Anticholinergic treatment improves glycaemic control in adolescent girls with insulin-dependent diabetes mellitus

Metabolic control often deteriorates during puberty in girls with insulin-d ependent diabetes. It is well accepted that there is an abnormality in the growth hormone (GH)-insulin-like growth facror-I (IGF-I) axis in these girl s, resulting in reduced IGF-I levels and elevated GH. As GH antagonizes ins ulin, attempts have previously been made to reduce excess GH secretion thro ugh anticholinergic treatment. However, most of these studies have been per formed on adult patients. The aim of the present study was to evaluate the effects of 12 wk of oral anticholinergic treatment with Pirenzepine, 100 mg twice daily, in 16 adolescent girls with diabetes. Serum samples of IGF-I, glycated haemoglobin and fasting IGF-binding protein 1 were analysed at in itiation and after 3, 8 and 12 wk of Pirenzepine therapy. Nocturnal urinary GH excretion was also examined. Glycated haemoglobin declined significantl y after 3 wk of Pirenzepine therapy (9.8 +/- 0.18 vs 9.2 +/- 0.17; p < 0.00 1) and was still improved at the end of the study. Unexpectedly, nocturnal urinary GH excretion did not change. Serum IGF-I continuously increased dur ing the study, while IGF-binding protein 1 levels were not significantly al tered. Conclusion: Anticholinergic treatment with Pirenzepine improves glycaemic c ontrol in adolescent girls with diabetes. Although nocturnal urinary GH exc retion was unchanged there may still be changes in pituitary GH secretion t o explain the improvement. Effects of Pirenzepine on gastrointestinal motil ity can represent other possible mechanisms behind the improved metabolic c ontrol.