Variations Of Hormones Levels And Related Influencing Factors After Transsphenoidal Adenomectomy Among Patients With Growth Hormone-secreting Pituitary Adenomas

ObjectiveTo evaluate variations between pre-and post-operative endocrine hormone levelsand biochemical remission rate among patients with growth hormone-secretingpituitary adenomas following transsphenoidal adenomectomy; and to provide a basisfor further treatment after surgery.Methods1. A analysis of47cases of patients with GH-secreting pituitary adenomas whounderwent TSA form September2007to September2012at Department ofNeurosurgery, Fuzhou General Hospital of Nanjing Military Region.29patients weremale and18were female; their ages ranged from23to60years (average age,43.2years). The follow-up duration ranged from6to10months (median follow-up,7months).2. All patients were divided into complete resection group and incomplete resectiongroup depending on the extent of tumor resection, were classified into remissiongroup and non-remission group according to postoperative nadir GH levels on anOGTT and serum IGF-1adjusted for age and sex, were grouped into micro-, macro-and giant-adenoma based on tumor size.3. All patients underwent adequate endocrinological evaluations. Serum GH levelswere checked preoperatively and postoperatively (2,24,48,72hours,1week,3months and6months after surgery). Serum IGF-1levels were measured beforesurgery, and1week,3months,6months after surgery. The nadir serum GH levelsafter OGTTs were determined1week,3months,6months postoperatively. Thelevels of PRL were performed before surgery, and1week,3months after surgery.MRI was taken before and within48h,3to4months after surgery.4. Data was presented as mean±standard deviation. Statistical analyses wereperformed with SAS8.1, the value of P＜0.05was considered significant. Results1. There were no differences in ratio of the sexes and ages for remission group andnon-remission group (P＞0.05). Biochemical remission rate of complete resectiongroup is84.62%(33/39), but none of the patients in the incomplete resection groupreceived surgical remission (0/8).2. The tumor sizes of remission group were smaller than those of non-remissiongroup. The difference was significant (P＜0.05).3. The biochemical remission rate of the micro-adenoma group was100.00%(4/4)after TSA, macro-adenoma group was75.00%(27/36), giant-adenoma group was28.57%(1/5), and their statistically differences among the three groups wereapparently (P＜0.05).4. The relationship between preoperative serum GH levels and biochemicalremission rate: preoperative serum GH level＜30μg/L, remission rate was80.00%(20/25) accordingly;30～50μg/L, remission rate was75.00%(12/16) respectively;＞50μg/L, remission rate was16.67%(1/5) correspondingly, and there werestatistically significant differences in the remission rates among the three groups (P＜0.05). Postoperative surgical remission rate of preoperative GH level＞50μg/L groupwas significantly lower than the other two groups (P＝0.0075and P＝0.0231); Butthe remission rate was no significant difference between preoperative GH＜30μg/Lgroup and30~50μg/L group (P＝0.7169).5. Serum GH levels and nadir serum GH levels after OGTTs measured in the sameperiod were significantly different between remission group and non-remission group(P＜0.05). The trend of serum GH levels in the early postoperative period (2,24,48,72h after surgery): began to decline immediately after surgery, dropped to the lowestlevel at24h, and then rebounded. The nadir serum GH levels after OGTTs checkedthree months after surgery were lowest in remission group.6. Serum IGF-1levels of remission group were lower than those of non-remissiongroup measured at the same time point, and the difference was statistically significant;Serum IGF-1levels were gradually decreased after surgery both in the remissiongroup and in the non-remission group, and there was also a statistically significantdifference in IGF-1levels pre-and post-operation; The IGF-1levels of postoperative3months in remission group basically returned to the age-and sex-matched normal levels, and completely back to normal6months after surgery, however, it had neverbeen able to return to normal levels in the non-remission group.7. Postoperative serum PRL levels were lower than preoperative levels, and thedifference was statistically appreciably; The PRL levels of3months after surgerywere lower than1week postoperatively, but the difference was not evidently.Conclusions1. Biochemical remission rate of GH-secreting pituitary adenoma aftertranssphenoidal surgery was irrelevant to age and sex. Not all cases whose immediatepostoperative MRI confirmed complete surgical resection could achieve remission.But those early postoperative MRI confirmed incompletely resected could hardly getremission.2. The relationship between biochemical remission rate and adenoma size:micro-adenoma group＞macro-adenoma group＞giant-adenoma group.3. Preoperative serum GH levels were closely related to biochemical remission rateafter TSA. Remission rate of GH＜50μg/L group was conspicuous higher than GH＞50μg/L group.4. Serum GH levels decreased significantly in the early stage after operation,obviously in24hours. Consequently, GH levels in24hours after surgery were shownto have good predictive power for surgical outcome.5. The nadir serum GH levels after OGTTs measured1week,3months and6months after surgery could be predictors of biochemical remission, especially datachecked3months postoperatively.6. Serum IGF-1levels determined3months,6months after surgery could be usedas important indicators for achieving biochemical remission.7. Serum PRL levels of GH-secreting pituitary adenomas declined after TSA.