Table 4—

Lung function and cognition in chronic obstructive pulmonary disease(COPD) patients

First author [Ref.]	Patients n	Description	Measures		Correlations
First author [Ref.]	Patients n	Description	Lung function	Cognition	Correlations
Fix 25	66	LongitudinalHypoxic COPD	FEV₁	NPT	Attention, vis-motor and perception
Grant 3	203	Case controlHypoxaemic COPD	FEV₁	NPT	Nil
Prigatano 26	100	COPD mild hypoxia form IPPB trial	FEV₁	NPT	Memory
Incalzi 43	84	Prospective COPD	FEV₁	MMSE	Decline in MMSEworse in severe airflow obstruction
Kozora 28	32	Mildly hypoxic COPD	Full PFT	NPT	Nil
Etnier 44	98	Older COPD mild disease and hypoxia	Full PFT	NPT	FVC associated with working memory6MWT associated with fluid intelligence and processing speed
Antonelli-Incalzi 45	381	COPD	GOLD stage	NPT/MMSE	Nil
Antonelli-Incalzi 45	381	Elderly	GOLD stage	NPT/MMSE	Nil
Liesker 29	30	Non-hypoxaemic	FEV₁	NPT	Nil
		COPD
		Case control
Ohrui 46	135	Respiratory failure on LTOT versus healthy cross section	FEV₁	MMSE	Nil

FEV₁: forced expiratory volume in 1 s; NPT: neuropsychological tests; IPPB: intermittent positive pressure breathing; MMSE: mini mental score examination; PFT: pulmonary function tests; FVC: forced vital capacity; 6MWT: 6-min walk test; GOLD: Global Initiative for Chronic Obstructive Lung Disease; LTOT: long-term oxygen therapy.