Non-alcoholic steatohepatitis (NASH), the severe form of
non-alcoholic fatty liver disease (NAFLD), is now the most common reason for a liver
transplant in women, older patients and people receiving Medicare insurance in
the United States, a review of liver transplants in 2019 has found.
The findings are published in Clinical Gastroenterology and
Hepatology and update
findings presented by another research group at the 67th Meeting of the American Association
for the Study of Liver Diseases in 2016.
NASH develops after chronic inflammation
caused by fat accumulation in the liver damages liver cells and structure.
Between 30 and 40% of adults in the United States have NAFLD and between 3 and 12% had NASH in studies published in 2011 and
2013 (Kim; Williams).
Glossary
- hepatocellular carcinoma (HCC)
Liver cancer. A long-term complication of chronic inflammation of the liver or cirrhosis.
The prevalence of NASH and NAFLD are growing in the United
States due to obesity and prevalence of NASH is especially high among people
with severe obesity (body mass index over 40).
Previous
research by the same group found that NASH was the fastest-growing cause of
hepatocellular carcinoma (HCC) in the United States between 2002 and 2016.
Researchers compared liver transplant waiting lists between
2002 and 2019 using the Scientific Registry of Transplant Recipients. A total of 168,441
people with chronic liver disease were listed for a transplant between 2002 and
2019, including 16.5% with HCC.
In 2002 the most common reasons for being placed on the
transplant waiting list were severe liver disease caused by hepatitis C (37%)
or alcoholic liver disease (16%). NASH was the reason for a liver transplant in
only 5% of cases. In patients with HCC, NASH was even less
common; only 1% of people with HCC had NASH, whereas 58% had hepatitis C.
In 2019 hepatitis C remained the leading indication for
liver transplant wait listing (40%) overall but in several sub-groups NASH had
become the most common reason. NASH
was the leading indication in women without HCC (34%), in patients older than
54 years (36%), and in patients on Medicare (41%). In trend analysis, NASH was
the most rapidly increasing indication for liver transplantation in patients
without HCC (Kendall tau=0.97; P<.001) and in patients with HCC
(tau=0.94; P<.0001).