Severe sleep apnea may damage liver

Severe Obstructive sleep apnea (OSA) - when breathing stops periodically during sleep - appears to be a risk factor for liver damage, regardless of whether or not a patient is obese, French researchers suggest in the medical journal Hepatology.

With OSA, the back of the throat collapses intermittently during sleep causing brief but often frequent episodes of arrested breathing. The problem is often associated with obesity, but it can occur in normal weight individuals as well. Because OSA disrupts sleep patterns, patient with the disorder often complain of daytime sleepiness.

Senior author hypothesized that insulin resistance related to OSA, as well as direct lack of oxygen to the liver, could possibly be the reason for liver disease associated with OSA.

Dr. Lawrence Serfaty and colleagues evaluated 163 patients referred to the Sleep Unit at Hospital Saint-Antoine in Paris for evaluation of suspected OSA. Sleep studies showed that 44 had severe OSA, 84 had moderate OSA and 35 had no evidence of OSA.

Testing revealed that liver tests were abnormal in 32 percent of those with severe OSA, 18 percent of those with moderate OSA and 8.6 percent with no OSA. Further analysis showed that severe OSA predicted abnormal tests, regardless of the patient's weight.

Biopsies confirmed the presence of liver disease in a higher percentage of patients with severe OSA compared with the other groups.

Based on these findings, the authors recommend testing for OSA in patients with liver disease than can't be attributed to some other cause.

SOURCE: Hepatology, June 2005.