Now that hepatitis C
can be successfully treated, non-alcoholic fatty liver disease (NAFLD) is
becoming an increasingly important cause of serious liver problems and
liver-related death among people living with HIV in the US, according to a
report at the International Liver Congress this month in Vienna.
Dr Zobair
Younossi of Inova Fairfax Medical Campus in Falls Church, Virginia, who
presented the findings at a press conference, said that given the increasing
impact of fatty liver disease among people with HIV, “clinicians must be
vigilant in identifying and managing NAFLD in these individuals."
As people
with HIV are living longer thanks to effective antiretroviral treatment, non-HIV-related
conditions such as cardiovascular disease, non-AIDS cancers and liver disease
account for a rising proportion of illness and death in this population. As
HIV-positive people become healthier, they are also more likely to be
overweight, Younossi noted.
Non-alcoholic
fatty liver disease and its more severe form, non-alcoholic steatohepatitis
(NASH), are characterised by the accumulation of fat in the liver. This
triggers inflammation, which over time can lead to the development of fibrosis,
cirrhosis and liver cancer. There are currently no effective treatments for NAFLD
and NASH, and management relies on lifestyle changes such as weight loss and
exercise.
Many
people living with HIV also have hepatitis B virus (HBV) or hepatitis C virus
(HCV). An effective HBV vaccine has been available since the late 1980s,
antiviral medications like tenofovir disoproxil fumarate (Viread) and entecavir (Baraclude)
can keep hepatitis B under control and hepatitis C can now be cured with direct-acting
antivirals. Among HIV-positive people in the US – like that country's population
as a whole – viral hepatitis is falling as a cause of serious liver disease while
NAFLD is rising.
Younossi
and colleagues looked at
the prevalence and mortality trends of NAFLD, viral hepatitis and other liver
diseases among HIV-positive people receiving Medicare, which generally is
available to those age 65 or older and some younger people with disabilities.
Searching medical records
of more than 47,000 HIV-positive people, the researchers identified 10,474, or
22.3%, with liver disease. Hepatitis C was the most common cause, accounting
for 5628 cases (53.7%), followed by NAFLD, at 2629 cases (25.1%). Other
causes were less common, including 1374 with hepatitis B (13.1%), 645 with
HBV and HCV co-infection (6.2%) and 198 with other liver diseases (1.9%).
Between
2006 and 2016, the prevalence of viral hepatitis among people with HIV
decreased from 27.8 to 24.1 per 100,000 population (an annual percentage change
of -0.9%), while the NAFLD rate more than doubled from 5.3 to 11.6 per 100,000
(an annual percentage change of +7.2%).
A
similar pattern was observed for mortality. Of the 2882 total deaths during
the study period, just over a third (36.2%) were related to liver disease. Of
these, half were attributable to HCV, 20.3% to NAFLD, 14.4% to HBV, 11.9% to
HBV/HCV co-infection and 3.9% to other liver diseases.
During
the same decade, mortality related to viral hepatitis fell from 3.8 to 2.6 per
100,000 (an annual percentage change of -5.2%), while deaths related to NAFLD rose from 0.2 to 0.8
per 100,000 (an annual percentage change of +8.9%).
In a multivariate analysis that took multiple risk
factors into account, HIV-positive people with liver disease had longer
hospital stays, higher inpatient and outpatient costs, and a higher risk of
dying within a year compared to those without liver disease.
A related
study at the conference looked at NAFLD in two cohorts of people living with
HIV in Canada and Italy who did not drink to excess and did not have hepatitis
B or C. Among 1228 people whose records were reviewed, 31.8% had NAFLD. Of
these, 25.2% were considered at risk for liver disease progression based on
elevated ALT levels or the presence of significant fibrosis.
"These studies indicate the changing profile of liver disease in
patients with HIV. Whilst viral hepatitis is still the major cause of liver
disease in such groups, NAFLD is becoming a much commoner problem," EASL
vice secretary Prof Philip Newsome of the University of Birmingham said in a conference
press release. "This reinforces the need to study therapeutic
agents in patients with NAFLD and HIV, an area which is seldom examined."