Sickle-cell trait as a risk factor for sudden death in physical training

Area of Science:

• Exercise Physiology
• Hematology
• Public Health

Background:

• Sudden death during exertion has been a concern, but its association with sickle-cell trait (hemoglobin AS) remained unclear.
• Previous case reports did not establish a definitive link between hemoglobin AS and exercise-related fatalities.

Purpose of the Study:

• To investigate the association between sickle-cell trait and sudden death during strenuous exercise in a large cohort.
• To quantify the risk of exercise-related sudden death in individuals with hemoglobin AS compared to those without.

Main Methods:

• Analysis of death records from 2 million U.S. Armed Forces recruits during basic training (1977-1981).
• Classification of deaths as non-sudden, sudden explained, or sudden unexplained based on autopsy and clinical data.
• Calculation of death rates and relative risks, accounting for race, age, sex, and prevalence of hemoglobin AS.

Main Results:

• Black recruits with sickle-cell trait had significantly higher rates of sudden unexplained death compared to those without hemoglobin S (32.2 vs. 1.2 per 100,000).
• The relative risk of sudden unexplained death for individuals with sickle-cell trait was 27.6 among black recruits and 39.8 among all recruits.
• This risk demonstrated a significant age-dependent increase, with the highest risk observed in older recruits (ages 26-30).

Conclusions:

• Recruits in basic training with sickle-cell trait exhibit a substantially increased risk of exercise-related sudden death.
• The risk of sudden unexplained death associated with sickle-cell trait is age-dependent.
• These findings highlight the importance of considering sickle-cell trait status in exercise-related risk assessments, especially in young adults undergoing intense physical training.