Abstract
Thirteen patients with active acromegaly despite previous surgery were treated with 30 mg lanreotide im twice a month for 9 months. In 10 subjects the treatment continued to 19 months.
GH serum levels of all patients decreased significantly from an initial value of 32.0 (29.4) mu g/l [median (standard error of median)] to 10.0 (3.6) and 19.1 (5.7) after 3 and 9 months of treatment, respectively. In the 10 patients with the treatment longer than one year the decrease in GH was from 46.8 (29.4) mu g/l to 12.5 (5.0) and 16.1 (5.3) after 13 and 19 months, respectively.
IGF-I serum levels decreased significantly from 1193 (73)mu g/l to 782 (99) and 621 (103) after 3 and 9 months, respectively, and were normalized in 3 patients. In the 10 patients treated for longer than one year, levels decreased significantly from 1318 (74) mu g/l to 653 (170) and 742 (180) after 13 and 19 months, respectively.
TGF BP-3 levels were reduced to the normal range in 6 patients and decreased from 8.7 (1.5)mg/l to 6.4 (0.8) and to 5.4 (1.0) after 3 and 9 months, respectively. In the patients with the 19 months treatment the decrease was from 9.3 (1.6)mg/l to 3.9 (0.9) and 4.8 (0.9) after 13 and 19 months, respectively.
The IGF BP-3 to IFG I ratio increased in 7 patients. This elevation significantly correlated with the decrease in bioassayable somatomedin.
Prolactin serum levels fell in all patients with increased prolactin secretion. Testosterone plasma levels increased in 4 out of 5 men without replacement therapy.
Clinical improvement was observed in all patients. A reduction of tumour mass was observed in five patients and complete disappearance of the tumour in one subject.
All patients complained of mild abdominal pain and softened stools for several days following the injections. However, these side effects never required interruption of treatment.
Asymptomatic microlithiasis was seen in only one patient after 13 months, which led to treatment being suspended for a period of 3 months after which it was resumed. Fasting serum insulin and insulin area under the curve (AUC) after oral glucose tolerance test (OGTT) fell in all patients.
Fasting blood glucose, fructosamine and glucose AUC after OGTT slightly increased during the treatment, but all blood glucose levels (fasting and during OGTT) remained within normal ranges. Lanreotide appears to be a safe and effective treatment in patients with active acromegaly unresolved by surgery.
The long-acting formulation avoids the drawbacks associated with either repeated daily injections or continuous infusions of somatostatin analogues.