Pulmonary function is associated with fibrosis severity in patients with biopsy-proven nonalcoholic fatty liver disease

Hyun Woo Lee; Dong Hyeon Lee; Jung-Kyu Lee; Seonhwa Lee; Bo Kyung Koo; Sae Kyung Joo; Eun Young Heo; Yong Jin Jung; Won Kim; Deog Kyeom Kim

doi:10.1111/liv.14626

Pulmonary function is associated with fibrosis severity in patients with biopsy-proven nonalcoholic fatty liver disease

Liver Int. 2020 Dec;40(12):3008-3017. doi: 10.1111/liv.14626. Epub 2020 Nov 17.

Authors

Hyun Woo Lee¹, Dong Hyeon Lee², Jung-Kyu Lee¹, Seonhwa Lee³, Bo Kyung Koo⁴, Sae Kyung Joo², Eun Young Heo¹, Yong Jin Jung², Won Kim^{2

5}, Deog Kyeom Kim^{1

5}

Affiliations

¹ Division of Respiratory and Critical Care, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea.
² Division of Gastroenterology and Hepatology, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea.
³ Department of Bio-convergence Engineering, Korea University, Seoul, South Korea.
⁴ Division of Endocrinology, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea.
⁵ Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.

PMID: 32737958
DOI: 10.1111/liv.14626

Abstract

Background & aims: The association between nonalcoholic fatty liver disease (NAFLD) and pulmonary function remains elusive because of the heterogeneous spectrum and inaccurate diagnostic methods of NAFLD, and insufficient pulmonary function data. We conducted this study to identify the association between histological severity of NAFLD and pulmonary function.

Methods: This study included patients ≥18 years old with baseline pulmonary function data between August 2014 and July 2019 within a biopsy-evaluated prospective NAFLD cohort. Cross-sectionally, pre-/post-bronchodilator spirometric data with diffusing capacity (DL_CO ) were compared according to histological severity of NAFLD in the various demographic and metabolic subgroups. Multivariable-adjusted analysis revealed specific histological features associated with reduced pulmonary function.

Results: In a total of 420 patients with biopsy-proven NAFLD, pre-/post-bronchodilator forced vital capacities (FVCs; a percentage of the predictive value) were inversely correlated with histological severity of NAFLD. Conversely, pre-bronchodilator forced expiratory volume in 1 second (FEV₁ )/FVC was positively correlated with NAFLD severity. Post-bronchodilator FVC (%) decreased and DL_CO /alveolar volume (V_A ) increased linearly with worsening histological severity of NAFLD in multivariable analysis. In particular, fibrosis stage remained a significant independent predictor of decreased post-bronchodilator FVC (%) (β-coefficient, 4.41; 95% confidence interval [-8.39, -0.43]; P = .031) even after adjusted for clinical variables, exclusively in age <65 years, female, never-smoker and nonchronic obstructive pulmonary disease subgroups.

Conclusions: Pulmonary function deteriorates with worsening histological severity of NAFLD, especially at the fibrosis stage. The common pathogenesis of reduced pulmonary function and NAFLD fibrosis progression should be further explored.

Keywords: biopsy; fatty liver disease; fibrosis; liver; nonalcoholic; pulmonary function.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Aged
Biopsy
Female
Fibrosis
Humans
Liver / pathology
Liver Cirrhosis / pathology
Lung
Non-alcoholic Fatty Liver Disease* / pathology
Prospective Studies
Severity of Illness Index