Influence of Interleukin-6 (174G/C) Gene Polymorphism on Obesity in Egyptian Children

Abstract

Background: Obesity is a multi-factorial chronic disorder. A considerable number of studies have been performed to figure out whether there is an association between obesity and polymorphisms of gene IL-6 (174G/C), but the results are equivocal.

Aim: This study aimed to find out whether the IL-6 (174G/C) gene was associated with the risk of developing obesity in Egyptian children.

Subjects and methods: The study included 149 children and adolescents with age ranged between 9.5 - 18 years. Eighty-five of them were obese which BMIZ-score is > 2, and sixty-four children with BMIZ-score ≤ 2 served as control group. Serum level of IL-6 and genetic analysis for IL-6 (174G/C) gene polymorphism were done.

Results: Obese children had significantly higher serum levels of IL-6 as compared to those of control children (P = 0.003). A high percentage of IL-6 polymorphism GC was found in obese subjects (93.7%), while the control group had a higher percentage of IL-6 polymorphism GG (70.6 %).

Conclusion: Our study showed that carriers of the C allele for the IL-6 (174G/C) polymorphism have higher BMI. As the G174C polymorphism is likely to affect IL-6 expression and its physiological regulation; consequently this polymorphism may affect adiposity.

Keywords: Children; Egypt; Interleukin-6(174 G/C); Obesity; polymorphism.

Figure 1

A) Agarose gel (3%) photographs of PCR-RFLP products (amplicons digested with restriction enzymes) depicting the genotypes of IL-6 polymorphisms PCR and digestion products run on 3% agarose gel electrophoresis. Lane 1: ΦX 174 marker/Hae III digest. Lane 2: The PCR amplified product (500 bp). Lanes 3, 4, 6 and 8: G/G genotype (264, 207 and 29 bp). Lanes 5, 7, and 9: G/C genotype (264, 207 and 122 bp); B) Fig (2): PCR and digestion products run on 3% agarose gel electrophoresis. Lane 1: ΦX 174 marker / Hae III digest. Lane 2: The PCR amplified product (500 bp). Lanes 3, 4, 6, 7, 8, 9, 10, 12: G/C genotype (500, 264, 122 and 85 bp)