EFFECT OF AGE AND GENDER ON SUDOMOTOR AND CARDIOVAGAL FUNCTION AND BLOOD-PRESSURE RESPONSE TO TILT IN NORMAL SUBJECTS

Normative data are limited on autonomic function tests, especially bey ond age 60 years. We therefore evaluated these tests in a total of 557 normal subjects evenly distributed by age and gender from 10 to 83 ye ars. Heart rate (HR) response to deep breathing fell with increasing a ge. Valsalva ratio varied with both age and gender. QSART (quantitativ e sudomotor axon-reflex test) volume was consistently greater in men ( approximately double) and progressively declined with age for all thre e lower extremity sites but not the forearm site. Orthostatic blood pr essure reduction was greater with increasing age. HR at rest was signi ficantly higher in women, and the increment with head-up tilt fell wit h increasing age. For no tests did we find a regression to zero, and s ome tests seem to level off with increasing age, indicating that diagn osis of autonomic failure was possible to over 80 years of age. (C) 19 97 John Wiley & Sons, Inc.