Endocrine Abstracts

Introduction: Transsphenoidal surgery (TSS) is the treatment of choice for patients with acromegaly. However, even after radical surgery persistence of acromegaly may remain up to thirty percent by resent studies (Starnoni, 2016). Nadir growth hormone (GH) level less than 1.0 μg/l on an early postoperative oral glucose tolerance test (OGTT) have been suggested as early predictor of surgical remission (Kim 2012). However, the value of this approach remains to be defined.

Aim: The purpose of our study is to evaluate the utility of measurement of GH level during a 2-week postoperative OGTT as a predictor for surgical outcome in patients with acromegaly.

Materials and methods: Ten patients (five women and five men) with an average age of 47.4±14.8 years (range 27–71 years) who had underwent total transsphenoidal adenomectomy performed by one neurosurgeon were included in this study. All patients harbored macroadenomas, with average size of 18.9±5.2 mm (range 13–29 mm). Measurement of GH level during OGTT was performed 14 days after surgery. The outcome of TSS was evaluated 6 months after surgery by OGTT and measurement of insulin-like growth factor 1 (IGF-1). The biochemical remission of acromegaly according to the 2010 remission criteria were defined as nadir GH level on an OGTT <0.4 μg/l along with age and gender normalized values of IGF-1.

Results: Initial basal GH level was 23.7±24.9 μg/l, initial IGF-1 patient /IGF-1ULN ratio was 2.7±0.6. Six months after surgery the remission of acromegaly was achieved in five patients (50%) – mean IGF-1 patient/IGF-1ULN – 0.7±0.2, mean nadir GH level on an OGTT – 0.30+0.09 μg/l. Nadir GH level on an 2-week postoperative OGTT was less than 1.0 μg/l in all patients with remission of acromegaly. Whereas, all patients with persistence of the disease had nadir GH levels >1.0 μg/l on an early postoperative OGTT.

Conclusion: Our initial data suggest that nadir growth hormone level on an 2-week postoperative OGTT less than 1.0 μg/l associated with remission of acromegaly 6 months after surgery. Further researches are required to specify long-term outcomes.