Very preterm infants — those born before 29 weeks of pregnancy — appear to have a bigger risk of high blood pressure in young adulthood, two small, preliminary Canadian studies suggest.
In one study, researchers found that the risk for high blood pressure was tied to smaller-than-normal kidneys at birth. A second study by the same researchers found a link between high blood pressure and impaired function in the cells that line blood vessels.
“These studies highlight how important it is for those born preterm to look after their health,” said Dr. Anne Monique Nuyt, who co-authored both studies. She’s a professor in the department of pediatrics at the University of Montreal.
Thanks to modern medicine, more very preterm infants have survived in the past 30 years than before, she said. But since these preemies are only now reaching their 30s and 40s, any potential health problems that may emerge as they reach their 60s and 70s aren’t yet known, Nuyt said.
Nuyt stressed that having higher blood pressure, smaller kidneys or problems with blood vessel cells won’t necessarily lead to heart disease.
“I can only say these are risk factors,” she said. Also, the study couldn’t prove a cause-and-effect relationship.
“I don’t want to be alarmist. These young adults are carrying on their own lives — they’re working, getting married and having children. But we have to make sure they are well looked after,” Nuyt said.
The results of the studies were scheduled to be presented Thursday at an American Heart Association meeting in Orlando, Fla. Findings presented at meetings are generally viewed as preliminary until they’ve been published in a peer-reviewed journal.
In laboratory tests, the researchers found that cells from preterm adults were slower to form colonies, which is an essential step in forming new tiny blood vessels. These vessels, called capillaries, carry oxygen and nutrients to the cells throughout the body, the study said.
This resulted in higher blood pressure and an enlargement of the heart’s left chamber, which pumps blood into the arteries. Both of these are risk factors for heart disease, Nuyt said.