Abstract
Background: Long-standing stress is an important risk factor for many diseases. Certain diseases are found to be associated with males than females. This difference may be due to the variation in the reactivity to stress exhibited by both the sexes which we assessed in the present study. The responses during stress are mediated partly by sympathetic and parasympathetic branches of autonomic nervous system (ANS). Heart rate variability (HRV) is a simple and non-invasive tool to study ANS. HRV can be analyzed by time domain and frequencydomain methods. The HRV in males and females during mental stress test may point to their disparity in autonomic response to stress and hence the predisposition to various diseases.

Aim and Objective: The objective of this study was to assess the autonomic activity in males and females at rest and during mental stress test using HRV.

Materials and Methods: There were 12 males and 18 females in the study who were selected based on inclusion and exclusion criteria. Mental arithmetic test is used to induce mental stress. HRV was calculated during baseline condition and mental stress test. Square root of the mean squared differences of successive NN intervals (RMSSD) and standard deviation of average NN intervals are the variables used in time domain analysis of HRV. Low-frequency (LF), high-frequency (HF), and LF/HF were used under frequency domain analysis.

Results: There was a statistically significant difference in RMSSD during mental stress test. None of the other variables did not show any difference between two groups at rest and also during mental stress test.

Conclusion: Less HRV in males during mental stress test indicates a shift of autonomic balance toward sympathetic activity in them. This shows that they are more predisposed to complications associated with stress.