Mental and physical stress as moderators of the postural response in insulin-dependent diabetic patients.

Two simple stressors, mental arithmetic and isometric handgrip, were studied as moderators of the physiological response to standing in insulin-dependent diabetic patients and in healthy controls. Continuous (beat-to-beat) measures were taken of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and skin conductance (SC) during postural change under baseline and stressor conditions. Diabetic patients without symptoms of neuropathy and healthy controls showed generally similar responses to postural change and to the stressor conditions. SBP and DBP were more responsive to the mental and physical stressors than were HR or SC, especially after standing. Two diabetic patients with postural hypotension showed significant increases in overall BP levels and less of a fall in BP during postural change under the stressor conditions, despite minimal HR or SC responses. Results indicate that these strategies are effective in increasing BP during postural change in both diabetic and nondiabetic individuals and may be useful in the management of orthostatic hypotension.