ABSTRACT Objective This study aimed to investigate the association between N‐acetylcysteine (NAC) use and dementia risk in elderly individuals diagnosed with Chronic Obstructive Pulmonary Disease (COPD). Methods Utilizing Taiwan's National Health Insurance Research Database (NHIRD), we conducted a population‐based cohort study of 105,144 elderly COPD patients to investigate the association between NAC use and dementia risk. Propensity score matching (PSM) ensured balanced covariates between NAC users and nonusers. Cox regression analysis and Poisson Regression analysis were employed to assess dementia risk, considering NAC dosage, treatment duration, and comorbidities. Competing risk analysis and Kaplan‐Meier method were used to account for mortality risk and estimate dementia incidence, respectively. Results Elderly NAC users demonstrated a significant association with a lower dementia risk (adjusted hazard ratio aHR: 0.76, 95% confidence interval CI: 0.74–0.78). Higher daily NAC intake was associated with a dose‐dependent decline in dementia risk, with optimal benefits observed at an average daily dose of 1.61 defined daily doses (DDD). Stratification by cumulative defined daily doses (cDDD) of NAC revealed a consistent dose‐response relationship, with progressively diminished dementia risk across quartiles of cDDD. Notably, NAC use was associated with a lower risk of Alzheimer's dementia (aHR: 0.68, 95% CI: 0.66–0.70) compared to non‐NAC antimucolytic users. Conclusions NAC use is associated with a dose‐dependent reduction in dementia risk among elderly COPD patients, particularly for Alzheimer's dementia. Our findings underscore the potential of NAC as a potential protective factor against dementia in this vulnerable population, warranting further investigation and consideration in clinical practice.
Sun et al. (Wed,) studied this question.