THE ASSOCIATION OF THE SEVERITY OF OBSTRUCTIVE SLEEP APNEA AND NON-ALCOHOLIC FATTY LIVER DISEASE
AMA Olympia, M.D., IHY Cua, M.D. St. Luke’s Medical Center, Quezon City
Significance: 12.2% of 1,102 Filipinos in a local hospital have non-alcoholic fatty liver disease (NAFLD). Evidence suggests that chronic intermittent hypoxia in obstructive sleep apnea (OSA) leads to NAFLD. Apnea-hypopnea index, oxygen desaturation index, lowest desaturation values, and percentage of sleep duration with SpO2 <90% are said to predict NAFLD. This study aims to determine the association of severity of OSA and NAFLD. Apnea-hypopnea index, lowest oxygen saturation and mean nocturnal oxygen saturation are also correlated with the NAFLD.
Methodology: This was a cross-sectional, single-center study involving adults diagnosed with obstructive sleep apnea by overnight polysomnography with records that include body mass index, liver ultrasound, liver function tests, and lipid profile. Subjects with excess alcohol consumption, use of hepatotoxic drugs, viral hepatitis and other chronic liver diseases were excluded. Comparison of the proportion of severity of NAFLD, demographics and clinical parameters with of severity of OSA, and parameters of OSA with NAFLD were analyzed using Chi-square and odds ratio.
Results: 281 subjects were included. The relationship between severity of OSA and severity of NAFLD is insignificant (p-value=0.368). Gender, ALT and BMI were significantly related to severity of OSA. All parameters of OSA had significant p-values. However, a pre-test for homogeneity revealed that only the lowest O2 saturation was homogenous.
Conclusion: There is no association between OSA and NAFLD which may be due to the inhomogenous sample size and the difference in readings by different ultrasonographists using different machines and ultrasonography being used as a substitute for biopsy.