Study Of Black Soldiers Finds Sickle Cell Trait Not Linked To Early Death
New research challenges the long-held belief that people with sickle cell trait, who are born with only a single copy of the sickle cell gene variant, are at risk of premature death.
People with the sickle cell gene variant do not have sickle cell disease, a blood disorder that shortens life span and causes sudden episodes of severe pain. People with the disease carry two copies of the gene, one from each parent.
In the first-of-its-kind study, researchers followed nearly 48,000 black American soldiers on active duty in the U.S. Army over a four-year period. All had undergone tests for the genetic trait.
“What we can say with confidence is that there’s no evidence that it increases mortality in this Army population, and that’s incredibly reassuring,” said study co-author Lianne Kurina. She’s an associate professor of medicine at Stanford University School of Medicine in Palo Alto, Calif.
Previous studies have linked sickle cell trait to sharply higher risks of sudden death among black military recruits and black football players on National Collegiate Athletic Association (NCAA) Division 1 teams. These studies traced some of the deaths to heat stroke, heat stress and “exertional rhabdomyolysis” — muscle deterioration due to extreme physical exertion.
The notion that sickle cell trait increases death risk has led to mandatory screening by some organizations, including the U.S. Air Force, U.S. Navy and the NCAA, the study authors noted.
The American Society of Hematology continues to believe that there’s a lack of data to support the presumption that mandatory screening will save lives, according to Dr. Alexis Thompson, the society’s vice president.
“These findings suggest that sickle cell trait alone does not increase an individual’s risk of sudden death,” said Thompson, a pediatric hematologist at Ann & Robert H. Lurie Children’s Hospital of Chicago.
Experts say the Army’s use of “universal precautions” — which require active duty soldiers to drink plenty of fluids, build up to strenuous exercise and rest when it’s hot — made a difference.