Liver disease in the morbidly obese: a review of 1000 consecutive patients undergoing weight loss surgery

Background: Liver disease among the morbidly obese is increasingly prevalent, contributing to significant morbidity. Obesity-related liver pathologies including nonalcoholic steatohepatitis (NASH) have become a leading cause for liver transplant. However, risk factors for developing severe liver disease in the morbidly obese remain unknown. The objective of this study was to determine the frequency of abnormal liver pathology and any relationship to patient-related factors.

Methods: One thousand consecutive patients undergoing weight loss surgery were reviewed. All patients had a liver biopsy at the time of surgery. Frequency of benign pathology, steatosis, NASH, and fibrosis on pathologic examination of liver biopsy specimens were recorded. Pathologic findings were compared and analyzed to age and body mass index (BMI) of all patients.

Results: All patients in the study population had a BMI>35 kg/m2. Of these patients, 80.2% had liver disease related to obesity on pathology, including 65.9% with steatosis (grade 1-3), and 14.3% with NASH and/or fibrosis. Mean BMI of patients with liver disease was 48.1 compared to a BMI of 47.7 with benign pathology (P=.523). Mean age of patients with and without abnormal pathology was 48.3 and 47.3, respectively (P=.294).

Conclusion: Liver disease is highly prevalent in the obese, but is not associated with increased age or BMI. Although all morbidly obese patients appear at significant risk for developing severe liver pathology, further risk factors are unknown.