Endocrine Abstracts

Aim: To compare gender frequency of leptin receptor gene (LEPR) genotype rates and leptinemia levels in overweight children.

Materials and methods: Three hundred children with adiposity were investigated (divided into groups: prepubertal (1st) m/f n=51/50, early pubertal (2nd) n=49/51, late pubertal (3d) n=50/49). 80 girls and 89 boys with obesity and 90 lean girls and 48 lean boys (control) were genotyped in 6 exon of LEPR gene (Q223R polymorphism). Serum leptin was detected by immunoenzyme method; insulin, testosterone estradiol levels – by radioimmunoassay technique. Statistical analysis was performed using SPSS 16.0 (P=0.05).

Results: There were no sex differences between leptin levels in 1st and 2nd groups (P=0.7) (P=0.1) in contrast to 3d group (P=0.0001). Leptinemia was increased in pubertal start (P=0.021) and subsequent leptin diminution with puberty development (P=0.024) in overweight boys. However we ascertained leptin levels constant rising in obese girl with pubertal progression (P=0.001). BMI and leptin (r=0.355, P=0.0001), insulin and leptin (r=0.371, P=0.0001) correlations were revealed. Leptinemia correlated with age (r=0.326, P=0.009) and serum testosterone concentration in pubertal boys (r=−0.444, P=0.0001), as compared to pubertal girls – only with estradiol concentration (r=0.356, P=0.031).

There were gender differences (χ²7.91; P<0.05) between genotypes rates occurrence in obese children: 14.6% boys and 2.5% girls had RR-genotype, 21.3% girls and 15.7% boys – QQ. As compared to lean children: RR-genotype was found in 19.1% girls and 14.6% boys, QQ-genotype – in 25.8% girls and 20.8% boys (P>0.05).

Conclusion: There was 6 time lower incidence of RR-genotype among obese girls than normal peers. No differences were found between overweight and normal boys in Q223R LEPR genotype rates occurrence. Q223R LEPR genotypes in girls with adiposity were significant differ from normal children irrespective of gender.