Caution for liver injury after bariatric surgery: logistic regression of risk factors for early elevation of liver enzymes after surgery

Abstract

The reasons for the influence of bariatric surgery (BS) on the early abnormal increase of liver enzymes and liver injury remain unclear. We found abnormal elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in liver chemistry early after BS. To investigate the risk factors for early elevation of ALT and AST after BS, we performed a regression analysis of 177 patients who underwent BS at our center. Follow-up data before and after BS were collected and divided into two groups according to whether ALT and/or AST increased and exceeded the clinical threshold one month after BS. Logistic regression analysis was used, and independent risk factors were screened. Waist circumference (WC) before BS was an independent risk factor (P < 0.05) for increased ALT and AST after BS, but other factors (P > 0.05), such as sex, type of BS, or body mass index (BMI), were not. The cutoff of WC to predict abnormal elevation of ALT and AST after BS was 117.35 cm (sensitivity, 0.75; specificity, 0.62) and 113.65 cm (sensitivity, 0.88; specificity, 0.48), respectively. WC is an independent risk factor for early liver injury after BS. Long-term liver-related follow-up is necessary.