Epidemiology
Meta-analysis of 11 studies links high Lp(a) to a doubled risk of diabetic retinopathy in type 2 diabetes (Int Ophthalmol 2024)
Original title: Elevated serum lipoprotein(a) levels as a potential risk factor for diabetic retinopathy in type 2 diabetes: a meta-analysis
This meta-analysis pooled 11 observational studies to examine the relationship between serum Lp(a) and diabetic retinopathy (DR) in people with type 2 diabetes. Compared with the lowest Lp(a) category, the highest category was associated with a significantly higher risk of DR (odds ratio 2.05, 95% CI 1.43-2.93, I2 = 83%, p < 0.001), an association driven predominantly by cross-sectional and case-control studies rather than cohort studies (p for subgroup difference = 0.03). The Lp(a)-DR link was consistent regardless of study country, Lp(a) cutoff, analysis model, or medication adjustment. A further analysis found elevated Lp(a) also significantly associated with proliferative DR specifically (odds ratio 1.90, 95% CI 1.03-3.48, p = 0.04). The findings position Lp(a) as a potential contributor to microvascular retinal complications in type 2 diabetes, extending its recognised role beyond macrovascular atherosclerotic disease, though high heterogeneity and reliance on non-cohort designs warrant cautious interpretation.
Original abstract
Purpose: This meta-analysis aimed to clarify the correlation between serum lipoprotein(a) [Lp(a)] levels and diabetic retinopathy (DR) in type 2 diabetes (T2D) individuals.
Methods: We searched electronic databases, including PubMed, Web of Science, and Embase, for relevant observational studies evaluating the association between serum Lp(a) levels and the risk of DR. Odds ratios (ORs) with 95% confidence intervals (CIs) were summarized to indicate the association between a high Lp(a) and the risk of DR. Data were extracted and pooled using a random-effects model to account for variability among studies. Heterogeneity was assessed using the I2 statistic, and publication bias was evaluated through funnel plots and Egger's test.
Results: Eleven observational studies were included. Compared to T2D patients of the lowest Lp(a) category, those of the highest Lp(a) category were associated with a higher risk of DR (OR: 2.05, 95% CI: 1.43-2.93, I2 = 83%, p < 0.001). Subgroup analyses suggested this association was predominantly observed in cross-sectional and case-control studies but not cohort studies (p for subgroup differences = 0.03). Additionally, the link between Lp(a) and DR was consistent across variables such as study country, Lp(a) cutoff values, analysis model (univariate or multivariate), and adjustment for concurrent medication use. A further meta-analysis suggested a significant relationship between elevated Lp(a) levels and proliferative DR (OR: 1.90, 95% CI: 1.03-3.48, I2 = 86%, p = 0.04).
Conclusion: Elevated serum Lp(a) levels are associated with an increased risk of DR in individuals with T2D.
Summary written by lp-a.org from the published abstract; figures as published. Page updated 18 August 2026. Methods.