Risk Factors for Rhabdomyolysis in the U.S. Army

Abstract

The standardized mortality rate of rhabdomyolysis (RM) in Active Duty U.S. Army Soldiers is considerably higher than in the civilian population. RM occurs when large amounts of intracellular contents from damaged skeletal muscle escape into circulation, leading to serious sequelae (e.g., acute renal failure, hyperkalemia, compartment syndrome). Extended physical exertion, especially in hot environments, and trauma can precipitate RM. The aim of this study was to identify RM risk factors among U.S. Active Duty Army (ADA) Soldiers. Methods: This nested case-control study used data from the Total Army Injury and Health Outcomes Database (years 2004Database (years -2006 to examine RM among ADA male Soldiers. Demographic and occupational variables were identified as potential risk factors. Each RM case was age and date-matched to 4 controls. Adjusted odds ratios (OR) were computed using conditional logistic regression analyses. (2) self-reported Black race, OR 2.56 (95% CI 2.2-3.0); and (3) length of service (0-90 days), OR 2.05 (95% CI 1.6-2.7). Conclusion: There is a substantially greater likelihood for male U.S. Army Soldiers to develop RM who: (1) have had a prior heat injury, (2) self-report in the Black racial category, and (3) who are within the initial 90 days of service. Greater awareness of the risk factors associated with RM may improve force health protection and readiness through targeted mitigation strategies.

Body Building and Aminotransferase Elevations: A Review

“…Hill et al 40 found that the strongest risk factors for rhabdomyolysis in army soldiers were prior heat stroke, black race and length of stay of less than 90 days. Although confounding factors such as hydration, temperature and humidity (which are known to increase risk for rhabdomyolysis) 7,40 were not considered, it seemed new recruits had double the likelihood compared to soldiers who were there for more than 90 days. 40 Those with length of stay greater than 1 year had an odds ratio of developing rhabdomyolysis below 1.00.…”

“…Although confounding factors such as hydration, temperature and humidity (which are known to increase risk for rhabdomyolysis) 7,40 were not considered, it seemed new recruits had double the likelihood compared to soldiers who were there for more than 90 days. 40 Those with length of stay greater than 1 year had an odds ratio of developing rhabdomyolysis below 1.00. 40 This suggests that subjects who are unaccustomed to exercise have higher risk of muscle damage.…”

Retrospective analysis of 116 cases of exertional rhabdomyolysis in newly enrolled cadets of a military academy in Beijing

“…Length of service is one of the factors that are highly correlated with age. Recruits were more than twice as likely to develop ER compared to those who had served more than 90 days [1] . There were mainly two hypothetical reasons to explain this difference, one was that new recruits often lacked exercise before enlistment, while the other potential objective reason was that the period immediately after enlistment was tight with a vigorous training schedule, and usually in the summer (August-September).…”

“…Intrinsic factors include younger age, shorter length of military service (recruit), poor physical tness, prior history of heat stroke, etc. [1,2] ; extrinsic factors include hot environments, unaccustomed strenuous training and so on [3] . In this study, the above risk factors were veri ed, and more potential risk factors or protective factors were systematically screened regarding demographics, medical history, exercise-related factors, and other health-related information, and the signi cance of association with ER was assessed.…”

“…Prolonged and unaccustomed intense physical activity, especially exercise that involves eccentric contractions of muscles in hot environments, would put trainees at risk of skeletal muscle injury, also known as exertional rhabdomyolysis (ER) or exercise-induced rhabdomyolysis. The severity of the disease ranges from self-limited mild conditions, such as asymptomatic elevated levels of serum muscle enzymes, to potentially life-threatening complications including extreme enzyme elevations, electrolyte imbalances, metabolic acidosis, and renal failure [1] .…”