Daytime sleep after glucose intake in patients with narcolepsy

Carbohydrate craving as well as increased body weight are frequently reported in narcolepsy, a sleep-wake-disorder characterized by excessive daytime sleepiness. So far, the interaction of glucose metabolism and sleep regulation is not yet understood completely. We investigated sleep parameters during a daytime nap after glucose intake in narcoleptic patients. So far, 20 patients (mean age 38±12,9 years, 6 females, BMI 27,9±4,1) diagnosed with narcolepsy and 13 control subjects matched for age, gender and BMI (mean age 34±10,6 years, 4 females, BMI 27,1±4,3) took part in the study. Subjects were offered either a 75g/300ml glucose drink or an artificially sweetened tea at 08:00 a.m. Sleep recordings were performed from 09:00–10:00 a.m. The number of narcoleptic patients displaying REM sleep during the nap dropped from 18 to 15 after glucose intake. However, latency to REM sleep (13,1 vs. 5,0min) and amount of sleep stage 1 (10,8 vs. 7,3min) decreased following glucose intake. None of the variables changed significantly in the control group. Spectral analysis of the sleep EEG is performed to further elucidate the interrelation between glucose levels and NREM-REM sleep regulation.