Effect of sodium oxybate on growth hormone secretion in narcolepsy patients and healthy controls.

Abstract

Hypocretin deficiency causes narcolepsy and may affect neuroendocrine systems and body composition. Additionally, growth hormone (GH) alterations my influence weight in narcolepsy. Symptoms can be treated effectively with sodium oxybate (SXB; γ-hydroxybutyrate) in many patients. This study compared growth hormone secretion in patients and matched controls and established the effect of SXB administration on GH and sleep in both groups. Eight male hypocretin-deficient patients with narcolepsy and cataplexy and eight controls matched for sex, age, BMI, waist-to-hip ratio, and fat percentage were enrolled. Blood was sampled before and on the 5th day of SXB administration. SXB was taken two times 3 g/night for 5 consecutive nights. Both groups underwent 24-h blood sampling at 10-min intervals for measurement of GH concentrations. The GH concentration time series were analyzed with AutoDecon and approximate entropy (ApEn). Basal and pulsatile GH secretion, pulse regularity, and frequency, as well as ApEn values, were similar in patients and controls. Administration of SXB caused a significant increase in total 24-h GH secretion rate in narcolepsy patients, but not in controls. After SXB, slow-wave sleep (SWS) and, importantly, the cross-correlation between GH levels and SWS more than doubled in both groups. In conclusion, SXB leads to a consistent increase in nocturnal GH secretion and strengthens the temporal relation between GH secretion and SWS. These data suggest that SXB may alter somatotropic tone in addition to its consolidating effect on nighttime sleep in narcolepsy. This could explain the suggested nonsleep effects of SXB, including body weight reduction.

• Authors: Claire E H M Donjacour, N Ahmad Aziz, Ferdinand Roelfsema, Marijke Frölich, Sebastiaan Overeem, Gert Jan Lammers, Hanno Pijl
• Journal: American journal of physiology. Endocrinology and metabolism (Am J Physiol Endocrinol Metab) Vol. 300 Issue 6 Pg. E1069-75 (Jun 2011) ISSN: 1522-1555 [Electronic] United States
• PMID: 21447786 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Intracellular Signaling Peptides and Proteins
• Neuropeptides
• Orexins
• Human Growth Hormone
• Sodium Oxybate

Topics

• Adult
• Body Composition (physiology)
• Body Mass Index
• Cataplexy (metabolism)
• Data Interpretation, Statistical
• Entropy
• Human Growth Hormone (blood, metabolism)
• Humans
• Intracellular Signaling Peptides and Proteins (deficiency)
• Male
• Narcolepsy (drug therapy, metabolism)
• Neuropeptides (deficiency)
• Orexins
• Polysomnography
• Sleep (drug effects)
• Sleep Stages (drug effects, physiology)
• Sleep, REM (drug effects)
• Sodium Oxybate (adverse effects, pharmacology, therapeutic use)
• Waist-Hip Ratio
• Weight Loss (drug effects)