The aim of this study was to assess the prevalence of diabetes and to study the effects of excess growth hormone (GH) on insulin sensitivity and beta-cell function in Korean acromegalic patients. One hundred and eighty-four acromegalic patients were analyzed to assess the prevalence of diabetes, and 52 naive acromegalic patients were enrolled in order to analyze insulin sensitivity and insulin secretion. Patients underwent a 75 g oral glucose tolerance test with measurements of GH, glucose, insulin, and C-peptide levels. The insulin sensitivity index and beta-cell function index were calculated and compared according to glucose status. Changes in the insulin sensitivity index and beta-cell function index were evaluated one to two months after surgery. Of the 184 patients, 17.4% were in the normal glucose tolerance (NGT) group, 45.1% were in the pre-diabetic group and 37.5% were in the diabetic group. The insulin sensitivity index (ISI0,120) was significantly higher and the HOMA-IR was lower in the NGT compared to the diabetic group (P = 0.001 and P = 0.037, respectively). The ISI0,120 and disposition index were significantly improved after tumor resection. Our findings suggest that both insulin sensitivity and beta-cell function are improved by tumor resection in acromegalic patients.
Acromegaly/*diagnosis/etiology/metabolism ; Adult ; Asian Continental Ancestry Group ; Blood Glucose/analysis ; C-Peptide/analysis ; Diabetes Mellitus/epidemiology ; Female ; Glucose Tolerance Test ; Human Growth Hormone/secretion ; Humans ; Insulin/blood/secretion ; *Insulin Resistance ; Insulin-Secreting Cells/cytology/*physiology ; Male ; Middle Aged ; Prediabetic State/epidemiology ; Republic of Korea