(Press-News.org) Pain will lessen over time
Results include longer distance and walking time
8.5 million people in U.S., 250 million worldwide, have PAD
CHICAGO --- No pain means no gain when it comes to reaping exercise benefits for people with peripheral artery disease (PAD), reports a new Northwestern Medicine study.
In people with peripheral artery disease, walking for exercise at an intensity that induces ischemic leg pain (caused by restricted blood flow) improves walking performance -- distance and length of time walking -- the study found. Walking at a slow pace that does not induce ischemic leg symptoms is no more effective than no exercise at all, the study showed.
This randomized trial is the first to show that a home-based walking exercise program improved walking ability in people with peripheral artery disease when exercise was conducted at a high intensity that induced ischemic leg symptoms but not when the exercise was conducted at a low intensity without ischemic leg symptoms.
"We've shown you have to walk to elicit ischemic leg pain to reap the benefits," said lead investigator Dr. Mary McDermott, professor of medicine at Northwestern University Feinberg School of Medicine. "It will lessen over time, and most people eventually will be able to walk further without discomfort."
The study was published in JAMA April 6, 2021.
McDermott's previous research suggested that pain during exercise prevented many people with PAD from walking.
While the trial did not identify the biological changes that lead to walking improvement, McDermott said prior research shows intensive exercise stimulates certain biologic pathways that promote improved mitochondrial activity, the cell's chemical energy source.
"Perhaps for people with PAD, the exercise promotes growth of new small blood vessels to their muscles," McDermott said.
About 8.5 million in the United States and about 250 million people worldwide have lower extremity peripheral artery disease (PAD). People with PAD have blockages in their arteries that slow or stop the blood flood flow to their legs. As a result, they have pain and difficulty walking even short distances. It is comparable to angina for people who have symptomatic heart disease. Few therapies exist to treat it.
The first month consisted of weekly in-person visits with the coach. These sessions helped the participants to learn the difference between walking at high versus low intensity, allowed them to learn to use the technology used to monitor their exercise intensity at home and helped them get started with their exercise activity. The program then consisted of telephone calls and remote monitoring by a coach.
The remote monitoring aspect is important, McDermott said. Although supervised exercise is covered by Medicare and other insurance companies, most people with PAD do not participate in supervised exercise because of the burden associated with traveling three times weekly to the medical center for participation.
For the study, 305 people with peripheral artery disease at four medical centers were randomized to high-intensity exercise, low-intensity exercise or a control group that got telephone calls that were not about exercise. Those randomized to an exercise intervention were asked to walk up to 50 minutes per session, five days a week. Those in high intensity were asked to walk at a pace that was fast enough to elicit ischemic leg symptoms during exercise. Those randomized to low intensity were asked to walk at a comfortable pace that did not induce ischemic leg symptoms.
Intensity was monitored remotely using an ActiGraph activity monitor that participants wore during exercise. These data were uploaded to the study website and viewed by study coaches. The six-minute walk, treadmill testing and patient-reported outcomes were measured at baseline and at 12-month follow-up.
Patients who participated in high-intensity walking exercise significantly improved the distance they could walk in six minutes compared to either the low-intensity group or the control group. The high-intensity exercise group also significantly improved the length of time they could walk on the treadmill at the end of the study, compared to each of the other two groups.
"Patients with PAD should be advised to walk for exercise at a pace that induces ischemic leg symptoms in order to get a benefit," McDermott said. "Exercise is the most effective non-invasive therapy to improve walking in people with PAD."
The next step in the research is to determine the biologic explanation for the finding that ischemia of the lower extremities appears necessary to gain benefit from walking exercise in people with PAD.
INFORMATION:
The research was funded by grant R01-HL122846 from the National Heart, Lung and Blood Institute of the National Institutes of Health.
Washington, D.C. - April 6, 2021 - A new study has demonstrated that autism spectrum disorder is related to changes in the gut microbiome. The findings are published this week in mSystems, an open-access journal of the American Society for Microbiology.
"Longitudinally, we were able to see that within an individual, changes in the microbiome were associated with changes in behavior," said principal study investigator Catherine Lozupone, PhD, a microbiologist in the Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado. "If we are going to understand the link between the gut microbiome and autism, we need more collaborative efforts across different regions and ...
Biophysicists from Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that a phenomenon known as diffusiophoresis, which can lead to a directed particle transport, can occur in biological systems.
