Long COVID linked to increased risk of fatty liver disease
Metabolism-associated fatty liver disease (MAFLD) was diagnosed in 55% of people with long COVID in a recent study published in Open Forum of Infectious Diseases. These findings add to evidence that long COVID, also known as post-acute COVID syndrome (PACS), can have far-reaching manifestations.
Resulting from fatty accumulation in the liver, non-alcoholic fatty liver disease (NAFLD) and its more severe form, non-alcoholic steatohepatitis (NASH), are responsible for an increasing proportion of advanced liver disease worldwide. As a result of inflammation, NAFLD can lead to fibrosis, cirrhosis and even liver cancer. Fatty liver disease is often associated with abdominal obesity, hypertension and abnormal levels of sugar and fat in the blood (metabolic syndrome), as evidenced by the new term MAFLD. In the absence of effective approved medical therapies, disease management depends on lifestyle changes, such as weight loss and exercise.
Jovana Milic from the University of Modena in Italy and her colleagues sought to establish the prevalence of MAFLD in people with post-acute COVID syndrome. Although it is well known that signs of abnormal liver function can be seen in acute COVID-19, some people experience long-lasting symptoms.
The researchers recruited 235 adults from a post-COVID outpatient clinic in Italy between July 2020 and April 2021. The median age was 61 and 69% were male. People with pre-existing hepatitis B, hepatitis C or heavy alcohol consumption were excluded. Hepatic steatosis was detected by transient elastography (FibroScan). Participants were diagnosed with MAFLD if they showed signs of fatty accumulation in the liver as well as being overweight or obese, type 2 diabetes, high blood pressure or high blood lipids. A fatty liver index (HSI) was calculated using liver enzyme levels and body mass index.
Overall, the group had severe COVID-19. They had all been hospitalized, 12 days on average, and 19% had received mechanical ventilation. Comorbidities were common: in the study population, 36% had insulin resistance, 30% had high blood pressure, and 28% had been diagnosed with metabolic syndrome.
Study participants were diagnosed with long COVID based on neurocognitive, psychological, respiratory, sensory, dermatological, or musculoskeletal symptoms. The first PACS clinic visit occurred an average of 143 days after their COVID-19 symptoms began. More than three quarters reported at least one PACS symptom cluster.
At the time of their first hospital admission, 37% were presumed to have MAFLD based on HSI scores. At the first post-COVID clinic visit, this increased to 55% as measured by transient elastography. The researchers noted that body mass index, insulin resistance, and metabolic syndrome were all independent predictors of MAFLD.
“MAFLD was highly prevalent after hospital discharge and may represent a specific PACS cluster phenotype, with potential long-term implications for metabolic and cardiovascular health,” the researchers concluded.
However, while this study found a correlation between MAFLD and post-COVID syndrome, it did not show that one caused the other. It is well known that obesity and other metabolic abnormalities increase the risk of severe COVID-19, but having COVID can also increase the risk of fatty liver disease.
Click here to read the study Open Forum on Infectious Diseases.
Click here for more information on fatty liver disease and COVID-19.