Visceral adipose tissue and inflammation correlate with elevated liver tests in a cohort of overweight and obese patients
Faculty of Medicine and Health Sciences
International journal of obesity
, p. 899-907
University of Antwerp
Objective: To study the relationship between elevated liver tests and high sensitive C-reactive protein (hs-CRP), as potential markers of liver inflammation and non-alcoholic steatohepatitis (NASH), with anthropometric and laboratory parameters in overweight patients, especially the relationship with visceral adipose tissue (VAT). Methods: Patients presenting to the obesity clinic were prospectively included. Detailed anthropometry, computed tomography (CT)-measured VAT, liver tests (aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT)) and hs-CRP were assessed, along with an extended series of biochemical parameters. Results: All 480 patients (gender distribution male (M)/female (F) (10/90%)) with complete data were included. Mean age was 39±13 years, mean BMI 34.5±6.0 kg m−2. In 37.3% of the patients one or more of the liver tests were elevated. VAT was positively related to AST (r=0.18, P<0.001), ALT (r=0.29, P<0.001), ALP (r=0.16, P<0.01) and GGT (r=0.39, P<0.001). Comparing subjects with high (VATgreater than or equal to113 cm2) vs low (VAT<113 cm2) VAT levels, significant differences were noted for AST (26±12 vs 24±12 U l−1, P=0.003), ALT (37±21 vs 31±21 U l−1, P<0.001), ALP (76±20 vs 71±18 U l−1, P=0.008), GGT (33±20 vs 25±15 U l−1, P<0.001) and hs-CRP (0.62±0.43 vs 0.52±0.48 mg dl−1, P<0.001). After correction for BMI the difference in AST and ALP between the high vs low VAT group disappeared. The differences for ALT and GGT remained significant (P=0.008 and P<0.001 respectively). After correction for hs-CRP the four different liver tests remained significantly higher in the high VAT group. A stepwise multiple regression analysis revealed that every single liver test has his own most important determinant; VAT and hs-CRP for AST, insulin resistance calculated with homeostasis model assessment (HOMA-IR) and hs-CRP for ALT and ALP, and triglycerides and VAT for GGT. Conclusion: In overweight and obese patients, liver tests, especially ALT and GGT, are associated with visceral fat mass. After correction for BMI and hs-CRP, ALT and GGT are significantly higher in patients with increased VAT, thereby supporting evidence for a potential key role of VAT in the pathogenesis of non-alcoholic fatty liver disease (NAFLD).