Exp Clin Endocrinol Diabetes 2004; 112 - P137
DOI: 10.1055/s-2004-819256

Association between serum ferritin and the insulin resistance syndrome (IRS) in a representative German population

CE Wrede 1, LC Bollheimer 1, R Buettner 1, A Schaeffler 1, J Schoelmerich 1, KD Palitzsch 2, C Hellerbrand 1
  • 1Dept. of Internal Medicine I, University of Regensburg
  • 2Dept. of Internal Medicine III, Hospital Neuperlach, Munich

Background: Unexplained hepatic iron overload with increased serum ferritin (SF) values has been associated with the insulin resistance syndrome (IRS), defined by the presence of increased body mass index (BMI), diabetes, hyperlipidemia or hypertension. In previous studies, the prevalence of IRS in patients with unexplained hepatic iron overload was found to be up to 95%. However, the association between IRS and SF in a representative population has not been investigated so far.

Methods: The 1200 study subjects had initially participated in the „German Diabetomobil Study“, a nationwide epidemiologic survey on metabolic disorders in the adult German population. To eliminate major causes of secondary iron overload, 114 (9.5%) subjects with excessive alcohol consumption and 16 (1.5%) subjects with serologic evidence for hepatitis B or C were excluded from further analysis. For all remaining 1070 probands, complete clinical data of SF, transferrin saturation (TFS), HbA1c, known diabetes, BMI, serum cholesterol, HDL-cholesterol and blood pressure were available.

Results: SF values were significantly increased in men and women with high BMI (>25kg/m2), diabetes, increased serum cholesterol (>200mg/dl), and increased systolic (>160mmHg) or diastolic (>95mmHg) blood pressure, respectively (p<0,05). Furthermore, with increasing number of IRS criteria SF values increased significantly (p<0,01). In contrast, TFS did not reveal a correlation with any of the parameters evaluated.

Discussion: This is the first study showing a significant correlation between SF and the presence of IRS criteria in a large representative population. Interestingly, the severity of the IR-syndrome seemed to be associated with increased ferritin levels indicating a causal connection. However, a secondary effect due to inflammation cannot be ruled out. Eventually, increased ferritin levels reflecting hepatic iron overload may provide both a potential pathophysiological link and prognostic marker for hepatic steatosis and steatohepatitis, hepatic injuries frequently seen in patients with IRS.