OBJECTIVE: This study is aimed at evaluating the association between long-term oxygen therapy (LTOT) and cognitive function in patients with chronic obstructive pulmonary disease (COPD). METHODS: We conducted a systematic literature search across major databases for observational studies comparing cognitive outcomes between COPD patients receiving LTOT (≥ 15 h/day) and those not receiving it. Cognitive performance was evaluated using validated tools like the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Trail Making Tests (TMT-A/B). Due to heterogeneity in study design and outcome measures, a narrative synthesis was performed. RESULTS: We included five studies involving 1849 participants (343 LTOT users) in this review. LTOT use was generally associated with a lower prevalence of cognitive impairment (18%-45%) and higher global cognitive scores, particularly in executive functions. MoCA-based assessments also consistently favored LTOT users, particularly in rural populations. However, findings were heterogeneous across studies. CONCLUSION: LTOT is associated with better cognitive performance in hypoxemic COPD patients. Prospective longitudinal studies are needed to establish causality between LTOT use and reduction in cognitive impairment in COPD.
Fawwad et al. (Thu,) studied this question.