Non-functioning pituitary macroadenomas: Benefit from early growth hormone substitution after surgery

Purpose: Data suggests that substitution of GH in GH-deficient patients may improve quality of life and reduce insufficiency associated symptoms. Unlike in corticotroph, thyreotroph, or gonadotroph insufficiency, GH-substitution is usually not started within the first 6 – 12 months after surgery. We aimed to investigate the effect of early-GH-treatment.

Methods: Data was reviewed from 21 patients who were diagnosed with GH-insufficiency using insulin hypoglycaemia test. We retrospectively assessed body-composition, metabolic and pituitary laboratory tests and quality of life for a period of 52 weeks after pituitary surgery in patients with early GH-substitution (= treated group, 11 patients) and no GH-treatment (= untreated group, 10patients).

Results: Follow up IGFI-levels of the treated group stayed within the normal range and differed significantly from the untreated group. Bioelectrical impedance analysis showed a significant decrease of impedance, a significant increase of lean body mass and a significant difference in health status in the treated group (p < 0.05). Average increase in HDL-level was 2.1 mg/dl in the untreated compared to an average decrease of 0.2 mg/dl in the treated group. Lp(a)-levels were reduced by 4.1 mg/dl in the treated and by 2.7 mg/dl in the untreated group.

Both groups showed an initial mean-life-satisfaction below average (-0.9 and -1.2). Within one year after surgery mean-health-status improved in both groups. Difference of health-status after 1-year compared to the health-status of the previous year was statistically different between both groups with a greater benefit in the treated group.

Finally there was a trend detectable pointing towards an improvement in pituitary function (LH- and FSH-recovery) if GH was substituted.

Conclusion: Early GH-supplementation leads to a significant improvement in quality-of-life and body-composition after pituitary surgery. It is possible that pituitary function recovers more with early-GH-substitution.