Infant adiposity at birth and early postnatal weight gain predict increased aortic intima-media thickness at 6 weeks of age: a population-derived cohort study.

Infant body composition and postnatal weight gain have been implicated in the development of adult obesity and cardiovascular disease, but there are limited prospective data regarding the association between infant adiposity, postnatal growth and early cardiovascular parameters. Increased aortic intima-media thickness (aortic IMT) is an intermediate phenotype of early atherosclerosis. The aim of the present study was to investigate the relationship between weight and adiposity at birth, postnatal growth and aortic IMT. The Barwon Infant Study (n=1074 mother-infant pairs) is a population-derived birth cohort. Infant weight and other anthropometry were measured at birth and 6 weeks of age. Aortic IMT was measured by trans-abdominal ultrasound at 6 weeks of age (n=835). After adjustment for aortic size and other factors, markers of adiposity including increased birth weight (β=19.9 μm/kg, 95%CI 11.1, 28.6; P<0.001) and birth skinfold thickness (β=6.9 μm/mm, 95%CI 3.3, 10.5; P<0.001) were associated with aortic IMT at 6 weeks. The association between birth skinfold thickness and aortic IMT was independent of birth weight. In addition, greater postnatal weight gain was associated with increased aortic IMT, independent of birth weight and age at time of scan (β=11.3 μm/kg increase, 95%CI 2.2, 20.3; P=0.01). Increased infant weight and adiposity at birth, as well as increased early weight gain, were positively associated with aortic IMT. Excessive accumulation of adiposity during gestation and early infancy may have adverse effects on cardiovascular risk.