Factor related to exercise capacity in asymptomatic middle-aged type 2 diabetic patients

Ugur-Altun, B., Altun, A., Tatli, E. & Tugrul, A. 2005. Diabetes Research & Ckinical Practice. 67: 130-136.


The achieved peak exercise capacity is a stronger predictor of cardiovascular and overall mortality as compared to available clinicals variables as well as established risk factor. Several studies shown increases in 1-METs of peak treadmill workload performance was associated with about 11 - 25% improvement in survival undescrore the relatively strong prognostic value of exercise capacity.

Cardiovascular morbidity could be reduced and prevented by aggresivce prevention and therapies among asymptomatic diabetic patients.

90 diabetes type 2 subjects recruited (base on WHO definition).
Inclusion criteria
- diabetis type 2 for at least a year
- no sign of abnormality on ECG tracing

Exclusion criteria
- diabestes less than a year
- history of miacadial infaction
- history of typical chest pain
- heart failure
- uncontrolled hypertension
- significant heart valve disease
- cardiomyopathy
- known serious arythmias
- left bundle branch block
- previosu coronary artery bypass surgery
- atrial fibrilation
- digoxin treatment
- severe chronic diasease or acute illness
- renal disease othe than diabteic neuropathy
- urinary tract infection
- insulin treated

Subjects were encouraged to go on with the exercise testing untill a symptom-limited maximal exercise and the exercise testing were done according to Bruce protocal on a treadmill. Exercise testing was defined as suboptimal if the subject fail to achieve 85% of their age-predicted HR. Results of the exercise test were analyzed by 2 person who was blinded to patient status.

Result shown that reduced exercise capacity was associated with increased insulin resistance in asymptomatic middle-aged type 2 diabetes patients. Reduced execise capacity also associated with age, female gender and family history.

There was an inverse relationship between achieved exercis capacity (METs) and age, as for this, there is a need to improve cardiorespiratory endurance with exercise training.

Available datea shown exercise training can delay onset of diabetes and improve othe risk factor such as hypertension and hyperlipedemia. Hyperinsulinism causes increased sympathetic tone, decreased vagal toned and impaired baroreflex activity, these are powerful and independent predictors of death among patients with and without CHD.

Author concluded that reduced exercise capacity was associated with increased insulin resistance and also associated with age, female gender and family hostory opf CHD.

Note; 1 MET = 3.5 ml of oxygen uptake per kilogram of body weight per min.