Low Cognitive Ability in Subjects With Bronchiectasis

Bronchiectasis may change cognitive function. The mechanism responsible for cognitive dysfunction in COPD may be neuronal damage caused by hypoxia. Cognitive function in patients with bronchiectasis is also likely to be affected by similar mechanisms. The goal of this study was to determine the frequency and determinants of low cognitive ability in subjects with stable bronchiectasis.

Thirty subjects with stable bronchiectasis and 25 healthy volunteers underwent a cognitive ability assessment using the Wechsler Adult Intelligence Scale. Bronchiectasis was diagnosed by high-resolution computed tomography of the chest. Age, body mass index, the Hospital Anxiety and Depression Scale, and pulmonary function were assessed. Perceived intensity of dyspnea after exercise (after climbing 3 flights of stairs) was estimated using a modified Borg scale.

Mean scores on the verbal and performance tests and full-scale IQ scores were significantly lower in subjects with bronchiectasis than in healthy volunteers. Low cognitive ability in subjects with bronchiectasis was associated with higher depression scores, lower oxygen saturation, and poor lung function after adjusting for potential confounders in multivariate analysis. Borg scores after exercise in subjects with bronchiectasis and low cognitive ability were higher than those in subjects with bronchiectasis and high cognitive ability, despite similar PaO2 and FEV1 in both groups.

Low cognitive ability in subjects with bronchiectasis may be associated with reduced lung function, more serious hypoxemia, and higher depressive symptoms. Subjects with bronchiectasis and low cognitive ability feel more intense dyspnea than do those with high cognitive ability.