Mattar SG et al. (2005) Surgically-induced weight loss significantly improves nonalcoholic fatty liver disease and the metabolic syndrome. Ann Surg 242: 610–620

The incidence of nonalcoholic fatty liver disease (NAFLD) is rising steadily; this might be caused by its association with severe obesity and metabolic syndrome. In a recent study, Mattar et al. examined the outcomes of laparoscopic weight-loss procedures in severely obese patients with NAFLD.

Overall, 70 patients were included in this study. Patients included in the study had undergone laparoscopic weight-loss surgery at the University of Pittsburgh, US between March 1999 and August 2004, had a diagnosis of NAFLD, and had agreed to undergo serial liver biopsies.

Postoperatively, patients experienced a loss of excess mean body weight of 59% ± 22%. Major improvements were also noted in the biochemical markers of metabolic syndrome, fasting blood glucose and hemoglobin A1c. Furthermore, there were marked improvements in liver steatosis (from 88% to 8%), inflammation (from 23% to 2%) and fibrosis (from 31% to 13%). Inflammation and fibrosis also resolved in 37% and 20% of patients, respectively.

The authors highlight the importance of obesity and, in turn, metabolic syndrome, in the NAFLD disease process. The authors conclude that surgical weight-loss procedures significantly improve NAFLD in obese patients, as a significant proportion experienced reversal of liver disease; furthermore, there were no deaths and few complications. Further studies are needed, however, to define the interactions between obesity, metabolic syndrome, and NAFLD.