▲(From Left) Professor Young Ju Jung and Professor Hong-Kyu Kim from the Department of Health Medicine at Asan Medical Center

A recent study has found that individuals with sarcopenic obesity, a condition characterized by low muscle mass and high visceral fat, have up to 4 times higher rates of lung function decline than those without sarcopenic obesity. Lung function decline is defined as a percentage of lung capacity below 80% compared to the standard lung capacity of Koreans.

A research team led by Professors Young Ju Jung and Hong-Kyu Kim from the Department of Health Medicine at Asan Medical Center analyzed abdominal CT scans and spirometry results from 15,827 adults who underwent medical checkups at the Health Screening and Promotion Center at Asan Medical Center between January 2012 and December 2013. The analysis showed that the male sarcopenic obesity group’s rate of lung function decline was 19.1%, more than 4 times higher than the 4.4% rate in the group with higher muscle mass and lower visceral fat. The lung function decline in women was also more than 3 times higher in the sarcopenic obesity group, at 9.7%, compared to 3.1% in the control group.

In contrast, individuals with the highest muscle mass and lowest visceral fat had the highest lung function among all groups, 3~5% higher than the sarcopenic obesity groups, regardless of gender. Forced vital capacity (FVC) in men with the highest muscle mass was 92.4%, 3.7% higher than the 88.7% in the lowest group, while women with the highest muscle mass recorded 95.6% and the lowest group 91.9%. Conversely, men with the highest visceral fat had an FVC of 88.1%, 5% lower than the 93.1% of the lowest visceral fat group. Lung function in women showed a 3.4% difference between the highest and lowest visceral fat groups. The difference in lung function in women between the highest and lowest visceral fat groups was recorded at 3.4%.

The researchers explained that higher muscle mass enhances the movement of respiratory muscles that directly affect breathing, such as the diaphragm and intercostal muscles. This results in rib cage expansion sufficient to allow better lung expansion and increased lung function. However, having more visceral fat, associated with visceral fat deposition, may reduce thoracic volume and trigger inflammatory responses, leading to weakened lung function.

The study findings were recently published in the international academic journal ‘Chest’, the official journal of the American College of Chest Physicians.