Relationship between hyperglycaemia and aerobic power in men with newly diagnosed type 2 (non insulin-dependent) diabetes.

Abstract

The aim of the study described here was to evaluate aerobic function during exercise and its determinants in middle-aged men with newly diagnosed Type 2 (non insulin-dependent) diabetes. Using breath-by-breath technique, we measured O2 uptake at anaerobic (ventilatory) threshold and at peak exercise in a group of diabetic men (n = 19; fasting blood glucose 8.6 +/- 0.7 mmol l-1, mean +/- SEM) without any disease or medication that could have had an influence on exercise performance, and compared the results to those observed in non-diabetic healthy control men (n = 18). There were no differences in physical activity or smoking habits between the groups. Oxygen uptake was lower in the diabetic men than in the control men both at anaerobic threshold (15.0 +/- 0.8 vs. 18.8 +/- 1.0 ml min-1 kg-1, P < 0.01) and at peak exercise (25.3 +/- 1.5 vs. 31.1 +/- 1.4 ml min-1 kg-1, P < 0.01). In the diabetic men peak O2 uptake showed an inverse linear correlation with age (r = -0.71, P < or = 0.001), fasting blood glucose (r = -0.49, P < 0.05) and glucose response in an oral glucose tolerance test (r = -0.43, P < 0.05). In addition, long-term smoking was associated with impaired peak O2 uptake. In a stepwise multiple regression procedure 75% of the total variance of peak O2 uptake in the diabetic men was explained by age, post-load blood glucose response and smoking history. Thus, in addition to ageing and smoking, hyperglycaemia is correlated with impaired aerobic power in men with newly diagnosed Type 2 diabetes.