Plasma Adiponectin Level In Patients With Wet Age-Related Macular Degeneration

Background: Age-related macular degeneration is among the mostcommon causes of blindness in the world and its incidence is on the rise.Particularly, the development of choroidal neovascularization is theprincipal cause of severe vision loss. Current therapeutic strategies,including photodynamic therapy and antiangiogenic drugs, focus onreversing neovascularization. The combination of the limited effectivenessof current treatments and the results of recent researches strongly suggestsystemic factors have an important role in disease severity and prognosis.Adiponectin (APN) is a novel protein hormone which is exclusivelysecreted from adipose tissue into the bloodstream, that modulates a numberof metabolic processes, including glucose regulation and fatty acidcatabolism. There are reports that have demonstrated the anti-neovascularization role of adiponectin. Thus, we focused on adiponectin inthis study.Objective: To observe plasma APN level in patients with wetage-related macular degeneration. We also observed APN receptors (AdipoR1and AdipoR2) levels on peripheral blood mononuclearcell(PBMC) in these patients.Methods: Subjects with diabetes mellitus, hypertension,hyperlipidaemia, nephropathy, coronary heart disease, heart failure andrenal failure were excluded. And fifteen patients(mean age69.07±6.71years) and15healthy volunteers(mean age64.2±7.46years) were includedin the present study. Plasma APN level was assessed by enzyme-linkedimmunosorbent assay. The expression of APN receptor mRNA onperipheral blood mononuclear cells was examined by real-time quantitativePCR. The correlations between two parameters, including plasma APN,AdipoR1/R2, homeostasis model assessment indexes of insulin resistance(HOMA-IR), plasma insulin and plasma glucose, were analyzed byPearson’s correlation.Results: APN concentrations in the patients were significantly lowerthan those in controls(1.18±0.65μg/ml for patients, n=15;2.00±0.63μg/mlfor controls, n=15; P=0.002). We also found there was significantly higherfasting plasma glucose concentration(5.42±0.64mmol/l for patients, n=15;4.79±0.39mmol/l for controls, n=15; P=0.003) in the patients than those incontrols. However, there was no significant difference in mRNA level ofAdipoR1and AdipoR2on PBMC between the two groups (P>0.05).Conclusion: The results show that plasma APN concentration waslower in patients with wet AMD. Our findings suggest that APN-related insulin resistance may be involved in the pathologic neovascularization ofwet age-related macular degeneration.