Aims: We sought to determine whether NAFLD is associated with poorer β-cell function and if any β-cell dysfunction is associated with abnormal markers of iron or inflammation.
Methods: This was a cross-sectional study of 15 non-diabetic adults with NAFLD and 15 non-diabetic age and BMI-matched controls. Insulin sensitivity was measured by isotope-labeled hyperinsulinemic-euglycemic clamps and β-cell function by both oral (OGTT) and intravenous glucose tolerance tests. Liver and abdominal fat composition was evaluated by CT scan. Fasting serum levels of ferritin, transferrin-iron saturation, IL-6, TNFα and hsCRP were measured.
Results: Compared to controls, subjects with NAFLD had lower hepatic and systemic insulin sensitivity and β-cell function was decreased as measured by the oral disposition index. Fasting serum ferritin and transferrin-iron saturation were higher in NAFLD and were positively associated with liver fat. Serum ferritin was negatively associated with β-cell function measured by both oral and intravenous tests, but was not associated with insulin sensitivity. IL-6, TNFα and hsCRP did not differ between groups and did not correlate with serum ferritin, liver fat or measures of β-cell function.
Conclusions: These findings support a potential pathophysiological link between iron metabolism, liver fat and diabetes risk.
Keywords: Fatty liver; Ferritin; Insulin secretion in vivo; Insulin sensitivity.
Published by Elsevier Inc.