Liver Steatosis and Fibrosis in OSA patients After Long-term CPAPTreatment: A Preliminary Ultrasound Study

In cases of morbid obesity, obstructive sleep apnea (OSA) was associated with biopsy-proven liver damage. The role of non-invasive techniques to monitor liver changes during OSA treatment with continuous positive airway pressure (CPAP) is unknown. We used non-invasive ultrasound techniques to assess liver steatosis and fibrosis in severe OSA patients at diagnosis and during long-term CPAP treatment. Fifteen consecutive patients with severe OSA (apnea hypopnea index 52.5±19.1/h) were studied by liver ultrasound and elastography (Fibroscan) at 6-mo (n=3) or 1-y (n=12) follow-up. Mean age was 49.3±11.9y, body mass index (BMI) was 35.4±6.4kg/m². Adherence to CPAP was ≥5h/night. At baseline, most patients had severe liver steatosis independent of BMI; at follow-up, liver steatosis was not statistically different, but a relationship between severity of steatosis and BMI became apparent (Spearman's rho: 0.53, p=0.03). Significant fibrosis as assessed by Fibroscan was absent at diagnosis or follow-up (failure or unreliable measurements in four markedly obese patients). Therefore, ultrasound liver assessment is feasible in most OSA patients, and CPAP treatment may positively affect liver steatosis.