| Glucose
tolerance and insulin secretion after administration of a glucose load
were determined in 11 clinically normal cats and 15 cats with spontaneous
hyperthyroidism. In six hyperthyroid cats, a glucose tolerance test was
repeated after treatment with radioactive iodine (131I). All cats had
similar baseline glucose concentrations. However, the cats with hyperthyroidism
had a significantly decreased glucose clearance, which was worse after
treatment. Hyperthyroidism also caused a marked increase in basal and
glucose-stimulated insulin secretion, which was not improved with treatment.
It is concluded that hyperthyroidism in cats may lead to long-lasting
alterations of glucose tolerance and insulin secretion which may not be
reversed by treatment. |