Cough reflex threshold in diabetes mellitus with and without autonomic neuropathy.
The cough reflex, a vagus-mediated respiratory protective reflex, was investigated in diabetics and healthy controls by establishing a cough reflex threshold to increasing concentrations of citric acid aerosol. Diabetics with autonomic neuropathy (n = 20), whether overtly symptomatic (n = 5) or evident only on certain non-invasive cardiovascular autonomic function tests, were found to have significantly (p < 0.05 by chi 2 test) raised cough reflex threshold (range 1 to > 100%, median value 50%) in contrast to either the non-neuropathic diabetics (n = 20) or normal controls (n = 20; range 1-10%, median value 2%). This difference suggests vagal (parasympathetic) denervation of the respiratory tract, with possible serious consequences, hitherto little appreciated.
Behera
D
D
Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Das
S
S
Dash
R J
RJ
Jindal
S K
SK
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D002648:Child; D002951:Citrates; D019343:Citric Acid; D003371:Cough / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012018:Reflex / Q000502:physiology*; D014630:Vagus Nerve / Q000503:physiopathology*
D002951:Citrates; D019343:Citric Acid