Sex difference in the relation between sellar volume and basal and GH-releasing hormone stimulated GH in acromegaly.

Sellar volume and both basal (r = +0.54, P less than 0.02) and GHRH-stimulated (r = +0.41, P less than 0.05) GH levels were directly correlated in a group of 28 patients with acromegaly as were the latter indices (r = +0.82, P less than 0.001). By subdividing the patients according to sex, a close relation between sellar size and both basal (r = +0.77, P less than 0.02) and stimulated GH (r = +0.71, P less than 0.02) was found only in the men, not in the women (r = +0.12 and r = +0.02, respectively, P greater than 0.10). The presence of a tight relation between sellar volume and basal and GHRH stimulated GH levels in male patients with acromegaly and its complete absence in women are equally intriguing and await further elucidation. A modulating role of gonadal steroids in the genesis of this sex differences remain to be assessed.