[Impaired exercise-induced blood pressure control in patients with Parkinson's disease and related disorders]

An almost directly proportional increase in blood pressure (BP) and heart rate with exercise intensity has been reported in healthy subjects. In contrast, patients with multiple system atrophy (MSA) and pure autonomic failure (PAF) characterized by autonomic failure exhibit exercise-induced hypotension (EIH), prolonged hypotension following the cessation of exercise and exaggerated orthostatic hypotension after exercise. EIH, which can be the earliest symptom of PAF, provides a clue to the diagnosis of autonomic failure. Exercise-induced hypertension, which may be due to adrenergic receptor supersensitivity, may also be observed. BP during and after exercise was significantly lower in patients with Parkinson's disease (PD) than in healthy subjects. Some PD patients exhibited symptoms related to EIH. PD patients who did not achieve 85％ of target HR with treadmill testing lacked BP elevations during sub-maximal and peak exercise. On the other hand, no significant difference was observed in exercise-induced BP elevations between PD patients with and without cardiac sympathetic denervation. Since BP control during exercise in PD was not affected by dosing with levodopa, exercise-related BP abnormalities in PD appear to manifest with the disease. These findings suggest that PD has impaired exercise-induced BP control, but not to the extent of MSA and PAF.