Endocrine Abstracts

Objectives: Neurogenetical predictors of psychological disturbances in children with severe obesity.

Methods: We examined 254 pubertal obese children: group1 (simple obesity) 187 children, 14.3±2.0 yrs, 30.4±2.8 kg/m²; group2 (severe obesity) 67 children, 14.7±2.1, 39.1±3.8. Control 80 children, 14.4±2.0 yrs, 19.7±1.7 kg/m². Dopamine levels were determined. Genotyping was performed on polymorphic genes COMT, MAOA, A1 Tag 1A allele of DRD2/ANKK1 polymorphism (rs1800497).

Results: A statistically significant difference between dopamine levels were in patients with simple (8.8(4.8; 20.7)) and severe obesity (48.8(29.8, 163.9)) ng/ml and AA genotype (P=0.05). We found the significant increasing of dopamine levels (82.5 [61.3; 116.3]) in boys with severe obesity and 3-3 MAOA genotype comparison to 4-4 genotype (35.7 [23.2; 54.9]) (U=4.0; P=0.03). We determined more frequent occurrence of GA (Val/Met) genotype COMT gene in children with severe obesity (54.3%) compared to simple disease (32.7%) (χ²=6.9; P=0.03). AA genotype frequency was 21.7% in patients with severe obesity, which were higher than control (16.6%) (χ²=14.6; P=0.006). We revealed significantly higher BMI in children with severe obesity and the presence of GA genotype (41.3±4.5 kg/m²) compared to GG (37.4±3.1) (P=0.006) and AA (38.6±2.8) (P=0.04) genotypes. The more frequent presence of A1 allele, associated with low dopamine D2 receptors density (A1A1 and A1A2) was detected in children with morbid obesity (17.9%) in comparison with alimentary obesity (4.8%), (χ²=9.7, P=0.008). The positive reliable correlation was found between A1A2 genotype and BMI (r_s=0.8, P=0.001).

Conclusions: A large frequency of AA genotype were found in children with severe and simple obesity. Higher BMI levels were in children with severe obesity and genotype GA. The more frequent presence of A1 TaqIA allele, associated with low dopamine D2 receptors density was found in children with morbid obesity.