Longitudinal Comparison of the Effect of Gastric Bypass to Sleeve Gastrectomy on Liver Function in a Bariatric Cohort: Tehran Obesity Treatment Study (TOTS)

Obes Surg. 2019 Feb;29(2):511-518. doi: 10.1007/s11695-018-3537-9.

Abstract

Background: Patients with morbid obesity commonly have fatty liver disease and elevated liver enzymes. While surgery effectively induces weight loss, bariatric techniques may differ regarding liver function improvement.

Objectives: To evaluate and compare the trends of liver function recovery after gastric bypass surgery (GB) with sleeve gastrectomy (SG).

Setting: University hospitals, Iran.

Methods: Adult bariatric candidates without a history of alcohol consumption or other etiologies of liver disease who underwent SG (n = 682) or GB (n = 355) were included. Trends of weight loss parameters and alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) at 0, 6 (in 90.4%), 12 (in 83.5%), and 24 months (in 67.1%) were compared using generalized estimating equations method.

Results: Overall, 1037 patients with mean age of 38.4 ± 11.2 and mean body mass index of 44.9 ± 6.2 kg/m2 were analyzed. Seventy-eight percent of patients had fatty liver by ultrasound. Both GB and SG patients lost significant weight, with GB patients having a higher percentage of excess weight loss at 24 months (80.1% vs. 75.9%, Pbetween-group = .008). SG patients showed more favorable trends in liver chemistries with significantly lower ALT at 12 months and AST and ALP levels at 6 and 12 months. However, the two groups were comparable at 24 months. Significantly more GB patients developed high ALT at 6 and high AST at 6 and 12 months. Undergoing GB was associated with smaller 0-12-month changes in ALT, AST, and ALP.

Conclusions: Bariatric surgery resulted in improvement in liver function parameters, with SG showing advantages over GB in the first postoperative year.

Keywords: Bariatric surgery; Gastric bypass; Liver function tests; Morbid obesity; Nonalcoholic fatty liver disease.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Alanine Transaminase / blood
  • Alkaline Phosphatase / blood
  • Aspartate Aminotransferases / blood
  • Female
  • Gastrectomy* / methods
  • Gastric Bypass* / methods
  • Humans
  • Male
  • Middle Aged
  • Non-alcoholic Fatty Liver Disease / blood
  • Non-alcoholic Fatty Liver Disease / etiology
  • Non-alcoholic Fatty Liver Disease / surgery*
  • Obesity, Morbid / blood
  • Obesity, Morbid / complications
  • Obesity, Morbid / surgery*
  • Recovery of Function
  • Treatment Outcome
  • Weight Loss

Substances

  • Aspartate Aminotransferases
  • Alanine Transaminase
  • Alkaline Phosphatase