Endocrine Abstracts

Introduction: The etiopathogenesis of obesity is represented by the endogenous circadian clock system, which has been shown to have a part in the regulation of body weight and energy homeostasis. The gene Circadian locomotor output cycles kaput (CLOCK) is part of the positive regulatory branch of the system. Polymorphism in CLOCK genes in human disorders characterized by alterations of endogenous circadian rhythms. Moreover, since in up to 30% of obese subjects seeking treatment obesity seems to be associated with binge eating disorder (BED) we explored whether the 3111T/C CLOCK gene SNP was associated specifically to this phenotype.

Objective: To investigate the association of 3111T/C CLOCK gene SNP with BED in obese children and adolescents.

Methods: A total of 319 obese children and adolescents (35.7% boys; aged 10.6±1.4 years, BMI 30.2±4.5 kg/m², ZBMI 2.3±0.3, 45.7% pubertal) were genotyped using Assay by Design kits Applied Biosystem. 121 cases completed the Binge Eating Scale questionnaire and were classified about the grade of eating compulsivity. SPSS v16 (SPSS Inc.) was used for data preparation and initial analysis of the data.

Results: Genotype frequencies did not significantly differ between sex (X2=1.78; d.f.=2; P=0.41). According to Binge Eating Scale questionnaire the sample consisted of 39.6% patients have BED, and allele CC was found in 75.0% of them, only 37.9% of the patients with allele TT presents BED (P=0.015). BED score was strongly associated in girls with presence of allele CC (19.8±2.36 vs 14.6±0.90; P=0.047) as compared to the TT genotype.

Conclusions: Present findings show the 3111T/C SNP of the CLOCK gene is associated to BED in obese children and adolescents. This association provides a critical starting point for an understanding of the likely polygenic contributions towards eating disorders.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.