Fatty liver disease occurs when an abnormally large amount of fat accumulates in liver cells. Lean fatty liver disease can develop even in people whose weight is within the normal range, but the risk generally rises as metabolic conditions such as abdominal obesity, diabetes and high blood pressure overlap.
If fatty liver disease persists for a long time and inflammation develops in the liver, causing progressive damage, scar tissue, or fibrous tissue, can build up in place of normal liver tissue. This is known as liver fibrosis.
A study released on the 26th found that the more severe the liver fibrosis in patients with fatty liver disease, the greater their risk of arrhythmia, particularly atrial fibrillation.
A research team led by Kim Seung-hyun, a professor of cardiology at Soonchunhyang University Seoul Hospital, and Ryu Dam, a professor of gastroenterology, analyzed the link between liver fibrosis and the subsequent development of arrhythmias in 10,263 patients with fatty liver disease. The team used data from Lifelines, a large population-based cohort study in the Netherlands.
The researchers used the FIB-4 index, which estimates the extent of liver fibrosis by combining liver enzyme levels, platelet counts and age without requiring a separate biopsy. They assessed the relationship between the degree of liver fibrosis and newly detected arrhythmias on electrocardiograms. Based on FIB-4 scores, the patients were divided into groups with high and low liver fibrosis burdens, and the researchers compared how many patients in each group newly developed arrhythmias.
The analysis found that patients with fatty liver disease and FIB-4 scores of 1.45 or higher had a fivefold higher risk of developing a newly detected arrhythmia during follow-up than those with scores below 1.45. Their risk of developing atrial fibrillation was 6.82 times higher. The association remained even after adjusting for all metabolic risk factors, including diabetes, high blood pressure and dyslipidemia.
Arrhythmia is a condition in which the heart beats too fast, too slowly or irregularly instead of maintaining a normal rhythm. Atrial fibrillation is a type of arrhythmia characterized by rapid, irregular beating in the atria, the heart's upper chambers. Atrial fibrillation increases the risk of blood clots and is considered a leading risk factor for stroke.
The study found that older patients with fatty liver disease faced a higher risk of developing atrial fibrillation. Participants age 50 and older with high FIB-4 scores had about a 2.7 times higher risk of developing atrial fibrillation than those without high scores. The difference remained statistically significant after adjusting for major metabolic risk factors. Their overall risk of developing arrhythmia also tended to be about twice as high. Among participants younger than 50, however, no new cases of arrhythmia occurred during the follow-up period, even when the liver fibrosis index was high.
Kim Seung-hyun, a professor of cardiology at Soonchunhyang University Seoul Hospital, said, “This study confirmed that liver fibrosis is an indicator not only of the prognosis of liver disease itself but also of the risk of developing arrhythmia. When treating patients with fatty liver disease, doctors should take an integrated approach that considers not only the progression of liver disease but also the risk of arrhythmias, including atrial fibrillation.”
Ryu Dam, a professor of gastroenterology at Soonchunhyang University Seoul Hospital, added, “In particular, patients age 50 and older with fatty liver disease and high liver fibrosis scores should be monitored regularly with the possibility of arrhythmia in mind.”
The study was published in May in the international journal 《Scientific Reports》.
