Serum ferritin as an independent predictor of new-onset type 2 diabetes

Ferritin is an acute-phase reactant. Since diabetes incidence is associated with dysadipocytokinaemia and elevated hepatic enzymes, the independence of the ferritin-diabetes association remains debated with respect to raised inflammatory markers. The association between baseline serum ferritin concentration and type 2 diabetes was studied in 360 clinically incident diabetes cases versus 758 controls within the European Prospective Investigation of Cancer-Norfolk Cohort Study. To this end, serum ferritin concentrations were classified in 5 groups: sex-specific quartiles of the normal range of ferritin and a group with clinically raised ferritin levels, yet below levels indicative of genetic haemochromatosis. Among incident diabetic cases, baseline serum ferritin levels were higher compared with controls (P<0.001 in men; P=0.005 in women). After adjustment for known risk factors and dietary factors measured by a 7-day food diary, the risk of diabetes was markedly increased in subjects with clinically raised ferritin levels compared with the lowest quartile (odds ratio 7.4; 95% CI, 3.5-15.4). Serum ferritin appears to play a role in the development of diabetes and may thus help understanding its aetiology.

Abstract