October - December 2007, Volume 3, Issue 4

Niculescu DA, Purice M, Lichiardopol R, Hortopan D, Dumitrascu A, Coculescu M

Reversal of impaired fasting glucose with long-acting somatostatin analogs in active acromegaly - a report of two cases

Acta Endo (Buc) 2007, 3 (4): 471-482
doi: 10.4183/aeb.2007.471

Glucose intolerance (impaired fasting glucose [IFG], impaired glucose tolerance [IGT] or diabetes mellitus) due to insulin resistance is a frequent complication of acromegaly due to excessive growth hormone (GH) production. Long-acting somatostatin analogs are known to reduce the GH and IGF-1 serum levels, and to inhibit at the same time the pancreas insulin release. The effect upon acromegalic patients who express IFG before therapy is controversial. We here present two male patients, 66 and 36 years old, with active acromegaly and IFG who were submitted to a treatment with long-acting somatostatin analog lanreotide. After being diagnosed with active acromegaly with high nadir serum GH levels along oral glucose tolerance test (OGTT), i.e. 149 ng/mL and 43 ng/mL respectively, the patients underwent complex therapy (surgery and radiotherapy) which reduced the GH serum levels (20.7 ng/mL and 3.5 ng/mL respectively) without curing the disease. The patients developed IFG with fasting serum glucose levels of 113 mg/dL and 101 mg/dL, respectively. The treatment with the long-acting somatostatin analog lanreotide (30 mg i.m., every two weeks) decreased the GH serum levels close to normal limits (1.5 ng/mL and 1.6, ng/mL respectively). The treatment with lanreotide normalised the fasting serum glucose levels (91 mg/dL and 81 mg/dL, respectively) together with a reduction of serum insulin levels from 14.2 mU/mL to 8.7 mU/mL and from 25.4 mU/mL to 11.5 mU/mL, respectively (HOMA decreased form 3.96 to 1.97 and 6.33 to 2.3, respectively). We discuss the mechanisms by which lanreotide can improve glucose tolerance in patients with active acromegaly despite lowering the serum insulin levels through a direct effect on insulin secretion.

Keywords: acromegaly; somatostatin analogs; impaired fasting glucose; insulin

Correspondence: Mihail Coculescu, Department of Endocrinology, “Carol Davila” University of Medicine and Pharmacy and Institute of Endocrinology, 34-36 Bd. Aviatorilor, 011863, Bucharest, Romania, Phone/Fax: + 4021 3198718, e-mail: m.coculescu@uni-davila.ro