Purpose: Obesity has been shown in a single-center study to be a risk factor for rhabdomyolysis. More recently, sickle cell trait, known to be more prevalent in blacks, has been shown to be a risk factor for rhabdomyolysis. We hypothesized that in trauma patients, black race and a higher body mass index (BMI) are associated with risk for rhabdomyolysis and acute kidney injury (AKI). Materials and Methods: The National Trauma Data Bank (NTDB) was queried (2013-2015) to identify patients age ≥18 years and grouped by BMI: normal (18.5-24.99 kg/m2), underweight (16.5-18.49 kg/m2), overweight (25-29.99 kg/m2), obese (30-34.99 kg/m2), severely obese (35-39.99 kg/m2), and morbidly obese (≥40 kg/m2). A multivariable logistic regression model was used to assess whether a higher BMI or black race was associated with rhabdomyolysis or AKI. Results: After adjusting for covariates, severe obesity (odds ratio (OR) = 1.42, confidence interval (CI) = 1.01-1.99, p < .001), morbid obesity (OR = 1.46, CI = 1.04-2.06, p < .001), and black race (OR = 1.52, CI = 1.24-1.88, p < .001) were associated with higher risk for rhabdomyolysis. Patients that were overweight (OR = 1.17, CI = 1.11-1.24, p < .001), obese (OR = 1.32, CI = 1.24-1.41, p < .001), severely obese (OR = 1.72, CI = 1.59-1.86, p < .001), morbidly obese (OR = 1.77, CI = 1.64-1.92, p < .001), or black (OR = 1.31, CI = 1.24-1.38, p < .001) were associated with higher risk for AKI. Conclusions: Black race was associated with an increased risk of rhabdomyolysis as well as AKI in trauma. BMI ≥25 kg/m2 was associated with increased risk for AKI with the morbidly obese having the highest risk. BMI ≥35 kg/m2 was found to be associated with increased risk of rhabdomyolysis. Future studies should investigate the role for routine screening of these high-risk populations and other potential associated factors such as adherence to weight-based fluid resuscitation.
Keywords: acute kidney injury; black; obesity; rhabdomyolysis; trauma.