Sleep duration and level of salivary C-reactive protein in adolescent students studying in different school start timing

Abstract

The purpose of this study is to investigate the association of adolescent sleep duration and day time sleepiness with salivary CRP level among school students studying in different school start timings. A total 488 healthy school students of adolescent age (12-14yrs), participated in the present study. Both boys and girls of 7th and 8th class having 3 different school start timings (7:30 am, 8:30 am and 10:00 am), not taking any type of medication previously were included. After taking consent from respective schools and parents, Epworth sleepiness scale and Munich chronotype questionnaires was asked to fill by them to get information about their sleep habitats, sleep duration during weekdays and weekends. Saliva sample of same students was taken in small vials of 1.5 ml at morning 9:00 am only. Sample was stored at 2-80C for further quantitative analysis. The test was performed using RHELAX CRP KIT. Present study reveals a significant negative correlation of C- reactive protein level with sleep duration (p<0.01). 7:30 am school students get less sleep duration (6.8 h) than 8:30 am (8.5 h) and 10:00 am (8.7 h) in weekdays. Also, the average ESS score of 7:30 am school timing students was more than other 2 delayed school start timing students. The percentage of sleep dissatisfaction was also higher in early school students (46%) than other 2 later school timings (28%, 20.09%) with almost 50% students having EDS. Statistical analysis of data revealed a significant positive correlation between CRP level with daytime sleepiness (ESS score) and sleep debt (p<0.01). In conclusion, earlier school start timing students are more sleep deprived with higher ESS score than delayed school start timing students. This chronic sleep deprivation is leading to increase in the level of CRP in saliva indicating CRP as a potent indicator of sleep deprivation. The findings of the present study suggest that delaying of school start timing will not only increase the sleep duration of students but also decrease the level of CRP with improvement of sleep quality and health of these adolescents.