Effects of exercise intervention on myocardial function in type 2 diabetes.
OBJECTIVE
To identify the effects of a 1-year exercise intervention on myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM).


METHODS
Randomised controlled trial, the Diabetes Lifestyle Intervention Study.


METHODS
University hospital.


METHODS
223 T2DM patients without occult coronary artery disease, aged 18-75 were randomised to an exercise training group (n = 111) or a usual care group (n = 112). Complete follow-up data were available in 176 (88 exercise, 88 usual care).


METHODS
Exercise training consisted of gym, followed by telephone-monitored home-based exercise training.


METHODS
Tissue Doppler-derived myocardial velocities, strain-rate and strain, body composition, glycated haemoglobin (HbA(1c)), maximum oxygen consumption (VO(2max)) and physical activity.


RESULTS
Overall changes in myocardial function were not different between groups despite improvements in waist circumference, fat mass, blood glucose, HbA(1c), insulin sensitivity, VO(2max) and 6-minute walk distance in the intervention group (p<0.05). The latter also spent significantly more time in vigorous activity (p<0.05). A post-hoc analysis revealed that intervention patients who spent more time in both moderate and vigorous activity showed a significant improvement in myocardial tissue velocity (p<0.01), HbA(1c) (p = 0.03) and VO(2max) (p = 0.03) compared to controls. Myocardial strain rate (p = 0.03) and HbA(1c) improved in intervention patients with the greatest increase in moderate activity (p = 0.03).


CONCLUSIONS
In patients with T2DM, current exercise recommendations led to an improvement in metabolic function, but failed to improve myocardial function in the overall group. Patients with greater increases in both moderate and vigorous activity showed improvements in myocardial function, glycaemic control and cardiorespiratory fitness.


BACKGROUND
ACTRN12607000060448.
School of Medicine, University of Queensland, Brisbane, Australia.
M D
MD
Hordern
J S
JS
Coombes
L M
LM
Cooney
L
L
Jeffriess
J B
JB
Prins
T H
TH
Marwick
D000293:Adolescent; D000328:Adult; D000368:Aged; D001823:Body Composition; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D003326:Coronary Circulation; D003924:Diabetes Mellitus, Type 2 / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D004452:Echocardiography; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006442:Glycated Hemoglobin; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D018608:Ultrasonography, Doppler; D055815:Young Adult
D006442:Glycated Hemoglobin