Chronic obstructive pulmonary disease (COPD) and metabolic fatty liver syndromes: a dangerous but neglected liaison

This perspective article aims at addressing the potential commonalities associated with chronic obstructive pulmonary disease (COPD) and the two metabolic fatty liver syndromes: nonalcoholic fatty liver disease (NAFLD) and metabolic (associated) fatty liver disease (MAFLD). To this end, we briefly review the definitions and burdens of COPD and NAFLD and highlight the differences in the diagnostic criteria of NAFLD and MAFLD. We also critically discuss the recent line of research trying to identify an association between COPD and NAFLD. Moreover, among the chief co-morbidities of COPD patients, we identify significant six that exert a major impact on the natural course of COPD: major cardiovascular events, cardiac arrhythmias, metabolic syndrome, obstructive sleep apnea, osteoporosis, and psychodepression. The potential role of NAFLD in each of these COPD co-morbidities is accurately examined based on published studies. We conclude that both COPD and NAFLD/MAFLD are heterogeneous systemic syndromes. While the complex mechanistic links underlying the association of NAFLD/MAFLD with COPD and its co-morbidities remain to be fully elucidated, we highlight that the diagnosis of metabolic fatty liver syndromes in patients with COPD might be clinically relevant, as it might allow identifying a subset of COPD individuals who, being at risk of severe clinical outcomes, would need more comprehensive treatment approaches.