Evaluation of Hepatic Steatosis and Fibrosis Using Transient Elastography in Patients With Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is an independent risk factor for non-alcoholic fatty liver disease. This study was planned to assess proportion of patients with OSA that have hepatic steatosis and fibrosis, as measured by transient elastography, to explore variables influencing their development and to find out the polysomnography parameters that predict the need for transient elastography screening in OSA.

Consecutive participants having polysomnography proven OSA were included in the study after screening for eligibility criteria. Data of the polysomnography were scored manually following standard criteria. Participants were subjected to transient elastography (Fibroscan®) and serum investigations after diagnostic polysomnography. The polysomnography, fibroscan®, and laboratory data were tabulated and analyzed.

A total of 71 participants were enrolled. 16.9% participants had mild OSA, 28.2% had moderate OSA, and remaining participants had severe OSA. Liver steatosis was found in 63.4% participants while hepatic fibrosis was noted in 9.9%. Oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and percentage of sleep spent below 90% oxygen saturation (T90) were significantly associated with the presence of hepatic steatosis and fibrosis. Receiver operating curve (ROC) showed that at the cut-offs of 73 events/hr, 13% and 72.2 events/hr, AHI, T90 and ODI, predicted hepatic fibrosis with area under ROC of 0.960, 0.944, and 0.933, respectively (P < 0.001).

Patients with OSA are at increased risk for development of hepatic steatosis and fibrosis. ODI, AHI, and T90 during polysomnography predict the presence of underlying hepatic fibrosis.