Continuous positive airway pressure therapy on nonalcoholic fatty liver disease in patients with obstructive sleep apnea

Abstract

Study Objectives: Obstructive sleep apnea (OSA) is associated with nonalcoholic fatty liver disease (NAFLD) and related advanced fibrosis. We studied the treatment of OSA with continuous positive airway pressure (CPAP) in a population with NAFLD. Methods: Using an institutional database (2010–2014), we identified patients with NAFLD and OSA and studied changes in serum aminotransferases before and after CPAP use. We defined suspected NAFLD (sNAFLD) as serum alanine aminotransferase (ALT) > 30 U/L for men and > 19 U/L for women in the absence of known causes of chronic liver disease. The aspartate aminotransferase (AST) to platelet ratio index (APRI) was used to determine significant fibrosis. Consistent CPAP use for more than 3 months with adequate adherence parameters defined good adherence. Results: Of 351 patients with OSA on CPAP treatment, majority (mean age 57.6 years, 59.3% male) had abnormal ALT, and 89.4% met the criteria for sNAFLD. The prevalence of sNAFLD was higher among patients with moderate to severe OSA (90.6%) versus mild OSA (86.3%). There was a statistically significant improvement in AST, ALT, and APRI with CPAP therapy (all P < .01). There was an apparent dose-response relationship: patients with good adherence to CPAP showed a significantly larger decrease in AST and ALT than did those with poor adherence (P < .01). Multivariable logistic regression analysis showed CPAP treatment with adequate adherence (odds ratio = 3.93, 95% confidence interval = 1.29–11.94) was an independent predictor of regression of sNAFLD after adjusting for obesity class and severity of OSA. Conclusions: OSA treatment with CPAP was associated with significant biochemical improvement and reduction in NAFLD-related fibrosis.