Influence of Stress on Quality of Sleep and QT Interval Variables among Young Adult Medical Students- A Cross-sectional Study

Abstract

Introduction: Stress affects different cardiovascular responses and trigger arrhythmias through Autonomic Nervous System (ANS) activation. Medical students generally tend to reduce their sleep, in order to adjust and cope with their stressful and demanding workload. Aim: To assess the correlation of QT intervals variables with quality of sleep and stress among young adult medical students. Materials and Methods: This cross-sectional study was undertaken in All India Institute of Medical Sciences, Mangalagiri, Andhra Pradesh, India, among 60 medical students taken as internal match for collection of data at the beginning of the academic year (unstressed) and three weeks before the term-end examination (stressed) during October 2019 to March 2020. Two validated questionnaires namely, Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality and the Medical Student Stress Questionnaire (MSSQ) to measure the stressors and the intensity of stress were used among the medical students. Short-term Electrocardiogram (ECG) recording was used to measure QT interval variables. Descriptive statistics and paired t-test were applied using Statistical Package for the Social Sciences (SPSS) version 19.0. The p≤0.05 was considered significant. Results: Academic Related Stress (ARS) showed a highly significant increase during the stressed conditions (p<0.001). The mean global PSQI score of 6.03±2.76 was significantly higher (p-value <0.001; PSQI >5) during the stressed conditions indicating poor quality of sleep, when compared to 4.50±2.87 recorded in unstressed conditions. In stressed conditions, QT interval measures had moderate correlation with ARS. Quality of sleep had negative correlations with all QT interval measures except for corrected QT interval (QTc) and QTCmin. Conclusion: Stress affects the sleep quality and induced QT changes which reflected difference in variability between ‘stressed’ and ‘unstressed’ times. However, there is no significant impact on QT duration among the young adult medical students.