Estimation of the prevalence of obstructive sleep apnea in non alcoholic fatty liver disease.

INTRODUCTION: The prevalence of non alcoholic fatty liver disease is increasing in parallel with the epidemic of obesity and metabolic syndrome. Recent data have shown frequent association between non alcoholic fatty liver disease (NAFLD) and obstructive sleep apnea. AIM: To estimate the prevalence of sleep disorders, to search an obstructive sleep apnea syndrome by conducting a ventilator polygraphy and to search the particularities of obstructive sleep apnea when its exists, in patients with NAFLD. METHODS: A prospective study, conducted over a period of 6 months, including patients followed for non-alcoholic fatty liver disease. We performed in all patients a Berlin questionnaire that assesses the risk of obstructive sleep apnea syndrome, an Epworth score that estimates the degree of daytime sleepiness and a ventilator polygraphy. RESULTS: We collected 37 patients. The mean age was 50,41±13,7 years. The sex ratio (M/F) was 0,42. Type 2 diabetes mellitus, arterial hypertension or dyslipidemia were recorded respectively in 37,8%, 40,5% and  37,8% of cases. Snoring was noted in 75,7%  of cases and excessive daytime sleepiness in 34,2% of cases. Obesity was observed in 73% and metabolic syndrome in 43,2% of cases. The Berlin Questionnaire was positive in 64,9% of cases. The average score of Epworth scale was 9,22±4,02 and 43,2% of patients had a score> 10. Ventilatorypolygraphy was positive in 13 cases (35,1%) with a mean AHI of  7,02±10,08.In these patients, obstructive sleep apnea was mild, moderate and severe in respectively 61,5%, 15,4% and 23,1% of cases. In univariate analysis, subjects with positive ventilator polygraphy had a significantly higher waist circumference (118,00 versus 109,58, p=0,05). Arterial hypertension was significantly associated with increased daytime sleepiness (p=0,018). In multivariate analysis, the only independent variable associated with excessive daytime sleepiness was arterial hypertension (OR=5,33 p=0,021). CONCLUSION: In our study, the prevalence of obstructive sleep apnea syndrome is high in patients with non alcoholic fatty liver disease. The only independent variable associated with excessive daytime sleepiness was arterial hypertension.