Relationship between carbohydrate intake and oral glucose tolerance test results among pregnant women

Aims: Evaluate the relationship between self-reported carbohydrate intake and oral glucose tolerance test (OGTT) results in pregnancy. Methods: We measured carbohydrate intake using 24-hour dietary recall and performed a 2 hour 75-gram OGTT in 95 pregnant women with risk factors for gestational diabetes (GDM) at a median of 26 weeks' gestation. We tested for associations between carbohydrate intake in the 24 hours preceding the OGTT and 60-minute OGTT glucose, glucose at other time points, and glucose area under the curve (AUC) using linear regression, with adjustment for potential confounders. Results: We observed an inverse linear relationship between carbohydrate intake (median 237 grams [interquartile range: 196, 303]) and 60-minute OGTT glucose. For every 50 gram reduction in carbohydrate intake, there was an 8.9 mg/dl increase in 60-minute OGTT glucose (P < 0.01) in an adjusted model. Lower carbohydrate intake was also associated with higher 30-minute (adjusted 13 =-6.5 mg/dl, P < 0.01) and 120-minute OGTT glucose (adjusted 13 =-8.1 mg/dl, P = 0.01) and AUC (adjusted 13 =-767, P < 0.01). Conclusions: Carbohydrate intake in the day preceding an OGTT in pregnancy is associated with post-load glucose values, with lower carbohydrate intake predicting higher glucose levels and higher carbohydrate intake predicting lower glucose levels. Carbohydrate restriction or excess before an OGTT may affect GDM diagnosis. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study revealed an association between carbohydrate intake before an OGTT during pregnancy and post-load glucose values. Lower carbohydrate intake was linked to higher glucose levels, while higher carbohydrate intake was associated with lower glucose levels. These findings suggest that carbohydrate restriction or excess before an OGTT may impact the diagnosis of GDM.