In a follow-up study done by theKarolinska Institute in Stockholm,Sweden, researchers found thatblood pressure (BP) readings werehigher in young men who were bornprematurely. A previous study hadshown that low birth weight in maleswas connected to higher adult BP,but, as Stefan Johansson, MD, of theInstitute noted, "we found thatpreterm birth provides a higher riskthan just being small at [birth]."
The findings, which were publishedin a report in Circulation: Journal of theAmerican Heart Association, camefrom a study of 329,495 Swedish menborn between 1973 and 1981 whohad BP measurements recorded atage 20. Full-term, moderately preterm,very preterm, and extremely pretermbirths were defined as births whichtook place at 37 to 41 weeks gestation,33 to 36 weeks, 29 to 32 weeks,and 24 to 28 weeks, respectively.
The risk of high systolic BPincreased steadily from 25% for moderatelypreterm to 93% for extremelypreterm, compared with full-termbirths. Being small for the length ofpregnancy was only a risk factor forhigh BP among men born at >33weeks.
The reasons for the link betweengestational age and BP are not clearbut "could involve structural changesin the vascular tree," Dr. Johanssonsaid. Hormone alterations could alsobe a factor.