Objective Low birth weight is associated with cardiovascular disease in later life. Endothelial dysfunction is considered a precursor of atherosclerosis and is linked to cardiovascular events in adults. We aimed to study endothelial function in newborns to find an early marker to identify and follow up children at high risk.

Methods 50 healthy newborns were included in the study and skin perfusion was measured by laser-Doppler flowmetry on the forearm in the first week of life. Endothelium induced vasodilatation was measured as maximum perfusion in response to acetylcholine delivered to the skin by iontophoresis. In addition endothelium independent vasodilatation was analyzed following delivery of nitroprusside. Vasodilatation was expressed as a percentage increase of baseline perfusion. Data were related to birth weight using linear regression analysis.

Results Baseline perfusion was not related to birth weight. Linear regression analysis revealed a significant linear relationship between birth weight and percentage increase of skin perfusion in response to acetylcholine (p = 0.04). A one standard deviation increase in birth weight was associated with an increase in response to acetylcholine of 73%. Endothelium independent vasodilatation was minimally influenced by birth weight.

Conclusions The data show considerable impact of birth weight on endothelial function in the first week after birth. In addition, endothelium independent vasodilatory capacity is not impaired in low birth weight infants. This may help to understand the mechanisms that predispose small for their gestational age infants to cardiovascular disease and to identify and follow up infants at risk.