Sleep extension improves neurocognitive functions in chronically sleep-deprived obese individuals

Abstract

Background: Sleep deprivation and obesity, are associated with neurocognitive impairments. Effects of sleep deprivation and obesity on cognition are unknown, and the cognitive long-term effects of improvement of sleep have not been prospectively assessed in short sleeping, obese individuals. Objective: To characterize neurocognitive functions and assess its reversibility. Design: Prospective cohort study. Setting: Tertiary Referral Research Clinical Center. Patients: A cohort of 121 short-sleeping (,6.5 h/night) obese (BMI 30-55 kg/m2) men and pre-menopausal women. Intervention: Sleep extension (468688 days) with life-style modifications. Measurements: Neurocognitive functions, sleep quality and sleep duration. Results: At baseline, 44% of the individuals had an impaired global deficit score (f-score 0-39). Impaired global deficit score was associated with worse subjective sleep quality (p = 0.02), and lower urinary dopamine levels (p = 0.001). Memory was impaired in 33%; attention in 35%; motor skills in 42%; and executive function in 51% of individuals. At the final evaluation (N = 74), subjective sleep quality improved by 24% (p