Study on the mechanism of abnormal growth hormone (GH) secretion in anorexia nervosa: no evidence of involvement of a low somatomedin-C level in the abnormal GH secretion.
The response of plasma growth hormone (GH) to an iv injection of synthetic human growth hormone-releasing factor (hGHRF-44) (2 micrograms/kg bw) was studied in 23 patients with anorexia nervosa. The basal plasma concentrations of somatomedin-C (Sm-C) in these patients were also measured. Basal plasma GH levels were above normal in 8 out of 23 patients and an exaggerated GH response to hGHRF-44 compared to that in age-matched normal females was found in 9 patients. Mean basal plasma Sm-C concentration in the patients was 0.41 +/- 0.04 U/ml (mean +/- SE), which was in the low normal limit. When 6 patients were reexamined after their weight gain of 4-18 kg as well as their normalization of basal plasma Sm-C levels, their elevation of basal plasma GH level was lowered and the responsiveness to hGHRF-44 improved. However, there was no significant correlation between the Sm-C concentration and basal plasma GH level as well as the integrated GH response to hGHRF-44 expressed as the area under the curve (OhGH). These findings, therefore, suggest that some factor(s) other than the lowered plasma Sm-C level are involved in the mechanism of abnormal GH secretion in patients with anorexia nervosa.
D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000503:physiopathology*; D001835:Body Weight; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000097:blood*; D008297:Male; D010902:Pituitary Gland / Q000503:physiopathology; D013002:Somatomedins / Q000097:blood*
D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone