Researchers: Repeated contractions increase vessel elasticity
Similar to the mechanism by which exercise helps muscles endure greater stress, short, repeated pressure cuff tightening can help strengthen blood vessels and prevent fatal heart attacks and strokes.
These are surprising conclusions from various studies, summarized by a team led by kinesiologist Dr. James Lang from Iowa State University, USA.
Researchers believe that the simple, non-invasive procedure can improve vascular and heart function, slightly lower blood pressure and reduce the workload on the heart. Findings from nearly 100 studies are published in a review in the Journal of Physiology. A kind of training is called remote ischemic preconditioning. They usually involve five minutes of increased pressure on the arm, followed by five minutes of rest, repeated three to four times.
Most studies show that one such session creates a protective window that peaks 48 hours later.
Experiments from Lang’s lab and replicated by other teams suggest that repeated sessions over several days may enhance protection and provide other health benefits.
Such an approach of training blood vessels to adapt safely to changes could have many applications, the researchers point out. According to them, it will be useful for people who are about to have an operation; for those who have already had a heart attack or stroke, which puts them at a higher risk of a repeat accident; for patients who cannot exercise, are at risk of hypertension or have sleep apnea.
Exercise increases the extent to which arteries can constrict or dilate.
Although the likelihood of side effects is low, Lang cautions against getting too carried away. Anyone interested in trying it on their own, outside of a research study, should definitely discuss it with their doctor.
Loss of elasticity of blood vessels increases the risk of high blood pressure, heart attacks and strokes, dementia.
Even astronauts can benefit from the method of increasing elasticity. They exercise up to 2 hours a day to prevent heart and muscle atrophy due to microgravity in space, the scientist explains.
According to Lang, incorporating blood pressure cuff sessions can effectively supplement astronaut training.
In one study by the team, researchers found that training for 7 days increased participants’ microcirculation by up to 50 percent. In another experiment, they measured a modest drop in blood pressure. Taken together, this improves blood vessel function and potentially reduces the workload on the heart.
One way Lang tested the method’s effect was by measuring how well a study participant’s blood vessels dilated when their skin was warm. Before and after the sessions, the researcher attached a small device to the participant’s arm. A small heater heats the skin, causing the blood vessels to dilate, and a doppler reflects light into the small vessels below. Like a weather radar that picks up changes in the atmosphere, the Doppler that Lang uses measures changes in the flow of red blood cells in the vessels.
Lang’s team set themselves a new challenge – whether they could help people with diabetes who struggle with hard-to-heal wounds. High blood sugar levels damage small vessels and nerves and facilitate the formation of plaque in the arteries. This makes it difficult for white blood cells and nutrients to reach the injured tissue. Overcoming such a problem will save many diabetics from infections and necrosis.