Aims: Narcolepsy with cataplexy (NC) is a rare, chronic disease, characterized by excessive daytime sleepiness, cataplexy, disrupted nocturnal sleep and manifestations of abnormal REM (Rapid Eye Movement) sleep. Human NC is probably caused by environmental and genetic factors, leading to dysfunctions in hypothalamic orexigenic neurons. Recent studies showed that NC was associated with an increase in Body Mass Index, despite a reduction in food intake. In the current study we investigated hormonal and metabolic patterns in patients with NC to determine whether an association between NC and hormonal and metabolic disorders may occur.
Methods: This was a casecontrol study approved by local Ethical Committee. We enrolled 23 patients with NC and two groups of control subjects, matched for age and BMI: in the first group we included 21 patients with other sleep disorders, while the second group composed by 19 patients was drawn from general population.
Results: In patients with NC we found a decrease in CSF orexinA (NC=13 pg/ml, controls=109 pg/ml; P=0), and a statistical significant increase in BMI and waist circumference; in the same patients an increase in plasma leptin levels, total and LDL cholesterol, and oestradiol, and a reduction in HDL cholesterol and plasma cortisol were also detected. These alterations, however, were detected only in male group. Our results confirm that NC is a disease due to low CSF orexinA levels, and it is associated not only with metabolic disorders, such as perturbations in lipid profile, leptin secretion and body fat distribution, but also with endocrine alterations, especially regarding cortisol and estradiol secretion.
Conclusions: Studies on narcolepsy may provide interesting clues about the peripheral role of orexin-A in modulating hormones and metabolic processes.
03 - 07 May 2008
European Society of Endocrinology