[A study on the endogenous cannabinoid system synthetic and catabolic enzyme levels in patients with obstructive sleep apnea].

OBJECTIVE

To observe the differences of endogenous cannabinoid system (ECS) synthetic and catabolic enzyme levels between the obstructive sleep apnea syndrome (OSA) patients and the control subjects.

METHODS

Patients with OSA confirmed by PSG in our Sleep Center were randomly recruited from July to December, 2009. Peripheral blood was obtained to isolate mononuclear cells and the mRNA levels of anandamide (AEA) synthase N-acylphosphatidylethanolamine hydrolyzing phospholipase D (NAPE), fatty acid amide hydrolase (FAAH) and 2-arachidonoylglycerol (2-AG) synthase diacylglycerol lipase (DAGL) and hydrolase monoacylglycerol lipase (MAGL) were measured by real-time polymerase chain reaction. The association between the severity of OSA and the enzyme levels were explored.

RESULTS

There was a significant difference in both the NAPE and MAGL levels between patients with OSA and the control subjects. The level of MAGL was related to some indices of severity of OSA, including the longest apnea time, lowest blood oxygen saturation and the micro-arousal index (r = 0.31, 0.24, 0.34, respectively, all P < 0.05). Compared with patients with OSA alone, patients with OSA complicated by hypertension showed a different level of FAAH (P < 0.05).

CONCLUSIONS

OSA altered the expression of the ECS synthetic and catabolic enzymes, leading to an increase in endogenous cannabinoid substances.