Background: This study compared the polymorphisms of angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type 1 receptor (AT1R) gene between type II diabetes with diabetic nephropathy (DN) in end-stage renal disease (ESRD) and those of the normal individuals in Taiwan.
Methods: 129 patients with type II diabetes in ESRD from three dialysis centers were compared to 116 age and blood pressure-matched normal individuals. Polymerase chain reaction (PCR) specific for ACE gene was tested for insertion/deletion polymorphism. M235T and T174M variant polymorphisms of the AGT gene and the AT1R A1166C polymorphism were also tested according to previously described protocols.
Results: Between the two groups, frequencies of the alleles and the genotypes in ACE gene polymorphism were comparable. There was no significant difference of the ACE insertion and deletion polymorphism and AT1R gene polymorphism between the two groups. The allele frequencies of AGT point mutation at 235 (M235T) was significantly higher in DM nephropathy but the genotypic frequencies were not. In the AGT point mutation at 174 (T174M), the frequencies of both of alleles and genotypes were significantly higher in the DM nephropathy patients.
Conclusions: In conclusion, there were significantly higher frequencies of alleles and genotypes in AGT point mutation at 174, which had never been reported before. In AGT point mutation at 235, there were significantly higher frequencies of alleles, but not genotypes in diabetic nephropathy. Our study suggested that the AGT gene plays an important role in diabetic nephropathy.