Changes of GH axis after Transsphenoidal Adenomectomy in Acromegalic Patients

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 88-129-Acromegaly & Prolactinoma
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-105
Cheol Ryong Ku*, Jae Won Hong, Eui Hyun Kim, Sun Ho Kim and Eun Jig Lee
Yonsei University College of Medicine, Seoul, South Korea
Objective: Treatment of acromegaly has been focused on the strictly lowering the serum GH and IGF-1 level. However, GH deficiency (GHD) influences on the quality of life, body composition, and lipid profile even in patients with acromegaly after a cure. Changes of GH axis in acromegalic patients so far have been poorly studied. The aim of this study was to evaluate the which parameters could predict the GHD after transsphenoidal adenomectomy (TSA) in remitted patients.

Research Design and Methods: Age- and sex-matched normal IGF-1 and a nadir serum GH level less than 0.4 ng/mL in the 75g oral glucose tolerance test (OGTT) were considered representative of biochemical remission. GHD was defined when the peak serum GH level was less than 3.0 ng/mL in insulin tolerance test (ITT) which was conducted at least 2 times at 1.5 years intervals. Nadir serum GH level in preoperative and postoperative OGTTs, random serum GH/IGF-1 level after 1, 6, 12, 18, 24, 48, and 72 hour after TSA were analyzed.

Results: One hundred and twenty three patients had been followed up for 4.91±2.49 years with OGTTs and the axis of GH had been evaluated 2.64±0.86 times with ITT for 4.44±2.13 years. Among them, 12 (9.8%) patients developed GHD after TSA. GHD patients were older (43.75±10.37 vs. 49.50±9.63; P=0.047) and female sex dominant (51% vs. 75%; P=0.084). Furthermore, GHD patients had significantly lower serum GH level at 72 hr and IGF-1 level at 6 months after TSA (0.74±0.89 vs. 0.34±0.33; P=0.019 and 358.34±158.46 vs. 208.19±123.99; P=0.008, respectively). There were no differences in Hardy classification, number of ITT and follow up duration between two groups. Although 8 of 12 GHD patients had appropriate GH response at first ITT (1.22±0.45 years), they developed delayed GHD at 3.08±0.70 years after TSA. The incidences of GHD were significantly accelerated across decreasing GH level at 72 hours after TSA quartile categories (P=0.044). Correlation analyses after adjustment for multivariable confounders showed that lower GH level at 72 hours after TSA were correlated with accelerated GHD (OR=0.466, P=0.016, 95% CI 0.250-0.866).

Conclusions: These data provide the first clinical evidence that severely decreased immediate-postoperative serum GH level at 72 hours after TSA could be an independent risk factor for accelerated GHD in acromegalic patients.

Nothing to Disclose: CRK, JWH, EHK, SHK, EJL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: National Research Foundation of Korea (NRF) grant 2012-0005434, Korea government (MEST)