Link Between Blood Pressure and Outside Temperature
for Seniors May Tie to Vitamin D
Researchers also urging close monitoring of elderly
with hypertension during weather extremes; second study says thinking
ability varies with blood pressure
Jan. 16, 2009 The recent discovery that the blood
pressure readings for senior citizens vary in reverse to the outside
temperature colder temperature equals higher blood pressure reading
may have something to do with the link between vitamin D and
hypertension, according to a spokesman for European cardiologists. The
French researchers also urge careful monitoring during extreme
temperatures.
The French study reported in the January 12 issue
of Archives of Internal Medicine (see sidebar link to story) has
found a strong correlation between blood pressure and outdoor
temperature in a large sample of the elderly.
Senior Citizens Ability to Think
Clearly Goes Down When Blood Pressure Goes Up
May Indicate mental
stress for elderly is partially responsible for the increase in
blood pressure
Jan. 16, 2009 - Adding
another reason for people to watch their blood pressure, a new
study from North Carolina State University shows that increased
blood pressure in older adults is directly related to decreased
cognitive functioning, particularly among seniors with already
high blood pressure. This means that stressful situations may
make it more difficult for some seniors to think clearly.
Dr. Jason Allaire, an
assistant professor of psychology at NC State who co-authored
the study, explains that study subjects whose average systolic
blood pressure was 130 or higher saw a significant decrease in
cognitive function when their blood pressure spiked.
However, Allaire notes,
study subjects whose average blood pressure was low or normal
saw no change in their cognitive functioning even when their
blood pressure shot up.
Specifically, Allaire says,
the study shows a link between blood pressure spikes in seniors
with high blood pressure and a decrease in their inductive
reasoning. "Inductive reasoning is important," Allaire says,
"because it is essentially the ability to work flexibly with
unfamiliar information and find solutions."
Allaire says the findings
may indicate that mental stress is partially responsible for the
increase in blood pressure and the corresponding breakdown in
cognitive functioning. However, Allaire notes that normal
fluctuations in blood pressure likely play a role as well.
The study, which is
published in the current issue of Journal of Gerontology:
Psychological Sciences, examined blood pressure and
cognitive functioning test data collected from a cohort of
adults aged 60-87 twice daily for 60 days.
The lead author is Alyssa A.
Gamaldo, a Ph.D. candidate in psychology at NC State. A second
co-author is Sarah R. Weatherbee, who is also a Ph.D. candidate
in psychology at NC State.
As a result, the investigators advise that, during
periods of extreme temperatures, careful monitoring of blood pressure
and antihypertensive treatment "could contribute to reducing the
consequences of blood pressure variations in the elderly".
Vitamin D Connection
Speaking on behalf of the European Society of
Cardiology (ESC), Professor Frank Ruschitzka from the University
Hospital, Zurich, says that the study reaffirms the place of the elderly
as a target group for blood pressure monitoring.
"The elderly, especially the increasing number of
octogenarians, should not be neglected. They need extra care, and will
benefit from monitoring and appropriate treatment. This study emphasizes
the need for year-round vigilance," Ruschitzka said.
One possible explanation for the study findings,
adds Professor Ruschitzka, lies in the emerging link between vitamin D
and blood pressure.
The elderly, especially those in care homes, are
subject to vitamin D deficiency, largely as a result of their limited
exposure to sunlight, and vitamin D deficiency can predispose to
hypertension via activation of the renin-angiotensin-aldosterone system.
"The benefit of sunlight on vitamin D levels in the
elderly is under appreciated," says Professor Ruschitzka. "Fifteen
minutes exposure to sunlight can produce the equivalent of 2000
international units vitamin D."
A report from the Framingham Heart Study published
in 2008 found that moderate vitamin D deficiency nearly doubles the risk
of myocardial infarction, stroke and heart failure over a mean of 5.4
years in patients with high blood pressure.
The Nurses Health Study, also reporting in 2008,
found that lower blood levels of vitamin D are independently associated
with an increased risk of hypertension; women with the lowest levels had
a 66 percent higher incidence of hypertension than those with the
highest levels.
Jan. 16, 2009 The recent discovery that the blood
pressure readings for senior citizens vary in reverse to the outside
temperature colder temperature equals higher blood pressure reading
may have something to do with the link between vitamin D and
hypertension, according to a spokesman for European cardiologists. The
French researchers also urge careful monitoring during extreme
temperatures.