Abstract
Background: Initiated by biological plausibility and supported by the pilot study, we observed possibility of associations between cardiovascular autonomic milieu and academic performances. As there are established cognitive ability differences among gender in literature, we designed a study to observe the differences in the basal autonomic activity as well as the manner of association between autonomic activity and academic performance between genders. Considerable lacunae in literature on this aspect also warranted for scientific introspection on this lacuna.

Aims and Objective: The aim of this study is to observe the association between resting short-term heart rate variability (HRV) indices and University marks of anatomy, biochemistry, and physiology in young male and female medical students.

Materials and Methods: Cross-sectional observational study with 102 healthy young participants in which 34 boys and 68 girls between 18 and 22 years were included by convenient sampling after assessing the inclusion and exclusion criteria. HRV is computed under standard conditions as per the task force recommendations in time and frequency domains. The academic performance is assessed by University examination marks at the end of the 1st year. The comparison of HRV parameters, academic performance, and their associations was analyzed separately by gender. Type 1 error allowance fixed at 5% but considering the high dispersion of HRV data, P values between 0.1 and 0.05 were also discussed.

Results: Mean RR intervals showed a negative correlation with academic performance in males. Time domain and geometric indices of HRV showed a negative correlation in boys but not in girls. In case of frequency domain indices, all indices of sympathetic activity showed a positive correlation with academic performance in boys and not in girls. Furthermore, sympathetic indices are more in males compared to females. All indices of parasympathetic reactivity were negatively correlated with academic performance in males.

Conclusion: High-sympathetic activity is correlated with better cognitive ability in males but the same association is not seen in females.

Key words: Heart Rate Variability; Gender; Cognition; Sympathetic; Academic; Performance; Medical; Students