Abstract
Abstract: :
Purpose: Current research results are inconsistent as to whether lipids are associated with the development of diabetic retinopathy (DR). We evaluated the relationship between serum lipid levels and DR in a large population with type 1 diabetes mellitus (DM). Methods: We studied the 1441 subjects participating in the Diabetes Control and Complications Trial (DCCT). Serum lipids (total cholesterol, LDL, HDL, total/HDL ratio, and trigycerides) were measured at baseline and then updated annually. We used Cox proportional hazards regression models with time-varying covariates to examine the relationship of the most recent lipid levels with progression of DR as well as development of hard exudate (HE) and clinically significant macular edema (CSME). Results: In models controlling for baseline DR level and treatment group, there were significant associations of total/HDL ratio (RR=2.60 for top versus bottom quintile, trend p-value <0.01) and triglycerides (RR=2.40, trend p-value <0.001) with progression of DR, but the magnitude and significance of these associations decreased with the addition of hemoglobin A1c (HbA1c) to the model (each p-value >0.1). However, in multivariate models adjusting for baseline DR level, treatment group, age, gender, HbA1c, smoking status, and duration of diabetes total/HDL ratio was a significant predictor of CSME (RR=3.89, trend p-value =0.03) and HE (RR= 2.71, trend p-value <0.001); and LDL was also associated with both CSME (RR=1.54, trend p-value =0.03) and HE (RR=1.88, trend p-value <0.001). Conclusions: The findings that elevated serum lipids are associated with increased risk of CSME and retinal HE but not independently with progression of DR suggest a relationship with breakdown of the blood-retinal barrier. Aggressive treatment of elevated lipids among diabetic subjects to prevent cardiovascular disease may also decrease risk of CSME and retinal HE, particularly if a reduction in total/HDL ratio can be achieved.
Keywords: clinical (human) or epidemiologic studies: ris • diabetic retinopathy • lipids