NAFLD remains a top public health threat

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of liver-related deaths and is associated with a variety of malignancies, according to a new study presented at the Digital International Liver Congress (ILC) 2020.

“[C]omparable and consistent measures of cause of deaths among NAFLD at the population level have not been produced previously” because most data come from tertiary care centres, the researchers said.

Records of 2,776,829 decedents, aged ≥20 years, were retrieved in 2017. Three percent (n=83,154) died due to liver-related conditions at a mean age of 64.6±13.8 years. Liver-related illnesses ranked as the eighth leading cause of death in the country that year. [ILC 2020, abstract AS158]

NAFLD emerged as the second-leading cause of liver-related deaths, accounting for 26.3 percent of such mortalities. It was behind alcoholic liver disease (27.9 percent) and was followed by chronic hepatitis C (12.1 percent) and B (0.3 percent) infections. In absolute terms, 43,187 of the decedents had NAFLD.

Further disaggregation of the NAFLD decedents showed that more than half of the deaths (53.1 percent) were caused by liver-related conditions. Other common causes of mortality were cardiovascular diseases (12.2 percent), nonliver cancers (6.6 percent), and diabetes-related issues (2.6 percent).  

There were 3,919 solid cancers reported in NAFLD decedents, accounting for 79.59 percent of cancer-related mortalities in this group. Such deaths were more common in men than in women NAFLD decedents (81.39 percent vs 76.09 percent). As expected, malignancies of the liver and intrahepatic bile ducts were the predominant solid cancers overall (42.55 percent) and in men (48.54 percent) and women (30.90 percent).

The researchers also recorded other cases of solid cancers, including malignancies of the trachea, bronchus, and lung (8.53 percent); of the colon, rectum, and anus (6.88 percent); of the pancreas (5.54 percent); of the breast (4.16 percent); and of the prostate (2.27 percent).

“NAFLD is the second-leading cause of liver-related mortality. Although liver cancer is the most common solid tumour in decedents with NAFLD, lung cancer, colorectal, pancreatic, and breast cancer are also the other common causes of cancer-related deaths,” the researchers said.

The results presented in the study agree with recent findings in literature, though some uncertainties remain. A 2018 study from South Korea, for instance, found that NAFLD was tied to a higher burden of hepatocellular carcinoma, colorectal cancer, and breast cancer. [J Hepatol 2018;68:140-146]

However, a systematic review and meta-analysis published the following year concluded that while NAFLD does exacerbate the risk of all-cause mortality, it does not do so for cancer- or cardiovascular disease-related deaths. Further studies are needed to better understand the interplay between NAFLD and other conditions, and how these contribute to mortality risk. [Sci Rep 2019;9:11124]