Rhabdomyolysis and Acute Kidney Injury after the New York City Marathon

The 2022 NYC Marathon was the hottest on record. At several hospitals near the race's finish, a larger volume of heat stress-related kidney injury was observed. We sought to examine the incidence of post-marathon rhabdomyolysis observed with respect to race day temperature and humidity.

All charts of patients who had a creatine phosphokinase (CPK) level >5,000 U/L on the date of the marathon and subsequent 4 days for the years 2017-2023 at four NYC hospitals were reviewed. Patients were included for analysis if marathon participation was indicated in the chart and no other causes of rhabdomyolysis were evident. Race day heat was measured as heat index to capture the effects of both temperature and humidity.

In 2022, there were 24 runners with post-marathon rhabdomyolysis, compared to 15 total patients for the other 5 marathons combined. Cases of post-marathon rhabdomyolysis strongly correlated to race day heat index. In addition to record heat, the 2022 NYC Marathon had the largest change in heat as compared to the previous 14-day average. The 2022 cohort skewed male (20 male: 4 female), was on average 32.2 years of age, and presented within 2 days of the marathon. The average peak CPK was 21,426 IU/L (range 5,177 to 88,430 IU/L). All patients received intravenous fluids. Only 1 patient had a further rise in creatinine, reaching a peak of 8.69 mg/dL (from 5.81 on arrival) before starting hemodialysis.

The 2022 NYC Marathon was the hottest on record, and was found to have the highest incidence of post-marathon rhabdomyolysis. Cases of rhabdomyolysis correlated with the race day heat index. Additionally, 2022 had the largest change in race day temperature, which may present an additional risk.