Body mass index-independent metabolic alterations in narcolepsy with cataplexy.

Abstract

STUDY OBJECTIVES:

To contribute to the anthropometric and metabolic phenotyping of orexin-A-deficient narcoleptic patients, and to explore a possible risk of their developing a metabolic syndrome.

DESIGN:

We performed a cross-sectional study comparing metabolic alterations in patients with narcolepsy with cataplexy (NC) and patients with idiopathic hypersomnia without long sleep time.

SETTING:

University hospital.

PATIENTS:

Fourteen patients with narcolepsy with cataplexy and 14 sex and age-matched patients with idiopathic hypersomnia without long sleep time.

INTERVENTIONS:

N/A.

MEASUREMENTS AND RESULTS:

Metabolic parameters were evaluated by measuring body mass index (BMI), waist circumference (also with abdominal computed tomography), blood pressure, and daily calorie intake (3-day diary). Chronotypes were assessed through the morningness-eveningness questionnaire. Lumbar puncture for cerebrospinal fluid orexin-A determination and HLA typing were performed. Patients with narcolepsy with cataplexy (all HLA DQB1*0602 positive and with cerebrospinal fluid orexin-A levels < 110 pg/mL) had a higher BMI and BMI-independent metabolic alterations, namely waist circumference, high-density lipoprotein cholesterol, and glucose/insulin ratio (an insulin resistance index), with respect to patients with idiopathic hypersomnia without long sleep time (cerebrospinal fluid orexin-A levels > 300 pg/mL). Despite lower daily food intake, patients with narcolepsy with cataplexy displayed significant alterations in metabolic parameters resulting in a diagnosis of metabolic syndrome in more than half the cases.

CONCLUSIONS:

BMI-independent metabolic alterations and the relative hypophagia of patients with narcolepsy with cataplexy, as compared with patients with idiopathic hypersomnia without long sleep time, suggest that orexin-A influences the etiology of this phenotype. Moreover, considering that these dysmetabolic alterations are present from a young age, a careful metabolic follow-up of patients diagnosed with narcolepsy with cataplexy is mandatory.

• Authors: Francesca Poli, Giuseppe Plazzi, Guido Di Dalmazi, Danilo Ribichini, Valentina Vicennati, Fabio Pizza, Emmanuel Mignot, Pasquale Montagna, Renato Pasquali, Uberto Pagotto
• Journal: Sleep (Sleep) Vol. 32 Issue 11 Pg. 1491-7 (Nov 2009) ISSN: 0161-8105 [Print] United States
• PMID: 19928388 (Publication Type: Journal Article)

Chemical References

• Blood Glucose
• HCRT protein, human
• HLA-DQ Antigens
• HLA-DQ beta-Chains
• HLA-DQB1 antigen
• Insulin
• Intracellular Signaling Peptides and Proteins
• Leptin
• Lipids
• Neuropeptides
• Orexins

Topics

• Adult
• Blood Glucose (metabolism)
• Body Mass Index
• Case-Control Studies
• Cataplexy (complications, immunology, metabolism)
• Cross-Sectional Studies
• Energy Intake
• Female
• HLA-DQ Antigens (physiology)
• HLA-DQ beta-Chains
• Histocompatibility Testing
• Humans
• Idiopathic Hypersomnia (complications, immunology, metabolism)
• Insulin (blood)
• Intracellular Signaling Peptides and Proteins (metabolism)
• Leptin (blood)
• Lipids (blood)
• Male
• Metabolic Syndrome (diagnosis, etiology)
• Middle Aged
• Neuropeptides (metabolism)
• Orexins