Transferrin receptor-1 gene polymorphisms are associated with type 2 diabetes.
BACKGROUND
Iron is involved in oxidative stress and type 2 diabetes (T2D). Transferrin receptor (TFRC) constitutes the major receptor by which most cells take up iron. The aim of this study was to evaluate whether TFRC gene polymorphisms are associated with T2D.


METHODS
We evaluated TFRC gene polymorphism (rs3817672, 210AG, S142G) in a sample of T2D patients and nondiabetic controls (n = 722), and 39 SNPs within the TFRC genomic region analysed by the Welcome Trust Case Control Consortium (WTCCC) (1921 T2D subjects and 3000 controls). In a subset of subjects, glucose tolerance and insulin sensitivity were also studied.


RESULTS
The frequency of the G allele at the position 210 of the TFRC gene was significantly higher in T2D patients. Both GG and GA genotypes had a 69% (P < 0.01) greater risk of developing T2D estimated under a dominant model. The increased prevalence of the G allele run in parallel to increased sex-adjusted log-serum ferritin and slightly increased soluble transferrin receptor among patients with T2D. Furthermore, post-load glucose and insulin sensitivity were significantly associated with circulating soluble transferrin receptor, and insulin sensitivity was significantly associated with serum ferritin among G allele carriers, (r = -0.33, P = 0.001) but not in AA homozygotes. Sixteen other TFRC SNPs were also associated to T2D according to the Welcome Trust Case Control Consortium data.


CONCLUSIONS
TFRC gene variants are associated with T2D.
Fernández-Real
José Manuel
JM
Section of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona and CIBER Fisiopatología de la Obesidad y Nutrición (CB06/03/010), Girona, Spain. jmfernandezreal.girona.ics@gencat.cat
Mercader
Josep Maria
JM
Ortega
Francisco José
FJ
Moreno-Navarrete
Jose Maria
JM
López-Romero
Pedro
P
Ricart
Wifredo
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics*; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011990:Receptors, Transferrin / Q000235:genetics*
D001786:Blood Glucose; D011990:Receptors, Transferrin; D005293:Ferritins