Beyond Smoking: Emerging Drivers of COPD and Their Clinical Implications in Low- and Middle-Income Countries: A Narrative Review.

Chronic obstructive pulmonary disease (COPD) is an escalating global health burden, with a disproportionate impact on low- and middle-income countries (LMICs). Although tobacco smoking is a well-established risk factor, emerging evidence highlights the significant role of non-smoking exposure in driving the prevalence of COPD in these regions. This narrative review synthesizes current data on key non-smoking contributors, including household air pollution, ambient urban pollution, occupational exposure, early-life respiratory insults, chronic infections, and socioeconomic adversity. These risk factors are associated with distinct COPD phenotypes, often marked by increased airway inflammation, reduced emphysema, and variable airflow limitation. Such presentations are particularly common among women and younger populations in LMICs. However, diagnostic and therapeutic challenges persist, owing to limited disease awareness, under-resourced health systems, restricted access to essential medications, and financial constraints impacting adherence. Despite the proven effectiveness of non-pharmacological measures and public health interventions, their implementation remains inadequate because of infrastructural and funding limitations. Bridging these gaps requires region-specific clinical guidelines, improved diagnostic infrastructure, expanded access to affordable treatment, and culturally sensitive interventions. Future priorities include identifying robust biomarkers, refining disease definitions to accommodate non-smoking phenotypes, and advancing implementation science to improve interventions. A coordinated, context-aware global response is essential to reduce the growing burden of COPD in LMICs and to ensure equitable respiratory health outcomes.