Non-alcoholic fatty liver disease is an independent risk factor for inflammation in obstructive sleep apnea syndrome in obese Asian Indians.

INTRODUCTION: Obstructive sleep apnea (OSA) has been estimated to affect 4-11% of the population and causes systemic inflammation which leads to metabolic syndrome (MS). Non-alcoholic fatty liver disease (NAFLD) is also associated with MS whether NAFLD is an additional risk factor for the systemic inflammation that occurs in OSA is unclear.

OBJECTIVE: In this study, we aimed to analyze the association of OSA and NAFLD with MS and systemic inflammation in Asian Indians.

METHODS: Total 240 (132 males and 108 females) overweight/obese subjects [body mass index (BMI > 23 kg/m2 )] were recruited; of these, 124 subjects had OSA with NAFLD, 47 had OSA without NAFLD, 44 did not have OSA but had NAFLD and 25 had neither OSA nor without NAFLD. Severity of NAFLD was based on abdomen ultrasound and of OSA on overnight polysomnography. Clinical examinations, anthropometry, body composition, metabolic parameters, and inflammatory biomarkers were recorded.

RESULTS: Serum levels of leptin, macrophage migration inhibitory factor (MIF), interleukin-6 (IL-6), high sensitive C-reactive protein (Hs-CRP), and tumor necrosis factor alpha (TNF-α) were significantly higher, and adiponectin levels were significantly lower in OSA with NAFLD subjects. Prevalence of MS was significantly increased in OSA and NAFLD subjects (p = 0.001). There was a strong association and correlation between leptin, IL-6, Hs-CRP, MIF, and TNF-α in OSA and NAFLD subjects. Multivariate logistic regression showed that OSA was positively associated with the NAFLD [odds ratio (OR), (95% confidence interval (CL) 3.12 (2.58-7.72), (P = 0.002)].

CONCLUSION: NAFLD is an additional risk factor in OSA subject which contributes to systemic inflammation in Asian Indians.