Vázquez-Moreno M, Locia-Morales D, Perez-Herrera A, et al. - As little is known about the relationship between haptoglobin level and cardiometabolic traits, researchers examined the correlation of HP rs2000999 with serum haptoglobin and childhood and adult obesity in up to 540/697 and 592/691 Mexican cases and controls, respectively. Anthropometric and biochemical data have been obtained. Using the Wald and inverse variance weighting methods, Mendelian randomization analysis was performed. Findings suggested a positive association of haptoglobin level with childhood and adult obesity. HP rs2000999 G allele was positively linked to haptoglobin level in children and adults. HP rs2000999 G allele was linked positively to childhood but not to adult obesity. After adjusting for haptoglobin level, the link between HP rs2000999 and childhood obesity was removed. For the first time in the Mexican population, the data provide evidence for a causal positive correlation between serum haptoglobin level and childhood obesity. The research leads to the genetic elucidation of childhood obesity and proposes haptoglobin as a significant biomarker and target of obesity treatment.