The relative risk factors of diabetic retinopathy

Objective To investigate the risk factors of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus. Methods Seven hundred and eight hospitalized patients with type 2 diabetes mellitus from August 2008 to December 2011 were enrolled in this study. All subjects in this study were divided into two groups based on the results of fundus examination, non-diabetic retinopathy(NDR) group including 498 cases and diabetic retinopathy(DR) group including 210 cases. The subjects were analyzed according to their age, sex, diabetic duration, blood glucose, blood lipids, blood pressure, liver function, renal function, 24 hour urine albumin excretion rate, complications , insulin usage and so on. The spearman analysis was used to analyze the relationship between the diabetic retinopathy and the diabetic nephropathy. Results The waist circumference, diabetic duration, systolic blood pressure, diastolic blood pressure, uric acid, uric acid excretion rate, fibrinogen, 24 hour urine albumin excretion rate, blood urine nitrogen, serum creatinine and blood viscosity of patients in DR group were significantly higher than those in NDR group, the difference was statistically significant((95±11), (93±10)cm, (12±7), (7±7)y, (144±23), (135±19) mm Hg(1 mm Hg=0.133 kPa), (83±12), (81±10) mm Hg, (316±87), (300±86) μmol/L, (26±15), (23±11)%, (3.5±1.1), (3.1±0.8) g/L, (125±122), (51±45)mg/24 h, (8±5), (6±3) mmol/L, (110±101), (71±48 )μmol/L, (39/115/44), (57/303/109), t=-2.069, -8.285, -4.807, -2.612, -2.104, -2.883, -4.186, -7.949, -5.132, -4.561, 6.513, respectively P<0.05), the hemoglobin, direct bilirubin, total bilirubin, alanine aminotransferase and creatinine clearance rate of patients in DR group were significantly lower than those in NDR group, the difference was statistically significant((8.9±2.2), (8.1±2.1) g/L, (4.5±2.3), (4.0±2.1) μmol/L, (13±6), (12±6) μmol/L, (27±22), (21±16) U/L, (117±43), (88±50) ml/min, t=-0.067, 2.719, 2.396, 3.220 and 6.548 respectively, P<0.05). Logistic regression analysis showed that diabetic duration, 24 hour urine albumin excretion rate and creatinine clearance rate were selected into the equation(P<0.05). Spearman analysis showed that severity of diabetic nephropathy was positively related to the occurrence and development of diabetic retinopathy(r=0.513, P<0.05). Conclusion Diabetic duration more than 5 years, increasing of 24 hour urine albumin excretion rate as well as decreasing of creatinine clearance rate are the independent risk factors of diabetic retinopathy in type 2 diabetic patients. Key words: Diabetes mellitus, type 2; Diabetic retinopathy; Urine albumin; Creatinine clearance; Risk factors