title: Association of coffee consumption and CYP1A2 polymorphism with risk of impaired fasting glucose in hypertensive patients.
abstract: Whether and how coffee use influences glucose metabolism is still a matter for debate. We investigated whether baseline coffee consumption is longitudinally associated with risk of impaired fasting glucose in a cohort of 18-to-45 year old subjects screened for stage 1 hypertension and whether CYP1A2 polymorphism modulates this association. A total of 1,180 nondiabetic patients attending 17 hospital centers were included. Seventy-four percent of our subjects drank coffee. Among the coffee drinkers, 87% drank 1-3 cups/day (moderate drinkers), and 13% drank over 3 cups/day (heavy drinkers). Genotyping of CYP1A2 SNP was performed by real time PCR in 639 subjects. At the end of a median follow-up of 6.1 years, impaired fasting glucose was found in 24.0% of the subjects. In a multivariable Cox regression coffee use was a predictor of impaired fasting glucose at study end, with a hazard ratio (HR) of 1.3 (95% CI 0.97-1.8) in moderate coffee drinkers and of 2.3 (1.5-3.5) in heavy drinkers compared to abstainers. Among the subjects stratified by CYP1A2 genotype, heavy coffee drinkers carriers of the slow *1F allele (59%) had a higher adjusted risk of impaired fasting glucose (HR 2.8, 95% CI 1.3-5.9) compared to abstainers whereas this association was of borderline statistical significance among the homozygous for the A allele (HR 1.7, 95% CI 0.8-3.8). These data show that coffee consumption increases the risk of impaired fasting glucose in hypertension particularly among carriers of the slow CYP1A2 *1F allele.
authors.affiliation: Department of Medicine, Vascular Medicine, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy, palatini@unipd.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Palatini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Benetti
authors.forename: Lucio
authors.initials: L
authors.lastname: Mos
authors.forename: Guido
authors.initials: G
authors.lastname: Garavelli
authors.forename: Adriano
authors.initials: A
authors.lastname: Mazzer
authors.forename: Susanna
authors.initials: S
authors.lastname: Cozzio
authors.forename: Claudio
authors.initials: C
authors.lastname: Fania
authors.forename: Edoardo
authors.initials: E
authors.lastname: Casiglia
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002110:Caffeine / Q000009:adverse effects* / Q000378:metabolism; D003069:Coffee / Q000009:adverse effects* / Q000378:metabolism; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D018149:Glucose Intolerance / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011110:Polymorphism, Genetic; D011236:Prediabetic State / Q000209:etiology / Q000235:genetics*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D003069:Coffee; D002110:Caffeine; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2