Endocrine Abstracts

Objective: Insulin like growth factors (IGFs) are important regulators of pancreatic β cell devolopment, growth and maintanence. Mutations in the IGF genes have been found to be associated with type 2 diabetes, myocardial infarction, birth weight and obesity. These associations could result from changes in insulin secretion. We aimed to investigate IGF- 1 gene polymorphism in obese patients with insulin resistance.

Methods: We included 100 obese patients with insulin resistance who applied to Endocrinology and Metabolism outpatient clinic and 30 healthy subjects to study. At baseline examinations, antropometric measurements were done. Genomic DNA from the patients and controls were prepared Investigated genomic areas were studied using specific primers by PCR methods. Amplified fragments were separated agarose gel electrophoresis and were identified using the u.v. gel documentation system.

Results: Thyroid function tests and serum IGFBP3 levels were similar between patients and controls whereas IGF, GH and cortisol levels were significantly lower in -obese insulin resistant patients. We categorized the IGF-1 (CA)₁₉ polimorphism area into 3 group as lower than192-bp(group 1), 192-194 bp (group 2), and higher than 194-bp (group 3). Group 3 was more frequent in both obese and control groups, When all parameters of group 3 were compared between obese (n:71) and control groups (n:28); weight, BMI, waist and hip circumference, fat distrubution, FBG, TG, HDL, LDL, AST, ALT, uric acid, insulin levels were significantly different between two groups. IGF-1 levels were also significantly lower in obese group (138.51±49.3) in than controls (218.14±69.15).

Conclusions: IGF-1 levels were significantly lower in obese than normal people, The most frequent IGF-1 gen polymorphism allel is > 194 bp in both obese insulin resistant patients and controls, IGF-1 levels and the other biochemical and hormonal parameters were similar in different genotype groups. The cause of lower IGF-1 levels in obese patients might be different from IGF-1 gene polymorphism and it may be insulin resistance.