Special Report

Health and Economic Burden of Nonalcoholic Fatty Liver Disease in the United States and Its Impact on Veterans

Fed Pract. 2019 January;36(1):14-19

References

1. Targher G, Bertolini L, Padovani R, et al. Prevalence of nonalcoholic fatty liver disease and its association with cardiovascular disease among type 2 diabetic patients. Diabetes Care. 2007;30(5):1212-1218.

2. Targher G, Bertolini L, Rodella S, et al. Non-alcoholic fatty liver disease is independently associated with an increased prevalence of chronic kidney disease and proliferative/laser-treated retinopathy in type 2 diabetic patients. Diabetologia. 2008;51(3):444-450.

3. Adams LA, Harmsen S, St Sauver JL, et al. Nonalcoholic fatty liver disease increases risk of death among patients with diabetes: a community-based cohort study. Am J Gastroenterol. 2010. 105(7):1567-1573.

4. Loomba R, Sanyal AJ. The global NAFLD epidemic. Nat Rev Gastroenterol Hepatol. 2013;10(11):686-690.

5. Younossi ZM, Koenig AB, Abdelatif D, Fazel Y, Henry L, Wymer M. Global epidemiology of nonalcoholic fatty liver disease-meta-analytic assessment of prevalence, incidence, and outcomes. Hepatology. 2016;64(1):73-84.

6. Angulo P, Machado MV, Diehl AM. Fibrosis in nonalcoholic fatty liver disease: mechanisms and clinical implications. Semin Liver Dis. 2015;35(2):132-145.

7. Satapathy SK, Sanyal AJ. Epidemiology and natural history of nonalcoholic fatty liver disease. Semin Liver Dis. 2015;35(3):221-235.

8. Estes C, Anstee QM, Arias-Loste MT, et al. Modeling NAFLD disease burden in China, France, Germany, Italy, Japan, Spain, United Kingdom, and United States for the period 2016-2030. J Hepatol. 2018;69(4):896-904.

9. Ahmed O, Liu L, Gayed A, et al. The changing face of hepatocellular carcinoma: forecasting prevalence of nonalcoholic steatohepatitis and hepatitis C cirrhosis. J Clin Exp Hepatol. 2018. In press.

10. Kanwal F, Kramer JR, Duan Z, Yu X, White D, El-Serag HB. Trends in the burden of nonalcoholic fatty liver disease in a United States cohort of veterans. Clin Gastroenterol Hepatol. 2016;14(2):301-308.

11. Kabbany MN, Conjeevaram Selvakumar PK, Watt K, et al. Prevalence of nonalcoholic steatohepatitis-associated cirrhosis in the United States: an analysis of national health and nutrition examination survey data. Am J Gastroenterol. 2017;112(4):581-587.

12. Goldberg D, Ditah IC, Saeian K, et al. Changes in the prevalence of hepatitis C virus infection, nonalcoholic steatohepatitis, and alcoholic liver disease among patients with cirrhosis or liver failure on the waitlist for liver transplantation. Gastroenterology. 2017;152(5):1090-1099.

13. Beste LA, Leipertz SL, Green PK, Dominitz JA, Ross D, Ioannou GN. Trends in burden of cirrhosis and hepatocellular carcinoma by underlying liver disease in US veterans, 2001-2013. Gastroenterology. 2015;149(6):1471-1482.

14. Wong RJ, Aguilar M, Cheung R, et al. Nonalcoholic steatohepatitis is the second leading etiology of liver disease among adults awaiting liver transplantation in the United States. Gastroenterology. 2015;148(3):547-555.

15. Belli LS, Perricone G, Adam R, et al; all the contributing centers (www.eltr.org) and the European Liver and Intestine Transplant Association (ELITA). Impact of DAAs on liver transplantation: major effects on the evolution of indications and results. An ELITA study based on the ELTR registry. J Hepatol. 2018;69(4):810-817.

16. Flemming JA, Kim WR, Brosgart CL, Terrault NA. Reduction in liver transplant wait-listing in the era of direct-acting antiviral therapy. Hepatology. 2017;65(3):804-812.

17. Mittal S, Sada YH, El-Serag HB, et al. Temporal trends of nonalcoholic fatty liver disease-related hepatocellular carcinoma in the Veteran Affairs population. Clin Gastroenterol Hepatol. 2015;13(3):594-601.

18. Mittal S, El-Serag HB, Sada YH, et al. Hepatocellular carcinoma in the absence of cirrhosis in United States veterans is associated with nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol. 2016;14(1):124-131.e1.

19. Sayiner M, Otgonsuren M, Cable R. Variables associated with inpatient and outpatient resource utilization among medicare beneficiaries with nonalcoholic fatty liver disease with or without cirrhosis. J Clin Gastroenterol. 2017;51(3):254-260.

