In nonalcoholic fatty liver disease, Roux-en-Y gastric bypass improves liver histology while persistent disease is associated with lower improvements in waist circumference and glycemic control.

BACKGROUND: In obese individuals undergoing Roux-en-Y gastric bypass (RYGB), nonalcoholic fatty liver disease (NAFLD) is seen in 75% to 100% of cases. This improves postsurgery, but some patients continue to have persistent NAFLD.

OBJECTIVE: The purpose of this study was to determine the factors associated with persistent NAFLD at 12 months post-RYGB.

SETTING: University Hospital, Canada, bariatric clinic.

METHODS: This is a prospective cohort study of 42 patients who underwent RYGB. Liver biopsy, biochemical and clinical parameters were collected pre- and 12 months post-RYGB. Based on histology at 12 months, patients were separated in 2 groups, normal liver (NL) and persistent NAFLD.

RESULTS: At baseline, NAFLD was diagnosed in 85.7% of patients and at 12 months post-RYGB, NAFLD was present in 19.1% of patients. Patients who had an NL at baseline remained with NL. RYGB resulted in significant decreases in body mass index, waist circumference, blood pressure, aspartate aminotransferase, alanine aminotransferase, fasting glucose and insulin, glycated hemoglobin, and triglycerides and significant increases in high-density lipoprotein cholesterol. Changes were similar in both groups except for waist circumference, which showed lower changes in those with persistent NAFLD. These patients also had significantly higher (P < .05) fasting glucose and insulin with a higher proportion of patients having insulin resistance compared with those with NL.

CONCLUSIONS: RYGB resulted in significant improvements in liver histology, biochemical, and clinical parameters. However, despite similar weight loss, persistent NAFLD was associated with less improvement in waist circumference and worse glycemic control.