Improvement of Metabolic Syndrome (MS) in Patients with Non-Alcoholic Fatty Liver Disease (NAFLD) after Bariatric Surgery

Abstract

Purpose: Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) are commonly found in morbidly obese patients undergoing bariatric surgery. This study aims to assess the impact of weight loss surgery on the clinical outcomes of morbidly obese patients with NAFLD. Methods: 286 morbidly obese patients with biopsy-proven NAFLD who underwent bariatric surgery were included. Clinical, demographic and histologic data were available at the time of surgery and for a follow-up period after surgery. MS was defined according to ATP III (The Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults). Results: Clinical, demographic and laboratory data for the entire cohort are as follows: age 44.0 ± 11.5, female 78%, BMI 48.7 ± 9.4, waist circumference 139 ± 20 cm, AST 23.9 ± 14.9, ALT 30.0 ± 20.1, diabetes mellitus (DM) 30.1% and MS 39.2%. Patients underwent restrictive, malabsorptive or combination surgical procedures. Of the entire cohort, 27.3% underwent malabsorptive surgery, 55.9% underwent restrictive surgery and 16.8% underwent combination restrictive-malabsorptive surgery. Mean weight loss after restrictive surgery was 33.7 ± 20.1 kg (follow up period 298 ± 271 days). On the other hand, the mean weight loss after malabsorptive surgery was 39.4 ± 22.9 kg (follow-up period 306 ± 290 days) and after combination surgery, the mean weight loss was 28.3 ± 14.1 kg (follow up period 281 ± 239 days). The amount of weight loss post-surgery was not significantly different among the three bariatric surgery procedures (P= 0.352). Regardless of the type of bariatric surgery, significant improvements were noted in DM (P-values from < 0.0001 to 0.0005), MS (P-values from < 0.0001 to 0.01), waist circumference (P-values < 0.0001), BMI (P-values < 0.0001), fasting serum triglycerides (P-value < 0.0001 to 0.001), and fasting serum glucose (P < 0.0001, except for the combination surgery). Additionally, a significant improvement in ALT/AST ratio (P= 0.0002) was noted only in those who underwent restrictive surgery. Conclusion: Weight loss after bariatric surgery is associated with a significant improvement in MS and other metabolic factors associated with NAFLD.