Abstract
Purpose: :
To assess the association of serum lipids with diabetic retinopathy (DR) and diabetic macular edema (DME), and to determine if there are differences in these relationships
Methods: :
Participants were recruited from specialized eye clinics in Melbourne, Australia. Fasting total-C [cholesterol], HDL-C, non-HDL-C [total-C-HDL-C], and LDL-C were assessed. DR was graded from fundus photographs using the modified Airlie House classification system into mild, moderate and severe non-proliferative DR and proliferative DR, and separately graded for presence of DME, including clinically significant macular edema (CSME). Macular thickness and morphology were assessed using optical coherence tomography (OCT, Zeiss Stratus, Dublin)
Results: :
500 participants [median (range) = 65 yr (29-90)] were included in this study. DR, DME and CSME were present in 301 (65.5%), 149 (33%), and 68 (15%) patients, respectively. Serum lipid levels were similar in persons with and without DR (e.g., total-C 4.8 vs. 4.6; p=0.17). In contrast, LDL-C was higher in patients with than without DME (2.4 vs. 2.6, p=0.06). Similarly, total-C, LDL-C, and non-HDL-C levels were significantly higher in those with than without CSME (4.6 vs. 5.2, 2.4 vs. 2.9, 3.2 vs. 3.8, p<0.001). In multivariate models adjusting for traditional risk factors and lipid medications, each SD increase in total-C; non-HDL-C; and LDL-C were associated with a 50% increase in odds of CSME. No significant relationship was found, however, between serum lipids, macular thickness and morphology, as assessed from OCT
Conclusions: :
Serum lipids are independently associated with the presence and severity of DME, but not presence and severity of DR, suggesting a differential impact of hyperlipidemia in the pathogenesis of DR and macular edema. These findings may explain discrepancies found in previous studies and suggest that differing therapies targeting at DR and DME may be required
Keywords: diabetic retinopathy • lipids