Fatty liver linked to heart failure in obese: study

Fatty liver is independently associated with heart failure in obese people, a new study has found.
Non-alcoholic fatty liver disease (NAFLD), also known as hepatic steatosis, is the most common liver disease, with a prevalence of up to 30 per cent in the general population and between 70 per cent and 90 per cent among persons who are obese or have type 2 diabetes.
NAFLD is considered as a manifestation of the metabolic syndrome, a group of risk factors like high blood pressure, excess abdominal fat and unhealthy cholesterol levels that raise the risk of heart attacks, strokes and other health problems.

Researchers from Leiden University Medical Centre in Netherlands used proton magnetic resonance imaging (MRI) spectroscopy to measure hepatic triglyceride content, a measure of fat in the liver, and cardiac MRI to assess left ventricular diastolic function in 714 men and women aged 45 to 65 years.
Of the 714 patients, 47 per cent were categorised as overweight, and 13 per cent were classified as obese.
The left ventricle is the heart's main pumping chamber, and diastolic function refers to the phase of the heartbeat when the heart relaxes to fill with blood.

Abnormalities of diastolic function, represented by inefficient filling of the heart, play a major role in exercise intolerance in patients presenting with heart failure.

Diastolic dysfunction has been clinically undervalued and is currently gaining major attention by cardiologists and general physicians, researchers said.
Results indicated that an increase in hepatic triglyceride content was associated with a decrease in mean left ventricular diastolic function in the obese subgroup of the study population.
The association between hepatic triglyceride content and left ventricular diastolic function existed independently of the metabolic syndrome, suggesting that fatty liver itself could, at least in obese people, pose a risk of heart dysfunction above and beyond known cardiovascular risk factors that are clustered within the metabolic syndrome.
"Our results may be of importance in cardiovascular risk stratification in obesity, because there is a large variation in the degree of hepatic steatosis in obesity," said Ralph L Widya from Leiden University Medical Centre.

"Also, more emphasis should be put on dietary interventions to reduce or prevent hepatic steatosis," he added.
The reasons for the link between fatty liver and heart function are unknown but could be related to several factors, including the presence of infection-fighting white bloods cells called macrophages or increased expression in the liver of small proteins known as cytokines, researchers said.
The findings were published in the journal Radiology.