Title : A correlation between caffeine consumption and sleep quality and mediating role of chronotype on this correlation : A cross-sectional study among sudanese adult medical students
Caffeine is one of the most widely consumed stimulants in the world , caffeine is commonly consumed to help offset fatigue, however, it can have several negative effects on sleep quality. Also chronotype are known to have an association with sleep quality . less study show the mediating role of chronotype on the relation between caffeine consumption and sleep quality . The aim of this study to assess the relationship between caffeine consumption and sleep quality and the mediating role of chronotype on this relationship .
Materials & Methods:
The cross-sectional study conducted among medical students of Al-Neelain university . sleep quality was measured using the Pittsburgh sleep quality index (PSQI) .Chronotype was assessed using Morningness - Eveningness questionnaire (MEQ).Caffeine consumption was assessed for amount, frequency of consumption before bedtime and timing before bed. SPSS version 26 was used to analyze the data .Hayes process macro was used to perform mediation analysis
Among 303 medical students who participate in the study ( 67.3%) were female . mean age was 22.71(±2.5) . The mean for chronotype (MEQ) was (52.12± 9.71) , with the majority were from neutral type (58.1%). More than half of participants (57.4%) had poor sleep quality. Majority of participants (75.2%) consume 0-200 mg per day . Multiple regression analysis revealed that MEQ scores was negatively associated with increased caffeine amount consumption (b=-2.43,P<0.01),indicating that increased caffeine amount consumption associated with evening chronotype .Chronotype has a statistically significant relation with both caffeine amount and caffeine consumption frequency before bed (p <0.05) . We found a strong statistically significant relation between global Pittsburgh sleep quality index (PSQI) score and chronotype (p <0.01) ,with definite morning has good sleep quality 4.50 ± (1.37) .The result revealed a significant indirect effect of impact of caffeine amount on (PSQI ) score (b=0.2601,t=3.195) , and the result for bias – corrected percentile bootstrap method showed that the total effect was positively significant (b=0.8875, p <0.05, SE=0.2709 , 95% CI ] 0.3544 - 1.4207 [ ) through partial complimentary mediation between caffeine amount and (PSQI) score . Caffeine consumption frequency before bed positively associated with higher levels of (PSQI) after controlling for chronotype indicating poor sleep quality (b=0.3596, p <0.01, SE=0.1361 , 95% CI ] 0.0917 - 0.6275 [ ).Caffeine Consumption timing before bed negatively associated with lower levels of (PSQI) after controlling for chronotype indicating good sleep quality (b=-0.5268, p <0.05, SE=0.2139 , 95% CI ] -0.9481 - -0. 1054 [ ).
We found that caffeine amount affect and lengthen chronotype period, which partially mediated the association between caffeine consumption and sleep quality . caffeine consumption timing before sleep did not affect chronotype but it had a good direct effect on sleep quality (good sleep quality) caffeine consumption frequency before sleep did not affect chronotype but it had a direct effect on sleep quality (bad sleep quality )
Audience Take Away
- Control and regulate the amount of coffee consumed and try to drink coffee in periods far from bedtime
- Reducing amount and frequency of caffeine consumed lead doctor to have good sleep quality ,which reflects on their daily activity and help them to Performs their job efficiently and accurate , that also help medical students to focus on their lessons and boost their understanding
- Yes, other study could direct research to detectexactly which level of caffeine in blood can affect sleep quality and lead to change in chronotype and to know which amount consumed equivalent to that level. Results can be taken into consideration to enhance quality of life