AUTHOR=Porter Jay W. , Pettit-Mee Ryan J. , Ready Sean T. , Liu Ying , Lastra Guido , Chockalingam Anand , Winn Nathan C. , Clart Laura , Kanaley Jill A. 

TITLE=Post Meal Exercise May Lead to Transient Hypoglycemia Irrespective of Glycemic Status in Humans

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00578

DOI=10.3389/fendo.2020.00578

ISSN=1664-2392

ABSTRACT=During exercise, there is coordination between various hormonal systems to ensure glucoregulation.  This study examined if hypoglycemia occurs during moderate-intensity exercise in non-obese and obese individuals with and without type 2 diabetes (T2D).  Eighteen non-obese, 18 obese and 10 obese with T2D were recruited.  Each subject completed 2 study days that included a standard meal at 1800-h followed by rest (NOEX) or exercise (PMEX; 45 min at 55% of VO2max 2-h post meal).  Glucose, insulin and glucagon concentrations were measured throughout this 5.5-h period. Subjects with T2D had elevated glucose responses to the meal on both study days, compared to non-obese and obese subjects (P<0.05).  During exercise on PMEX, subjects with T2D had a greater drop in glucose concentration (-98.4±13.3 mg/dL) compared to obese (-44.8±7.1 mg/dL) and non-obese (-39.3±6.1 mg/dL; P<0.01) subjects.  Glucose levels decreased more so in females than males in both conditions (P<0.01).  Nadir glucose levels <70 mg/dL were observed in 33 subjects during NOEX and 39 subjects during PMEX.  Obese males had a larger exercise-induced insulin drop than obese females (P=0.01).  During PMEX, peak glucagon concentrations were elevated compared to NOEX (P<0.001).  Male participants with T2D had an increased glucagon response during NOEX and PMEX compared to females (P<0.01).  In conclusion, in sedentary individuals there is a dramatic drop in glucose levels during moderate-intensity exercise, despite appropriate insulin concentrations prior to exercise, and glucagon levels rising.  Moderate-intensity exercise can lower exercise glucose concentrations below 60 mg/dL, and many individuals will be asymptomatic.