Relationship between Clinical and Endocrinological Features following Transsphenoidal Surgery for Acromegaly

Abstract

Fourteen patients with acromegaly who had undergone transsphenoidal surgery were followed for 1 to 7 years (average, 4.3 years). Pre- and postoperative growth hormone (GH) levels, changes in the GH response to thyrotropin releasing hormone (TRH) tolerance testing, and the correlation between clinical improvement and postoperative GH and somatomedin-C levels were studied. Clinical improvement was assessed by scoring of the pre and postoperative symptoms. A significant correlation was found between the postoperative GH and somatomedin-C levels (p<0.01). All patients with postoperative somatomedin-C levels of less than 2 IU/ml, including one of the three patients whose postoperative GH levels were between 5 and 10 ng/ml, showed clinical improvement. Normal responses to TRH testing were rare and were poorly correlated with clinical improvement. These results suggest that somatomedin-C is more useful than GH in predicting clinical improvement following surgery for acromegaly.