Endocrine Abstracts

GH suppression during OGTT is the gold-standard test in diagnosis and monitoring of acromegaly. However, discrepancies between GH nadir and IGF-I have been described and have triggered search for factors modifying the extent of GH suppression. Cut-offs at 1.0 or 0.4 ng/ml are currently recommended with modern, highly sensitive GH assays. To establish assay specific GH nadir cutoffs for the 22kD GH specific IDS-iSYS assay, we examined 381 subjects (319 females, 62 males) with n...

GH consists of various molecular isoforms. Most abundant is 22 kDa-GH (80–90% of total GH), followed by 20 kDa-GH (5–15% of total GH). The biological significance of 20 kDa-GH remains unclear, but its effects appear comparable to those of 22 kDa-GH. Acromegaly is characterized by chronic GH excess. Data on GH isoforms in acromegaly are scarce, but an increased 20 kDa-/22 kDa-GH-ratio (20k-ratio) has been described. Our aims were to compare the 20k-ratio in a larger c...