Decreased Serum Adiponectin: An Early Event in Pediatric Nonalcoholic Fatty Liver Disease

Objective

To evaluate the relative concentrations of cytokines in pediatric nonalcoholic fatty liver disease (NAFLD).

Study design

Thirty children were evaluated at a fasting morning visit to a pediatric research unit.

Results

Compared with normal-weight children (n = 12) and children who were overweight (n = 11), children who had presumed NAFLD (elevated Alanine aminotransferase [ALT] with negative work-up) (n = 7) had significantly lower mean serum adiponectin levels (P = .004). Adiponectin negatively correlated with body mass index (r = −0.60, P = .001), insulin (r = −0.74, P < .001), glucose (r = −0.52, P = .004), and ALT (r = −0.53, P = .003). There was no difference between normal-weight, obese, and presumed NAFLD subjects in mean serum tumor necrosis factor α and interleukin-6 and -8 concentrations nor in tumor necrosis factor α and interleukin-8 and -10 levels in an ex vivo lipopolysaccharide-stimulated system.

Conclusions

Serum adiponectin is reduced in children with elevated ALT, similar to adults. However, children with presumed NAFLD do not have elevated pro-inflammatory cytokine levels. This suggests that depressed adiponectin plays a more proximal role than elevated levels of circulating pro-inflammatory cytokines in the development of NAFLD in children.

ALT, Alanine Amino transferase, BMI, Body mass index, CRP, C-reactive protein, ELISA, Enzyme-linked immunosorbent assay, IL-6, Interleukin-6, IL-8, Interleukin-8, IL-10, Interleukin-10, LPS, Lipopolysaccharide, NAFLD, Nonalcoholic fatty liver disease, NASH, Nonalcoholic steatohepatitis, TNF-α, Tumor necrosis factor-α