Influence of GSTT1 and GSTP1 polymorphisms on type 2 diabetes mellitus and diabetic retinopathy risk in the Chinese population: a case control study
Background: Studies have revealed the association of glutathione S-transferases (GSTM1 and GSTT1) deletion (null) polymorphism with the risks of developing type 2 diabetes mellitus (T2DM) and its complications. The present study aimed to investigate the relationship between GSTT1/ GSTP1 gene polymorphisms and the risks of T2DM and diabetic retinopathy (DR) in a Chinese population.Methods: In this case-control study, a total of 336 subjects with T2DM and a defined ophthalmologic status were
... ic status were recruited from the Second People's Hospital of Yunnan Province between June 2014 and October 2016. Seventy-two age-matched healthy controls were also enrolled. Physical examinations and laboratory tests were performed. The frequencies of GSTT1 genotypes in all participants were determined by polymerase chain reaction (PCR) followed by agarose gel electrophoresis. Genotyping of GSTP1 gene was identified by PCR amplification followed by sequencing.Results: Compared with healthy controls, the GSTT1-null genotype was significantly more common in diabetic patients with or without DR (all P < 0.05). However, there was no difference in the frequencies of the GSTP1 genotype (AA, GA, GG) between diabetic patients with or without DR and healthy controls. Furthermore, neither the GSTP1 nor GSTT1 genetic polymorphism was associated with the development of DR. In the present study, the risk of developing T2DM was significantly higher in subjects carrying the combined heterozygous GSTP1 (AG) and null GSTT1 genotypes (OR = 0.40, 95% CI = 0.21-0.74, P = 0.02).Conclusions: The deletion of the GSTT1 genotype was associated with a higher risk of developing T2DM, whether alone or in combination with GSTP1, indicating that the null genotype of GSTT1 may serve as a potential biomarker for T2DM in the Chinese population, which is helpful for clinicians to make more effective risk-based decisions.