Being overweight or obese as a risk factor for acute liver injury secondary to acute acetaminophen overdose

Purpose: Increased incidences of hepatotoxicity have been observed in obese patients with acute acetaminophen overdose. We evaluate whether the status of being overweight or obese is associated with increase in the development of hepatotoxicity and acute liver injury (ALI) in patients with acute acetaminophen overdose. Methods: This was a retrospective cohort study comparing the risk of hepatotoxicity and ALI between overweight or obese patients (body mass index [BMI] ≥ 25) and normal BMI patients (BMI ≤ 24.9) presenting with acute acetaminophen overdose at Siriraj Hospital during January 2004 to June 2012. All patients were treated with intravenous N-acetylcysteine. Psi parameters were calculated. High psi was defined as psi of ≥5.0 mM-hour. Data were analyzed using multinomial logistic regressions, odds ratio (OR), stratified OR, and 95% confidence interval (CI). Results: There were 197 patients who fulfilled the criteria for analysis, 35 (17.8%) were obese, 24 (12.2%) were overweight, and 138 (70%) were normal BMI cases. Hepatotoxicity and ALI developed in 25 (12.7%) and 40 (20.3%) cases, respectively. Multinomial logistic regression revealed that the overweight-obesity status and log₁₀(psi value) were significant risk factors of ALI, with OR (95% CI) of 2.68 (1.21-5.95) and 1.74 (1.27-2.38), respectively, while only log₁₀(psi) was a significant risk factor of hepatotoxicity with OR (95% CI) 378.51 (39.49-3627.99). From stratification, overweight-obesity had significant odds ratios for ALI in strata with low acetaminophen concentration, early initiation of N-acetylcysteine and low psi. Conclusion: We conclude that being overweight or obese is an independent risk factor of ALI in acute acetaminophen overdoses.