Curing hepatitis C improves cognitive function, especially
in older people already showing signs of cognitive impairment, a Spanish study
has found.
Cognitive impairment covers a wide spectrum of problems with
memory, concentration, learning, attention span, decision-making ability and
difficulties with mental tasks in everyday life. Some people with hepatitis C
refer to these problems as ‘brain fog’. Cognitive impairment is more commonly
observed in people with cirrhosis. In people with decompensated cirrhosis, it
is an early sign of the onset of hepatic encephalopathy.
As cognitive impairment has a significant effect on quality
of life, Spanish researchers wanted to find out whether direct-acting antiviral
treatment reduced cognitive impairment. Learning that curing hepatitis C can
reduce cognitive impairment might also encourage people to overcome their
reluctance to start direct-acting antiviral treatment.
Glossary
- decompensated cirrhosis
The later stage of
cirrhosis, during which the liver cannot perform some vital functions and
complications occur. See also ‘cirrhosis’ and ‘compensated cirrhosis’.
- encephalopathy
-
A disease or infection affecting the brain.
The researchers carried out an observational study in
randomly selected people with hepatitis C alone attending a viral hepatitis
clinic in Madrid between 2015 and 2017.
Cognitive function was assessed prior to treatment, 12 weeks
after completion of treatment and 48 weeks after the end of treatment.
The study excluded people co-infected with HIV, people with
more advanced hepatocellular carcinoma, recent harmful alcohol consumption,
cardiovascular disease or another comorbid condition likely to have an
independent effect on cognitive health, or people with a portosystemic shunt.
One hundred and fifty-two out of 912 patients treated for
hepatitis C during the study period were recruited (a maximum of three eligible
patients per week). One hundred and thirty-five completed the study and
achieved viral eradication. Participants had a median age of 57 years and 57%
were male. 32.5% had cirrhosis (27% decompensated).
Participants with cirrhosis were significantly more likely
to have diabetes (31% vs 6%, p<0.001), higher body mass index (28.5 vs 26,
p=0.007) and were more likely to be receiving treatment with beta blockers and
diuretic agents as well as hypoglycaemic agents.
The prevalence of alcohol use disorder, substance abuse,
anxiety and depression, each of which might affect cognitive function, was low
in the study population.
Cognitive function was measured by tests of visuo-motor
function, executive function tests to assess planning ability, flexibility and
verbal reasoning, and tests of processing speed, memory, attention span and
working memory. The researchers also carried out five cognitive tests used to
diagnose hepatic encephalopathy.
Cognitive
impairment (either HCV-related cognitive impairment in people without cirrhosis or covert
hepatic encephalopathy in people with cirrhosis) was defined as being below one
standard deviation in more than two cognitive domains.
At
study entry, 34% of people with cirrhosis and 14% without cirrhosis had
cognitive impairment. At baseline, arterial hypertension significantly
increased the risk of cognitive impairment (odds ratio 3.5, 95% CI 1.01-11.4),
as did prior hepatic encephalopathy (OR 13.8, 95% CI 0.7-273) and anxiety (OR
1.2, 95% CI 1.1-1.4).
A
greater number of years of education was associated with a reduced risk of
cognitive impairment (OR 0.80, 95% CI 0.7-0.9).
After
eradication of hepatitis C, people with cirrhosis showed significant improvements
in measures of motor function, executive function, processing speed, attention
and global cognitive function. They also showed improvements in Psychometric
Hepatic Encephalopathy Scores.
People with cirrhosis also experienced significant improvements in mood and some measures of
health-related quality of life.
However,
patients with cirrhosis at baseline still displayed worse cognitive performance
than patients without cirrhosis 48 weeks after completing treatment. The
researchers did not report on changes in liver function after cure in people
with cirrhosis, so it is not possible to judge if differences exist in
cognitive function between people with compensated and decompensated cirrhosis.
Patients
without cirrhosis showed significant improvement in visuospatial function,
executive function, processing speed, attention, working memory and global
cognitive function. They also showed improvements in Psychometric Hepatic
Encephalopathy Scores.
Improvement
in cognitive function was significantly greater in patients with cognitive
impairment at baseline, especially those with worse cognitive impairment, and
in older patients.
The
study authors conclude that curing hepatitis C can improve cognitive function
regardless of liver disease stage, with the greatest benefits in older people and
those with lower brain reserve.