Body Mass Index Moderates the Association between Sleep Quality and Vigilance on a Test of Inhibitory Control

Objective: Sleep problems are common among college students and related to numerous adverse outcomes including impaired cognitive performance. Obesity may confer an elevated risk of cognitive deficits with poor sleep given its relationship with poorer sleep quality and impaired cognition. Thisstudy examined whether the relationship between reduced sleep quality and poorer vigilance and inhibitory control were moderated by elevated body mass index (BMI). Method: Participants were 85 college students who completed a computerized task of inhibitory control that required vigilance (go/no-go [GNG] task) and the Pittsburgh Sleep Quality Index, a measure of sleep quality. Results: Poor sleep quality was observed in 63.5% of the sample and was related to more omission errors on the GNG task and increased BMI. Results further revealed that BMI moderated the relationship between sleep quality and performance on the GNG task such that individuals in the severely obese range of BMI had more omission errors with poorer sleep quality, while there was no association between sleep and GNG performance among normal weight and overweight individuals. Conclusions: These findings highlight the likely contribution of obesity to decreased vigilance with poor sleep. Future research is needed to confirm these findings using objective measures of sleep quality (e.g., actigraphy, polysomnography).