Haemodynamic and hormonal responses to exercise: Studies in patients with diabetes mellitus and adrenomedullary deficiency

The haemodynamic and hormonal responses of patients with autonomic neuropathy and others with adrenomedullary deficiency were compared with mild hypertensives (range of blood pressure 90-100 mmHg diastolic and 140-160 mmHg systolic) and uncomplicated diabetics during standard exercise and postural manoeuvres using continuous arterial blood pressure monitoring. There was no difference in these parameters between the groups when at rest or on standing. During exercise there was no significant difference in blood pressure and heart rate between the groups and all showed significant increases in plasma noradrenaline (mean rise for all groups 2730-22 105 pm 1(-1), P less than 0.03) and (in all but the adrenalectomized subjects) adrenaline (mean rise for remaining three groups 946-3384 pm 1(-1), P less than 0.03; adrenalectomized group showed no rise). The group with autonomic neuropathy showed a significant rise in plasma cortisol from basal 450 +/- 40 to 845 +/- 72 nm 1(-1), P less than 0.005 after exercise, but the other groups showed no significant change. The maximum level attained for plasma cortisol in the adrenalectomized subjects after exercise was significantly less (260 +/- 41 nm 1(-1) than in the diabetic groups (696 +/- 68 nm 1(-1) (non-neuropaths), 845 +/- 72 nm 1(-1) (neuropaths), P less than 0.01). We have demonstrated normal blood pressure and pulse responses to posture and sustained exercise in diabetics with autonomic neutropathy. The findings of similarly normal responses in patients with adrenomedullary deficiency suggest that circulating adrenaline is not obligatory to a normal haemodynamic response to exercise.