aranyWalking is beneficial for lots of reasons, and one of its key benefits is its role in protecting our hearts. Zoltan Arany, MD, PhD, a scientist in Beth Israel Deaconess Medical Center's Cardiovascular Institute, investigates the biological mechanisms of cardiac health and heart disease.

His laboratory recently published a study in the medical journal Proceedings of the National Academy of Sciences (PNAS) describing the importance of a gene called PGC-1alpha, which was found to play a key role in heart health. Here, Dr. Arany talks about his research — and the benefits of walking.

Your study looked at a condition called PAD. Can you explain what that is?

PAD stands for peripheral artery disease, which is a condition that develops when the arteries in the legs become clogged with plaque deposits and result in reduced blood flow to the limbs. This results in leg pain and disability. PAD affects 8 million individuals in the U.S. and is the leading cause of limb amputations.

How is PAD related to cardiac health?

PAD is a warning sign that fatty deposits in the arteries may also be reducing blood flow to a person's heart or brain, putting him or her at risk for a heart attack or stroke.

What is angiogenesis and what role does it play in this process?

Angiogenesis is the name for a biological process in which new blood vessels grow and develop. Our bodies have a terrific built-in "alarm" system that indicates when our blood circulation is impaired — when, for example, arteries are clogged with plaque. This "alarm" can trigger the angiogenic process whenever an injury or artery blockage has left normal tissue starved for blood.

What did your latest research find?

Last year, I led a research team that discovered that a gene called PGC-1alpha contributed to "turning on" the angiogenic process. We found that this gene can sense when levels of oxygen and nutrients are dangerously low, as would occur when tissue is damaged following cardiac disease or in PAD In response, PGC-1 alpha then activates the process that leads to the formation of new blood vessels.

With the current study, we wanted to find out if exercise could activate this gene. We did this by studying two groups of mice in cages equipped with electronically monitored running wheels; one group of mice had the gene, the other didn't. Follow-up tests found that the mice that were lacking the PGC-1alpha gene failed to grow new blood vessels even though they exercised. The other group of mice showed robust growth.

So, with this research we have shown that this protein can single-handedly transform muscle to be capable of greater endurance and increase the blood vessel content of that muscle. Being able to increase blood vessel density could help wound healing and even prevent amputations in millions of patients with diabetes and vascular disease of the limbs, including PAD.

What advice would you give to patients?

Exercise remains one of the most effective interventions for a number of chronic diseases, including obesity, diabetes, atherosclerosis and neurodegenerative diseases. PAD is a leading cause of morbidity and the most common cause of limb amputation in the U.S. and yet even the best medical therapy available is less effective than simply taking a daily walk. So, my advice is: Keep moving!

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.

August 2010

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