Exercise and 24-h Glycemic Control: Equal Effects for All Type 2 Diabetes Patients?

VAN DIJK, JAN-WILLEM1; MANDERS, RALPH J. F.1; CANFORA, EMANUEL E.1; MECHELEN, WILLEM VAN2; HARTGENS, FRED3; STEHOUWER, COEN D. A.4; VAN LOON, LUC J. C.1

Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e31827ad8b4
Clinical Sciences
Abstract

Purpose: We assessed the effect of a single bout of moderate-intensity exercise on subsequent 24-h glycemic control in 60 type 2 diabetes patients. Moreover, we examined whether individual responses to exercise were related to subjects’ baseline characteristics, including age, body mass index, diabetes duration, exercise performance, medication, and HbA1c content.

Methods: Sixty type 2 diabetes patients (insulin-treated, n = 23) participated in a randomized crossover experiment. Patients were studied on two occasions for 3 d under strict dietary standardization but otherwise free-living conditions. Parameters of glycemic control (means [95% confidence interval]) were assessed by continuous glucose monitoring over the 24-h period after a single bout of moderate-intensity endurance-type exercise or no exercise at all (control).

Results: Type 2 diabetes patients experienced hyperglycemia (blood glucose >10 mmol·L−1) for as much as 8:16 h:min (6:44 to 9:48 h:min) per day. The prevalence of hyperglycemia was reduced by 31% to 5:38 h:min (3:17 to 7:00 h:min) over the 24-h period after the exercise bout (P < 0.001). Moreover, exercise lowered average blood glucose concentrations by 0.9 mmol·L−1 (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 after 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 diabetes 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.

Author Information

1Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+, Maastricht, THE NETHERLANDS;2Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, THE NETHERLANDS;3Departments of Epidemiology and Surgery, CAPHRI School for Public Health and Primary Care; and 4Department of Internal Medicine, CARIM Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, THE NETHERLANDS

Address for correspondence: Luc J.C. van Loon, Ph.D., Department of Human Movement Sciences, Maastricht University Medical Centre+, PO Box 616, 6200 MD Maastricht, The Netherlands; E-mail: L.vanloon@maastrichtuniversity.nl.

Submitted for publication July 2012.

Accepted for publication October 2012.

©2013The American College of Sports Medicine