OBJECTIVETo investigate the relationship of angiotensin I-converting enzyme (ACE) gene polymorphism to diabetic retinopathy and diabetes myocardial infarction.

METHODSACE insertion/deletion(I/D) polymorphism was determined by PCR.

RESULTSNo evidence showed that ACE gene was associated with diabetic retinopathy. By comparison of the type 2 diabetes patients with myocardial infarction versus those without-myocardial infarction, it was found that the frequencies of homozygote DD (41.2% versus 33.2%) and of allele D (64.7% versus 55.0%) increased remarkably; the difference was statistically significant (P<0.05).

CONCLUSIONAllele D(RR=1.50) and genotype DD(RR=1.33) seemed to be a genetic risk factor for type 2 diabetes myocardial infarction.

Adult ; Aged ; Diabetes Mellitus, Type 2 ; complications ; Diabetic Retinopathy ; etiology ; genetics ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; etiology ; genetics ; Peptidyl-Dipeptidase A ; genetics ; Polymorphism, Genetic ; Risk Factors

OBJECTIVETo investigate the association of the polymorphism in manganese superoxide dismutase (Mn-SOD) gene in Chinese type 2 diabetic patients with diabetic retinopathy.

METHODSThe Ala(-9)Val polymorphism of the Mn-SOD gene was determined by polymerase chain reaction and direct sequencing in 198 normal control subjects and 264 patients with type 2 diabetes mellitus, among them there were 139 non-diabetic retinopathy (NDR) subjects and 125 subjects with diabetic retinopathy (DR).

RESULTSThere was no statistic difference in the frequencies of VV genotype and V allele between the type 2 diabetic group and the control group. However, the frequencies of VV genotype and V allele were significantly higher in the DR group than that in the NDR group (chi-square (2)=5.015, P=0.025; chi(2)=10.253, P=0.001),but there was no statistic difference in the NDR group compared with the control group (P > 0.05). The presence of V allele was shown to be associated with diabetic retinopathy (OR=1.96, 95%CI: 1.29-2.97). Furthermore, the subjects carrying the VV genotype had lower serum Mn-SOD level (P=0.025) and had a tendency of higher total serum SOD activity, but this tendency had no statistic significance.

CONCLUSIONThe Ala(-9)Val polymorphism in the Mn-SOD gene may not be related to the etiology of type 2 diabetes, but it seems to contribute to the development of diabetic retinopathy in Chinese type 2 diabetic patients.

Alleles ; Asian Continental Ancestry Group ; genetics ; DNA ; analysis ; Diabetes Mellitus, Type 2 ; complications ; genetics ; Diabetic Retinopathy ; etiology ; genetics ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide ; genetics ; Superoxide Dismutase ; genetics

PURPOSE: Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that can increase adhesion molecule expression on monocytes and produce superoxide anions. Hyperglycemia induces MCP-1 production in vascular endothelial cells and retinal pigmented epithelial cells, and has been implicated as a causal factor in the facilitation of vascular complications in diabetes. In the present study, we evaluated the association of a single nucleotide polymorphism (SNP) in the MCP-1 gene with proliferative diabetic retinopathy (PDR) in a Korean population with type 2 diabetes. MATERIALS AND METHODS: We conducted a case-control study, which enrolled 590 subjects with type 2 diabetes, and SNP genotyping of c.2518A/G in the MCP-1 gene was performed using polymerase chain reaction followed by digestion with PvuII restriction enzyme. RESULTS: The prevalence of c.2518A/G polymorphism in diabetic patients was 13.2% (A/A), 47.1% (A/G) and 39.7% (G/G). In patients with diabetic retinopathy, the prevalence of PDR was significantly higher (p=0.009) in diabetic subjects with the c.2518A/A genotype (35.9%; n=78) compared to those with either the A/G or G/G genotype (22.3%, n=512). The prevalence of any other micro and macro-complications, including nephropathy and cerebrovascular events, were not different according to the c.2518A/G genotype. CONCLUSION: Our new genetic findings suggest that the c.2518A/A genotype in MCP-1 could be used as a susceptibility gene to predispose Koreans exhibiting type 2 diabetes for the development of PDR.
Aged ; Case-Control Studies ; Chemokine CCL2/*genetics ; Diabetes Mellitus, Type 2/*complications ; Diabetic Retinopathy/etiology/*genetics ; Female ; Genetic Association Studies ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Middle Aged ; *Polymorphism, Single Nucleotide ; Republic of Korea

OBJECTIVETo evaluate the potential role of insulin-like growth factor-1 receptor mRNA (IGF-IR mRNA) in the onset and development of retinopathy in diabetic rats.

METHODSA diabetic model was duplicated in Wistar rats. The early changes in the retina were examined using light and transmission electron microscopy. Expression of IGF-IR mRNA was analyzed using in situ hybridization.

