Nonalcoholic fatty liver disease is associated with decreased lung function

Area of Science:

• Pulmonology
• Hepatology
• Epidemiology

Background:

• Nonalcoholic fatty liver disease (NAFLD) prevalence is increasing globally.
• The relationship between NAFLD and respiratory health, specifically lung function, requires further investigation.
• Understanding this association is crucial for comprehensive patient care.

Purpose of the Study:

• To investigate the association between NAFLD and lung function in a general population.
• To analyze both cross-sectional and longitudinal data to clarify this relationship.
• To identify potential risk factors for lung function decline in NAFLD patients.

Main Methods:

• Cross-sectional and longitudinal analyses were performed on 11,892 participants.
• Nonalcoholic fatty liver disease was diagnosed using hepatic sonography.
• Lung function was assessed via spirometry, including forced expiratory volume in 1-second and forced vital capacity.
• Propensity score matching was used for longitudinal analysis.

Main Results:

• Nonalcoholic fatty liver disease was significantly associated with lower baseline lung function (FEV1 and FVC) in both men and women.
• Longitudinal analysis revealed no significant difference in lung function decline rates between NAFLD and control groups in matched cohorts.
• However, individuals with high NAFLD fibrosis scores (NAFLD fibrosis score and FIB-4) exhibited a faster decline in forced vital capacity.

Conclusions:

• Nonalcoholic fatty liver disease is linked to diminished lung function at the population level.
• NAFLD itself does not appear to accelerate lung function decline in a matched cohort.
• Hepatic fibrosis severity is a significant predictor of accelerated forced vital capacity decline, highlighting the importance of fibrosis assessment.