Date of Award
8-23-2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Exercise Science
Advisor(s)
Joon Young Kim
Keywords
Diabetes;Incretins;Lifestyle;Obesity
Subject Categories
Life Sciences | Physiology
Abstract
Over the past few decades, the rates of type 2 diabetes (T2D) have seen a sharp rise in youth and young adults. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), the two known incretin hormones, have recently gained attention as pharmacological agents to treat T2D in both youth and young adults. Despite the efficacy of these pharmacological agents to treat T2D, lifestyle interventions are still the first-line treatment for youth and young adults at heightened risk of T2D. Therefore, we sought to assess the incretin response to lifestyle interventions in youth and young adults through separate longitudinal studies in each age group. First, we assessed the incretin response to a 12-week lifestyle intervention in 9 youths with obesity and impaired glucose tolerance (IGT). Second, we assessed the incretin response to two different time-restricted eating protocols via a 4-week randomized controlled trial in 13 young adults with obesity and normal glucose tolerance (NGT). A significant decrease in the GIP, glucose, and insulin response was observed in the first study. Conversely, in the second study, GIP significantly increased from pre to post intervention. These findings suggested the relationship of GIP to β-cell function (βCF) differs by glycemic status. To verify this hypothesis, we examined whether the correlation of GIP to βCF differed by glycemic status using samples previously collected from 139 youths with obesity across the glycemic spectrum (NGT-IGT-T2D). We observed a correlation of GIP to βCF in youth with NGT only, but no relationship with dysglycemia (IGT/T2D). These findings suggest that the GIP response to a lifestyle intervention is mediated by baseline glycemic status as dysglycemia appears to interfere with the relationship of GIP to βCF. These findings are novel and greatly add to the growing field of incretin physiology. Future studies will be able to gauge the efficacy of lifestyle interventions based on the individual’s glycemic status and changes in GIP concentrations.
Access
Open Access
Recommended Citation
Rosenberg, Jared, "The Incretin Response to Lifestyle Interventions in Young Adults and Youth with Obesity" (2024). Dissertations - ALL. 2002.
https://surface.syr.edu/etd/2002
