title: Excess body iron and the risk of type 2 diabetes mellitus: a nested case-control in the PREDIMED (PREvention with MEDiterranean Diet) study.
abstract: A prospective nested case-control study within the PREvention with MEDiterranean Diet (PREDIMED) was conducted to evaluate the relationship between excess body Fe (measured as serum ferritin (SF), soluble transferrin receptor (sTfR) and sTfR:ferritin ratio) and the risk of type 2 diabetes mellitus (T2DM) in a Mediterranean population at a high risk of CVD, without T2DM at the start of the study. The study contained 459 subjects, 153 with incident T2DM (cases) and 306 without incident T2DM (controls). The follow-up period was for 6.0 (interquartile range 3.9-6.5) years. For each incident diabetic subject, two subjects were selected as controls who were matched broadly for age as well as for sex, intervention group and BMI. We observed a relationship between SF values >257 μg/l in males and >139 μg/l in females and the risk of T2DM, following adjustment in the conditional logistic regression model for high-sensitivity C-reactive protein, fasting glucose and other components of the metabolic syndrome (OR 3.62, 95% CI 1.32, 19.95; P= 0.022). We also found an association between low sTfR:ferritin ratio levels and the incidence of T2DM (OR 3.02, 95% CI 1.09, 8.39; P= 0.042), but no association with sTfR (OR 1.29, 95% CI 0.51, 3.23; P= 0.722). Oxidative stress has been hypothesised to contribute to the development of insulin resistance and β-cell dysfunction, the two key events in the clinical development of T2DM. Following adjustment for other risk factors for T2DM, excess body Fe (measured as SF and sTfR:ferritin ratio) was associated with an increased risk of developing T2DM in a Mediterranean population at a high risk of CVD.
authors.affiliation: Nutrition and Public Health Unit, Universitat Rovira i Virgili,C/Sant Llorenç 21, 43201 Reus,Tarragona,Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Arija
authors.affiliation: Nutrition and Public Health Unit, Universitat Rovira i Virgili,C/Sant Llorenç 21, 43201 Reus,Tarragona,Spain.
authors.forename: José C
authors.initials: JC
authors.lastname: Fernández-Cao
authors.affiliation: Reus-Altebrat Primary Care, Institut d'Investigació en Atencio Primària (IDIAP) Jordi Gol,Reus,Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Basora
authors.affiliation: Pere Virgili Health Research Institute, Universitat Rovira i Virgili,C/Sant Llorenç 21, 43201 Reus,Tarragona,Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Bulló
authors.affiliation: Nutrition and Public Health Unit, Universitat Rovira i Virgili,C/Sant Llorenç 21, 43201 Reus,Tarragona,Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Aranda
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Instituto de Salud Carlos III,Madrid,Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Estruch
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Instituto de Salud Carlos III,Madrid,Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Martínez-González
authors.affiliation: Pere Virgili Health Research Institute, Universitat Rovira i Virgili,C/Sant Llorenç 21, 43201 Reus,Tarragona,Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Salas-Salvadó
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology* / Q000378:metabolism* / Q000517:prevention & control; D038441:Diet, Mediterranean; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011990:Receptors, Transferrin / Q000097:blood; D012307:Risk Factors; D013030:Spain
chemical_list: D011990:Receptors, Transferrin; D005293:Ferritins; D007501:Iron