Aim To compare gender and pubertal insulinemia levels and frequencies of Insulin gene (INSG) genotype rates in lean (control (C)) and obese (O) children.

Methods 578 O and 204 C children were investigated (divided into groups: prepubertal O (1^st-o) m/f n=178/117 and C (1^st-c) n=51/46, early pubertal (2^nd-o) n=67/41 and (2^nd-c) n=16/17, late pubertal (3^rd-o) n=88/87 and (3^rd-c) n=14/60). 129 O girls and 144 O boys and 104 lean girls and 55 lean boys were genotyped in INSG (A-23HphIT polymorphism). Serum insulin was detected by radioimmunoassay technique. Statistical analysis was performed using SPSS 16.0 (p=0.05).

Results Insulin ranges were significantly higher in O children than in Cl regardless of pubertal stage and sex: p=0,0001 between the 1^st-o and 1^st-c, p=0,001 in the 2^nd groups and p=0,0001 in the 3^rd groups respectively. Correlations between insulinemia and BMI (r=0.4, p=0,0001) were revealed. There were gender differences (hi-square 6.56; p< 0.05) between genotypes rates occurrence in O children: 51.9% girls and 61.8% boys had AA-genotype, 13.2% girls and 4.9% boys - TT, versus to C children: AA-genotype was found in 61.5% girls and 56.4% boys, TT-genotype - in 3.8% girls and 5.5% boys (p>0.05). Insulin level was higher in O children with AA homozygote genotype in compared with TT-genotype (p=0,003). There were no changes of insulin values in control group irrespective of the genotype polymorphisms.

Conclusion A-23HphIT INS genotypes in girls with adiposity were significant differ from normal children irrespective of gender. Insulin level in obese children depends on A-23HphIT INS polymorphisms.