Deciphering the Interactions Between Food Intake, Sleepiness, and Nighttime Sleep Quality in Patients With Type 1 Narcolepsy and Idiopathic Hypersomnia

Links between sleep and food intake are manyfold. In healthy individuals, sleep deprivation promotes obesity by stimulating food intake of high glycemic index (GI) foods. Conversely, high GI foods induce sleepiness. Obesity is observed in 30-50% of patients with Narcolepsy type 1 (NT1). Its determinism may involve transient changes in basal metabolism at the early stage of the disease, eating disorders, disrupted nighttime sleep and sleepiness. In contrast, patients suffering from idiopathic hypersomnia (IH), whose nocturnal sleep is generally long and of good quality, rarely present with obesity. By studying the relationships between diet, body composition and sleep patterns in these two populations and in healthy controls, the NARCOFOOD study aims to provide a better understanding of the determinants of obesity in narcolepsy and, more generally, of the effects of food intake on sleepiness.

Patients will be recruited at the Lyon and Clermont-Ferrand sleep centers and Controls at the Lyon Neuroscience Research Center. Data from clinical evaluation (including body mass index and body composition), and questionnaires (sleep quality, insomnia, sleepiness, anxiety and depression, impulsivity, eating behaviors) will be collected. During 4 days, at home, the following parameters will be explored : 1) eating behaviors (meals' photos) and sugar consumption (FreeStylePro sensor measuring interstitial glucose) 2) sleep/wake rhythm (diary and actigraphy) 3) nocturnal sleep parameters (Somfit device) 4) sleepiness (Karolinska sleepiness scale and EEG markers of sleepiness with the Somfit device) before and after meals.

The hypothesis is that increased sleepiness would favor food intake of high GI foods, which would worsen sleepiness in all 3 groups, with a more pronounced effect in NT1. Compared to IH patients and controls, NT1 patients may present more snacking of high GI foods, especially at night if sleep is disrupted, and this would be correlated with body composition.

The findings will help to better understand the mechanisms of obesity in narcolepsy and may lay the ground for the development of new therapeutic strategies in disorders of hypersomnolence, targeting dietary behaviors.