A study to access impairment of autonomic nervous system in obesity

Abstract

Background: Obesity which is itself a significant health hazard is also associated with dysfunctioning of autonomic nervous system (ANS). Aims and Objective: This study was conducted to assess autonomic dysfunction in obese and compare it with age-matched controls. Materials and Methods: The study group consisted of 55 healthy obese people (median 35 ± 6.0 years of age) and the control group consisted of 55 healthy non-obese people (median 31 ± 5.2 years). Six non-invasive autonomic function tests were performed out of which four were based mainly on parasympathetic control heart rate response to standing (30:15 ratio). The standing to lying ratio, Valsalva ratio, and the resting heart rate and the other two tests were based on sympathetic control (isometric handgrip exercise test systolic blood pressure (SBP) and cold-pressor test SBP, and diastolic BP). Results: Present study showed significantly lower values (P ≤ 0.005) for the parasympathetic tests in the study group when compared to controls indicating impaired parasympathetic function. Similarly, the findings of sympathetic tests in study groups were significantly less (P ≤ 0.005) as compared to the controls indicating impaired sympathetic function. Conclusion: Thus, in obesity activity of both sympathetic as well as parasympathetic divisions of ANS (autonomic nervous system) are affected, which may be the cause of various complications associated with obesity.