Cognitive Impairment Linked to COPD Worsening, Study Says

Cognitive issues were seen in patients with chronic obstructive pulmonary disease (COPD) who had exacerbations and regular use of long-term oxygen therapy (LTOT), according to a recent study.

The authors, writing in Clinical Respiratory Journal, noted that the findings have implications for patient self-management of their chronic disease, and that clinicians should screen for worsened cognitive function.

A complete understanding of CD in COPD is still unknown, despite the fact that poorly controlled COPD has negative effects on workplace participation, health status, and leads to higher health care costs. The prevalence of CD in COPD varies between 10.4% and 48.5%, the authors wrote, and it depends on the type of neuropsychological evaluation as well as the study population.

The hypothesis in this study was that the Mini‐Mental State Examination (MMSE) could be useful in evaluating the cognitive status of patients with COPD.

In this study, conducted in Turkey, the patients were awaiting hospital discharge after acute exacerbation; they were compared with stable outpatients with COPD and with healthy controls. The study also evaluated the impact on cognitive status in patients dependent on LTOT and compared them with those not on LTOT in order to see the efficiency of long-term oxygen therapy.

The 121 participants, aged 40 to 80, were divided into 3 groups:

• Exacerbation of COPD (COPD‐E)
• Stable COPD (COPD‐S)
• Control group

Patients with COPD were divided into 2 groups, those using LTOT and those who were not.

The LTOT group was receiving continuous oxygen therapy at home 24 hours a day to maintain oxygen saturation between 88% and 95%; the continuous oxygen therapy had been given for more than 2 years.

All the patients were receiving combination medical therapy consisting of long‐acting beta agonists, inhaler steroids, and long‐acting anticholinergic agents.

The patients (52.9% male, mean age 67) were asked the MMSE questions in their native language.

Results showed that scores were lower in the COPD‐E group (18.9) than in the COPD‐S group (25.7). There was no significant different between those with stable COPD and the control group.

Those in the COPD-E group had older average age, and older age was related to a lower MMSE score, compared with those in the stable group or the control group.

MMSE scores were also low in the LTOTD group (18.8) compared with those not on LTOT (24.9); the authors said this is important because MMSE identifies clinically significant CD.

The presence of 4 comorbidities also had an effect on MMSE scores compared with patients with none or 1 comorbidity, the researchers said.

In addition, their study showed that “low MMSE was related with decreased pO2 and sO2 values and increased pCO2 values. Our study showed that was a negative correlation between MMSE scores and pCO2. Because of CO2 retention and systemic inflammation, COPD patients have a decreased cognitive function.”

Taking CD into account can improve recovery time, quality of life and lower hospitalization risk, the authors said.

Reference

Çilingir BM, Günbatar H, Çilingir V. Cognitive dysfunction among patients in chronic obstructive pulmonary disease: Effects of exacerbation and long‐term oxygen therapy. Clin Respir J. Published online August 8, 2020. doi: 10.1111/crj.13250