Ghrelin concentrations in acromegalic patients in relation to the administered therapy.

OBJECTIVES: Very little is still known about ghrelin in cases of GH hypersecretion. We decided to evaluate whether ghrelin concentrations in acromegalic patients differ according to the administered therapy (surgical and/or with long acting octreotide). We wanted to assess the correlation between serum ghrelin levels and 1) the treatment applied in the past or being applied at the time of our study 2) GH, IGF-1 and insulin concentrations.

MATERIAL: Serum ghrelin, GH, IGF-1 and insulin were measured in 42 acromegalic patients who had received surgical and/or long acting octreotide therapy or who hadn't receive any treatment at all. According to the applied treatment, we divided the patients into groups, as follows: 1) LAO/+/, surgery /-/, 2) LAO /+/, surgery /+/, 3) LAO /-/, surgery /-/, 4) LAO /-/, surgery /+/. Ghrelin was also evaluated in 18 control healthy subjects.

RESULTS: The difference between mean ghrelin level in the healthy subjects and acromegalic patients was not statistically significant (p=0.08). LAO /-/, surgery /-/ patients showed fasting ghrelin levels indistinguishable from those seen in healthy subjects (p=0.1). There wasn't any statistically significant difference between LAO /-/, surgery /-/ patients and LAO /-/, surgery /+/ group (p=0.14). Serum ghrelin levels in LAO /+/, surgery /+/ group were significantly lower from those observed in LAO /-/, surgery /+/ patients (p=0.006). A similar reduction in ghrelin levels was also found in patients LAO /+/ (both after and without surgery) compared to LAO /-/ patients (both after or without surgery) (p=0.001). Serum ghrelin levels showed a significant negative correlation with IGF-1 concentration and a tendency to a statistically significant correlation with GH in LAO /-/ group (p<0,05).

CONCLUSIONS: Ghrelin concentrations were significantly lower in acromegalic patients who had been receiving long acting somatostatin analogue treatment; there was no significant difference in serum ghrelin levels between patients who had and who had not undergone surgery. A significant negative correlation between ghrelin and IGF-1 and a tendency to such correlation between ghrelin and GH was observed in LAO /-/ group of patients.