Interethnic differences in the relevance of CYP2C9 genotype and environmental factors for diclofenac metabolism in Hispanics from Cuba and Spain

The aims of this study were to evaluate the diclofenac metabolism in Hispanics from Cuba and Spain and its relation to ethnicity, CYP2C9 genotypes and environmental factors. Diclofenac hydroxylation capacity (concentration ratios of diclofenac/metabolites in 8-h urine) was studied in 160 Cuban (classified as 76 Cuban-Whites—CWs and 84 Cuban-Mestizos—CMs) and 148 Spaniard (SPs) healthy volunteers. Diclofenac and its main metabolites, 4′-hydroxy (OH), 3′-OH and 5-OH diclofenac, and CYP2C9*2 to *6 and *8 alleles were also determined in 132 and 128 CWs and CMs, respectively. Gender, tobacco, caffeine and ethanol consumption were also evaluated. The mean diclofenac/4′-OH diclofenac ratio was higher in CMs (0.72±0.25) than in CWs (0.64±0.20; P