Association between glucose peak time in oral glucose tolerance test and insulin secretion during pregnancy.
Level 3 - non-randomized controlled study
Prospective observational cohort study
PubMed 41161863 · doi:10.1080/14767058.2025.2578121
What was done
A prospective study evaluated 2,601 pregnant women at 24–28 weeks of gestation using an oral glucose tolerance test (OGTT) and islet function testing. Women were categorized into four groups by blood glucose peak time: GR1 (30 min), GR2 (60 min), GR3 (120 min), and GR4 (180 min), and into two insulin response profiles (Peak 1 vs. Peak 2). Investigators assessed pancreatic beta-cell function, calculated Spearman correlation between glucose and insulin peak timings, and performed multivariate logistic regression to identify predictors of delayed insulin secretion (Peak 2) in women with gestational diabetes mellitus (GDM) and normoglycemic controls.
What was found
Insulin sensitivity and early insulin secretion were poorer in GR3 and GR4 than in GR1 and GR2. Peak times of glucose and insulin secretion showed a moderate positive correlation (Spearman r = 0.54). In women with GDM, independent predictors of the Peak 2 delayed insulin pattern were GR4 (OR 8.30, 95% CI 2.49–27.73, p < 0.001) and 120-minute glucose level (OR 2.94, 95% CI 2.39–3.60, p < 0.001). Among normal pregnant women, GR4 (OR 10.11, 95% CI 3.94–25.94, p < 0.001) and 120-minute glucose level (OR 4.37, 95% CI 3.30–5.79, p < 0.001) were also independent predictors.
Why it matters
Identifying a delayed glucose peak during standard mid-gestation screening provides a practical marker of underlying pancreatic beta-cell dysfunction and insulin resistance, even in women without overt gestational diabetes.
Limits
The abstract does not provide the exact breakdown of participant numbers between GDM and non-GDM cohorts. Clinical maternal or neonatal outcomes (such as macrosomia or preeclampsia) were not reported, and testing was restricted to a single gestational window (24–28 weeks).
Cited by
- supports In a standard oral glucose tolerance test, blood glucose levels peak in approximately 40 to 60 minutes.