Abstract
Purpose :
Though impaired lipid homeostasis is thought to contribute to the pathogenesis of age-related macular degeneration (AMD), it is unknown what elements of lipid homeostasis are dysregulated in AMD or when this dysregulation occurs relative to AMD stage. In this meta-analysis, which is an update to that performed by Wang et al. in 2016, we evaluated which aspects of lipid homeostasis are more dysregulated in certain stages of AMD.
Methods :
We performed a systematic review using Medline, Embase, and Web of Science to identify articles from database inception to May 2022 that reported blood/serum levels of lipids (triglycerides [TG], total cholesterol [TC], high-density lipoprotein [HDL], and low-density lipoprotein [LDL]) in patients with AMD compared with controls. We meta-analyzed the data by generating multi-level random-effects models using restricted maximum likelihood estimation. Standard errors were adjusted using the Knapp-Hartung correction.
Results :
Our updated meta-analysis included fifty-six studies, almost 3 times as many studies as the 2016 study. Compared to controls, patients with AMD had significantly higher serum LDL (standardized mean difference [SMD] = 0.13; 95% confidence interval [CI]: 0.02 to 0.24). There were no significant differences in serum TG, TC, or HDL between patients with AMD and controls. We also performed sub-analyses by dividing patients into those with early to intermediate non-exudative AMD, advanced neovascular AMD, and advanced non-exudative AMD. Compared to controls, patients with early to intermediate non-exudative AMD had significantly lower serum TG (SMD = -0.03; 95% CI: -0.06 to 0.00), lower serum TC (SMD = -0.01; 95% CI: = -0.03, -0.00), and higher serum HDL (SMD = 0.07; 95% CI: 0.04 to 0.11). Finally, patients with advanced exudative AMD had significantly higher serum LDL (SMD: 0.33; 95% CI: 0.04 to 0.62) compared with non-AMD controls. There were no other significant differences identified.
Conclusions :
We found that there are differences in systemic serum lipid profiles in patients with AMD compared with non-AMD controls. Of note, the specific pattern of impaired lipid homeostasis appears to be distinct based on AMD stage. These findings highlight the heterogeneity of AMD, suggesting that distinct pathophysiological mechanisms may be involved in different stages of AMD, and may inform the development of novel therapeutic approaches.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.