Influence of growth during infancy on endothelium-dependent vasodilatation at the age of 6 months.

Low birth weight and accelerated infant growth are associated with cardiovascular disease in adulthood. Endothelial dysfunction is regarded as a precursor of atherosclerosis and is also related to infant growth. We aimed to examine whether an association between infant growth and endothelial function is already present during discrete periods of growth during the first 6 months of life in healthy term infants. A cohort of 104 newborns was studied in the first week after birth and reexamined at the age of 6 months. Maximum vasodilatation in response to acetylcholine (endothelium dependent) and nitroprusside (endothelium independent) was measured in the vasculature of the forearm skin, using laser Doppler flowmetry and iontophoresis. Growth was calculated as difference in Z scores for weight, length, weight-for-length, and head circumference. Multivariable multilevel linear regression was used for the analysis. Growth from 0 to 1 month (calculated as difference in weight) was the only window in the first 6 months of life that was significantly and inversely associated with endothelium-dependent vasodilatation at 6 months (b=-11.72 perfusion units per Z score, P=0.01 in multivariable analysis). Birth size was not important when considered simultaneously with infant growth. Maximum endothelium-independent vasodilatation was not associated with birth size or growth parameters. We conclude that growth in the first month of life is inversely associated with endothelium-dependent vasodilatation at the age of 6 months in healthy term infants, regardless of birth size.