Dementia risk increases with greater acute exacerbation severity among patients with COPD

Key takeaways:

• Patients with acute COPD exacerbations had increased dementia risk with ICU admission from the ED vs. hospital admission or exclusive ED treatment.
• A lower risk for dementia may be found with a bronchodilator.

Patients with COPD first visiting the ED with acute exacerbations faced greater risks for dementia with ICU admission vs. hospital admission or exclusive ED care, according to study results published in BMC Pulmonary Medicine.

“Bronchodilator administration might be associated with a decreased risk of developing dementia,” Kuo-Hua Chia, a resident in the department of emergency and critical care medicine at Changhua Christian Hospital in Taiwan, and colleagues wrote. “More importantly, patients who suffered acute exacerbations of COPD and initially visited the ED and required ICU admission had a higher risk of developing dementia.”

Chia and colleagues analyzed 51,318 adults (50.3% men; 42.8% aged 30 to 50 years; 14.6 mean hospital visits within 5 years) with COPD and 51,318 adults without COPD who were matched based on age, sex and number of hospital visits from the Taiwanese government deidentified health care database to determine COPD patients’ risk for dementia development over a 5-year follow-up period.

Researchers also sought to understand how severity of acute exacerbations (solely ED treatment, hospital admission or ICU admission) and medication (bronchodilators) influenced this risk.

Through Cox regression analysis, researchers assessed the risk for dementia and adjusted for confounding variables, such as demographics and baseline comorbidities.

Of the two cohorts, dementia was found in more patients with COPD than those without COPD (1,025 patients vs. 423 patients).

In unadjusted analysis, researchers found a 2.51 (95% CI, 2.24-2.81) times higher risk for dementia in patients with COPD compared with those without COPD, similar to the 2.42 hazard ratio (95% CI, 2.16-2.71) found in adjusted analysis.

Researchers noted that a mean 2.6 years passed before patients with COPD were diagnosed with dementia.

In terms of medications, 10,856 (21.2%) patients with COPD received short-term bronchodilators, whereas 14,865 (29%) received long-term bronchodilators. Compared with the risk for dementia observed above, researchers found a decrease in this risk when patients received short-term (adjusted HR = 2.12; 95% CI, 2.05-2.62) or long-term (aHR = 2.1; 95% CI, 1.91-2.45) bronchodilator treatment.

Notably, researchers wrote that this result could be due to patients with asthma — who have reduced risks for dementia as they are generally younger — getting miscoded for COPD.

In the ED, researchers observed 3,451 acute exacerbations of COPD, of which 1,284 patients needed to be further admitted to the hospital and 164 needed to be admitted to the ICU.

When evaluating dementia risk according to exacerbation severity, those admitted to the ICU showed the greatest risks for dementia (aHR = 11.05; 95% CI, 7.77-15.71). An increased risk was also found in patients who needed to be hospitalized (aHR = 8.52; 95% CI, 7.23-10.03), whereas treatment in the ED was not as high (aHR = 2.11; 95% CI, 1.68-2.65).

One notable study limitation was the absence of data on patients with COPD that may play a role in dementia risk. Significant risk factors for dementia that researchers did not have information on included smoking status, arterial blood gas, carbon dioxide retention, pulmonary function tests, FVC and hypoxia.

“In this study, we demonstrated that medications and the different severities of acute exacerbations of COPD were important risk factors for the occurrence of dementia,” Chia and colleagues wrote.