Associations of iron markers with type 2 diabetes mellitus and metabolic syndrome: Results from the prospective SHIP study

Abstract

AimsTo assess the role of serum ferritin and transferrin with prevalent and incident type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) and whether these associations are independent of inflammatory markers and hepatic enzymes. MethodsWe analyzed data from 3,232 participants aged 20–81 years of the population-based Study of Health in Pomerania (SHIP) from Northeast Germany with a median follow-up time of 10.6 years. Logistic and Cox regression analyses were performed. ResultsSerum ferritin concentrations were associated with a higher prevalence of T2DM (total population OR: 1.16 [95% CI: 1.07, 1.26]; men OR: 1.18 [95% CI: 1.08, 1.30) and MetS (total population OR: 1.27 [95% CI: 1.16, 1.38]; men OR: 1.26 [95% CI: 1.15, 1.38]) in the total population and men independently of inflammatory markers and hepatic enzymes. In longitudinal analyses, baseline ferritin concentrations were associated with a higher risk of incident T2DM in women (HR: 1.38 [95% CI: 1.10, 1.71]), but not in men or in the total population and also with a higher risk of incident MetS (HR: 1.09 [95% CI: 1.01, 1.17]) in the total population. These longitudinal associations attenuated considerably after adjustment for hepatic enzymes but not inflammatory markers. Transferrin was not associated with any of the outcomes. ConclusionsOur results suggest a link between ferritin and T2DM and MetS, which might be partially explained by hepatic dysfunction.