Obesity is a major health problem worldwide and constitutes a sanitary emergency in Mexico, especially
childhood obesity. Several studies have proved the relationship between
obesity and oxidative stress and the influence of
genetic predisposition. This work was aimed to analyze the association of
antioxidant enzyme polymorphisms with
overweight and
obesity in Mexican children and adolescents. A case-control study was performed in 585 children and adolescents aged 3 to 17 years, using two criteria to classify
obesity: body mass index (BMI) and body fat percentage (
BFP). Anthropometric and biochemical measurements were carried out, and
malondialdehyde serum levels were determined. Genotyping was done with the Axiom Genome-Wide LAT microarray, including 68 single nucleotide polymorphisms (SNPs) of the
glutathione peroxidase (GPX) and
paraoxonase (PON) families. We found six haplotypes associated with
obesity-two of them (one in GPX3 and the other in GPX5 and GPX6) in a protective direction when
obesity was classified by BMI. The other four haplotypes were associated with
obesity when classification was based on
BFP-one of them in GPX3 in a protective direction and the others in PON genes conferring
obesity risk. In addition, two SNPs, GPX3 rs922429 and GPX4 rs2074451 showed protection against
obesity classified by
BFP. This study showed
genetic susceptibility to oxidative stress in relation to
obesity in Mexican children and opens up the possibility that some genetic loci related to
obesity are not identified when weight classification is based on BMI.