Exercise-induced improvements in glucose effectiveness areblunted by a high glycemic diet in adults with prediabetes

Adithya Hari, Ciaran Fealy, Thomas P. J. Solomon, Jacob M. Haus, Karen R. Kelly, Hope Barkoukis, John P. Kirwan*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


AimsGlucose effectiveness (GE) refers to the ability of glucose to influence its own metabolism through insulin-independent mechanisms. Diminished GE is a predictor of progression to type 2 diabetes. Exercise training improves GE, however, little is known about how dietary interventions, such as manipulating the glycemic index of diets, interact with exercise-induced improvements in GE in at-risk populations.MethodsWe enrolled 33 adults with obesity and pre-diabetes (17 males, 65.74.3 years, 34.94.2kgm(-2)) into a 12-week exercise training program (1 hday(-1) and 5 dayweek(-1) at 85% of maximum heart rate) while being randomized to concurrently receive either a low (EX-LOG: 40 +/- 0.3au) or high (EX-HIG: 80 +/- 0.6au) glycemic index diet. A 75-g oral-glucose-tolerance test (OGTT) was performed before and after the intervention and GE was calculated using the Nagasaka equation. Insulin resistance was estimated using a hyperinsulinemic-euglycemic clamp and cardiorespiratory fitness using a VO2max test.Results: Both EX-LOG and EX-HIG groups had similar improvements in weight (8.6 +/- 5.1kg, P0.05) and increased by 20% post-intervention in the EX-LOG arm (GE: 0.07-0.57mgdL(-1)min(-1), P

Original languageEnglish
Pages (from-to)211-217
Number of pages7
JournalActa Diabetologica
Issue number2
Publication statusPublished - Feb 2019


  • Aerobic exercise training
  • Glycemic index
  • Diet
  • Glucose effectiveness
  • Hyperinsulinemic-euglycemic clamp
  • Prediabetes

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