The long-held belief that people with sickle-cell trait are at increased risk of early death has been challenged by a new study. But a new study could challenge the notion on the basis of detailed followup of almost 48,000 black American soldiers on active duty in the US Army.

Study researchers have followed the soldiers, who have undergone tests for the genetic trait, for over a four-year period. The research paper published in the New England Journal of Medicine had access to medical and administrative data of all the active duty soldiers in the US.

The researchers did not find any major difference in death risk. One of the important factors being noticed by the study researchers was black soldiers with sickle cell trait were 54% more likely than the ones without the condition to suffer exertional rhabdomyolysis.

A person having sickle cell trait is the one being born with just a single copy of the sickle cell gene variant. These people do not have sickle cell disease, a blood disorder that shortens life span and leads to sudden, but severe incidents of pain.

Owing to the notion that sickle cell trait increases death risk, many organizations have made it compulsory to get its screening done. But as per the American Society of Hematology, there is dearth of data to support the mandatory screening.

“These findings suggest that sickle cell trait alone does not increase an individual's risk of sudden death”, affirmed the researchers.

Dr. Rakhi Naik from Johns Hopkins University in Baltimore was of the view that the study findings show that there is a need to come up with formal protocols for ‘universal precautions’, which includes active duty soldiers to have plenty of fluids, carry out strenuous exercise and rest when it is quite hot outside.

According to a report in IB Times by Seerat Chabba, "A new study carried out by a team of Stanford scientists showed that carrying a single copy of the sickle cell gene variant may not increase a person’s risk of premature death. Shortening of the life span is a result of the blood disorder but people with the disease carry two copies of the gene — one from each parent."

However, the study found that carriers of the sickle cell trait were more likely to develop exertional rhabdomyolysis, a condition where skeletal muscle tissue breaks down, usually due to strenuous exercise. Other factors like gender, age and lifestyle also affected the exertional rhabdomyolysis cases. While women had a significantly lower rate, soldiers over the age of 36 saw a 57 percent heightened risk. The risk was significantly higher in soldiers who were obese or smoked.

A report published in the Washington Post said, "Sickle cell disease occurs in 1 out of every 365 black people born in America, according to the Centers for Disease Control and Prevention. They carry two copies of a gene for sickle cell disease. Those who carry only one copy of the gene are said to have sickle cell trait. About 1 in 13 black Americans have sickle cell trait. An earlier study found that sickle cell trait may lead to an increased risk of sudden death, but the new study comes to a different conclusion."

Stanford researchers reviewed the health records of 47,944 black soldiers with known sickle cell trait status who served between 2011 and 2014. The records were from the Stanford Military Data Repository data set, a digital archive of health encounters at military and civilian medical institutions. The records also include basic health information and certified records of physical performance and mortality of all active duty U.S. Army soldiers.

"Health experts have long thought that individuals who are born with sickle cell gene variants are at increased risk for premature death regardless if a person carries only a single copy of the gene variant. Findings of a new study, however, challenges this notion as researchers found that those who were born with sickle cell trait do not have increased mortality risk," according to a news report published by Tech Times.

Although the 54 percent difference may sound a lot, it is far less than the 300 percent increase associated with use of ordinary prescription drugs. The heightened risk linked to sickle cell trait is, in fact, just about the same as that incurred by smoking, increasing age and obesity. "Sickle cell trait was not associated with a higher risk of death than absence of the trait, but it was associated with a significantly higher risk of exertional rhabdomyolysis."



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