Liver steatosis evaluated through chemical-shift magnetic resonance imaging and liver enzymes; effect of weight loss obtained with intragastric balloon and gastric banding

Introduction: Liver steatosis (LS) is frequent in morbid obesity. Liver biopsy is required for definite diagnosis of LS, but can not be used for follow-up studies. Spectroscopy-magnetic resonance imaging (MRI) and chemical-shift MRI are accurate indices of LS, more than CT scans or echography, and can be used in follow-up studies. Methods: We evaluated the effect of weight loss on LS, evaluated through chemical-shift MRI (MRI-LS) and liver enzymes (AST, ALT, gGT, ALP). 18 obese subjects (16 W/2 M, BMI 43.7±6.6 kg/m2) underwent intragastric balloon (BIB) or gastric banding (LAGB), and 12 obese subjects (7 W/5 M, BMI 41.1±9.1 kg/m2) received hypocaloric diet; all subjects were re-evaluated after 6 months. Results: At baseline, MRI-LS correlated with echography-LS (p=0.006), ALT (p=0.0004), AST (p=0.006), gGT (p=0.01). After 6 months, subjects undergoing BIB or LAGB had significant changes of BMI (p=0.0001), ALT (p=0.0001), AST (p=0.0001), GGT (p=0.04), ALP (p=0.0001), and of MRI-LS (P=0.003). Diet-treated obese subjects had no significant change of any parameter under study. Also after 6 months, MRI-LS correlated with ALT (p=0.001), AST (p=0.006), gGT (p=0.01), and ALP (p=0.001). Conclusion: These data indicate that significant weight loss is associated with decrease of liver steatosis evaluated through MRI and change of liver enzymes.