ArticleEuropean journal of clinical pharmacology2007
Comparisons of CYP1A2 genetic polymorphisms, enzyme activity and the genotype-phenotype relationship in Swedes and Koreans.
Article in European journal of clinical pharmacology, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 90 papers, 6 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
90 citing papers in PubMed, 6 syntheses or guidelines pooled it, 262 citations in OpenAlex.
- Effects of Caffeine Dose and Administration Method on Time-Trial Performance: A Systematic Review and Network Meta-Analysis.Nutrients · 2025Pooled it
- Effect of caffeine ingestion on time trial performance in cyclists: a systematic review and meta-analysis.Journal of the International Society of Sports Nutrition · 2024Pooled it
- A systematic review and meta-analysis of the association between clozapine and norclozapine serum levels and peripheral adverse drug reactions.Psychopharmacology · 2021Pooled it
- The impact of genetic polymorphisms on CYP1A2 activity in humans: a systematic review and meta-analysis.The pharmacogenomics journal · 2018Pooled it
- The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis.Sports medicine (Auckland, N.Z.) · 2018Pooled it
- CYP1A2 rs762551 polymorphism contributes to cancer susceptibility: a meta-analysis from 19 case-control studies.BMC cancer · 2012Pooled it
- Influence of the CYP1A2 c.European journal of nutrition · 2024Trial
- Genetic Polymorphisms in ADORA2A and CYP1A2 Influence Caffeine's Effect on Postprandial Glycaemia.Scientific reports · 2019Trial
- CYP1A2 Genotype Variations Do Not Modify the Benefits and Drawbacks of Caffeine during Exercise: A Pilot Study.Nutrients · 2017Trial
- CYP1A2, GSTM1, and GSTT1 polymorphisms and diet effects on CYP1A2 activity in a crossover feeding trial.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2009Trial
- The ratio of specific polychlorinated biphenyls as a surrogate biomarker of cytochrome P4501A2 activity: a pharmaco-metabonomic study in humans.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2008Trial
- PharmVar GeneFocus: CYP1A2-Clinical Impact, Genetic Variation, and Updated Nomenclature.Clinical pharmacology and therapeutics · 2026Review
- Unraveling the complexities of caffeine: metabolism, genetics, evolution, and health.Hereditas · 2026Review
- CYP1A2 expression and activity in a large panel of human nonneoplastic surgical liver samples: Influence of genetics, lifestyle, and other factors.Drug metabolism and disposition: the biological fate of chemicals · 2025Article
- Caffeine and Sports Performance: The Conflict between Caffeine Intake to Enhance Performance and Avoiding Caffeine to Ensure Sleep Quality.Sports medicine (Auckland, N.Z.) · 2025Review
- In Vitro Evaluation of CYP-Mediated Metabolism of Fezolinetant and Pharmacokinetic Interaction Between Fezolinetant and Fluvoxamine in Healthy Postmenopausal Smokers and Nonsmokers.Journal of clinical pharmacology · 2025Article
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- Association between CYP1A2 gene variants -163 C/A (rs762551) and -3860 G/A (rs2069514) and bladder cancer susceptibility.BMC cancer · 2024Article
- A Comprehensive Review of Schizophrenia and Antipsychotic Metabolism as a Predictor of Treatment Response.Cureus · 2024Review
30 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
6 authors at 3 institutions in 2 countries.
Funding
Abstract
objectivesTo investigate the CYP1A2 genotype-phenotype relationship and to compare CYP1A2 genetic polymorphisms and enzyme activity in terms of the effect of smoking and oral contraceptive (OC) use in Swedes and Koreans.
methodsCYP1A2 enzyme activity was determined in 194 and 150 healthy Swedish and Korean subjects, respectively, on the basis of the 4-h plasma paraxanthine/caffeine (17X/137X) ratio determined using high-performance liquid chromatography. Genotyping for the -3860G>A, -2467delT, -739 T>G, -729 C>T, -163C>A and -3113A>G polymorphisms was performed by PCR-restriction fragment length polymorphism analysis.
resultsThe mean 17X/137X ratio was 1.54-fold higher in Swedes than in Koreans (mean difference: 0.16; 95% CI of the mean difference: 0.12, 0.20; p < 0.0001). Smokers had a significantly higher 17X/137X ratio (higher CYP1A2 activity) than non-smokers, while Swedish OC users had a significantly lower 17X/137X ratio than non-users (mean difference: 0.31, 95% CI of the mean difference: 0.23, 0.39; p < 0.0001). No effect of gender differences on enzyme activity was observed. Four known (CYP1A2*1A, *1D, *1F, and *1L) and two novel haplotypes (CYP1A2*1V and CYP1A2*1W) were found. CYP1A2*1K was rare in Swedes and absent in Koreans. No significant genotype-phenotype relationship was observed, with the exception of CYP1A2*1F in Swedish smokers, where it was associated with higher enzyme inducibility (p = 0.02). Koreans displayed a significantly lower mean 17X/137X ratio than Swedes having the same CYP1A2 genotype, smoking habit and OC use.
conclusionsWe found significant differences in CYP1A2 enzyme activity between Swedes and Koreans that could not be explained by environmental factors or the CYP1A2 haplotypes examined, despite differences in allele frequencies. None of the investigated CYP1A2 haplotypes are critical in inducing variations in enzyme activity, with the exception of CYP1A2*1F.
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