A new US study offers more evidence that
childhood experience may have health effects that echo into adulthood.
Based on health data for 500 unrelated
black men over age 20 enrolled in the Howard University Family Study,
researchers found those who had lived with one parent rather than two as
children had higher average blood pressure readings.
The men who had grown up in single-parent
households also had a 46% greater risk of developing high blood
pressure, also known as hypertension."These differences in mean blood
pressure and the prevalence of hypertension among men raised in two-parent
households vs. single-parent households during childhood are quite
significant," Debbie Barrington said.
Barrington led the study at the National
Institute on Minority Health and Health Disparities with colleagues at the
National Institutes of Health in Bethesda, Maryland.
Childhood living arrangements
About 1 in 3 US adults has high blood
pressure, according to the Centres for Disease Control and Prevention. High
blood pressure increases the risk of heart attack and stroke, which are leading
causes of death.
Generally, the lower the maximum blood
pressure (the top number), the better, with a reading under 120 millimetres of
mercury (mmHg) considered best.
Previous studies have linked childhood
living arrangements to aspects of high blood pressure, but this one is the
first to examine black men a population at particular risk for hypertension.
Men who had lived with both parents as
children tended to have a maximum blood pressure 4.4 mmHg lower than those who
had never lived with both parents. The differences in maximum blood pressure
between men raised by two parents versus one were greater than the changes
produced by some common prescription blood pressure medications, Barrington
The men from two-parent households also
tended to have a smaller difference between maximum and minimum blood pressure
as the heart pumps, and a lower average pressure, all of which are usually for
The gaps widened further for men who had
lived with both parents between ages 1 and 12, averaging 6.5 mmHg lower maximum
blood pressure readings than men from single-parent households, according to
the results published in the journal Hypertension.
It might not actually be the presence or
absence of parents that directly affects blood pressure, but the number of
parents in the home could indicate other important childhood risk factors,
Children who grow up in single-parent
households are more likely to experience poverty, and early childhood poverty
has been linked to later health problems like hypertension, she said.
Among the study participants, "Those
men who grew up in two parent households during childhood were also more likely
to experience less economic hardship and subsequently less stress in early
life," she said.
"Less childhood stress potentially
delays the rise of blood pressure that increases with age, lowering one's risk
of hypertension in adulthood. "Childhood family living arrangements might,
for research purposes, be equivalent to social and economic status, Barrington
said, though she did not collect economic data on the men's childhood
If that kind of economic background
information had been taken into account, she said, the protective effect of
having two parents in the home might have been smaller or might have
'Hard-wiring' for hypertension
Research has shown that living with two
parents improves the social circumstances of black American boys, increasing
their academic success and employment prospects and decreasing the likelihood
of drug and alcohol abuse, Barrington pointed out.
"There is substantial evidence that
changes in family structures can augment environmental stressors and unmask
genetic, ethnic and cultural factors in the African-American predilection for
hypertension," said Richard Millis, who was not involved in the study.
To begin to translate these results to useful
principles in daily life, the medical community should begin by "educating
the educators", namely nurses, doctors and health professionals, said
Millis, an associate professor of physiology and biophysics at Howard
University College of Medicine in Washington, DC. Doctors can then help patients
understand how lifestyle choices might reverse "hard-wiring" for
hypertension, he said.
One interesting place to start would be to
research the "critical period" of childhood between ages 1 and 12,
the study authors write. Until the new results are replicated, black Americans
should continue to follow Institute of Medicine recommendations for blood
pressure screening and decreasing salt, fat and sugar in their diets,
"Our study suggests that there may be
a link between childhood family living arrangements and blood pressure in black
men," she said. "It does not suggest that those men who did not live
with both parents during childhood are destined to have high blood pressure in