In order to perform their biological functions, cells must ensure that their logistical schedules are implemented smoothly, such that the necessary molecular cargoes are delivered to their intended destinations on time. Most of the known transport mechanisms in cells are based on specific interactions between the cargo to be transported and the energy-consuming motor ...
The founding chair of the Biomedical Engineering Department at the University of Houston is reporting a new deep neural network architecture that provides early diagnosis of systemic sclerosis (SSc), a rare autoimmune disease marked by hardened or fibrous skin and internal organs. The proposed network, implemented using a standard laptop computer (2.5 GHz Intel Core i7), can immediately differentiate between images of healthy skin and skin with systemic sclerosis.
"Our preliminary study, intended to show the efficacy of the proposed network architecture, holds promise in the characterization of SSc," reports Metin Akay, John S. Dunn Endowed Chair Professor of biomedical engineering. ...
WASHINGTON--Raindrops on other planets and moons are close to the size of raindrops on Earth despite having different chemical compositions and falling through vastly different atmospheres, a new study finds. The results suggest raindrops falling from clouds are surprisingly similar across a wide range of planetary conditions, which could help scientists better understand the climates and precipitation cycles of other worlds, according to the researchers.
Raindrops on Earth are made of water, but other worlds in our solar system have precipitation made of more unusual stuff. On Venus, ...
As part of an international collaboration, researchers from ELTE Eötvös Loránd University developed a new animal model to study a rare genetic disease that can lead to blindness at the age of 40-50. The new model could open up new perspectives in our understanding of this metabolic disease and will also help to identify new potential drug candidates, according to the recent study published in Frontiers in Cell and Developmental Biology.
Pseudoxanthoma elasticum (PXE) is a rare genetic disease with symptoms that usually manifest in adolescence or in early adulthood. The symptoms are caused by the appearance of hydroxyapatite crystal deposits in the subcutaneous connective tissue and retina ...
The universe is expanding at an ever-increasing rate, and while no one is sure why, researchers with the Dark Energy Survey (DES) at least had a strategy for figuring it out: They would combine measurements of the distribution of matter, galaxies and galaxy clusters to better understand what's going on.
Reaching that goal turned out to be pretty tricky, but now a team led by researchers at the Department of Energy's SLAC National Accelerator Laboratory, Stanford University and the University of Arizona have come up with a solution. Their analysis, published April 6 in Physical Review ...
Nursing mothers who receive a COVID-19 vaccine may pass protective antibodies to their babies through breast milk for at least 80 days following vaccination, suggests new research from Washington University School of Medicine in St. Louis.
"Our study showed a huge boost in antibodies against the COVID-19 virus in breast milk starting two weeks after the first shot, and this response was sustained for the course of our study, which was almost three months long," said first author Jeannie Kelly, MD, assistant professor of obstetrics and gynecology. "The antibodies levels were still high at the end of our study, so the protection likely extends even longer."
Based ...
Cells from individuals with Major Depressive Disorder (MDD) were found to have higher than expected rates of methylation at specific sites on their DNA, when compared to cells from healthy individuals without MDD, according to a study by a multidisciplinary team of UC San Francisco scientists, in collaboration with others. Methylation is a process by which DNA is chemically modified at specific sites, resulting in changes in the expression of certain genes. Methylation of particular sets of genes, called "DNA methylation clocks," typically change in predictable ways as people ...
During the early phase of the pandemic, approximately 40% of the COVID-19 literature was shared as preprints - freely available manuscripts that are shared prior to peer-review. In a new study publishing in the open access journal PLOS Biology, researchers led by Dr Jonathon Coates (Queen Mary University of London), Dr Nicholas Fraser (Leibniz Information Centre for Economics, Germany) and Dr Liam Brierley (University of Liverpool) explore the crucial role of preprint servers in hosting COVID-19 related science and how these preprints have been used to disseminate knowledge of COVID-19, leading to cultural shifts in journalistic and policy practices.
There has been a rapid and incredible scientific response to the COVID-19 pandemic, with research ...
Innovation and advances in technology have facilitated agricultural activity in recent years, as traditional irrigation techniques have been supplanted by pressure-basedones, improving water efficiency but increasing energy dependence. This drives up the Agriculture sector's energy costs, some of the highest in the European Union.
With the aim of increasing the energy efficiency of irrigation, researchers at the Hydraulics and Irrigation Group with the María de Maeztu Unit of Excellence,at the Department of Agronomy of the University of Cordoba (DAUCO), Juan Antonio Rodríguez Díaz and Jorge García Morillo, have field-tested a low-cost technology that takes advantage of the excess pressure on the grid to generate energy. This ...
