Extra-Hepatic Manifestations of Nonalcoholic Fatty Liver Disease: A Review

Nonalcoholic fatty liver disease (NAFLD) is now the leading cause of chronic liver disease worldwide with a strong association with metabolic syndrome. NAFLD is truly a systemic disease and is associated with a plethora of extra-hepatic manifestations or comorbidities. These are either related to secondary effects of associated obesity or from pathophysiological effects of insulin resistance in NAFLD. Three most common causes of increased morbidity and mortality associated with NAFLD are cardiovascular disease, liver disease, and cancer. In this narrative review, we will discuss comprehensively on cardiovascular disease, type 2 diabetes mellitus, and chronic kidney disease and will also highlight on malignancy especially colorectal cancer, pulmonary disorders including obstructive sleep apnea, endocrine disorders such as hypothyroidism and polycystic ovarian syndrome, dermatological disorders especially psoriasis, and hematological associations including iron overload and susceptibility to thrombosis. In addition to focusing on pathogenesis of these extrahepatic manifestations, we will highlight their clinical implications for physicians in routine clinical practice. Further, there remains an unmet need for safe and effective therapies and examining their benefits on these extra-hepatic manifestations among patients with NAFLD.