Glucose Peak Time During OGTT: A Marker for Metabolic Health and Insulin Resistance

Authors

Ulices Villalobos, The University of Texas at El PasoFollow
Jehu Apaflo, The University of Texas at El PasoFollow
Zahra Fatahimeiabadi, The University of Texas at El PasoFollow
Joshua Labadah, The University of Texas at El PasoFollow
Irene John Tomy, The University of Texas at El PasoFollow
DWAIPAYAN SAHA, The University of Texas at El PasoFollow
Preyangsee Dutta Dr., The University of Texas at El PasoFollow
Sudip Bajpeyi, University of Texas at El PasoFollow

Abstract

The Oral Glucose Tolerance Test (OGTT) screens for impaired glucose tolerance and diabetes. While a high overall glucose surge during a 3 hour OGTT indicates glucose intolerance, the glucose peak time offers valuable insights into metabolic health. PURPOSE: This study examines whether glucose peak time during an OGTT is indicative of glucose intolerance and insulin resistance. METHODS: Participants (n=208; 101 females, 107 males; Age 28.1 ± 10.6 years; BMI 28.3 ± 6.3 kg/m²) consumed 75 grams of glucose drink and completed an OGTT with blood glucose levels measured at 0, 30, 60, 90, 120, 150, and 180 minutes. Fasting glucose and fasting insulin levels were measured, insulin resistance was assessed using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) calculated as: (Fasting Blood Glucose x Fasting Insulin)/22.5. The glucose area under the curve (AUC) over three hours was calculated using the trapezoid method. Participants were categorized into two groups based on their glucose peak time: those whose glucose peaked at or before 30 minutes (≤30) and those who peaked after 30 minutes (>30). Long-term glycemic control was assessed by glycated hemoglobin (HbA1c). An unpaired t-test was used to compare groups. RESULTS: The group whose glucose peaked after 30 minutes (>30) during the OGTT showed significantly greater insulin resistance, indicated by elevated fasting insulin levels (12.9±9.9 vs. 9.9±5.3 µU/mL; p<0.05), higher HOMA-IR values (3.4±3.2 vs. 2.2±1.2; p<0.05), higher glucose intolerance (426.9±110.9 vs. 363.3±45.8; p <0.01) and exhibited higher HbA1c levels (5.6±1.2 vs. 5.2±0.3%; p<0.05) compared to the group whose glucose peaked at or before 30 minutes (≤30). CONCLUSION: A delayed glucose peak (>30) during an OGTT indicates greater insulin resistance, glucose intolerance, and poorer long-term glucose control. This finding suggests that glucose peak time may be a valuable and affordable marker for identifying individuals at risk of insulin resistance. These findings highlight the potential of glucose peak timing as an early diagnostic tool for metabolic dysfunction.

Recommended Citation

Villalobos, Ulices; Apaflo, Jehu; Fatahimeiabadi, Zahra; Labadah, Joshua; John Tomy, Irene; SAHA, DWAIPAYAN; Dutta, Preyangsee Dr.; and Bajpeyi, Sudip (2025) "Glucose Peak Time During OGTT: A Marker for Metabolic Health and Insulin Resistance," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 17, Article 116.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss17/116