A variant of the IGF-I gene is associated with blood pressure but not with left heart dimensions at the age of 2 years: the Generation R Study

Abstract

Background and objective: A common variant of the IGF-I gene has been shown to be associated with cardiovascular disease in adulthood. The objective of this study was to examine whether this variant of the IGF-I gene is associated with blood pressure and left heart dimensions in early childhood. Research design and methods: This study was embedded in the Generation R Study, a population-based prospective cohort study from foetal life onwards. IGF-I promoter region was genotyped in DNA obtained from cord blood. Blood pressure (systolic and diastolic) and echocardiography (left ventricular mass, left atrial diameter and aortic root diameter) measurements were performed at the age of 2 years. Analyses were performed in 538 subjects. Results: Eight alleles of the IGF-I promoter region were identified. In total, 43% of the subjects were homozygous for the 192 bp allele (wild type), 46% were heterozygous and 11% were non-carriers. Significantly lower systolic and diastolic blood pressures were found in non-carrier subjects (difference compared with homozygous subjects: K4.4 (95% confidence interval (CI) K7.8 to K1.1) mmHg and K3.5 (95% CI: K6.9 to K0.1) mm respectively). No significant differences were found for left heart dimensions at the age of 2 years. No association was found when we used a previously proposed alternative classification of the IGF-I gene. Conclusion:The variant type of the IGF-I promoter region is associated with lower blood pressure but not with left heart dimensions at the age of 2 years. Follow-up studies are needed to examine whether these differences persist in later life.

The Generation R Study: design and cohort update 2017

“…Dual X Energy Absorptiometry (DXA) scanning and Fractional exhaled Nitric Oxide (FeNO) measurements have been performed in a smaller subgroup [60, 61]. Blood pressure was measured at the age of 24 months [62, 63]. Observations of parent–child interaction and behaviour, such as executive function, heart rate variability, infant-parent attachment, moral development, and compliance with mother and child have been repeatedly performed and with father and child once [64–68].…”

The Generation R Study: design and cohort update 2012

“…Also, strategies for genetic scoring analyses are being developed to estimate predictive values of identified genetic variants [171,172]. Although a GWAS is available in children, we use DNA from both children and parents for genotyping for candidate gene or replication studies [173][174][175][176][177][178][179][180][181][182]. Missing data in DNA samples in children will be collected by blood sampling or other methods at follow-up measurements.…”

Genetics of the renin-angiotensin system with respect to cardiac and blood pressure phenotypes in healthy newborn infants

“…These data are updates for a newborn infant group because previously published normative values collected in a small pediatric sample were acquired for subjects of different ages (0-18 years). 14,15 In other studies data obtained by Vogel et al 16 in a small study showed a higher LVM/m 2 in newborns, however Kozak-Barany et al found a lower LVM/BSA in a small group of healthy newborns. 17 This discrepancy could result from different techniques of assessing left ventricular parameters and the differences between populations.…”