This study was aimed to investigate the prevalence of diabetic retinopathy and its associated factors in rural Korean patients with type 2 diabetes. A population-based, cross-sectional diabetic retinopathy survey was conducted from 2005 to 2006 in 1,298 eligible participants aged over 40 yr with type 2 diabetes identified in a rural area of Chungju, Korea. Diabetic retinopathy was diagnosed by a practicing ophthalmologist using funduscopy. The overall prevalence of diabetic retinopathy in the population was 18% and proliferative or severe non-proliferative form was found in 5.0% of the study subjects. The prevalence of retinopathy was 6.2% among those with newly diagnosed type 2 diabetes and 2.4% of them had a proliferative or severe non-proliferative diabetic retinopathy. The odds ratio of diabetic retinopathy increased with the duration of diabetes mellitus (5-10 yr: 5.2- fold; > 10 yr: 10-fold), postprandial glucose levels (> 180 mg/dL: 2.5-fold), and HbA1c levels (every 1% elevation: 1.34-fold). The overall prevalence of diabetic retinopathy in rural Korean patients was similar to or less than that of other Asian group studies. However, the number of patients with proliferative or severe non-proliferative diabetic retinopathy was still high and identified more frequently at the time of diagnosis. This emphasizes that regular screening for diabetic retinopathy and more aggressive management of glycemia can reduce the number of people who develop diabetic retinopathy.
Aged ; Blood Glucose/analysis ; Cohort Studies ; Diabetes Mellitus, Type 2/complications ; Diabetic Retinopathy/complications/*epidemiology/ethnology ; Female ; Hemoglobin A, Glycosylated/analysis ; Humans ; Male ; Middle Aged ; Odds Ratio ; Prevalence ; Republic of Korea/epidemiology ; Risk Factors ; Rural Population

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