Premature birth cuts short kidney development, resulting in smaller kidney size and higher blood pressure in adulthood, according to a study presented at the American Heart Association's Council on Hypertension 2016 Scientific Sessions.

"Adults born preterm may not present with the 'classical' risk factors for heart disease, but they are at increased risk of hypertension and insulin resistance and certainly require regular medical follow-up," said Anne Monique Nuyt, M.D., senior author of the study and head of the division of neonatology at the Sainte-Justine University Hospital and Research Center of the University of Montreal, Canada.

Researchers compared kidney size, function, and blood pressure in 40 adults (average age 23.6) born at 29 weeks of gestation or earlier with 40 adults (average age 23.3) born at full term. They found that young adults born preterm had:

  • Significantly smaller kidneys relative to their body size;
  • Significantly higher systolic (higher number) and diastolic (lower number) blood pressure, both on waking and averaged over 24 hours.

While the differences in blood pressure were not large - for example, the average daily systolic blood pressure was 5 points higher in the adults born preterm (120 mmHg) than those born full term (115 mmHg) - the findings raise concerns about high blood pressure and heart disease risk as adults born preterm enter middle-age.

"It is well known that blood pressure will increase more markedly with aging in people who have higher blood pressures in their young adult lives than those who had lower values. We do not know for certain whether this will be the case for individuals born preterm because the first survivors of extreme prematurity are only entering their thirties and forties," Nuyt said.

Co-authors are Katryn Paquette, M.D.; Thuy Mai Luu, M.D., M.Sc.; Anik Cloutier, M.Sc.; Marie-Amélie Lukaszewski, Ph.D.; Mariane Bertagnolli, Ph.D.; Ramy El-Jalbout, M.D. and Anne-Laure Lapeyraque, M.D., M.Sc. Author disclosures are on the abstract.

The Canadian Institutes of Health Research supported the study.