Lipoprotein and apolipoprotein levels in age-related macular degeneration: A meta-analysis

PurposeDrusen, the hallmark of AMD, are lipoprotein-rich particles. However, the role of systemic lipid metabolism in their formation remains controversial. This meta-analysis explored the association between ApoA1, ApoA2, ApoB and Lp(a) serum levels and AMD.MethodsWe systematically searched MEDLINE, Cochrane Library, EMBASE and Scopus for relevant studies. WMD meta-analyses were performed for ApoA1 and ApoB, whereas SMD meta-analyses were conducted for ApoA2 and Lp(a) serum levels in AMD patients vs healthy controls.ResultsA total of 11 studies with 5,084 subjects for ApoA1, 4,179 for ApoB, 3,177 for ApoA2 and 3,228 for Lp(a) were included. No significant differences were observed between AMD patients (all subtypes) and controls for serum ApoA1 (WMD = 0.29 mg/dL, -3.75 to 4.32, p = 0.89), ApoB (WMD = -2.16 mg/dL, -5.67 to 1.34, p = 0.23), or Lp(a) (g: -0.14, -0.54 to 0.27, p = 0.50). ApoA2 was significantly different (g = 0.2, 0.07 to 0.34, p = 0.003). In severe AMD (geographic atrophy, neovascular AMD), meta-analysis revealed no significant difference for ApoA1 (WMD = -2.68 mg/dL, -8.87 to 3.52, p = 0.4) or ApoB (WMD = -0.42 mg/dL, -6.20 to 5.32, p = 0.89).ConclusionThis meta-analysis discovered no meaningful association between systemic levels of ApoA1, ApoB, or Lp(a) and the presence or severity of AMD. Despite a significant change in ApoA2, utilizing a Reference Change Value based interpretation, we conclude that observed differences in analyzed markers represent physiological and analytical noise rather than true biological change. Our findings suggest that systemic ApoA1, ApoB, and Lp(a) levels are not elevated in individuals with AMD, though the potential role of ApoA2 warrants further investigation.