Associations between paraoxonase 1 (PON1) polymorphisms and susceptibility and PON1 activity in rheumatoid arthritis patients, and comparison of PON1 activity in patients and controls: a meta-analysis

Objectives: We reviewed the associations between paraoxonase 1 (PON1) polymorphisms and susceptibility and PON1 activity in rheumatoid arthritis (RA) patients and compared PON1 activity between RA patients and controls. Methods: We conducted a meta-analysis of PON1 Q192R and L55M polymorphism and RA risk data and determined the associations between PON1 Q192R polymorphism and PON1 activity in RA patients. We also compared serum/plasma PON1 activity levels in RA patients and controls. Results: Twelve studies were included in this meta-analysis. No association was observed between RA and the PON1 192R allele in any study subject (OR = 0.967, 95% CI = 0.829–1.129, p = 0.674). Analysis using recessive, dominant, or homozygous contrast models revealed no association between the PON1 192R allele and RA. Meta-analysis showed no association between RA and the PON1 55M allele (OR = 1.400, 95% CI = 0.738–2.658, p = 0.308). In the meta-analysis, PON1 activity was significantly higher in the RR genotype than in the QQ (SMD = 2.975, 95% CI = 2.157–3.792, p < 0.001) and QR (SMD = 1.265, 95% CI = 0.898–1.633, p < 0.001) genotypes. PON1 activity was significantly lower in the RA group than in the control group (SMD = − 3.176, 95% CI = − 5.070 to − 1.283, p < 0.001). Conclusions: We found no association between the PON1 Q192R and L55M polymorphisms and susceptibility to RA, while PON1 Q192R polymorphism was associated with PON1 activity in RA patients; we found significantly lower PON1 activity in RA patients.Key points• PON1 Q192R polymorphism is associated with PON1 activity in RA patients.• PON1 activity is significantly lower in RA patients.