A Study Of Effect Of Age On Cardiovascular Autonomic Function Tests In Healthy Subjects Of B.L.D.E.A’s Shri B.M.Patil Medical College, Bijapur

Abstract

Background & Objectives: Ageing is a physiological process. With advancement of age there is a progressive declination of almost all bodily functions including autonomic nerve function. Thus this study was designed to evaluate the effect of ageing on cardiovascular autonomic function in healthy subjects. Methods: The autonomic function tests analyzed were Valsalva maneuver, Heart rate response to deep breathing, Heart rate response to standing, Blood pressure response to standing, Blood pressure response to Sustained Hand Grip in 152 healthy subjects in the age range of 18-65 years of BLDEA’S Shri B M Patil Medical college Bijapur. The subjects were divided into four groups according to age (Group I 18-19 years, Group II 20-34 years, Group III 35-54 years, Group IV 55-65 years). The various autonomic function tests were graded by using Ewing & Clarke scores. Unpaired Student’s t-test, One Way ANOVA, Pearson correlation were used for statistical analysis. Results: The following variations observed were statistically significant: 1) Valsalva maneuver gradually decreased from 1.50 + 0.37 (Group I) to 1.24 + 0.18 (Group IV) 2) HR response to deep breathing gradually decreased from 24.23 + 5.46 bpm (Group I) to 10.40 + 7.65 bpm (Group IV) 3) HR response to standing gradually decreased from 1.30 + 0.18 (Group I) to 1.12 + 0.15 (Group IV) 4) BP response to Sustained Hand Grip gradually decreased from 26.37 + 9.24 (Group I) to 13.29 + 4.79 (Group IV). X BP response to standing showed an insignificant increase in SBP (8.9 + 3.04 to 13.29 + 4.79) on standing as age advances. All these parameters except BP response to standing were negatively correlated with age & these relationships were statistically significant. Parasympathetic, Sympathetic & Total autonomic function score showed gradual increase in the abnormal score as age advances in both sexes. Interpretation & Conclusion: 1) Autonomic function tests showed gradual decrease in function as age advances in both sexes (18-65 years) in different age groups. 2) Heart rate variation during deep breathing (r= -0.635) & Blood pressure response to Sustained Hand Grip (r= -0. 516) appear to be more sensitive parameters amongst the three Parasympathetic function tests & the two Sympathetic function tests respectively 3) There is a gradual increase in the abnormal autonomic function score of both sexes as age advances in different age groups. 4) Parasympathetic & Sympathetic function tests showed more decline in females as compared to males of the same age group.