EFFECTS OF MEAL INGESTION AND ACTIVE STANDING ON BLOOD-PRESSURE IN PATIENTS GREATER-THAN-OR-EQUAL-TO-60 YEARS OF AGE

Postprandial hypotension and orthostatic hypotension occur often in el derly patients. In the present study, we examined hemodynamic and humo ral responses to meal ingestion and active standing in 20 patients gre ater than or equal to 60 years of age who were free of apparent autono mic and cardiac dysfunction. For a time-control study, water was given instead of a meal to 19 of the 20 patients. After the meal ingestion, there was a fall in systolic blood pressure (BP) in 6 patients of >20 mm Hg, whereas the fall in systolic BP during the control study was n ot >20 mm Hg in any patient. The low-frequency power of the systolic B P wave, an index of peripheral sympathetic activity, was significantly increased only in the patients without postprandial hypotension. The postprandial changes in systolic BP were correlated with the changes i n the low-frequency power of the systolic BP wave (r = 0.61; p <0.01), but they were not correlated with the changes in plasma norepinephrin e, insulin, cardiac output, or parameters obtained by the spectral ana lysis of the RR interval. The systolic BPs in the upright position wer e comparable offer the meal and the water ingestion. Thus, the effects of meal ingestion and upright position on BP are not additive, Dysfun ction of peripheral sympathetic control of vascular tone may contribut e to the postprandial hypotension in elderly patients. (C) 1998 by Exc erpta Medica, Inc.