Nonalcoholic fatty liver disease: A spectrum of clinical and pathological severity

Background & Aims: The spectrum of nonalcoholic fatty fiver disease ranges from fatty liver alone to nonalcoholic steatohepatitis. Most previous studi es have short follow-up and have not carefully delineated different histolo gical types when determining clinical outcomes. The aim of this study was t o compare clinical characteristics and outcomes of patients with different types of nonalcoholic fatty liver. Methods: All liver biopsy specimens from 1979 to 1987 with fat accumulation were assessed for inflammation, balloon ing degeneration, Mallory hyaline, and fibrosis. Biopsy specimens were also assessed for histological iron and hepatitis C RNA. Outcomes were cirrhosi s, mortality, and liver-related mortality. Results: Of 772 liver biopsy spe cimens, complete data were available in 132 patients. Fatty liver (type 1) did not differ from the other three types combined with respect to gender, race, age, or obesity. Cirrhosis was more common in the other types combine d (22%) than fatty liver alone (4%; P < 0.001). Overall mortality, histolog ical iron, and hepatitis C did not differ between groups. Most of the liver -related deaths were in type 4. Conclusions: The outcome of cirrhosis and l iver-related death is not uniform across the spectrum of nonalcoholic fatty liver. These poor outcomes are more frequent in patients in whom biopsies show ballooning degeneration and Mallory hyaline or fibrosis.