Effects of sleep deprivation on neurocognitive capacities in obese individuals not qualifying for sleep treatment: A systematic review

BackgroundObesity is an independent predictor of sleep deprivation (SD) and neurocognition. The effects of obesity on neurocognitive performance have mostly been studied for SD conditions requiring treatment, e.g., severe obstructive sleep apnea (OSA). We reviewed studies assessing the effects of SD on neurocognitive capacities in obese individuals not qualifying for an SD treatment.MethodsWe conducted a descriptive systematic review. We searched for studies using three electronic databases: MEDLINE®, Psych Info®, and EMBASE® (1980-2016). We included studies that compared the effects of SD in obese participants to that of obese participants without SD condition or non-obese participants under SD condition. We excluded studies on participants qualifying for SD treatment, such as treatment for severe OSA, or obesity-associated comorbidities.ResultsOf 859 studies, 17 met the inclusion criteria. These studies assessed the effects of eight SD conditions on 22 neurocognitive tasks in obese participants. Obese individuals with mild to moderate OSA show significantly lower neurocognitive performance compared to obese individuals without OSA, on tasks assessing vigilance (four studies), phonemic fluency (one study), executive function (one study), and verbal memory (one study). Two studies found that obese adolescents with shorter sleep hours performed worse on a global cognition scale and for fine motor skills. Studies noted that extending sleep hours resulted in better performance on tasks relating to attention, intelligence, and decision-making.ConclusionAvailable studies suggest that SD might worsen neurocognitive capacities in obese individuals. Such impairments in obese individuals might have clinical implications, such as increased injury risks.