The incidence of obesity is increasing and contributes to the rising incidence of fatty liver. Body mass index (BMI) is used to assess the degree of obesity but does not take into account the pattern of body fat distribution.
To confirm the increasing incidence of fatty liver in an autopsy study. We hypothesized that a standardized measurement of abdominal subcutaneous adipose tissue (ASAT) might be a good noninvasive method for differentiating steatohepatitis from steatosis.
Consecutive complete adult postmortem cases were studied and liver sections were assessed with a steatohepatitis scoring system. Spleen weight, ASAT, and clinical information were obtained. Spleen histology was assessed in a subset of patients having splenomegaly in the absence of cirrhosis.
Patients with human immunodeficiency virus, hepatitis C virus, and appreciable alcohol use were excluded. Of 306 cases, the frequency of fatty liver was 51.6% with 33.3% having simple steatosis and 18.3%, having steatohepatitis. Mean ASAT was 3.7 cm in the steatohepatitis group versus 2.6 cm in the steatosis group (P < .001); this difference was greater in patients with a BMI less than 25 kg/m(2) (P = .05). Fibrocongestive splenomegaly was noted in 9 of 38 patients with nonalcoholic steatohepatitis (24%) in the absence of cirrhosis.
In this series of autopsy cases, a dramatic increase in the prevalence of fatty liver disease is demonstrated. Thicker ASAT is associated more with steatohepatitis than with simple steatosis, especially in patients with BMI below 25 kg/m(2). Fibrocongestive splenomegaly may occur in the absence of cirrhosis in the presence of steatohepatitis.