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 6-12months after surgery. We aimed to investigate the effect of early-GH-substitution on body-composition, metabolic and pituitary-laboratory-tests, and quality-of-life.

METHODS: Data was reviewed from 21 adult-patients who were diagnosed with insufficiency of GH-axis using insulin-hypoglycemia-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-substitution (= untreated group, 10-patients).

RESULTS: Follow-up-IGF-I-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 2.1mg/dl in the untreated compared to an average decrease of 0.2mg/dl in the treated-group. Lp(a)-levels were reduced by 4.1mg/dl in the treated and by 2.7mg/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. The difference in 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 detectably pointing towards an improvement in pituitary-function (LH- and FSH-recovery) if GH was substituted.

CONCLUSION: Early GH-substitution 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.