20. Younossi ZM, Zheng L, Stepanova M, Henry L, Venkatesan C, Mishra A. Trends in outpatient resource utilizations and outcomes for Medicare beneficiaries with nonalcoholic fatty liver disease. J Clin Gastroenterol. 2015;49(3):222-227.

21. Allen AM, Van Houten HK, Sangaralingham LR, Talwalkar JA, McCoy RG. Healthcare cost and utilization in nonalcoholic fatty liver disease: real-world data from a large US claims database. Hepatology. 2018;68(6):2230-2238.

22. Younossi ZM, Blissett D, Blissett R, et al. The economic and clinical burden of nonalcoholic fatty liver disease in the United States and Europe. Hepatology. 2016;64(5):1577-1586.

23. Armstrong MJ, Hazlehurst JM, Parker R, et al. Severe asymptomatic non-alcoholic fatty liver disease in routine diabetes care; a multi-disciplinary team approach to diagnosis and management. QJM. 2014;107(1):33-41.

24. Ekstedt M, Franzén LE, Mathiesen UL, et al. Long-term follow-up of patients with NAFLD and elevated liver enzymes. Hepatology. 2006;44(4):865-873.

25. Kim D, Choi SY, Park EH, et al. Nonalcoholic fatty liver disease is associated with coronary artery calcification. Hepatology. 2012;56(2):605-613.

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29. Agrawal S, Duseja A, Aggarwal A, et al. Obstructive sleep apnea is an important predictor of hepatic fibrosis in patients with nonalcoholic fatty liver disease in a tertiary care center. Hepatol Int. 2015;9(2):283-291.

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Incidence

There are limited studies on NAFLD incidence. The largest study of US veterans to date used liver enzymes as its diagnostic criteria and reported an annual NAFLD incidence of 2 to 3 per 100 persons (over 9 years from 2003 to 2011).¹⁰ There are a few studies from Asia and Europe, and a recent pooled meta-analysis of these studies reported the incidence of NAFLD in Asia to be 52.3 per 1,000 person-years; the incidence in Western countries was 28 per 1,000 person-years.⁵ These variances may be explained, in part, to disparities in race/background. For example, Hispanics and South Asians (ie, people from Bangladesh, India, or Pakistan) are at higher risk for NAFLD/NASH.¹¹ These findings reinforce the need for further studies to better estimate the true incidence of NAFLD among veterans.

Chronic Liver Disease, Cirrhosis, and Hepatocellular Carcinoma

The prevalence of NASH cirrhosis also has been evaluated using serologic scores, such as aspartate aminotransferase to platelet ratio index (APRI). The National Health and Nutrition Examination Survey (NHANES) database was reviewed, and data for adults in 2 separate periods were analyzed (1999-2002 and 2009-2012) and the prevalence of NASH cirrhosis was noted to have increased 2.5-fold over the period (0.072% vs 0.178%, P < .05).¹¹Based on data from the HealthCore Integrated Research Database from 2006 to 2014, about 15% of cirrhosis cases were attributed to NAFLD, and about 24% each were attributed to hepatitis C virus (HCV) and alcoholic liver disease.¹² A review of about 60,000 veterans with cirrhosis between 2001 and 2013 revealed a prevalence of NAFLD-related cirrhosis of about 15%, while 48% were attributed to HCV.¹³ In contrast to the continued increase in NAFLD prevalence, the number of patients with HCV-associated liver disease has been in gradual decline since the advent of direct acting antiviral medications in 2011.¹²

Based on data from the United Network for Organ Sharing (UNOS), the number of patients awaiting liver transplant due to NAFLD nearly tripled from 2004 to 2013, and in 2013 NAFLD became the second leading disease among waitlisted patients for liver transplantation.¹⁴ Dynamic Markov modeling predicts that cases of decompensated NASH cirrhosis (ie, liver failure) will rise by 161%, from about 144,000 to 376,000 cases over the next 15 years.⁸ These projections predict that NAFLD will overtake HCV as the leading cause of chronic liver disease among patients awaiting a liver transplant and will pose a significant clinical and economic burden in the coming years.

Aside from cirrhosis due to NAFLD, NAFLD-related HCC has been on the rise and has overtaken HCV-related HCC. UNOS data from 2003 to 2015 have shown a 2-fold decline in liver transplantation for HCV-associated HCC; however, the same period saw a 10-fold increase in liver transplantation for NAFLD-associated HCC.^15,16 This trend in NAFLD-related HCC is expected to grow from 5,000 to 6,000 cases in 2005 to 45,000 cases by 2025.⁹ More surprisingly, studies from the US veteran population have reported that patients with NAFLD-related HCC are less likely to have cirrhosis compared with patients with HCV- or alcohol-related HCC.¹⁷ Among all US veterans who developed HCC in the absence of cirrhosis between 2005 and 2010, NAFLD and metabolic syndrome seemed to be the leading risk factors for development of HCC.¹⁸ These trends raise concern for the rise in noncirrhotic HCC in the NAFLD population and highlight the need to improve current screening guidelines for this subset of patients.