Tuesday, April 19, 2011
Cysteine as a Biomarker for Obstructive Sleep Apnea
There is an article in the Chest Journal about cysteine and obstructive sleep apnea (OSA). Homocysteine and cysteine are reagarded as cardiovascular risk factors. The researchers performed an overnight sleep study, fasting blood draws, physical exam, ECG, and an echocardiogram patients. The researchers included non-overweight patients to account for the possible influence of obesity. A proportion of the patients were randomized to measure the effect of CPAP treatment on the obtained measurements.
The results showed that cysteine levels were highter in OSA patients than with control subjects, but homocysteine levels were not different. Cysteine levels were also higher in the non-overweight patients with OSA than in those non-overweight patients without OSA. There was a significant decrease in cysteine levels after 6 months of effective CPAP therapy.
The authors conclude that cysteine could be a potential biomarker for OSA, regardless of obesity. One thing not mentioned in the abstract is if the researchers analyzed the cysteine levels based on OSA severity.