Sleep and QT parameters in young adults

Quantity of sleep is known to affect cardiovascular events. This study aimed to evaluate the chronic effect of quantity and quality of sleep on electrocardiographic indices like QT interval, heart rate-corrected QT interval (QTc), QT dispersion (QTd) and QTc dispersion (cQTd) among healthy young adults.

101 medical students (39 women) in the age group of 18 to 22 years were included. Self reported duration of sleep and sleep latency was noted for past month. The quality of sleep assessed using the Pittsburgh Sleep Quality Index (PSQI).QT, QTc, QTd, cQTd were measured from ECG recordings of the subjects.

The analysis of the data was done by grouping and comparing the subjects according to sleep duration (<7 and >7 hours) PSQI scores (in <5 & >5) and sleep latency (<30min and > 30min).

The mean and SD of electrocardiographic indices studies for the whole sample were within the normal limits. There was no significant statistical difference observed in QT, QTc, QTd, cQTd values among the respective groups though the values tend to be shorter in the groups with PSQI >5,sleep duration<7 hours & with sleep latency >15 minutes. QT, QTc, QTd, cQTd were inversely correlated with PSQI and sleep latency directly sleep duration respectively.

The quantity and quality of sleep during past one month does not influence electrocardiographic indices in healthy young adults.