Introduction and Aims: Serum ferritin has been found closely related with diabetes and glucose metabolism, but its impacts on diabetic nephropathy remains unknown. This study aimed to explore the association between serum ferritin and microalbuminuria in type 2 diabetes. Methods: Eight hundred and fifty one type 2 diabetes subjects were selected from a cohort participating in a glycemic control study in Taiwan in 2008. We used urine albumin-to-creatinine ratio to define microalbuminuria; serum ferritin was divided into quartiles for analysis. Logistic regression and trend tests were used to delineate the association between serum ferritin and microalbuminuria. Results: Diabetes subjects with higher ferritin tended to have earlier diabetes onset, more metabolic disorders, higher high-sensitivity C-reactive protein (hsCRP), and higher prevalence of microalbuminuria. Compared with those in the lowest quartile, diabetes subjects in the highest ferritin quartile were 53% (P=0.032) more likely to develop microalbuminuria. After controlling for demographics, metabolic profiles, and other inflammatory markers, the effect of serum ferritin levels on microalbuminuria remained significant (P for trend < 0.001). This independent relationship was not changed either for those who had better glycemic control or those who had not used an angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB). Conclusions: The current study shows an independent dose-response effect of serum ferritin on microalbuminuria in type 2 diabetes patients.
