[Nonalcoholic fatty liver disease: evolution after gastric bypass]

Nonalcoholic fatty liver disease is highly prevalent among morbidly obese patients and can progress from steatosis to steatohepatitis and chronic liver disease.

To determine the effect of gastric bypass operation in the incidence of fatty liver disease and associated co-morbidities in morbidly obese patients.

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.

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.

The weight loss secondary to the gastric bypass is associated with decrease in the incidence of nonalcoholic fatty liver disease and other co-morbidities.