Fetal and Maternal Peroxisome Proliferator‐activated Receptor γ2 Pro12Ala Does Not Influence Birth Weight

Abstract

The association between the peroxisome proliferator-activated receptor (PPAR)␥2 Pro12Ala polymorphism and insulin resistance is reported to depend on low birth weight. Low birth weight itself has been linked to type 2 diabetes and cardiovascular diseases in adulthood. We assessed whether the PPAR␥2 Pro12Ala polymorphism determines body size at birth and whether metabolic differences between the genotypes are already detectable in the newborn. This study was conducted at the obstetrics department of the Charité, Berlin, Germany. One thousand nine hundred thirty white woman/child pairs were consecutively included and genotyped. The newborn's weight, length, and head circumference were measured. Total glycated hemoglobin in blood served as a surrogate of fetal insulin resistance and glucose use. We found that neither the fetal nor the maternal Pro12Ala genotype determined body size or total glycated hemoglobin at birth. The results suggest that the PPAR␥2 Pro12Ala polymorphism is not relevant for intrauterine growth. Previously reported effects of PPAR␥2 Pro12Ala on insulin resistance seem to arise later in life.

Effect of the Ala12 Allele in the PPARγ-2 Gene on the Relationship Between Birth Weight and Body Composition in Adolescents: The AVENA Study

“…This is good agreement with Pfab et al (43) who reported that neither fetal nor maternal PPAR␥-2 genotypes affected birth weight of the 1950 newborns studied.…”

No evidence that established type 2 diabetes susceptibility variants in the PPARG and KCNJ11 genes have pleiotropic effects on early growth

“…Such a finding would be consistent with the largest studies previously performed at each variant [5,8].…”

“…In addition, we have previously demonstrated that this sample is able to detect other well-established genotypephenotype correlations [9,10]. Overall, the most likely conclusion is that these two variants have little or no effect on early growth phenotypes, a finding which would be consistent with the previous large-scale studies [5,8].…”

“…A recent study suggested that carriers of the alanine allele were more likely to have a lower birthweight due to shorter gestation and, indeed, a higher frequency of alanine carriers was observed in the pre-term group [7]. In contrast, the largest study to date, involving 1,930 women and child pairs, found no association between the P12A variant and indices of early growth [8]. Finally, a large-scale study, which found evidence for higher birthweight amongst infants carrying type 2 diabetes-susceptibility alleles at the TCF7L2 locus, attributed this to an indirect effect mediated by the effects of maternal genotype on glucose levels during the pregnancy [9].…”

Polymorphism Pro12Ala of <i>PPARG</i> in Prepubertal Children with Premature Adrenarche and Its Association with Growth in Healthy Children

“…The follow-up of our study group will show whether the finding applies to Finnish children with PA. The results regarding the relationship between the minor Ala12 variant and birth measures have been contradictory [20,27,29,30]. The biggest studies on infants have shown no difference in birth measures concerning Pro12Ala polymorphism of PPARG [30], which is in line with our findings.…”