Two distinct patterns of childhood growth may raise the odds of developing high blood pressure later in life, a new study suggests.
Low birth weight has been linked to high blood pressure and heart disease in adulthood by a number of studies. Researchers suspect that poor growth in the womb may “program” the body’s metabolism and development in ways that raise the odds of cardiovascular disease.
In the new study, researchers identified two different patterns of childhood growth, from birth to age 11, that were linked to high blood pressure in older age.
People with the first pattern tended to be short and underweight at birth, and to then gain weight slowly until age 2. After 2 years of age, they put pounds on more rapidly, so by the age of 11, they were of average body size.
People with the second pattern were also relatively short at birth and gained weight slowly throughout childhood, but by age 11, they were shorter and thinner than average.
More than one health aspect affected
These findings suggest that childhood growth affects adult blood pressure through more than one mechanism, according to the study authors, led Dr. Johan G. Eriksson of the National Public Health Institute in Helsinki, Finland.
It’s also possible that childhood growth could affect a person’s likelihood of responding to a given blood pressure drug, the researchers write in Hypertension, an American Heart Association journal.
The findings are based on 2,003 men and women who’d been part of a Helsinki study that tracked their health from birth. At the current assessment, the participants were 62 years old and approximately one third had been diagnosed with high blood pressure.
Eriksson’s team found that, compared with their peers with normal blood pressure, the subjects with high blood pressure were more likely to be obese and to have diabetes. Their childhood growth pattern was also distinct. Following pattern one, they were more likely to have been small up to age 2, and then grow rapidly thereafter.
Two paths to high blood pressure
The researchers found that another 40 percent of the study participants had previously undiagnosed high blood pressure. These men and women were more likely to be overweight and have unhealthy cholesterol levels than their peers with normal blood pressure.
They were also more likely to have the second pattern of childhood growth — small birth size with continuing slow growth to age 11.
The two early growth patterns may lead to high blood pressure in two different ways, Eriksson and his colleagues speculate.
One theory is that restricted fetal growth may contribute to high blood pressure because it stymies the normal development of the kidneys, which remove waste fluids from the blood.
In the case of the first growth pattern, where small birth size is followed by rapid growth after age 2, the catch-up growth may further overload the tiny blood vessels in the kidneys, according to the researchers.
They speculate that the second growth pattern, where growth remains relatively slow to age 11, may alter liver development, which continues after birth. This would be consistent with the fact that people with this growth pattern tended to have high cholesterol, the researchers note.
According to Eriksson’s team, all of this raises the possibility that these two groups will have different responses to various types of blood pressure medications, because the drugs act through different mechanisms.
More research, however, is needed to answer that question.