Airway Hypersensitivity, Reflux, and Phonation Contribute to Chronic Cough.
OBJECTIVE
Although chronic cough is common, its etiology is often elusive, making patient management a challenge. Gastroesophageal reflux and airway hypersensitivity can cause chronic cough. We explored the relationship between reflux, phonation, and cough in patients with idiopathic chronic cough.


METHODS
We performed a blinded, cross-sectional study of nonsmoking patients with chronic cough (duration, >8 weeks) refractory to reflux treatment referred to the Digestive Disease Center at Vanderbilt University. All underwent 24-hour acoustic recording concurrently and temporally synchronized with ambulatory pH-impedance monitoring. Cough, phonation, and pH-impedance events were recorded. We evaluated the temporal relationship between cough and phonation or reflux events using Poisson and logistic regression.


RESULTS
Seventeen patients met the inclusion criteria (88% female; 100% white; median age, 63 years [interquartile age range, 52-66 years]; mean body mass index, 30.6 [interquartile range, 27.9-34.0]); there were 2048 analyzable coughing events. The probability of subsequent coughing increased with higher burdens of preceding cough, reflux, or phonation. Within the first 15 minutes after a cough event, the cough event itself was the main trigger of subsequent cough events. After this period, de novo coughing occurred with increases of 1.46-fold in association with reflux alone (95% confidence interval, 1.17-1.82; P < .001) and 1.71-fold in association with the combination of phonation and reflux events.


CONCLUSIONS
Antecedent phonation and reflux increased the rate of cough events in patients with idiopathic chronic cough. Reflux events were more strongly associated with increased rate of coughing. Our findings support the concept that airway hypersensitivity is a cause of chronic cough, and that the vocal folds may be an effector in chronic cough ClinicalTrials.gov number: NCT01263626.
Vanderbilt Voice Center, Vanderbilt University Medical Center, Nashville, Tennessee; Center for Surgical Quality and Outcomes Research, Vanderbilt University Medical Center, Nashville, Tennessee.
David O
DO
Francis
Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee.
James C
JC
Slaughter
Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee.
Fehmi
F
Ates
Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee.
Tina
T
Higginbotham
Vanderbilt University Medical School, Vanderbilt University Medical Center, Nashville, Tennessee.
Kristin L
KL
Stevens
Vanderbilt Voice Center, Vanderbilt University Medical Center, Nashville, Tennessee.
C Gaelyn
CG
Garrett
Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee. Electronic address: michael.vaezi@vanderbilt.edu.
Michael F
MF
Vaezi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003371:Cough / Q000209:etiology*; D003430:Cross-Sectional Studies; D055154:Dysphonia / Q000150:complications*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012130:Respiratory Hypersensitivity / Q000150:complications*; D055815:Young Adult
Cough; GERD; Hypersensitivity; Phonation; Reflux