The adjusted impact of different severities of acute exacerbations and medications on the risk of suffering dementia in COPD patients

Background: Although a relationship between chronic obstructive pulmonary disease (COPD) and dementia has been reported, the initial severity upon emergency department (ED) visits and the medications used (for COPD) are not well evaluated as risk factors for increasing (or decreasing) dementia occurrence. We aimed to analyze the impact of different severities of COPD acute exacerbations (AEs) and different medications on the risk of suffering dementia in COPD patients.Method: This study was a 5-year follow-up of the Taiwanese government deidentified health-care database (from January 1, 2000, to December 31, 2010). The study group included 51,318 patients who were diagnosed with COPD and 51,318 matched (in terms of age, sex, and the number of hospital visits) non-COPD patients from the remaining patients as the control group. Each patient was followed up for 5 years to analyze the risk of dementia with Cox regression analysis. Demographics, baseline comorbidities, medications (antibiotics, bronchodilators, corticosteroids), and the severity upon initial ED visit (only ED treatment, hospital admission, or ICU admission) were all considered confounding factors between the two groups.Results: Among the study and control groups, 1,025 (2.0%) and 423 (0.8%) patients suffered from dementia, respectively. The unadjusted HR for dementia was 2.51 (95% CI: 2.24-2.81) in the study group. Bronchodilator treatments obviously decreased the HRs, especially in those who received long-term (>1 month) treatment (HR=2.10, 95% CI: 1.91-2.45). Furthermore, among 3,451 COPD AE patients who initially visited the and ED, patients who required ICU admission (n=164, 4.7%) were at a very high risk of dementia occurrence (HR=11.05, 95% CI: 7.77-15.71).Conclusion: Long-term bronchodilator administration was associated with a decreased risk of suffering dementia. More importantly, patients who suffered COPD AEs and initially visited the ED and required ICU admission were at a very high risk of developing dementia.