Nonalcoholic steatohepatitis in nondiabetic obese patients

Nonalcoholic steatohepatitis (NASH) is a major disorder in patients with persistent changes in aminotransferase activity who test negative for viral markers and autoantibodies. Although NASH has been correlated with obesity, no study has been carried out exclusively with nondiabetic obese patients.

To evaluate the occurrence of NASH in obese patients without diabetes mellitus and to assess the severity of histological involvement of the liver.

Serum aminotransferase levels were evaluated in 912 obese patients seen at an outpatient clinic in Porto Alegre, Brazil, from 1997 to 1999. Sixty-eight patients were found to have altered aminotransferase levels in more than one test. Thirty-five patients were excluded due to the presence of diabetes mellitus (n=12), the presence of viral markers (n=11), alcohol consumption (n=8) and the use of hepatotoxic drugs (n=4). NASH was diagnosed when histological findings revealed macrovesicular steatosis associated with lobular inflammatory infiltrate and hepatocellular injury.

Of the 912 obese patients studied, 33 patients with altered aminotransferase levels underwent liver biopsy. Four patients were excluded because they had steatosis only; the remaining 29 patients (3.18%) fulfilled the diagnostic criteria established for NASH. The mean age of the 29 patients was 42.2 +/- 11.9 years; 65.52% of the patients were women. Grading of histological findings revealed mild disease in 58.6% of cases; important proliferation of fibrous tissue was absent in most cases.

NASH is a common disease among nondiabetic obese patients with altered aminotransferase levels, and it usually manifests as a mild clinical condition, although more severe lesions may be observed.