Abstract
Background: Driving is one of the hazardous occupations which will lead to stress and strain and lead to heart diseases, and also, the obesity will also known to precipitate most of the cardiovascular diseases. Change in the autonomic nervous system activity will induce and precipitate many cardiovascular diseases.

Aims and Objective: Heart rate variability (HRV), a non-invasive technique, is a useful technique used to assess the activity of the autonomic nervous system which will influence the cardiovascular system.

Materials and Methods: In this study, we assessed the effect of driving stress on autonomic modulation and obesity, and body mass index (BMI) which is the indicator of the obesity is calculate here. 80 truck drivers were analyzed with time and frequency domains of HRV in normal and deep breathing.

Results: Analysis result showed that in time domain HRV significantly decreased as the years of driving increases, but not with the increased BMI. While in low-frequency (LF) component significantly increased and High frequency (HF) component has significantly decreased with the duration of driving exposure, but no such significant changes is seen with the increase of BMI.

Conclusion: This result shows that, as the exposure of driving increases, it increases the sympathetic activity and decreases the parasympathetic activity. However, BMI does not affect this group, indicating that the occupational stress is the detrimental factor that may affect the mortality and morbidity due to cardiovascular disease and then obesity.

Key words: Heart Rate Variability; Standard Deviation of all NN Intervals; Low Frequency; High Frequency; Body Mass Index; Stress; Occupational Hazards