Body Mass Index Alone Does Not Predict the Amount of Steatosis in Livers of Patients without Alcoholism or Viral Hepatitis: A Retrospective Autopsy Study.
Jaclyn F Hechtman, Adrienne C Jordan, Maria I Fiel, Irini A Scordi-Bello. Mount Sinai School of Medicine, New York, NY
Background: Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disorders in western countries. Moderate to severe steatosis is a contraindication for living-donor liver transplantation. In living-related donation, >15% steatosis is a contraindication. Studies using ultrasonography to assess NAFLD in the general population report that up to 94% of obese individuals have NAFLD.
Design: The purpose of this study was to determine whether body mass index (BMI) alone, in the absence of alcohol or viral disease can predict the severity of steatosis. Bland hepatic steatosis (BHS) and steatohepatitis (SH) were assessed histologically in 72 autopsy cases. Steatosis was graded as 0 (<5%), 1 (up to 33%), 2 (up to 66%) or 3 (>66%). Steatohepatitis was graded as 0 (absent), 1 (mild), 2 (moderate) or 3 (severe). BMI, subcutaneous fat thickness, heart weight, and liver weight were obtained from autopsy reports. Admission alanine aminotransferase levels (ALT) and diagnoses of diabetes mellitus were obtained from medical charts. Exclusion criteria included diagnoses of viral hepatitis and/or alcoholism.
Results: We studied a total of 72 cases. 62.5% were categorized as obese (BMI>=30) and 37.5% were non-obese (BMI<30). The age range was 21-89 years. 37.5% were male and 62.5% were female. 47.2% had a clinical diagnosis of type II diabetes. Statistical analysis revealed that there was a positive correlation between BMI and liver weight, subcutaneous fat, and heart weight (p<0.05). There was no correlation between BMI and BHS. In patients with BMI<30, 88.9% had no or mild BHS and 11.1% had moderate or severe BHS. In obese patients with BMI≥30, 82.2% had no or mild BHS and 17.8% had moderate or severe BHS. Overall, 11/72 patients had 5% to 33% steatosis, and 11/72 patients had >33% steatosis. Although a higher percentage of obese patients exhibited moderate to severe steatosis, this increase was not statistically significant (p=0.450). There was no correlation between BMI and ALT. 10/72 patients exhibited mild, 1/72 moderate and 2/72 severe SH. Both patients with severe SH were obese.
Conclusions: BMI alone is not a reliable predictor of the degree of steatosis. The majority of obese patients in our study had only mild steatosis. Just as many non-obese patients had moderate to severe steatosis. While the numbers are small and the study is retrospective, it highlights the complexity of NAFLD and the inability of one single variant to predict its severity. Liver biopsy remains the gold standard for assessing any liver for donation.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 1, Wednesday Morning