Abstract
Purpose: :
To determine whether formed blood elements and levels of clotting factors are associated with proliferative diabetic retinopathy (PDR) and macular edema (ME) in persons with long duration type 1 diabetes (T1D) while accounting for diabetic nephropathy (DN).
Methods: :
Persons with T1D were identified in 1979-80. Data for this study are from the examination of the survivors (n=428) in 2005-07. Urine was tested for protein and blood was tested for clotting factors and blood elements. Fundus photographs were graded for the presence and severity of diabetic retinopathy and ME.
Results: :
PDR was present in 47% and ME in 32% of the cohort. While controlling for duration of diabetes and other factors, the presence of DN was strongly associated with increased odds (reported as odds ratio [OR]; 95% confidence interval [CI]) of PDR (6.94; 4.36-11.05) and of ME (5.02; 2.90-8.68). Von Willebrand factor was associated with increased odds of PDR in those with DN (1.39; 1.09-1.77; p=0.008). White blood cell count (data reported as OR per quintile 1.43; 95% CI 1.06-1.93; p for trend per quintile=0.019), fibrinogen (1.28; 1.01-1.64; 0.045), and interleukin-6 (1.31; 1.02-1.69; 0.038) were associated with PDR in those without DN. Hematocrit was significantly associated with decreased odds of PDR in those without DN (0.72; 0.54-0.95; 0.021). White blood cell count was associated with increased odds of ME (1.38; 1.05-1.82; 0.021) in those with DN, but none of the variables we examined were associated with ME in those without DN.
Conclusions: :
The presence of DN is strongly associated with increased odds of PDR and ME in persons with long-term T1D. There were small but significant contributions of some blood elements and clotting factors to the retinal outcomes. Prospective study of pathways associated with DN that may affect the development of PDR and ME are needed to understand the role of the kidney in the pathogenesis of DR.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • diabetes