Association between birth weight and adolescent systolic blood pressure in a caucasian birth cohort differs according to skin type, CRH promoter or 11beta-HSD2 genotype.

Abstract

To examine whether the inverse association between birth weight and blood pressure varies by skin pigmentation and/or related genotypes. 671 children from a predominantly caucasian birth cohort were followed-up to adolescence (mean (SD) age 14.4 (0.64)). Data on birth weight, socioeconomic status, maternal antenatal smoking, adolescent blood pressure and polymorphisms of candidate genes were obtained and analysed by multiple linear regression. An increase in birth weight of 1 kg was associated with an non-significant difference in adolescent systolic blood pressure of -0.53 mm Hg (95% CI -1.72 to 0.66) per kg after adjustment for child age and cohort entry criteria. The inverse association between birth weight and systolic blood pressure was stronger for those with darker skin (> or =2% melanin) (difference in effect, p = 0.02), those with more copies of the C allele of corticotropin-releasing hormone (CRH) +T1273C (p = 0.06), and those with more copies of the short (< or =236 bp) form of the 11beta-HSD2{CA}n(repeat) microsatellite (p = 0.03). These findings add to the evidence that cortisol-related pathways may account for at least part of the observed birth weight-blood pressure associations.