[Nonalcoholic fatty liver disease: evolution after gastric bypass].

BACKGROUND: Nonalcoholic fatty liver disease is highly prevalent among morbidly obese patients and can progress from steatosis to steatohepatitis and chronic liver disease. AIM: To determine the effect of gastric bypass operation in the incidence of fatty liver disease and associated co-morbidities in morbidly obese patients.
METHODS: Patients were prospectively evaluated in the pre-operative period and after at least 6 months after operation. We analysed: antropometric data, co-morbidities, use of medications, cholesterol and triglycerides levels, liver tests and incidence of nonalcoholic fatty liver disease. All patients with abnormal liver tests were subjected to per-operative liver biopsy.
RESULTS: Twenty eight patients with nonalcoholic fatty liver disease with a mean body mass index of 42 +/- 4 kg/m(2) were evaluated. Twenty five patients had 59 co-morbidities and the most frequent were: elevated triglycerides (n = 23), elevated cholesterol (n = 13) and elevated blood pressure (n = 11). Biopsy was done in 22 patients: 10 presented moderate steatosis, 5 mild steatosis and 7 steatohepatitis. After follow-up of 230 days in average they presented weight excess loss of 64%, body mass index reduction to 29,6 +/- 3 kg/m(2) and 21 co-morbidities in 13 patients. There was a significant decrease in the number of patients with elevated triglycerides, elevated cholesterol, elevated blood pressure and in the incidence of nonalcoholic fatty liver disease.
CONCLUSION: The weight loss secondary to the gastric bypass is associated with decrease in the incidence of nonalcoholic fatty liver disease and other co-morbidities.