IGF(CA)19 and IGFBP-3-202A/C gene polymorphism in patients with acromegaly

We aimed to investigate IGF-1 and IGFBP-3 gene polymorphisms in patients with acromegaly.

We included 34 patients with acromegaly and 37 healthy subjects to study. At baseline examinations, antropometric measurements were done. Genomic DNA from the patients and controls were prepared. Serum, glucose, insulin, total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol, growth hormone (GH), Insulin-like growth factor I (IGF-I) and IGFBP-3 levels of subjects were analyzed.

The frequency of genotype IGF-1(CA)19 and IGFBP3-202 A/C gene was significantly different between control and patients. In acromegalic patients, a significant difference in the serum IGF-1 levels and LDL cholesterol levels among the three IGF(CA)19 genotype. LDL levels were positively correlated with IGF-1. Subjects having >194 bp genotype had higher IGF-1 and LDL cholesterol levels. We observed that the patients with 194 bp genotype have more invasive and bigger tumors and they require adjunctive therapies. Clinical characteristics among the three IGFBP3-202 A/C genotype, AA, AC and CC, did not display any significant difference.

In our study, 194 bp allele (20 CA repeats) of the IGF-I promoter have higher circulating IGF-I levels than others. We have found that the patients with 194 bp genotype are the resistant patients with active disease and they required high dose medication. We think this study may help to define the patients, who are resistant to drug therapy, and possible cardiovascular disease.