Muscle-to-Fat Ratio Key to Lung Function

TOPLINE:

An increased muscle-to-fat (MF) ratio is associated with improved lung function in men and nonsmoking women of middle age. Increases in the MF ratio are linked to a reduced decline in lung function over time compared with a decrease in MF ratio. 

METHODOLOGY:

• This prospective community-based cohort study explored the long-term relationship between lung function and MF ratio in a middle-aged general population.
• Overall, 4712 participants (mean age, 53.9 years; 45.8% men) from rural and urban communities in Korea were enrolled between 2005 and 2014, with a median follow-up of 8 years.
• Participants were required to have valid results from spirometry and body composition analysis. Those with chronic lung disease, missing smoking data, or body mass index ≤ 18.5 or ≥ 30.0 were excluded.
• Lung function parameters (forced expiratory volume in 1 second [FEV₁], forced vital capacity [FVC], and FEV₁/FVC ratio) and the MF ratio (total body muscle mass/fat mass) were analyzed biannually.

TAKEAWAY:

• An increase in the annual rate of change in the MF ratio was significantly associated with an increased rate of lung function change in both men and women (all P
• With each increase in the MF ratio, significant improvements in the FEV₁/FVC ratio were observed in men (0.320%) and nonsmoking women (0.265%; both P 
• The group with an increased MF ratio demonstrated a significantly smaller decline in lung function than the group with a decreased MF ratio. This was evident in both men (P P = .005)
• A higher MF ratio was associated with a reduced risk for airflow obstruction in both men (P P = .014).

IN PRACTICE:

“…the probability of airflow obstruction decreases as the MF ratio increases. Therefore, individuals with altered body composition, especially of the MF ratio, should be monitored for lung function deterioration and the possibility of developing obstructive lung diseases,” the authors wrote.

SOURCE:

The study was led by Eunwoo Kim, Yonsei University College of Medicine, Seoul, Republic of Korea. It was published online on December 26, 2024, in Respiratory Research.

LIMITATIONS:

Airway obstruction was defined solely by pulmonary function tests, without considering symptoms, which constitutes a major limitation in the study. Additionally, the use of the standard definition of FEV₁/FVC

DISCLOSURES:

No funding sources were reported, and there were no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.