Gender and age differences in the growth hormone response to pyridostigmine.

Thirty healthy subjects 12 males and 18 females were given the acetylcholinesterase inhibitor pyridostigmine (120 mg) orally. The growth hormone (GH) response was measured as the maximum GH level post-pyridostigmine relative to baseline. Twenty-six subjects increased their GH level in response to pyridostigmine. Responses in females were considerably greater than those in males and correlated closely with serum oestradiol levels. Overall there was a significant negative correlation between GH response and age.