Endocrine Abstracts

Background: Growth hormone (GH) deficiency causes visceral obesity and fatty liver and increases cardiovascular event risks. Because serum high-sensitivity C-reactive protein (hs-CRP) levels, which has been used to estimate those risks, was reported to be decreased by GH supplementation therapy in GH deficient patients, it has been suggested that inflammatory processes might be activated in GH deficient state. However, the clinical factors associated with increased hs-CRP levels in patients with GH deficiency have been still unknown.

Patients and Methods: We retrospectively reviewed charts of 134 patients with non-functioning pituitary adenoma (NFPA) and Rathke’s cysts who underwent preoperative GH-releasing peptide-2 (GHRP-2) tests and investigated the association between GH secretion and background characteristics. Patients who had a history of pituitary surgery, severe renal insufficiency or active inflammatory diseases or received GH supplementation therapy were excluded. GH secretion was determined by GHRP-2 tests.

Results: Among 134 patients (94 NFPAs and 40 Rathke’s cysts), 46 (34%) presented severe GH deficiency, as diagnosed using GHRP-2 tests. Serum hs-CRP levels were significantly higher in the patients with severe GH deficiency than in those without severe GH deficiency (723 [299-1285] vs 278 [124-561] ng/ml, P < 0.001). Serum hs-CRP levels were significantly higher in men (P=0.003) and in patients with diabetes mellitus (P=0.040) and were significantly correlated with age (r_s=0.19, P=0.039), body mass index (r_s=0.37, P < 0.001), serum levels of gamma-glutamyl transpeptidase (r_s=0.28, P=0.001), creatinine (r_s=0.30, P < 0.001), low-density lipoprotein cholesterol (r_s=0.21, P=0.013), triglyceride (r_s=0.38, P < 0.001) and free thyroxine (r_s=-0.30, P =0.001), blood hemoglobin A1c levels (r_s=0.20, P=0.018), peak GH response to GHRP-2 (r_s=-0.47, P < 0.001) and IGF-1 SD score (r_s=-0.18, P=0.040). In the multiple regression analysis, peak GH response to GHRP-2 was a significant variable for determining serum hs-CRP levels (α=-0.340, P=0.003) after adjustment with age, sex, BMI, smoking, alcohol consumption, hypertension, diabetes mellitus, serum levels of gamma-glutamyl transpeptidase, creatinine, triglyceride and free thyroxine and adrenal function.

Conclusion: GH deficiency was significantly associated with increased serum hs-CRP levels independent to obesity and liver dysfunction in adult patients with non-functioning pituitary tumors. GH deficient state might cause inflammation independent to development of visceral obesity and fatty liver.