Background: We aimed to study serum retinol and alpha-tocopherol in a cohort of obese patients and their possible association with several obesity-related conditions, given that the former may be implicated in a diminished capacity of anti-inflammatory and antioxidant potential in obese patients.
Methods: Eighty patients with morbid obesity participated in the study. Many clinical and biochemical variables were measured including serum retinol, alpha-tocopherol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations. Fatty liver was detected by ultrasonography.
Results: Both serum retinol and alpha-tocopherol inversely correlated with body mass index (r = -0.334, P = 0.002 and r = -0.299, P = 0.007, respectively). Serum retinol inversely correlated with AST (r = -0.236, P = 0.036) and ALT (r = -0.241, P = 0.032). Multivariate regression analyses confirmed these results after correcting for the effects of other variables. Eighty-five percent of patients had fatty liver. When restricting the analysis to them, multivariate regression identified male sex (beta = 0.451, P = 0.003), age (beta = -0.275, P = 0.039), and serum retinol concentrations (beta = -0.414, P = 0.005) as predictive variables on serum AST (R (2) = 0.230, F = 3.408, P = 0.009) and male sex (beta = 0.448, P = 0.003), age (beta = -0.236, P = 0.046), insulin resistance determined by homeostasis model assessment (beta = 0.243, P = 0.050), and serum retinol concentrations (beta = -0.305, P = 0.022) as predictive variables on serum ALT (R (2) = 0.296, F = 5.817, P = 0.001).
Conclusion: Serum retinol and alpha-tocopherol concentrations are inversely associated with body mass index in morbid obesity, and serum retinol is also inversely associated with serum concentrations of transaminases in those patients with nonalcoholic fatty liver disease.