These things just worry people for no reason. I assume babies within the normal birth weight range will not show any considerable variation in 'vascular resistance', or in blood pressure later on. The research paper doesn't actually specify what they would consider low birth weight, just that they found a correlation in boys between birth weight and certain aspects of cardiovascular physiology (so lower birth weight boys have an increased risk of circulatory disease, high blood pressure later in life - but i'd imagine the risk is higher for people who smoke every day and live in mcdonalds, for example, so nothing worth worrying about).
Sorry if that made no sense - I'm still half asleep. The research article is here...
https://eurheartj.oxfordjournals.or...ht&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT