Women with non-alcoholic fatty liver disease
(NAFLD) had a higher risk of cardiovascular events including chest pain and
heart failure compared to women without the condition – and about the same risk
as men with NAFLD – in a study presented at the 2017 AASLD
Liver Meeting this week in Washington, DC.
The researchers calculated that a 50-year-old woman
with fatty liver disease had about the same cardiovascular risk as a
53-year-old man with NAFLD, a 58-year-old man without NAFLD or a 67-year-old
woman without NAFLD.
These findings show that the normal protective
effect of female sex on cardiovascular risk is lost in women with fatty liver
disease, Alina Allen, MD, of the Mayo Clinic said at an AASLD press conference.
NAFLD and its more severe form, NASH (non-alcoholic steatohepatitis), refer to the build-up of fat in the
liver in people who do not drink heavily. Fatty liver disease, which is often
associated with obesity and metabolic syndrome, is now the most common chronic
liver disease worldwide. Over time, fat accumulation in the liver and the
accompanying inflammation and build-up of scar tissue (fibrosis and cirrhosis)
can interfere with normal liver function and lead to liver cancer.
Fatty liver disease is also associated with a higher risk of cardiovascular
events – and in fact people with NAFLD are more likely to die of heart disease
than of liver disease.
Allen and colleagues conducted a study to assess the cardiovascular risk
among women with NAFLD. Women in the general population have about a 20% lower
risk of cardiovascular events than men and experience heart attacks about five
years later, according to Allen, but it is not known whether this is the case
for people with fatty liver disease.
The researchers evaluated a community cohort
of adults diagnosed with NAFLD in Minnesota between 1997 and 2014. Each of the
3869 individuals with fatty liver disease was matched with multiple people of
the same age and sex in the general population in the same community, for a
total of 15,209 control subjects.
About half of the study participants were women and
the median age was approximately 53 years. Women and men with NAFLD had more
cardiovascular risk factors at baseline than the general population group,
including higher body mass index and higher rates of pre-existing heart
disease, diabetes and high blood pressure.
Over a follow-up period of up to about 20 years, the
researchers looked at new cardiovascular events including angina (chest pain),
myocardial infarction (heart attack), heart failure, stroke and atrial
fibrillation (a type of irregular heartbeat), comparing their likelihood among
people with NAFLD and the general population group.
At the time of NAFLD diagnosis, women and men with
fatty liver disease were about equally likely to have a history of chest pain,
heart failure and stroke. These rates were higher than those for either women
or men without NAFLD. Men with NAFLD had more heart attacks and atrial
fibrillation than women with NAFLD, but among both men and women with NAFLD, these
rates were higher than those for the same sex in the general population.
Women in the general population had a lower likelihood
than men of experiencing new cardiovascular events during follow-up. Among
people with NAFLD, however, incidence rates for women and men were comparable.
Similarly, women and men with NAFLD were about equally likely to develop
diabetes or high blood pressure if they did not already have it, and they were
more likely to do so than people of either sex without NAFLD.
Within the general population, being female decreased
the risk of cardiovascular events by 23%, or by 26% after controlling for
various cardiovascular risk factors. For women and men with NAFLD, the likelihood
was close to equal. But despite the similarity in their rates of cardiovascular
events, women with NAFLD had a higher survival rate than men with NAFLD.
"We noted that in subjects with NAFLD, the risk for these events
was higher in women than in men, contrary to those without the liver
disease," Allen said in an AASLD press release. "In NAFLD, the
protective effect of the female sex on cardiovascular risk disappears.
Additionally, we noted cardiovascular events started at an earlier age for
these women than in the general population."
Based on these findings, the researchers suggested
that cardiovascular risk assessment in people with NAFLD should take
sex-related differences into account, as women with fatty liver disease may
require more aggressive prevention measures – such as weight loss, better diet
and more exercise, or use of aspirin or statins – to avoid adverse