Epidemiological characteristics and risk factors of diabetic retinopathy in type 2 diabetes mellitus in Shandong Peninsula of China

AIM: To determine the epidemiological characteristics and estimate the risk factors of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM) in Shandong Peninsula of China.METHODS: The cases of T2DM admitted to Affiliated Hospital of Medical College of Qingdao University, Shandong Province, China, from January 2006 to December 2010 were retrospectively reviewed. The epidemiological characteristics of DR were estimated. The cases were divided into two groups according to degrees of retinopathy: non-DR group and DR group. Logistic regression analysis was used to study the related risk factors of DR.RESULTS: The prevalence of DR in patients with T2DM was 25.08% (834/3326). There was significant difference between the average age for men (59.08±15.43 years) and for women (62.92±18.19 years,P=0.0021). The majority of DR occurred in women (female: male ratio=1.76:1,P<0.0001). The incidence rate of DR in urban (489/834) was higher than that in rural area (345/834, P<0.0001). In 834 DR patients, the mean duration of T2DM was 8.90±4.15 years (range: 0-16 years); 440 people (52.76%) had received varying degrees of health education about prevention and primary care of DM; and 473 people (56.71%) suffered from other DM complications confirmed at the same time. In addition, the incidence rate of monocular (551/3326) and binocular retinopathy (283/3326) were statistically different (P<0.0001). Factors associated (P<0.05) with the presence of DR included old age, lower health educational level, intraocular surgery history, longer duration of T2DM, accompanying with other DM complications, no standard treatment procedure, lower body mass index (BMI) and higher fasting plasma glucose (FPG), glycated hemoglobin A1C (HbA1C), urine albumin (UA), total cholesterol (TC), low-density-lipoprotein cholesterol (LDL-C). The risk factors (P<0.05) independently associated with the presence of DR were: longer duration of T2DM, lower health educational level, higher FPG, higher UA, lower BMI and higher TC.CONCLUSION: DR is highly prevalent in the patients with T2DM in Shandong Peninsula of China. Besides blood glucose, many factors are associated with the present and development of DR.