Regular exercise could reduce complications of sickle cell traitApril 26, 2012
Reducing oxidative stress through exercise may eventually be used to treat sickle cell disease
SAN DIEGO-Sickle cell disease (SCD), an inherited condition that causes red blood cells to sometimes deform into a crescent shape, affects an estimated 100,000 Americans, typically those of African descent. However, far more have sickle cell trait (SCT), caused when individuals carry just a single copy of the disease-causing mutation in their genes. Rather than all their red blood cells being affected, those with SCT carry a mix of affected red blood cells and normal ones. Previously, researchers and physicians had assumed that those with SCT were immune from the increased burden of sickness and death that those with SCD carry. However, recent research suggests that the same morbidity and mortality that follow SCD patients at an increased rate also affect those with SCT to a lesser extent.
Nearly all these adverse effects are consequences of oxidative stress, a condition in which free radicals overwhelm the body's natural antioxidants. In healthy individuals, oxidative stress has been linked with conditions including cancer, heart disease, and simply aging; in sickle cell disease patients, oxidative stress is thought to play a role in causing the inflammation, problem with the linings of blood vessels, and blood cell blockages that cause complications from this disease.
However, scientists have long known that exercise increases the level of antioxidants present in the body, defending against oxidative stress. In a new study, researchers compare the effects of exhaustive exercise on people with SCT who exercise regularly with those who don't. They found that training regularly seems to offset the burden of exhaustive exercise by lowering the levels of molecules associated with oxidative stress, increasing antioxidant molecules, and increasing nitric oxide, a molecule important for opening blood vessels which could play a role in preventing the blood vessel occlusion that sometimes occurs in SCD and SCT.
The study is the result of efforts undertaken by Vincent Pialoux, Erica N. Chirico, Camille Faes, Emeline Aufradet, and Cyril Martin of the University Lyon I, Leonard Feasson of the University of Saint-Etienne, and Laurent Messonnier of the University of Savoie. An abstract of their study entitled, "Physical Activity Blunts Oxidative Stress Reponse to Exercise in Sickle Cell Trait Carriers," will be discussed at the meeting Experimental Biology 2012, being held April 21-25 at the San Diego Convention Center. The abstract is sponsored by the American Physiological Society (APS), one of six scientific societies sponsoring the conference which last year attracted some 14,000 attendees.
Training Reduces Oxidative Stress
Dr. Pialoux, who led the study, and his French colleagues collaborated with colleagues at the University of Yaounde I in Yaounde, Cameroon, where the rate of SCD and SCT is significantly higher than in France. The researchers recruited 18 volunteers with SCT and 22 others without this trait. Each group was further subdivided into those who had exercised consistently for several years by playing soccer for at least eight hours per week and those who considered themselves sedentary for at least the last two years.
Each volunteer's blood was tested for the presence of molecules that signal oxidative stress, others that act as antioxidants, and nitric oxide metabolites. These volunteers then pedaled on a stationary bicycle, with the researchers ratcheting up the workout's intensity every few minutes until the volunteers bowed out from exhaustion. After the workout, the researchers tested the volunteers' blood again at regular intervals to assess the same molecules.
Results showed that well-trained volunteers with SCT had significantly lower levels of molecules associated with oxidative stress, higher levels of antioxidant molecules, and higher levels of nitric oxide metabolites than untrained volunteers with SCT.
Results Could Apply to SCD
These results suggest that regular exercise might help combat the problems likely caused by oxidative stress that increase morbidity and mortality in people with SCT, Pialoux says. "In this population, regular physical activity might be seen as a treatment," he adds.
The findings could hold promise for patients with SCD as well, he says. Since exercise is known to trigger the painful and damaging episodes known as sickle cell crisis, in which large red blood cells become sickled and block blood vessels, doctors often advise SCD patients to avoid exercise. However, if these patients exercise regularly and become trained over time, the associated reduction in oxidative stress might improve their condition, Pialoux explains.
"We think that regular physical exercise that's controlled by a physician and performed at low intensity could be a strategy to limit the disease burden in SCD patients," he says. He and his colleagues are currently testing this strategy in animal models of the disease, with plans to eventually test human subjects.
Federation of American Societies for Experimental Biology
Related Oxidative Stress Current Events and Oxidative Stress News Articles
Research finds cranberries are an effective approach to help reduce antibiotic use
An international team of scientists presented new evidence showing how cranberries are poised to be a compelling tool to help reduce antibiotic resistance and oxidative stress.
Gut microbiota regulates antioxidant metabolism
A recently published study shows that gut microbiota regulates the glutathione and amino acid metabolism of the host.
Obese people need more vitamin E, but actually get less
A recent study suggests that obese people with metabolic syndrome face an unexpected quandary when it comes to vitamin E - they need more than normal levels of the vitamin because their weight and other problems are causing increased oxidative stress, but those same problems actually cause their effective use of vitamin E to be reduced.
UCI study finds jet lag-like sleep disruptions spur Alzheimer's memory, learning loss
Chemical changes in brain cells caused by disturbances in the body's day-night cycle may be a key underlying cause of the learning and memory loss associated with Alzheimer's disease, according to a University of California, Irvine study.
Scientists uncover signal for when a pregnant woman is about to go into labor
During the last few weeks of a woman's pregnancy, many keep an overnight bag ready to go at a moment's notice in case they begin to go into labor.
Exotic berry skin and pulp found to have high antioxidants levels
The exotic Ceylon gooseberry fruit is an attractive purple berry that is produced in the southwest tropics of Brazil and is often used in jams and drinks and also sold as a fresh fruit.
Study shows antioxidant use may promote spread of cancer
A team of scientists at the Children's Research Institute at UT Southwestern (CRI) has made a discovery that suggests cancer cells benefit more from antioxidants than normal cells, raising concerns about the use of dietary antioxidants by patients with cancer.
Protecting newborn brains using hypothermia
A unique study at Children's Hospital Los Angeles of newborns treated with hypothermia for hypoxic-ischemic encephalopathy (HIE) - a condition that occurs when the brain is deprived of an adequate oxygen supply - confirms its neuroprotective effects on the brain.
Endoplasmic reticulum stress plays significant role in type 2 diabetes
A new research report published in the October 2015 issue of the Journal of Leukocyte Biology, suggests that the endoplasmic reticulum plays a more important role in type 2 diabetes and its complications than previously believed.
Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders
First-trimester ultrasound scanning to pinpoint placental vascular disorders may be used to identify women at risk of developing serious obstetric complications. A new study in The American Journal of Pathology finds that patients with the highest degree of uterine artery blood flow resistance have an almost five-fold increased chance of developing preeclampsia, fetal growth restriction, or stillbirth than other pregnant women.
More Oxidative Stress Current Events and Oxidative Stress News Articles