Poster Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Glucose and insulin profiles during an oral glucose tolerance test (oGTT) are similar between fed and fasted states in a cohort of university students. (#222)

Lisa K Akison 1 , Linda A Gallo 1 2 , Johanna L Barclay 2 , Aowen Zhuang 2 , Cortina Chen 1 , Amelia K Fotheringham 2 , Karen M Moritz 1 3
  1. School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
  2. Mater Research, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
  3. Child Health Research Centre, Centre for Children’s Health Research, The University of Queensland, South Brisbane, QLD, Australia

The rising incidence of obesity in Australia is linked to an increased prevalence of type-2 diabetes-mellitus, which currently affects 7% of the population. Oral glucose tolerance test (oGTT) is the standard method for assessing glycaemic response to a glucose challenge and an important measure of an individual’s metabolic health. Typically, an oGTT is performed after fasting, but is this absolutely required and how do results compare to a fed state? We addressed this question using a cohort of university students within a tight age range (18-26). Participants were recruited from a third-year biomedical practical class from The University of Queensland (2016-2017), with complete data obtained from 277 students. Students were divided randomly into fasted (9-hours, n=177) or fed (n=100) groups. Baseline (T0) blood glucose levels were measured using a glucometer, followed by a glucose load (75mg/300ml) and blood glucose measurements at T30, T60 and T120 minutes post-load. A subset of students (n=29 fasted and n=20 fed) also had plasma insulin levels measured at the same time points via ELISA. T0 blood glucose levels were significantly elevated in the fed (median 5.4mmol/L) compared to fasted group (median 4.6mmol/L) in both males and females. However, analysis of area under the curve (AUC) indicated that the glucose profiles were not significantly affected by fasting. T120 glucose levels were in the normal range in both groups. Similarly, T0 plasma insulin levels were elevated in the fed (median 21.7mU/L in males and 30.6mU/L in females) compared to the fasted group (median 6.2-6.5mU/L), but total AUC was not different. This suggests that while a fed state mildly elevates baseline blood glucose and insulin levels, it did not impact on the subsequent glucose or insulin profiles following a glucose challenge, at least in the young, healthy individuals examined in this cohort.