A Comparative Study of Autonomic Cardiovascular Parameters in Obese and Non-Obese Adults

ABSTRACT

Globally, the epidemic of obesity in children and young adults is on a constant rise over the past decade. Obesity makes individual highly susceptible to a variety of chronic diseases and their complications. An altered autonomic response in the form of enhanced baseline sympathetic activity, feeble response to sympathetic stimuli and compromised parasympathetic activity is observed in obesity. We have assessed potentially perturbed autonomic responses in young overweight/obese first year medical students. Methods: This cross sectional analytical study was undertaken in the research lab of the Department of Physiology, M.K.C.G. Medical College over a period of 12 months on 300 students (both males and females) to determine sympathetic and parasympathetic responses to stress using hand-grip dynamometer and sinus arrhythmia test respectively. Independent ‘t’ test, Pearson’s correlation coefficient and multiple linear regression analysis in SPSS 20.0 was used to statistically ascertain the differences for the aforementioned parameters between obese and non-obese adults. Results: Weight, Body mass index (BMI), waist hip ratio (WHR), Pulse rate (PR), baseline systolic blood pressure (BSBP) & baseline diastolic blood pressure (BDBP) is significantly greater in obese than in non-obese. BMI shows positive correlation with BSBP & BDBP (r=0.660**; p<0.001 & 640**; p<0.001) and negative correlation with ΔDBP, and E/I Ratio. A negative correlation is appreciated amongst ΔDBP and BMI (R2 = 39.6). A similar negative correlation is again seen between E/I ratio and BMI (R2 = 37.2). Conclusion: Obesity potentially alters autonomic balance with increased sympathetic and reduced parasympathetic tone posing elevated risk of cardiovascular and cerebrovascular accidents.