AIMS: To investigate the distribution characteristics of CYP1A2 in a Chinese population, and to examine gender-related differences in CYP1A2 activity. METHODS: Two hundred and twenty-nine healthy subjects, 120 men and 109 women, were enrolled in this study. CYP1A2 activity was measured by plasma paraxanthine/caffeine (1,7X/1,3,7X) ratio 6 h after administration of 300 mg caffeine. The concentrations of paraxanthine and caffeine in plasma were detected by h.p.l.c. RESULTS: A 16-fold variation of CYP1A2 activity (range 0. 09 to 1.46) was shown in this study. The coefficient of variation (CV %) of CYP1A2 activity was 62.9%. Non-normal distribution of CYP1A2 activity was indicated by the Shapiro-Wilk test (P<0.001). Probit plots of CYP1A2 activity revealed a bimodal distribution with breakpoint of 1,7X/1,3,7X ratio of 0.12. The percentage of poor metabolizers (PMs) was 5.24% (95% CI: 2.35% approximately 8.13%) in this Chinese population. Residual analysis of the data also supported bimodality (P<0.01). The CYP1A2 activity of men was higher than that of women (median: 0.33 vs 0.23, P<0.001). A probit plot of CYP1A2 activity in men was shifted to the left compared with that in women. Based on phenotype, the gender-related difference was observed in extensive metabolizers (EMs) (P<0.001), but not in PMs (P >0.1). In addition, there was no sex-related difference in the incidence of PMs (P >0.1). CONCLUSIONS: There is a phenotypic polymorphism in CYP1A2 activity in this Chinese population, and CYP1A2 activity is higher in men than that in women.
AIMS: To investigate the distribution characteristics of CYP1A2 in a Chinese population, and to examine gender-related differences in CYP1A2 activity. METHODS: Two hundred and twenty-nine healthy subjects, 120 men and 109 women, were enrolled in this study. CYP1A2 activity was measured by plasma paraxanthine/caffeine (1,7X/1,3,7X) ratio 6 h after administration of 300 mg caffeine. The concentrations of paraxanthine and caffeine in plasma were detected by h.p.l.c. RESULTS: A 16-fold variation of CYP1A2 activity (range 0. 09 to 1.46) was shown in this study. The coefficient of variation (CV %) of CYP1A2 activity was 62.9%. Non-normal distribution of CYP1A2 activity was indicated by the Shapiro-Wilk test (P<0.001). Probit plots of CYP1A2 activity revealed a bimodal distribution with breakpoint of 1,7X/1,3,7X ratio of 0.12. The percentage of poor metabolizers (PMs) was 5.24% (95% CI: 2.35% approximately 8.13%) in this Chinese population. Residual analysis of the data also supported bimodality (P<0.01). The CYP1A2 activity of men was higher than that of women (median: 0.33 vs 0.23, P<0.001). A probit plot of CYP1A2 activity in men was shifted to the left compared with that in women. Based on phenotype, the gender-related difference was observed in extensive metabolizers (EMs) (P<0.001), but not in PMs (P >0.1). In addition, there was no sex-related difference in the incidence of PMs (P >0.1). CONCLUSIONS: There is a phenotypic polymorphism in CYP1A2 activity in this Chinese population, and CYP1A2 activity is higher in men than that in women.
Authors: Junling Yang; Minxia M He; Wei Niu; Steven A Wrighton; Li Li; Yang Liu; Chuan Li Journal: Br J Clin Pharmacol Date: 2012-02 Impact factor: 4.335
Authors: Els Van Peer; Frank Jacobs; Jan Snoeys; Jos Van Houdt; Ils Pijpers; Christophe Casteleyn; Chris Van Ginneken; Steven Van Cruchten Journal: Pharm Res Date: 2017-01-17 Impact factor: 4.200
Authors: Jose Rodríguez-Morató; Albert Goday; Klaus Langohr; Clara Pérez-Mañá; Magí Farré; Rafael de la Torre Journal: Obes Surg Date: 2017-11 Impact factor: 4.129
Authors: T Simon; L Becquemont; B Hamon; E Nouyrigat; Y Chodjania; J M Poirier; C Funck-Brentano; P Jaillon Journal: Br J Clin Pharmacol Date: 2001-11 Impact factor: 4.335