Prevalence of Nonalcoholic Steatohepatitis-Associated Cirrhosis in the United States: An Analysis of National Health and Nutrition Examination Survey Data

• Published in: The American journal of gastroenterology Vol. 112; no. 4; pp. 581 - 587
• Main Authors: Kabbany, Mohammad Nasser, Selvakumar, Praveen Kumar Conjeevaram, Watt, Kymberly, Lopez, Rocio, Akras, Zade, Zein, Nizar, Carey, William, Alkhouri, Naim
• Format: Journal Article
• Language: English
• Published: United States Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins 01.04.2017
• Subjects: Diabetes Mellitus - epidemiology; Female; Gastroenterology; Humans; Insulin Resistance; Liver Cirrhosis - epidemiology; Liver Cirrhosis - etiology; Male; Metabolic Syndrome - epidemiology; Middle Aged; Non-alcoholic Fatty Liver Disease - complications; Non-alcoholic Fatty Liver Disease - epidemiology; Nutrition Surveys; Obesity - epidemiology; Prevalence; Severity of Illness Index; United States - epidemiology
• ISSN: 0002-9270; 1572-0241
• DOI: 10.1038/ajg.2017.5

Nonalcoholic fatty liver disease (NAFLD) includes a wide spectrum of manifestations ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), fibrosis and eventually cirrhosis. The prevalence of NAFLD has been shown to be increasing over time; however, the prevalence of NASH cirrhosis and advanced fibrosis over time has not been well studied. Estimate the changes in prevalence of NASH cirrhosis and NAFLD-associated advanced fibrosis among adults in the United States. National Health and Nutrition Examination Survey (NHANES) data obtained during the periods from 1999-2002 and 2009-2012 were analyzed to estimate the prevalence of NASH cirrhosis and NAFLD-associated advanced fibrosis in subjects aged ≥18 years at the time of enrollment. We excluded patients with viral hepatitis, excessive alcohol consumption, aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >500 and patients who were pregnant. Cirrhosis was defined by AST to platelet ratio index (APRI) >2 and abnormal liver function tests. NASH cirrhosis was defined as cirrhosis that presented with at least one of the following: obesity, diabetes, insulin resistance (HOMA-IR≥3), and metabolic syndrome. Advanced fibrosis was defined by using well-established cutoff values for APRI, fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS). Population weighted prevalence was calculated separately for two groups to account for complex sampling method of NHANES. A total of 7034 NHANES participants from 1999-2002 and 2009-2012 group were included with mean age of 46.2±0.59 and 47.3±0.51 years, respectively, at the time of screening. The prevalence of NASH cirrhosis was significantly higher in 2009-2012 group (0.178% with an estimated 417,524 American adults with NASH-associated cirrhosis) compared to 1999-2002 group (0.072%); P value<0.05. The prevalence of NAFLD with advanced fibrosis also increased from 0.84 to 1.75% during the same time period (P value<0.001) corresponding to 4,104,871 American adults. During these time periods, there were also significant increases in obesity (29.8 vs. 36.6%), diabetes (8.3 vs. 11.9%), and insulin resistance (34.7 vs. 42.1%); P value <0.005 for all of them. There has been a 2.5-fold and 2-fold increases in the prevalence of NASH cirrhosis and NAFLD-associated advanced fibrosis, respectively, in 2009-2012 compared to 1999-2002. Extrapolation of NHANES data suggests that in 2010, 417,524 in the US had NASH cirrhosis, and 4,104,871 had NAFLD-associated advanced fibrosis. This represents a major disease burden and suggests the need for widespread programs to identify and treat those affected, and public health efforts aimed at controlling the burden of NAFLD and its complications.