GLUCOSE-METABOLISM AND CATECHOLAMINE RESPONSES DURING PHYSICAL EXERCISE IN NON-INSULIN-DEPENDENT DIABETES

Blood glucose, lactate, insulin, C-peptide, norepinephrine and epineph rine concentrations were determined in non-insulin-dependent diabetic patients and in healthy controls before, during and after moderate exe rcise, to evaluate the effects of physical exercise on glucoregulation . Ten diabetic and ten healthy control females bicycled 14 minutes at 60% of their maximal heart rates. In the diabetic patients, there were no significant changes in blood glucose levels post-exercise, while i n controls the 60 minute post-exercise levels were higher than those m easured in mid-exercise (p < 0.05). Lactate concentrations increased w ith exercise in both groups in a similar manner, with highest values a t the end of exercise. No significant changes in insulin and C-peptide levels were induced with exercise in either group. Norepinephrine and epinephrine concentrations increased 2.5-3 fold with exercise in both groups (p < 0.05 for all values) but in the diabetics an earlier and prolonged catecholamine response was observed. We propose that catecho lamines prevent hypoglycaemia during exercise when changes in insulin and C-peptide do not occur. Tn diabetic patients with good metabolic c ontrol, the glucoregulatory response to exercise is not worse than in anthropometrically similar controls with similar levels of fitness.