Sedentary behavior and obstructive airway diseases: a narrative review of bidirectional associations, mechanisms, and clinical implications

Obstructive airway diseases (OADs), including chronic obstructive pulmonary disease (COPD), asthma, and bronchiectasis, are major contributors to global morbidity and mortality. Sedentary behavior (SB), defined as any waking behavior characterized by energy expenditure ≤ 1.5 metabolic equivalents (METs) in a sitting, reclining, or lying posture, has emerged as a potentially modifiable factor in these conditions. However, the direction and magnitude of the association between SB and OADs remain uncertain. This narrative review aims to synthesize current evidence on the relationship between SB and OADs, with a focus on bidirectional associations, disease-specific patterns, underlying mechanisms, and intervention strategies. A narrative review of the literature was conducted, including evidence from observational studies, randomized controlled trials, qualitative studies, systematic reviews, Mendelian randomization (MR) studies, and other relevant literature examining sedentary behavior, physical activity, and obstructive airway diseases. Sedentary behavior is associated with adverse health outcomes across OADs, with the strength of evidence varying across diseases, while causal relationships have not been clearly established. Behavioral interventions show modest but variable effectiveness in reducing sedentary time. Future research should leverage well-designed longitudinal, Mendelian randomization, and target trial emulation designs to clarify causality and inform clinical and public health strategies.