Stiffening of the arteries usually related to aging can be
detected in early adulthood using a method known as pulse wave
velocity, according to a new study led by researchers at King's
College London with the University of Glasgow. Alongside a lack of
physical activity, stresses such as perceived racism were also
associated with stiffening of the arteries of the 21-23 year-olds
who took part in the multi-ethnic study.
Arterial stiffness, measured as aortic pulse wave velocity
(PWV), has become a useful indicator of cardiovascular risk.
However, few studies have investigated its development over time,
particularly in young adults and ethnic minority populations. As
arterial stiffening develops over the course of one's life,
detecting factors that determine its progression should be useful
in delaying or preventing a decline in arterial health.
The study tested how factors measured twice previously in
childhood in the Determinants of Adolescent, now young Adult,
Social wellbeing and Health (DASH) study, particularly body size
and blood pressure, affected the emergence of aortic stiffness in
young adults. The DASH study is based at the MRC/CSO Social and
Public Health Sciences Unit at the University of Glasgow.
Of the original DASH cohort of 6,643 London children from 51
schools covering six ethnic groups tested at ages 11-13, 4,785 were
seen again at ages 14-16 and in 2013, 666 took part in a pilot
follow-up aged 21-23 years. These young adults had aortic
stiffness, blood pressure and body size recorded and they were also
asked to fill out a questionnaire on social factors such as health
behaviors and social economic background. Reported racism was
assessed via questions on unfair treatment on the grounds of race,
skin color, country of birth, or religion in various locations
(school, street, work, etc). Half of the participants also wore an
ActivePal monitor to measure their physical activity over five
days.
The study found that arterial stiffness increased with blood
pressure, greater waist/height ratio, lack of physical activity,
and reported racism. Around half of the young adult cohort reported
racism, with a greater proportion in the ethnic minority groups
than their White peers reporting such incidents.
Despite greater exposure to risk from childhood (overweight,
deprivation, racism) among groups such as Black Caribbeans or Black
Africans, arterial stiffness was lower compared to their White
British peers. However, even at lower blood pressures, some people
had stiffer arteries than others.
By age 21-23 years nearly half of the men smoked, as did a third
of the women. About half the ethnic minority sample reported racism
at 21-23 years, with a steep rise between 14-16 years and 21-23
years. Both men and women spent some 70% of their waking hours
sedentary. However, time spent in moderate to vigorous activity
(about 36 minutes a day) was associated with lower (better)
arterial stiffness.
Limitations of the study included the fact that physical
activity was not measured in detail in the baseline survey of the
cohort. The study also had a relatively small sample size of
around 100 people per ethnic group and the subgroup in which
physical activity was measured was smaller because of cost
issues.
Professor Kennedy Cruickshank, first author and DASH's
cardiovascular advisor at King's College London, said: "Stiffening
or hardening of arteries is now recognised as a powerful indicator
of lifetime risk, even after accounting for blood pressure's
impact. Its effects are on heart and blood vessel disease, stroke
and dementia. Our study of young people shows that such arterial
stiffening can be detected in the early 20s age group, together
with effects from waist size. It confirms the likely importance of
exercise in maintaining a healthy body and circulation. We also
found reported racism had an effect, which needs to be explored
further to understand the mechanisms behind it, probably related to
stress hormones."
Professor Seeromanie Harding, lead investigator of the DASH
study at King's College London and previously at the University of
Glasgow, said: "DASH is a unique study because there are few
cohorts with an ethnically diverse composition in early adulthood.
This is a time when physical health is at its peak, yet when early
signs of disease begin to appear. The findings help us understand
factors such as being overweight that may adversely affect the
cardiovascular health of young people from different ethnic
minority populations. They also signal what might protect them as
they age."
This paper, Ethnic Differences in and Childhood Influences on Early Adult Pulse
Wave Velocity, is published in Hypertension.