Polymorphism Pro12Ala of PPARG in Prepubertal Children with Premature Adrenarche and Its Association with Growth in Healthy Children

Abstract

Background: The peroxisome proliferator-activated receptor-γ2 (PPARγ2) participates in the regulation of insulin sensitivity, and has connections to the GH-IGF system and ACTH-adrenal androgen axis. We hypothesized that PPARG Pro12Ala polymorphism leading to decreased receptor activity could contribute to the premature onset of adrenarche (PA). Methods: We performed a cross-sectional association study in 73 prepubertal children with PA and 97 age- and sex-matched healthy control children. Growth data, baseline hormone levels, and the values of oral glucose tolerance test (OGTT) were compared with PPARG genotypes. Results: We found no difference in the genotype distribution of PPARG between the PA and control children. The minor Ala12 variant was associated with lower current height SD scores (SDS) in the controls, but no similar association was seen in the PA children. Birth measures and current weight for height were equal between the genotype groups in both control and PA children. The Ala12 variant was associated with trends for a lower serum IGF-I level and lower serum insulin concentration at the 120-min time point of OGTT in control children. Conclusions: The Pro12Ala genotype of PPARG was not associated with PA. The minor Ala12 variant was associated with lower height SDS in healthy prepubertal children indicating its possible effects on growth.