Peak nasal inspiratory flow in chronic obstructive pulmonary disease

The nasal airflow in chronic obstructive pulmonary disease (COPD) is poorly characterized. Peak nasal inspiratory flow (PNIF) is a valuable instrument for assessing nasal airflow and the effect of pulmonary pathology such as COPD on PNIF remains unknown. To test the hypothesis that nasal airflow is reduced in COPD, we assessed airflow using PNIF in COPD and a control group. We also explored whether there is an association between COPD, chronic rhinosinusitis without nasal polyps (CRSsNP), and other predefined covariates with PNIF.

Ninety patients with COPD and 67 controls underwent PNIF and spirometry. The associations between PNIF and COPD and pre-bronchodilator forced expiratory volume in the first second (FEV1) (% predicted) were assessed by multivariable linear regression in two separate models.

PNIF was significantly lower in the COPD group than in the control group. Multivariable linear regression showed that COPD and pre-bronchodilator FEV1 (% predicted) were significantly associated with lower PNIF after adjustment for age, sex, CRSsNP, weight and height. CRSsNP was not associated with PNIF in either of the adjusted regression analyses.

PNIF is lower in COPD than in a control group. The finding of a low PNIF in the absence of disease in the upper airways may be due to obstructive lower airways diseases and special care should be taken when interpreting PNIF values in patients with COPD or reduced FEV1.