FOR IMMEDIATE RELEASE
October 6, 2009
Contact: Donna Krupa
Office: (301) 634-7253
commoff@the-aps.org
A Simple Way for Middle Aged
and Older Adults to Assess How Stiff their Arteries Are: Reach for their
Toes
The
important relationship between flexibility and health
BETHESDA, Md. (Oct. 6, 2009) — How far you can
reach beyond your toes from a sitting position – normally used to define the
flexibility of a person’s body – may be an indicator of how stiff your
arteries are.
A study in the American Journal of Physiology
has found that, among people 40 years old and older, performance on the
sit-and-reach test could be used to assess the flexibility of the arteries.
Because arterial stiffness often precedes cardiovascular disease, the
results suggest that this simple test could become a quick measure of an
individual’s risk for early mortality from heart attack or stroke.
“Our findings have potentially important clinical
implications because trunk flexibility can be easily evaluated,” said one of
the authors, Kenta Yamamoto. “This simple test might help to prevent
age-related arterial stiffening.”
It is not known why arterial flexibility would be
related to the flexibility of the body in middle age and older people. But
the authors say that one possibility is that stretching exercises may set
into motion physiological reactions that slow down age-related arterial
stiffening.
The study “Poor trunk flexibility is associated with
arterial stiffening” appears in the American Journal of Physiology –
Heart and Circulatory Physiology. The authors are: Kenta Yamamoto of the
University of North Texas and the National Institute of Health and
Nutrition, Japan; Hiroshi Kawano, Yuko Gando and Mitsuru Higuchi of Waseda
University, Japan; Motoyuki Iemitsu of International Pacific University,
Japan; Haruka Murakami, Michiya Tanimoto, Yumi Ohmori, Izumi Tabata,
Motohiko Miyachi of the National Institute of Health and Nutrition; and
Kiyoshi Sanada of Ritsumeikan University, Japan. The American
Physiological Society published the study.
Arteries should be elastic
Healthy blood vessels are elastic, and elasticity helps
to moderate blood pressure. Arterial stiffness increases with age and is a
risk factor for cardiovascular disease and death. Previous studies have
established that physical fitness can delay age-related arterial stiffness,
although exactly how that happens is not understood. The authors noted that
people who keep themselves in shape often have a more flexible body, and
they hypothesized that a flexible body could be a quick way to determine
arterial flexibility.
The researchers studied 526 healthy, non-smoking
adults, 20 to 83 years old, with a body mass index of less than 30. They
wanted to see whether flexibility of the trunk, as measured with the sit and
reach test, is associated with arterial stiffness. The researchers divided
the participants into three age groups:
The researchers asked participants to perform a
sit-and-reach test. The volunteers sat on the floor, back against the wall,
legs straight. They slowly reached their arms forward by bending at the
waist. Based on how far they could reach, the researchers classified the
participants as either poor- or high-flexibility.
The researchers also measured blood pressure and the
speed of a pulse of blood as it flowed through the body. They measured how
long the pulse takes to travel between the arm and the ankle and between the
neck and the leg. They also measured aortic pressure in some participants
and tested the participants for cardiorespiratory fitness, muscular strength
and endurance.
The study found that trunk flexibility was a good
predictor of artery stiffness among middle age and older participants, but
not among the younger group. In middle age and older participants, they also
found that systolic blood pressure (the peak pressure that occurs as the
heart contracts) was higher in poor-flexibility than in high-flexibility
groups.
What’s happening?
Why would the flexibility of the body be a good
indicator of arterial stiffness? In the study, the authors speculate on why
this would be. One possibility is that there is a cause and effect: the
stretching exercises that provide flexibility to the body may also slow the
age-related stiffening of the arteries. The study found that arterial
stiffness among middle age and older people was associated with trunk
flexibility but was independent of muscle strength and cardiorespiratory
fitness (as measured by performance on an exercycle). In addition, they
cited another recent study that found that middle age and older adults who
began a regular stretch exercise program significantly improved the
flexibility of their carotids, a major artery found in the neck.
“Together with our results, these findings suggest a
possibility that improving flexibility induced by the stretching exercise
may be capable of modifying age-related arterial stiffening in middle-aged
and older adults,” Dr. Yamamoto said. “We believe that flexibility exercise,
such as stretching, yoga and Pilates, should be integrated as a new
recommendation into the known cardiovascular benefits of regular exercise.”
However, there are other possibilities as to why bodily
flexibility should be an indicator of arterial stiffness. One possibility is
that it is related to the higher blood pressure that was seen in the poor
flexibility group. Another possibility is that the amount of collagen and
elastin, which makes the muscles flexible, also makes the arteries flexible.
Further research is needed to understand whether there is a cause-effect
relationship between flexibility and arterial stiffness, they said.
Editor’s Notes: To arrange an interview with
Dr.Yamamoto, please contact Donna Krupa
(301) 634-7253 or at
commoff@the-aps.org.
To read the full study click
here.
Funding: Ministry of Education, Culture, Sports,
Science and Technology (Japan) and Ministry of Health, Labor and Welfare
(Japan).
Physiology is the study of how molecules,
cells, tissues and organs function to create health or disease. The American
Physiological Society (APS) has been an integral part of this scientific
discovery process since it was established in 1887.
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