LONDON: Blood vessel changes linked to poor health later in life can be spotted within a few years in boys born small, say scientists.

Eight-year-olds who were smaller at birth were more likely to have “vascular resistance”, reported the European Heart Journal.

The Southampton University team said this could contribute to high blood pressure decades later.

However, no such problem was seen in low birth weight girls.

Previous work has linked birth size to later heart disease and diabetes.

None of the 140 eight or nine year olds tested in this study would showed any actual signs of heart disease, a condition which normally emerges far later in life.

However, scientists believe that even at this age, the arteries of these children may show differences which might raise the risk of problems decades on.

In particular, they tested for how a child’s response to stress might affect vascular resistance, a property of blood vessels which makes it harder for the blood to be pumped through,

While vascular resistance does not cause an immediate problem for a child, there is some suggestion that higher levels, particularly if sustained after a stressful event, might increase the chance of blood pressure problems in adulthood.

All the children underwent a public speaking and mental arithmetic test designed to make them nervous, and increase their heart-rate.

Although all the children were in the “normal” range of birth weights, boys at the lower end of the scale were more likely to have higher vascular resistance than those born bigger.

The difference in resistance levels between bigger and smaller birth weight boys was particularly strong half an hour after the test, suggesting some additional difference in the boys’ ability to restore normal levels.