Effects of exercise in the postprandial and fasted state on glycemia and markers of inflammation in persons prone to or with diabetes

Abstract

The prevalence of hyperglycemia and diabetes is increasing worldwide. It is therefore crucial to develop simple and effective strategies for diabetes prevention and to clarify related physiological mechanisms. The purpose of this thesis was to test if one bout of exercise performed in either the postprandial or the fasted state acutely affects glucose values and markers of inflammation, and to test whether regular postprandial exercise can improve glycemia in persons prone to or with diabetes. To answer the research questions, we performed two studies. In Study 1, we assessed the acute response on interstitial glucose values and markers of inflammation of exercise performed either before (fasted) or after breakfast (postprandial), utilizing a randomized crossover design. Interstitial glucose was measured continuously until the next morning, while the markers of inflammation; sVCAM-1 and CRP were assessed 10.1139/apnm-2016-0467during the first 3.5 hours after breakfast and once next morning. Study 2 was a randomized controlled study, encompassing an intervention group undertaking regular postprandial exercise during 12 weeks, and measures of HbA1c, fasted blood glucose, and glucose tolerance. The results from Study 1 showed that postprandial exercise decreased peak glucose values and glycemic variability, while this was not the case for fasted exercise. Merged data from both exercise interventions showed that exercise per se increased sVCAM-1, with no substantial difference between the two types of exercise. CRP remained unchanged. In Study 2, none of the measured glycemic variables seemed to change as a result of regular postprandial exercise. Thus, postprandial exercise improves glycemia acutely, but apparently not in the long term.