Abstract
Purpose :
Although many polymorphisms associated with POAG risk have been reported, only few studies have analyzed their additive effects. We investigated, in a southern European Mediterranean population, the association between relevant POAG polymorphisms, identified by initial genome-wide association studies (GWASs) and POAG risk, both separately and as an aggregated multi-locus genetic risk score (GRS). Also, bearing in mind that oxidative stress is a factor increasingly recognized in the pathogenesis of POAG, we analyzed the potential association of the GRS with plasma concentrations of antioxidant vitamins (C and E).
Methods :
We carried out a case-control study including 391 POAG cases and 383 healthy controls, and analyzed four genetic polymorphisms (rs4656461-TMCO1, rs4236601-CAV1/CAV2, rs2157719-CDKN2B-AS1 and rs3088440-CDKN2A) by qRT-PCR. An unweighted GRS including the four non-linked polymorphisms was constructed. Plasma vitamin C and E concentrations were measured by high performance liquid chromatography (HPLC). We used IBM SPSS Statistics software (version 24.0, IBM Corporation 2017, Armonk, NY, USA) for statistical analyses of data.
Results :
A strong association between the GRS and POAG risk was found. When three categories of the GRS were considered, subjects in the top category of the GRS were 2.92 (95% confidence interval (CI): 1.79-4.77) times more likely to have POAG compared with participants in the bottom category (p < 0.001). Moreover, the GRS was inversely correlated with plasma vitamin C (p = 0.002) and vitamin E (p = 0.001) concentrations, even after additional adjustment for POAG status.
Conclusions :
We have found a strong association between the GRS and POAG risk in this Mediterranean population. While the additional correlation found between GRS and low levels of vitamins C and E does not indicated a causal relationship, it does suggest the need for new and deeper research into the effects of oxidative stress as a potential mechanism for those associations.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.