Glucose metabolism and beta receptor function in atopic asthmatics.
Severe asthma and diabetes have been reported not to co-exist in the same patient. Various studies have attributed this to the possible association of asthma with hyperinsulinism, increased responsiveness to insulin or to beta-blockade. Previous studies have not addressed all these possible mechanisms in the same patient. In this prospective study, 7 atopic asthmatics and 7 age and sex-matched healthy controls underwent glucose, insulin and glucagon tolerance tests. The results showed no evidence of hyperinsulinism or increased responsiveness to insulin. Intravenous administration of glucagon, however, showed a lesser increase of glucose and insulin in asthmatics. Since glucagon has a beta-agonist effect on the liver and activates glycogenolysis and gluconeogenesis via beta-receptor stimulation and stimulates insulin secretion by activating adenylate cyclase of pancreatic beta-cells through beta-receptors, the results of glucagon tolerance test in our study may therefore suggest the presence of partial beta-blockade in atopic asthmatics.
Karnik
A M
AM
Department of Medicine, Kuwait University, Safat.
Gumaa
K A
KA
Guindi
R T
RT
Fenech
F F
FF
D000328:Adult; D001249:Asthma / Q000378:metabolism* / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism*; D005934:Glucagon / Q000494:pharmacology*; D006801:Humans; D007275:Injections, Intravenous; D007328:Insulin / Q000494:pharmacology; D008297:Male; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D011943:Receptors, Adrenergic, beta; D005934:Glucagon