CARBOHYDRATE-TOLERANCE AND SERUM-LIPIDS IN ACROMEGALY BEFORE AND DURING TREATMENT WITH HIGH-DOSE OCTREOTIDE

Carbohydrate tolerance and serum lipids were studied in 14 patients with acromegaly before and in response to treatment with high dose somatostatin analogue (octreotide) over a 14-week period. Patients were assessed with respect to growth hormone (GH) profile, IGF1, HbA1, fasting lipids, and the GH, glucose, and insulin response to a standard 75 g oral glucose tolerance test (OGTT) before and during therapy. Prior to treatment mean fasting serum insulin levels were 11.7 +/- 2.8 (+/- SE) mU l-1 with a mean insulin response to OGTT of 49.8 +/- 10.8 mU l-1. Twelve of the 14 patient responded to octreotide with a reduction in mean 24-h serum GH (32.9 +/- 9.3 to 4.3 +/- 0.9 mU l-1), suppression of GH at 60 min during OGTT (3.0 +/- 0.8 mU l-1) and normalization of serum IGF1 (71 +/- 7 to 27 +/- 3 (normal 9-48 nmol l-1). In this group the fasting insulin levels fell to 2.2 +/- 0.7 mU l-1 (p < 0.01), and mean insulin response during OGTT was reduced (46.6 +/- 15.0 to 12.3 +/- 2.3 mU l-1) (p < 0.01). Despite the reduction in insulin secretion there was no significant deterioration in fasting blood glucose (4.8 +/- 0.2 vs 4.6 +/- 0.4 mmol l-1), HbA1 (7.2 +/- 0.3 vs 6.8 +/- 0.3%) or mean blood glucose response to OGTT (7.9 +/- 0.7 vs 8.2 +/- 0.5 mmol l-1). Fasting triglycerides were reduced with treatment from 1.5 +/- 0.2 to 1.1 +/- 0.1 mmol l-1 (p = 0.04) in the responsive group, but serum cholesterol levels were not significantly altered (5.3 +/- 0.3 vs 5.2 +/- 0.3 mmol l-1).