Cognitive Impairment and Clinical Characteristics in Patients With Chronic Obstructive Pulmonary Disease: Retrospective Study

Chronic obstructive pulmonary disease (COPD) is considered "a progressive but potentially treatable and preventable disease". The clinical view of COPD is moved from a lung-centered model to a novel one that considers COPD as an "umbrella" term encompassing different pulmonary and extra-pulmonary manifestations.

Prior researches suggest the presence of impaired lung function may be linked to cognitive impairment (CI). Among these studies, one prospective found that a diagnosis of COPD is associated with an increased risk of mild cognitive impairment (MCI), mainly nonamnestic MCI (NA-MCI), in a dose-response relationship between COPD duration and risk of MCI. Moreover, CI associated with severe COPD stage increases mortality. Among these studies only one shows that CI decreases adherence to pharmacological and non-pharmacological therapies. However, while it is well known that an MMSE score of 23-24 points or less is predictive of poor inhaler technique no studies report the impact of CI on PR outcomes. It has been reported that patients with MMSE < 24 walk lesser, at the basal level, than patients with a MMSE score > 24 (146 ±134 versus 242 ± 152 m) in the six minutes walking tests (6MWT) but no data are reported after rehabilitation. On the other hand, some papers report an association between participation in exercise rehabilitation programs and enhanced performance on cognitive tests.

The aim of this study is to compare cognitive functioning in patients with COPD referred for pulmonary rehabilitation to the response of the programme itself. More specific objectives of the present study are to:

• Study whether and to what extent CI in patients with COPD impacts outcomes of pulmonary rehabilitation such as 6MW distance (6MWD), Barthel and Borg scales for assessing dyspnea, Maugeri Foundation Respiratory Failure Questionnaire and the disease-specific respiratory quality of life (QoL) [St. George's Respiratory Questionnaire (SGRQ) and the Medical Research Council (MRC)].
• Investigate clinical and demographic characteristics of patients with COPD with cognitive impairment.

The hypothesize is that COPD patients with CI have worse response to PR compared with patients with no CI.