The assessment of growth hormone deficiency following pituitary surgery a need for greater awareness
Anthony Lewis, Hamish Courtney, Steven Hunter, David McCance, Brian Sheridan & Brew Atkinson
Pituitary surgery frequently leads to one or more anterior pituitary hormone deficiencies but the incidence of GH deficiency is unclear. The aim of our study was to establish the incidence of GH deficiency in patients post hypophysectomy. Current NICE guidelines recommend GH replacement in severely GH deficient patients who have one or more other pituitary hormone deficiencies and diminished QoL by AGHDA.
Thirty-five patients (M:F 15:20; age range 2373 yrs, median 49 yrs) were studied 46 weeks after pituitary surgery (none had previous surgery). All patients had macroadenomas, thirty were non-functioning, 4 prolactinomas and one a thyrotroph adenoma. All patients were tested for GH deficiency using an ITT. All achieved symptomatic hypoglycaemia. Severe GH deficiency was defined as peak value <9 mU/L and partial GH deficiency as between 9 and 20 mU/L.
Thirteen patients had their GH status assessed pre-operatively (the remainder went straight to surgery). Of these 13, 3 (23%) were normal, 2 (15%) had partial and 8 (62%) had severe GH deficiency. Post-operatively, 30 of the 35 (86%) were GH deficient, of whom 9 (26%) had partial and 21 (60%) severe GH deficiency. For 4 (19%) patients with severe GH deficiency this was an isolated defect, while the remainder had one or more other hormone deficits. The 3 patients with normal pre-operative GH status remained normal post-operatively. Four of the severely GH deficient patients have since been commenced on GH replacement.
In conclusion, GH deficiency is common after pituitary surgery. We identified 13 (37%) patients not currently receiving GH who, if QoL was impaired, would qualify for replacement. An additional 13 (37%) patients were GH deficient but do not meet current NICE guidelines for treatment. We are placing greater emphasis on post-operative GH assessment as a suboptimal outcome may occur if GH is not replaced. The effect of the surgery itself on development of GH deficiency is unclear and we propose to examine the GH status of a cohort of patients both before and after pituitary surgery.