RESUMEN
Objective:To analyzed clinical characteristics of pituitary growth hormone(GH) adenomas patients with different responses to oral glucose inhibitory GH test.Methods:The clinical data of 50 patients with pituitary GH adenomas newly diagnosed with complete test data and case data in the Department of Endocrinology of Chinese PLA General Hospital was retrospectively analyzed from 2016 to 2021. The cases were divided into two groups according to the cutoff point of GH elevating to 50% of basaline during oral glucose test: abnormal elevation group(A group, n=16) and non-elevation group(B group, n=34). The clinical features, biochemistry, iconography, and immunohistochemistry of the two groups were analyzed. Results:The serum total cholesterol(TC)[(3.9±0.8) vs (4.6±0.9)mmol/L], 120 minutes insulin after glucose loading [11.2(4.4, 25.0) vs 92.0(10.8, 311.8)mU/L], long [1.0(0.4, 2.1) vs 1.5(0.5, 7.3) cm] and short[0.6(0.3, 1.3) vs 1.0(0.5, 5.8)cm] diameters of adenomas in A group were less than those in B group(all P<0.05) while insulin-like growth factor Ⅰ(IGF-Ⅰ) level was higher [(908.2±233.7) vs (743.1±273.1) ng/mL, P<0.05]. There were no significant differences in sex, age, disease course, clinical features, random GH, homeostasis model assessment of insulin resistance index(HOMA-IR), pituitary adenoma site, and invasive properties between the two groups. The immunohistochemical positive rates of ACTH(33% vs 0%) and prolactin(100% vs 28.6%)in A group were higher than those in B group( P<0.05). Conclusion:Pituitary GH adenomas patients with a paradoxical GH response pattern display lower serum TC and 120 minutes insulin levels as well as higher IGF-Ⅰ concentration and proportion of pituitary microadenomas. " Pure" growth hormone tumors may represent entities of a particular class of diseases in acromegaly.