Background: Data on plasma acylated ghrelin (AG) and unacylated ghrelin (UAG) levels in acromegaly are limited. High AG/UAG ratios are linked with type 2 diabetes, obesity, and hyperphagia (e.g., in Prader-Willi syndrome). Objective: To assess fasting plasma AGand UAG levels, and the AG/UAG ratio in acromegaly patients receiving combination treatment of long-acting somatostatin analogs (LA-SSAs) and pegvisomant (PEGV; n = 60). We used as controls acromegaly patients whose disease was controlled with PEGV monotherapy and medically näve patients with active acromegaly. Methods: Fasting venous blood samples were collected and directly stabilized to inhibit deacylation of AG. Plasma AG and UAG levels were determined by double-antibody sandwich enzyme immunoassay, and the AG/UAG ratio was calculated. Results: Plasma AG and UAG levels were significantly lower in patients with acromegaly receiving combination treatment [median, interquartile range (IQR): AG: 8.5 pg/mL, 2.9 to 21.1 pg/mL; UAG: 26.9 pg/mL, 11.2 to 42.1 pg/mL] compared with patients using PEGV alone [AG: 60.5 pg/mL (IQR, 58.8 to 77.4 pg/mL); UAG: 153.7 pg/mL (IQR, 127.3 to 196.0 pg/mL)] and medically näve patients with acromegaly [AG: 24.0 pg/mL (IQR, 12.6 to 49.7 pg/mL); UAG: 56.3 pg/mL (IQR, 43.4 to 61.5 pg/mL)]. However, AG/UAG ratios were similar in all groups. Conclusions: Although plasma AG and UAG are suppressed during combination treatment with LASSAs and PEGV, the AG/UAG ratio remained similar. This shows that SSAs decrease both AG and UAG levels, which suggests that they do not alter metabolism significantly in acromegaly patients.

dx.doi.org/10.1210/jc.2017-00147, hdl.handle.net/1765/108029
Journal of Clinical Endocrinology and Metabolism
Erasmus MC: University Medical Center Rotterdam

Muhammad, A, Delhanty, P.J.D, Huisman, M. (Martin), Visser, J.A, van der Lely, A-J, & Neggers, S.J.C.M.M. (2017). The acylated/unacylated ghrelin ratio is similar in patients with acromegaly during different treatment regimens. Journal of Clinical Endocrinology and Metabolism, 102(7), 2425–2432. doi:10.1210/jc.2017-00147