Affiliations: Genetics Department, Universidade Federal do Rio
Grande do Sul, Porto Alegre, RS, Brazil | Endocrinology Division, Hospital de Clínicas de
Porto Alegre, Porto Alegre, RS, Brazil | Endocrinology Division, Grupo Hospitalar
Conceição, Porto Alegre, RS, Brazil
Note: [] Corresponding author: Israel Roisenberg, Ph.D., Departamento de
Genética, Instituto de Biociências, Universidade Federal do Rio
Grande do Sul (UFRGS), Caixa Postal 15053, 91501-970, Porto Alegre, RS, Brasil.
Tel.: +55 51 3316 6736; Fax: +55 51 3316 7311; E-mail: israberg@ufrgs.br
Abstract: Catalase is a central antioxidant enzyme constituting the primary
defense against oxidative stress. In this study, we investigated whether the
functional –262C/T polymorphism in the promoter of catalase gene is
associated with the presence of diabetic retinopathy (DR), diabetic nephropathy
(DN) and ischemic heart disease (IHD) in 520 Caucasian-Brazilians with type 2
diabetes. The –262C/T polymorphism was also examined in 100 Caucasian
blood donors. Patients underwent a clinical and laboratory evaluation
consisting of a questionnaire, physical examination, assessment of diabetic
complications and laboratory tests. Genotype analysis was performed using the
polymerase chain reaction followed by digestion with restriction enzyme. The
genotype and allele frequencies of the –262C/T polymorphism in patients
with type 2 diabetes were very similar to those of blood donors (T allele
frequency=0.20 and 0.18, respectively). Likewise, there were no differences in
either genotype or allele frequencies between type 2 diabetic patients with or
without DR, DN or IHD. Thus, our results do not support the hypothesis that the
–262C/T polymorphism is related to the development of DR, DN or IHD in
patients with type 2 diabetes. Further studies are necessary to elucidate the
role of catalase gene polymorphisms in the pathogenesis of diabetic
complications.
