High Blood Pressure Drug Helps Senior Citizens Grow
Muscles Like 30-Year-Olds
We were able to make our 70-year-olds look like
30-year-olds, at least in terms of muscle growth
Aug. 20, 2010 Senior citizens lose muscle mass
due to age-related changes in the thin blood vessels that supply muscles
with the amino acids they need for growth. Researchers have now found a way
to use widely available blood pressure drugs to fight this muscle loss
associated with aging.
"When a young person eats food, insulin secretion
causes the blood vessels in the muscle to dilate, so a lot of blood goes
into the muscle and a lot of amino acids are available to build muscle
proteins," said Professor Elena Volpi, University of Texas Medical
Branch at Galveston, senior author of a paper in the online version of
the journal of Diabetes.
Post-meal blood vessel expansion occurs in young,
not old; Muscles of young people look 50 years older by making muscle
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telomeres in aging, cancer and maybe immortality; seniors with short
telomeres most likely to die see below story - Dec. 1, 2009
"Older people's blood vessels have far less
response to insulin, but we found that if you give them a drug that
causes them to dilate, you can increase the nutritive flow to the
muscles and completely restore normal growth."
(See link to earlier story on this research in top story in sidebar on
left.)
Drugs that cause blood vessels to widen, called
vasodilators, are commonly used to control high blood pressure and
prevent angina. The UTMB study used sodium nitroprusside, a drug used in
hospitals and administered intravenously.
Hydralazine belongs to the general class of
medicines called antihypertensives. It is used to treat high
blood pressure (hypertension).
Hydralazine works by relaxing blood vessels and
increasing the supply of blood and oxygen to the heart while
reducing its workload.
Hydralazine is available only with your doctor's
prescription.
FDA Warnings
● Do not use these drugs if you are also taking
bisulfates.
● Women who are pregnant or nursing should talk to their
doctor before they start using these drugs.
● People who have diabetes, heart disease, or uremia (build up
of waste in your blood) should talk to their doctor about the
risks of using any of these drugs.
● People taking diuretics (water pills), insulin, phenytoin,
corticosteroids, estrogen, warfarin, or progesterone should talk
to their doctor about the risks of using any of these drugs.
Common Side Effects
● Headache
● Upset stomach
● Dizziness
● Growth in body hair
Warning Signs
Call your doctor if you have any of these
signs:
● Fever
● Fast heartbeat
● Fainting
● Chest pain
● Problems breathing
● Sudden weight gain
For more information about the risks and side
effects for each drug, check
Drugs@FDA.
The researchers enrolled 12 healthy older
volunteers for the study, and separated them randomly into two
six-person groups.
Working in UTMB's Clinical Research Center, the
investigators performed the delicate task of inserting catheters into
the arteries and veins for feeding and draining the subjects' leg
muscles. They then used the arterial catheter to infuse the muscles with
insulin at levels similar to those generated by a meal.
One group of volunteers was given the vasodilator
drug, while the other received a placebo.
Blood sample and muscle biopsy analysis produced
estimates of muscle protein synthesis and breakdown. The results were
impressive: virtually normal muscle growth in the older subjects given
the vasodilator with insulin.
"By giving them this vasodilator, we were able to
make our 70-year-olds look like 30-year-olds, at least in terms of
muscle growth," said postdoctoral fellow Kyle Timmerman, a lead author
of the paper. The study was co-led by medical student and graduate
research fellow Jessica Lee.
While the researchers cautioned that larger studies
would be needed to confirm their findings, they expressed optimism about
vasodilator drugs' potential as tools for keeping older people from
falling into frailty, and living happier, healthier and more independent
lives.
"If by improving blood flow during and immediately
after eating we can improve muscle growth in response to meals in older
people, then we're going to have a major new tool to reduce muscle loss
with aging," Volpi said. "By itself, that could mean a substantially
decreased risk of physical dysfunction and disability."
This report, "Pharmacological vasodilation improves
insulin-stimulated muscle protein anabolism but not glucose utilization
in older adults," is available in the "Online Ahead of Print" section of
the journal of the American Diabetes Associaton, Diabetes.
Click here to abstract.
Other authors of the paper include assistant
professor Satoshi Fujita, senior study coordinator Shaheen Dhanani,
assistant professor Hans Dreyer, graduate student Christopher Fry,
assistant professor Micah Drummond, professor Melinda Sheffield-Moore
and professor Blake Rasmussen.
The National Institute on Aging, the UTMB Claude D.
Pepper Older Americans Independence Center and the UTMB Clinical and
Translational Science Award supported this research.
To learn more about volunteer opportunities for
Pepper Center studies call 800-298-7015 .
Source:
University of Texas Medical Branch at Galveston -
www.utmb.edu
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