Peripheral Leptin Levels in Narcoleptic Patients
Narcolepsy is a severe sleep disorder that in most patients is characterized by the deficiency of central orexin. Clinically, narcolepsy is associated with obesity. Currently, there is a literature controversy about the potential alteration of leptin levels in narcoleptic patients. Theoretically, diminished leptin levels could partially contribute to the observed overweight of patients. Two studies have reported decreased leptin levels, whereas a larger, recent study failed to detect differences between patients and controls.To help settle the controversy, we have measured peripheral leptin levels in 42 narcoleptic patients and in 31 body mass index-matched controls.No significant differenc…
Basal metabolic rate in narcoleptic patients.
PATIENTS SUFFERING FROM NARCOLEPSY TEND TO BE OBESE.1,2 AMONG OTHER HYPOTHESES LOWER RESTING ENERGY EXPENDITURE HAS BEEN SUSPECTED to be the cause of the narcolepsy-associated obesity.3,4 The use of indirect calorimetry is a well-established noninvasive method to measure the energy expenditure (EE) and the resting (basal) metabolic rate (BMR). Chabas et al. recently published an evaluation of eating behavior and energy balance of 7 typical and 6 atypical narcoleptic patients and 9 controls using indirect calorimetry. Narcoleptic patients were found to have a lower energy expenditure (EE) than controls (n = 13, P = 0.07). Thus, it was concluded that narcolepsy associated obesity could be the…
Season of birth effect in narcolepsy
The causes of narcolepsy are unknown.1 Genetic factors such as positivity for HLA DR2 or certain genotypes of tumor necrosis factor–alpha or the orexin gene only explain a fraction of the risk. A season of birth effect has been observed in numerous studies for schizophrenia and bipolar disorder with a 10% excess of birth in winter and spring.2 Among the underlying factors discussed are infectious agents as well as seasonal variations in nutrition, light effects, and toxins.2 Most recently, the vitamin D hypothesis has been revisited.3 The production of vitamin D is associated with exposure to sunlight and the active 1,25 dihydroxyvitamin D3 is a potent modulator of immune functions,4 a dysf…
Prevalence of eating disorders and eating attacks in narcolepsy
Norbert Dahmen, Julia Becht, Alice Engel, Monika Thommes, Peter TonnPsychiatry Department, University of Mainz, GermanyAbstract: Narcoleptic patients suffer frequently from obesity and type II diabetes. Most patients show a deficit in the energy balance regulating orexinergic system. Nevertheless, it is not known, why narcoleptic patients tend to be obese. We examined 116 narcoleptic patients and 80 controls with the structured interview for anorectic and bulimic eating disorders (SIAB) to test the hypothesis that typical or atypical eating attacks or eating disorders may be more frequent in narcoleptic patients. No difference in the current prevalence of eating disorders bulimia nervosa, b…