Medicine and Science in Sports and Exercise
Author:
Keywords:
Science & Technology, Life Sciences & Biomedicine, Sport Sciences, TYPE 2 DIABETES MELLITUS, EXERCISE, GLYCEMIC CONTROL, POSTPRANDIAL HYPERGLYCEMIA, GLYCEMIC VARIABILITY, CONTINUOUS GLUCOSE MONITORING, GLUCOSE VARIABILITY, PREVALENCE, MANAGEMENT, THERAPY, Aged, Blood Glucose, Cross-Over Studies, Diabetes Mellitus, Type 2, Exercise, Humans, Hyperglycemia, Middle Aged, Netherlands, Time Factors, 1106 Human Movement and Sports Sciences, 1116 Medical Physiology, 1117 Public Health and Health Services, 3202 Clinical sciences, 3208 Medical physiology, 4207 Sports science and exercise
Abstract:
PURPOSE: We assessed the impact of a single bout of moderate-intensity exercise on subsequent 24 h glycemic control in 60 type 2 diabetic patients. Moreover, we examined whether individual responses to exercise were related to subjects' baseline characteristics, including age, BMI, diabetes duration, exercise performance, medication, and HbA1c content. METHODS: Sixty type 2 diabetic patients (insulin-treated n=23) participated in a randomized crossover experiment. Patients were studied on 2 occasions for 3 days under strict dietary standardization, but otherwise free-living conditions. Parameters of glycemic control (means [95%CI]) were assessed by continuous glucose monitoring over the 24 h period following a single bout of moderate-intensity endurance-type exercise or no exercise at all (control). RESULTS: Type 2 diabetic patients experienced hyperglycemia (blood glucose >10 mmol/L) for as much as 8:16 h:min (6:44 to 9:48) per day. The prevalence of hyperglycemia was reduced by 31% to 5:38 h:min (3:17 to 7:00) over the 24 h period following the exercise bout (P< /0.001). Moreover, exercise lowered average blood glucose concentrations by 0.9 mmol/L (0.7 to 1.2) and reduced glycemic variability (P< /0.05). The response to exercise showed considerable variation between subjects, and correlated positively with HbA1c levels (r=0.38, p< /0.01). Nevertheless, even well-controlled patients with an HbA1c level below 7.0% (n=28) achieved a 28% reduction in the daily prevalence hyperglycemia following exercise (P< /0.01). CONCLUSIONS: A single bout of moderate-intensity exercise substantially improves glycemic control throughout the subsequent day in insulin- and non-insulin treated type 2 diabetic patients. Of all baseline characteristics, only subjects' HbA1c level is related to the magnitude of response to exercise. Nevertheless, the present study demonstrates that even well-controlled patients benefit considerably from the blood glucose-lowering properties of daily exercise.