy because of a possible negative effect on fetal outcome. The current study sought to assess the effect of acute caffeine ingestion on glucose tolerance in women with or without gestational diabetes mellitus (GDM). MethodsNineteen women whose routine GDM test was negative (control) and eight women with an initial positive GDM screen completed two trials one week apart in a double-blind randomized crossover study. Following an overnight fast, subjects ingested caffeine (3 mg/kg pre-pregnancy body weight) or an identical-appearing placebo (gelatin) capsule and one hour later began a 75 g 2-hour oral glucose tolerance test. ResultsIn the control group, caffeine did not significantly affect blood glucose, insulin, or C-peptide. In the GDM group, glucose area under the curve (AUC) was greater (P < 0.01), C-peptide AUC was greater (P < 0.05), and insulin sensitivity index was lower (18%, P < 0.05) after caffeine than after placebo. ConclusionCaffeine impaired insulin sensitivity in women with GDM. Additional research regarding more specific dietary caffeine recommendations for women with GDM is warranted.