Creatine Kinase Elevations and Risk of Renal Failure and Dialysis in Patients With Rhabdomyolysis

Background Rhabdomyolysis is characterized by muscle necrosis, which releases creatine kinase (CK) into the circulation. Acute kidney injury (AKI) is a common complication resulting from renal ischemia, tubular obstruction, and tubular injury due to heme pigments. While a correlation between AKI and CK levels has been reported previously, the precise relationship is unclear. This study examines the relationship between CK levels and outcomes of renal failure and dialysis within seven days of rhabdomyolysis diagnosis. Method This retrospective study utilized the TriNetX database to evaluate 93,479,176 patients from 56 healthcare organizations in the United States from 2003 to 2023. A total of 73,036 adults ≥18 years old were identified with a CK value ≥ 1,000 U/L within three days after a rhabdomyolysis diagnosis. Patients were further stratified based on CK values (1K-5K, 5K-10K, 10K-50K, 50K-100K, and >100K). Exclusion criteria included a rhabdomyolysis diagnosis more than 20 years prior, history of dialysis, and renal failure (Cr ≥4). Descriptive statistics and relative risks of dialysis and renal failure were calculated for each subgroup compared to those with CKs between 1K and 5K (control). Results There was a statistically significant increase in risk of dialysis and renal failure (Cr ≥4) for each progressive cohort compared to the control group, with CK 1K-5K (Dialysis 1.84%, Cr ≥4 6.38%), 5K-10K (2.88%, 7.99%), 10K-50K (5.02%, 13.73%), 50K-100K (8.79%, 21.01%), and >100K (8.81%, 24.97%), respectively. Conclusions This is the largest study to date evaluating the association between CK levels and rhabdomyolysis severity. With each progressive increase in CK, the risk of renal failure (CR ≥4) and the need for dialysis also increased.