Diabetes onset at an earlier age and high HbA1c levels as risk factors of diabetic retinopathy

AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectional survey of diabetic patients in Subei district,China.Data covering physical measurements,fasting blood-glucose(FBG),glycosylated hemoglobin(Hb A1 c),blood lipid,urinary albumin/creatinine ratio(UACR),ocular fundus examination,and diabetes treatment records were collected.An independent sample t-test were used to analyze differences.A Logistic regression analysis was applied to study the independent risk factors of DR.RESULTS:A total of 1282 patients with type 2 DM were enrolled,and 191 cases had DR(14.9%).The age at diabetes onset,education level,alcohol consumption,Hb A1 c level,UACR level,and hypoglycemic drugs were independent influencing factors for DR.The older the onset of diabetes,the less likely to develop DR(OR:0.958,95%CI:0.942-0.975,P=0.000).Patients were then divided in terms of age at diabetes onset as follows:<50 y,50-59 y,60-69 y,and≥70 y.Compared with diabetes onset age<50 y,50-59 y(OR:0.463,95%CI:0.306-0.699,P=0.000),60-69 y(OR:0.329,95%CI:0.203-0.535,P=0.000)and≥70 y(OR:0.232,95%CI:0.094-0.577,P=0.002)were at a lower risk of DR.The prevalence of DR was highest in patients with diabetes onset age<50 y(29.5%,P<0.05).The Hb A1 c level(8.67±1.97)%and proportion of insulin injection(52.5%)in patients with diabetes onset<40 y were higher than in patients with older diabetes onset age(P<0.05).CONCLUSION:Diabetes onset at an earlier age and uncontrollable high Hb A1 c level could be independent risk factors for DR.