Serum ferritin, a predictor of insulin resistance?

Abstract

[Rationale]: Excess body iron has been related with oxidative stress, and several components of the metabolic syndrome (MetS). Here we present the relationship between serum ferritin levels -subrogate marker of body iron- and serum lipids, abdominal adiposity, insulin resistance and leptin levels. [Methods]: The design was a cross-sectional observational pilot study. Fifty subjects (aged 18-65; 55% men) with at least two MetS risk factors (according to WHO criteria) were recruited in the Madrid region. Blood pressure, BMI, and waist-to-hip ratio (WHR) were determined. Biochemical determinations were: serum ferritin, serum transferrin, transferrin saturation, soluble transferrin receptor (sTfR), fasting glucose, insulin, lipids, C-reactive protein, and leptin. An oral glucose tolerance test was also performed and postprandial insulin and glucose levels were measured and the areas under the curve calculated for the period 0¿120 min (AUC). The homeostasis model assessment index (HOMA-IR) and homeostasis model assessment index-beta (HOMA-B) were calculated. Data were analyzed by categorical principal components analysis (CATPCA) and stepwise multiple linear regression models. [Results]: Serum ferritin was significantly related with WRH (r=0.485, p=0.001) and marginally with triglycerides. In the best regression model, predictors of ferritin were insulin postprandial AUC, HOMA-B, and leptin (r=0.859, p<0.001). [Conclusions]: New significant associations between serum ferritin and markers of insulin resistance were found in a population (n=50) at high cardiometabolic risk. These results should be confirmed in a wider population, in order to contribute to the elucidation of the role of iron in cardiometabolic pathologies.