RESULTSWeak expression of IGF-IR mRNA (5%) was found in retinas of normal rats, but was significantly increased (15% and 18%) in the retinas of diabetic rats after 3 and 6 months of diabetes (P < 0.01). In situ hybridization and morphological study demonstrated that there was a positive correlation between IGF-IR mRNA expression and retinal changes at various stages.

CONCLUSIONIncreased IGF-IR mRNA might play an important role in the onset and development of diabetic retinopathy.

Animals ; Blood Glucose ; analysis ; Diabetic Retinopathy ; etiology ; Glycated Hemoglobin A ; analysis ; Insulin-Like Growth Factor I ; physiology ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptor, IGF Type 1 ; genetics ; Retina ; metabolism ; pathology

OBJECTIVETo evaluate the role of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and plasma homocysteine levels in patients with type 2 diabetes mellitus and diabetic retinopathy (DR).

METHODSTotal of 208 patients with type 2 diabetes mellitus and 57 controls were recruited into the study. MTHFR genetic C677T polymorphisms were determined by PCR-RFLP. Plasma total homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection.

RESULTSThe frequencies of MTHFR TT homogeneous type, CT heterogeneous type and allele T (28.18%, 41.82%, 49.09%) were significantly higher in the type 2 diabetes mellitus with diabetic retinopathy group than those without retinopathy (18.37%, 29.59%, 33.16%) and those of controls (17.54%, 28.07%, 31.58%). The presence of the T allele appeared to have a strong association with the development of diabetic retinopathy. The odds ratio was 1.94 with a 95% confidence interval of 1.31 - 2.88. Moreover, plasma homocysteine levels were remarkably higher in patients with TT or CT genotype than in patients with the CC genotype.

CONCLUSIONMTHFR gene C677T mutation associated with a predisposition to increased plasma homocysteine levels may be considered as a genetic risk factor for diabetic microangiopathy (such as DR) in Chinese patients with type 2 diabetes mellitus.

Aged ; Diabetes Mellitus, Type 2 ; complications ; Diabetic Retinopathy ; etiology ; Female ; Genotype ; Homocysteine ; blood ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2) ; Middle Aged ; Mutation ; Oxidoreductases Acting on CH-NH Group Donors ; genetics ; Polymorphism, Genetic

OBJECTIVETo evaluate the role of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and plasma homocysteine levels in Chinese patients with type 2 diabetes mellitus and diabetic retinopathy (DR).

METHODSMTHFR genetic C677T polymorphisms were determined by PCR-restriction fragment length polymorphism. Total plasma homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection.

RESULTSThe frequencies of MTHFR T homogenetic type and CT heterogenetic type and allele T (28.18%, 41.82%, 49.09%) in type 2 diabetic patients with diabetic retinopathy were significantly higher than those in diabetic patients without retinopathy (18.37%,29.59%,33.16%) or the normal controls (17.54%, 28.07%, 31.58%). Howerver, there were no significant differences in the frequency of MTHFR genotype and allele between the type 2 diabetic patients without retinopathy and the normal controls. The presence of T allele appeared to have a strong association with the development of diabetic retinopathy. The odds ratio was 1.94 and the 95% confidence interval was 1.31-2.88. Moreover, the plasma homocysteine levels in patients with TT or CT genotype were markedly higher than those in patients with CC genotype.

CONCLUSIONMTHFR gene C677T mutation associated with a predisposition to increase of plasma homocysteine may represent a genetic risk factor for diabetic retinopathy in Chinese type 2 diabetes mellitus.

Adult ; Alleles ; DNA ; genetics ; metabolism ; Deoxyribonucleases, Type II Site-Specific ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; complications ; genetics ; Diabetic Retinopathy ; blood ; etiology ; genetics ; Female ; Gene Frequency ; Genotype ; Homocysteine ; blood ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2) ; Middle Aged ; Oxidoreductases Acting on CH-NH Group Donors ; genetics ; Point Mutation ; Polymorphism, Genetic

OBJECTIVETo identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM).

METHODSFrom November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed.

RESULTSA total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09).

CONCLUSIONSMicroalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.

Albuminuria ; epidemiology ; urine ; Aldehyde Reductase ; genetics ; Asian Continental Ancestry Group ; China ; Cohort Studies ; Diabetes Mellitus, Type 2 ; complications ; drug therapy ; ethnology ; genetics ; Diabetic Retinopathy ; drug therapy ; ethnology ; etiology ; genetics ; Female ; Gene Frequency ; Humans ; Hypoglycemic Agents ; administration & dosage ; adverse effects ; therapeutic use ; Insulin ; administration & dosage ; adverse effects ; therapeutic use ; Logistic Models ; Male ; Multivariate Analysis ; Polymorphism, Single Nucleotide ; Risk