Natural history of exertional rhabdomyolysis: a population-based analysis.

Exertional rhabdomyolysis is a potentially catastrophic syndrome with an incidence and rate of recurrence that are unknown. In this study patients with rhabdomyolysis were identified retrospectively from the Wilford Hall Medical Center records. A population-based analysis was performed on exertional rhabdomyolysis patients enrolled in basic military training. A retrospective cohort was analyzed for rate and risks of recurrence. Of 177 rhabdomyolysis patients, 63 were exertional in mechanism. The rate of renal failure was lower in exertional rhabdomyolysis patients (odds ratio 0.45, 95% confidence interval 0.22-0.95, P = 0.04). There were 44 cases of exertional rhabdomyolysis from a population of 198,399 total military trainees over the study period, or 22.2 cases per 100,000 per year. A cohort of 22 exertional rhabdomyolysis patients was followed for a mean of 31.2 months, with only 1 recurrence (recurrence risk of 0.08% per person per year). Exertional rhabdomyolysis is associated with lower rates of complications than other causes of rhabdomyolysis. Among young, physically active patients, the incidence of exertional rhabdomyolysis is low, as is the risk of recurrence.