Upregulating substance P levels to treat obstructive sleep apnea.

BACKGROUND

The neuropeptide (tachykinin) substance P is widely distributed in the central and peripheral nervous systems. Substance P has been suggested to function as a neurotransmitter, cotransmitter, or neuromodulator in the central and peripheral nervous system. substance P also influences sleep physiology. Neurokinin 1 (NK-1) receptors may also be implicated in the control of sleep/wake behavior. Obstructive sleep apnea syndrome (OSAS) is defined as repeated episodes of upper airway occlusion during sleep with subsequent excessive daytime sleepiness (EDS). Substance P levels are found to be significantly lowered in patients with OSAS.

OBJECTIVE

The aim of this review was to investigate the relationship between substance P, EDS and other OSAS complications.

METHODS

The literature was searched using standard methods. Medline and Embase were searched systematically from 1974 to the end of February 2008 for relevant articles published in English.

RESULTS/

CONCLUSION

EDS seen in some OSAS patients may be associated with various pathophysiological mechanisms including changes in substance P levels. Intravenous substance P administration in OSAS patients can be effective in the treatment of EDS. Further studies on the possible relationship between low serum substance P and hypertension, reproductive function disorders, memory and learning problems in OSAS cases is required.