SISANews

Varianti genetiche della paraoxonasi 1 influenzano il rischio cardiovascolare

L'effetto antiossidante della HDL è attribuito principalmente alla paraoxonasi, una proteina plasmatica ancorata alle particelle contenenti apo A-I. Le varianti genetiche con bassa attività antiossidante rappresentano un fattore di rischio indipendente per la cardiopatia ischemica. Con tutte le cautele del caso, si può ipotizzare un intervento terapeutico indirizzato all'aumento dell'attività paraoxonasica. Già la vitamina C, I polifenoli e le statine si sono dimostrate attive in questo senso.

Paraoxonase variants relate to 10-year risk in coronary artery disease: impact of a high-density lipoprotein-bound antioxidant in secondary prevention

Regieli JJ, Jukema JW, Doevendans PA, Zwinderman AH, Kastelein JJ, Grobbee DE, van der Graaf Y.

J Am Coll Cardiol 2009;54:1238-1245

OBJECTIVES: We investigated the effects of paraoxonase (PON)-1 variants on long-term clinical outcome in patients with coronary artery disease (CAD). BACKGROUND: PON-1 is a potential therapeutic target to further reduce cardiovascular risk because it is a detoxifying esterase with antioxidant properties. The PON-1 knockout models result in higher susceptibility to atherosclerosis, and PON activity contributes to cardiovascular risk in humans. Human gene variants determine PON activity; however, the impact of these variants on recurrent cardiovascular events in vascular disease is as of yet unknown. METHODS: We conducted a 10-year follow-up study of 793 CAD patients in the REGRESS (REgression GRowth Evaluation Statin Study) trial cohort, using nationwide registries. Genotypes were obtained of 2 PON-1 isotypes (L55M, rs854560, and Q192R, rs662), which were previously associated with PON activity. Absolute and relative risks by genotype were estimated using Kaplan-Meier and proportional hazards analyses. RESULTS: Carriership of the PON-1 glutamine isotype at codon 192 and methionine at codon 55 was associated with a higher risk of death due to ischemic heart disease. Hazard ratios per allele copy were 1.71 (95% confidence interval: 1.0 to 2.8, p=0.03) for the glutamine isotype at codon 192 and 1.56 (95% confidence interval: 1.1 to 2.3, p=0.03) for methionine at codon 55. Both isotypes had previously been related to lower PON activity. No effect was observed on all-cause mortality. CONCLUSIONS: PON-1 gene variants influence the 10-year risk of fatal complications from CAD in male patients, despite no effect on all-cause mortality. These long-term findings confirm functional data on PON-1 activity, emphasize the relevance of this pathway in vascular disease, and enforce its putative role as a target to modify and estimate cardiovascular risk.

J Am Coll Cardiol 2009;54:1238-1245