Airway function and markers of airway inflammation in patients with treated hypothyroidism.
BACKGROUND
There is increasing evidence of an association between organ specific autoimmune diseases, particularly autoimmune thyroid disease and respiratory morbidity. A study was undertaken to determine whether patients with autoimmune thyroid disease have objective evidence of airway inflammation and dysfunction.


METHODS
Twenty six non-smoking women with treated hypothyroidism and 19 non-smoking controls completed a symptom questionnaire and underwent full lung function tests, capsaicin cough reflex sensitivity measurement, methacholine challenge test, and sputum induction over two visits.


RESULTS
Symptoms of cough (p = 0.01), dyspnoea (p = 0.01), sputum production (p = 0.004), and wheeze (p = 0.04) were reported more commonly in patients than controls. Patients with hypothyroidism had heightened cough reflex sensitivity compared with controls (geometric mean concentration of capsaicin causing five coughs: 40 v 108 mmol/l; mean difference 1.4 doubling doses; 95% confidence interval of difference 0.4 to 2.5; p = 0.008) and a significantly higher proportion of patients had airway hyperresponsiveness (methacholine provocative concentration (PC(20)) <8 mg/ml: 38% v 0%; p = 0.016). Patients with hypothyroidism also had a significantly higher induced sputum total neutrophil cell count (p = 0.01), total lymphocyte count (p = 0.02), and sputum supernatant interleukin-8 concentrations (p = 0.048).


CONCLUSIONS
Patients with treated hypothyroidism report more respiratory symptoms and have objective evidence of airway dysfunction and inflammation.
Birring
S S
SS
Institute for Lung Health, Department of Respiratory Medicine, Glenfield Hospital, Leicester LE3 9QP, UK. sb134@le.ac.uk
Patel
R B
RB
Parker
D
D
McKenna
S
S
Hargadon
B
B
Monteiro
W R
WR
Falconer Smith
J F
JF
Pavord
I D
ID
D015415:Biomarkers / Q000032:analysis; D001991:Bronchitis / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007037:Hypothyroidism / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D007958:Leukocyte Count; D008875:Middle Aged; D009504:Neutrophils; D013183:Sputum / Q000166:cytology; D018709:Statistics, Nonparametric; D014797:Vital Capacity / Q000502:physiology
D015415:Biomarkers
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