Study of Autonomic Function Tests in Geriatric Population

Autonomic dysfunction worsens with old age. It results from an imbalance between the sympathetic and parasympathetic divisions. Autonomic function tests were carried out in 50 healthy subjects in the age group of 65 to 90 years and compared with 50 controls in the age group of 25 to 65 years. The Parasympathetic activity was assessed by heart rate response to deep breathing, valsalva maneuver and orthostatic tests. Sympathetic function was assessed by blood pressure response to cold pressor test and sustained hand grip exercise. We found a decline in sympathetic and parasympathetic function with advancing age. No gender variation in both sympathetic and parasympathetic function was observed in this study. The E: I ratio values were significantly decreased in geriatric population. (p-value 0.037). In cold pressor test, the SBP and DBP difference values were significantly reduced in geriatric population. (p-value-0.000). Heart rate response to hand grip test was reduced significantly (p-value-0.035). Autonomic status will have an important bearing on determining the therapeutic strategy and drug action in the elderly inwhom theremay be altered responsiveness to autonomic reflexes and receptor sensitivity. KEY WORDS: Autonomic function, sympathetic, parasympathetic, blood pressure, cold pressor test and hand grip exercise.