Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes.
OBJECTIVE
Cardiovascular events and death are better predicted by postprandial glucose (PPG) than by fasting blood glucose or HbA(1c). While chronic exercise reduces HbA(1c) in patients with type 2 diabetes, short-term exercise improves measures of insulin sensitivity but does not consistently alter responses to the OGTT. The purpose of this study was to determine whether short-term exercise training improves PPG and glycaemic control in free-living patients with type 2 diabetes, independently of the changes in fitness, adiposity and energy balance often associated with chronic exercise training.


METHODS
Using continuous glucose monitors, PPG was quantified in previously sedentary patients with type 2 diabetes not using exogenous insulin (n = 13, age 53 ± 2 years, HbA(1c) 6.6 ± 0.2% (49.1 ± 1.9 mmol/mol)) during 3 days of habitual activity and during the final 3 days of a 7 day aerobic exercise training programme (7D-EX) which does not elicit measurable changes in cardiorespiratory fitness or body composition. Diet was standardised across monitoring periods, with modifications during 7D-EX to offset increases in energy expenditure. OGTTs were performed on the morning following each monitoring period.


RESULTS
7D-EX attenuated PPG (p < 0.05) as well as the frequency, magnitude and duration of glycaemic excursions (p < 0.05). Conversely, average 24 h blood glucose did not change, nor did glucose, insulin or C-peptide responses to the OGTT.


CONCLUSIONS
7D-EX attenuated glycaemic variability and PPG in free-living patients with type 2 diabetes but did not significantly alter responses to the laboratory-based OGTT. These effects appeared to be independent of changes in fitness, body composition or energy balance. ClinicalTrials.gov numbers: NCT00954109 and NCT00972452.


BACKGROUND
This project was funded by the University of Missouri Institute for Clinical and Translational Sciences (CRM), NIH grant T32 AR-048523 (CRM), Diabetes Action Research and Education Foundation (JPT). Medtronic supplied CGMS sensors at a discounted rate.
Department of Nutrition and Exercise Physiology, 10A McKee, University of Missouri, Columbia, MO, 65211, USA.
C R
CR
Mikus
D J
DJ
Oberlin
J
J
Libla
L J
LJ
Boyle
J P
JP
Thyfault
D050154:Adiposity / Q000502:physiology; D001786:Blood Glucose / Q000502:physiology; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D004032:Diet; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000502:physiology
D001786:Blood Glucose; D002096:C-Peptide; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human