Effect of Sandostatin((R)) LAR((R)) on serum leptin levels in patients with acromegaly

OBJECTIVE Serum leptin levels are decreased in patients with acromegaly and rise after GH is normalized by surgical treatment. We have evaluated the e ffect of Sandostatin (R) LAR (R) on leptin levels in acromegalic patients s ince there are recent data to suggest that somatostatin, in addition to its GH lowering effect, also reduces serum leptin levels in humans. METHODS Nineteen patients with active acromegaly were studied. Eleven patie nts received monthly injection of Sandostatin (R) LAR (R) and eight patient s underwent transsphenoidal surgery. Serum concentrations of leptin, GH, IG F-1 and insulin were measured before and after treatment. RESULTS Serum leptin concentrations were lower in patients with active acro megaly than controls matched for age, sex and body mass index (BMI) [2.79 m ug/l (2.60) vs. 4.41 mug/l (5.07); median (inter-quartile range); P < 0.01] . A positive correlation between serum leptin concentrations and BMI was ob served in the controls (r = 0.46, P < 0.05) but not in the acromegalic pati ents before treatment (r = 0.32, ns). In the group of patients treated with Sandostatin (R) LAR (R), a marked reduction in GH and IGF-1 was achieved b y week 8 and GH and IGF-1 remained suppressed throughout the 6 months of tr eatment. There was no change in BMI. A significant increase in leptin level s only became evident after 6 months of treatment [2.99 mug/l (2.60) vs. 4. 21 mug/l (3.84), P < 0.05]. Leptin levels also significantly increased afte r transsphenoidal surgery [3.05 mug/l (5.73) vs. 5.19 mug/l (4.93), P < 0.0 5]. The positive correlation between serum leptin concentrations and BMI wa s restored in acromegalic patients both after treatment with Sandostatin (R ) LAR (R) (r = 0.62, P < 0.05) and after surgery (r = 0.81, P < 0.05). CONCLUSION Leptin concentrations were decreased in patients with active acr omegaly and lowering GH by either Sandostatin (R) LAR (R) or transsphenoida l surgery led to an increase in leptin concentrations.