High lipoprotein (a) levels are associated with an increased risk of retinal vein occlusion

Abstract

Introduction: Retinal vein occlusion (RVO) is one of the most common retinal vascular disorders affecting ocular vessels. Few studies, with conflicting results and conducted in limited study populations, have hypothesised the role of high levels of lipoprotein (a) [Lp(a)] in the occurrence of RVO. The aim of this study was to investigate, in a large group of RVO patients, the role of such an emerging thrombophilic parameter on the pathogenesis of RVO.

Materials and methods: We compared 262 patients [median age: 66 years (15-88); 122 M, 140 F] with 262 age- and sex-comparable healthy subjects.

Results: Circulating concentrations of Lp(a) were found to be significantly different in patients when compared to healthy subjects [189 (60-1898)mg/L vs. 119.5 (6-1216)mg/L; p<0.0001, respectively]. No significant differences were observed relating to the different types of occlusion (central or branch occlusion). In order to investigate the possible association between high Lp(a) levels and the disease we performed a logistic regression analysis. In the univariate analysis, Lp(a) levels>300mg/L were found to be associated with an increased risk of RVO (OR: 2.39, 95%CI 1.39-3.59; p<0.0001). Following this, three models of multivariate analysis were performed, firstly by adjusting for age, gender, and traditional cardiovascular risk factors, secondly for triglycerides and thirdly for homocysteine levels. In all the models, Lp(a) levels>300mg/L confirmed their role as a risk factor for RVO [first model, OR: 2.15 (95%CI 1.39-3.32), p=0.0001; second model, OR: 3.11 (95%CI 1.77-5.62), p<0.00001; third model, OR: 3.48 (95%CI 1.88-6.43), p<0.00001].

Conclusions: This study reports that, in a large population of RVO patients, high Lp(a) concentrations are significantly related to RVO, independent from other traditional and emerging risk factors, suggesting that they may play a role in its pathogenesis.