Elevated concentrations of liver enzymes and ferritin identify a new phenotype of insulin resistance: effect of weight loss after gastric banding

Background: Several studies have associated elevated liver enzymes (LFTs), obesity, and type 2 diabetes (T2DM), and a link has been established between insulin resistance (IR) and elevated ferritin concentrations. We examined the relationship between LFTs, ferritin, and IR in morbid obese subjects and the effect of weight loss after bariatric surgery. Methods: We measured liver enzymes, ferritin, insulin resistance, and glucose tolerance (by OGTT) in 159 morbid obese subjects (BMI=44.4±0.4 kg/m2) at baseline, 6 months and 1 year after laparoscopic-adjustable-gastric banding (LAGB). Subjects were divided in two groups: increased LFTs (ALT>30; AST/ALT<1) vs. normal LFTs. Results: A large proportion of morbid obese subjects had increased LFTs (44%) which were associated with increased IR and ferritin, suggesting potential liver disease. A majority of the morbidly obese with increased LFTs, IGT, and T2DM, were male and had almost double ferritin concentrations, strongly correlated with ALT (r=0.43, p<0.0001). Both ferritin and ALT correlated with waist circumference and IR. One year after, LAGB glucose tolerance improved, LFTs and IR were reduced; ferritin did not change significantly, but was still correlated with IR. Conclusions: Ferritin may be an additional useful marker for more severe hepatic IR.