Dataset Information

Urine excretion of caffeine and select caffeine metabolites is common in the U.S. population and associated with caffeine intake.

ABSTRACT: Caffeine is a widely consumed psychoactive stimulant and is of epidemiologic interest. Major sources of caffeine are challenging to standardize, and the use of biomarkers is proposed as an alternative means of assessing intake.We described urine caffeine and caffeine metabolite concentrations (n = 2466) and excretion rates (n = 2261) in the US population ?6 y by age, sex, race-ethnicity, and caffeine intake (from foods, beverages, and dietary supplements).We measured caffeine and 14 of its metabolites in spot urine samples from the cross-sectional NHANES 2009-2010 by use of LC-tandem mass spectrometry.Caffeine and its metabolites were detectable in the urine of most persons, generally at concentrations ?1 ?mol/L. Median concentrations (95% CI) ranged from 0.560 (0.497, 0.620) ?mol/L to 58.6 (48.6, 67.2) ?mol/L; median excretion rates from 0.423 (0.385, 0.468) nmol/min to 46.0 (40.7, 50.2) nmol/min. Urine concentrations and excretion rates for 9 analytes (caffeine, theophylline, paraxanthine, 1-methylxanthine, 1-methyluric acid, 1,3-dimethyluric acid, 1,7-dimethyluric acid, 1,3,7-trimethyluric acid, and 5-acetylamino-6-amino-3-methyluracil) had moderate correlations with caffeine intake (Spearman ? = 0.55-0.68, P < 0.0001); the remaining analytes had low correlations (? = 0.15-0.33, P < 0.0001). We observed larger differences in geometric mean concentrations and excretion rates between the highest vs. lowest quartiles of caffeine intake for these 9 compounds than the rest. Consistent with dietary caffeine intake, we observed that urine concentrations and excretion rates for most compounds were significantly (P < 0.05) higher in men than women, non-Hispanic whites than Hispanics and non-Hispanic blacks, and highest in persons aged 40-59 y.Excretion of caffeine and its metabolites in urine is common in the US population. According to the observed associations between spot urine concentrations or excretion rates with caffeine intake, several of these compounds show promise as potential biomarkers of caffeine intake.

SUBMITTER: Rybak ME

PROVIDER: S-EPMC5724768 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Urine excretion of caffeine and select caffeine metabolites is common in the U.S. population and associated with caffeine intake.

Rybak Michael E ME Sternberg Maya R MR Pao Ching-I CI Ahluwalia Namanjeet N Pfeiffer Christine M CM

The Journal of nutrition 20150204 4

<h4>Background</h4>Caffeine is a widely consumed psychoactive stimulant and is of epidemiologic interest. Major sources of caffeine are challenging to standardize, and the use of biomarkers is proposed as an alternative means of assessing intake.<h4>Objective</h4>We described urine caffeine and caffeine metabolite concentrations (n = 2466) and excretion rates (n = 2261) in the US population ≥6 y by age, sex, race-ethnicity, and caffeine intake (from foods, beverages, and dietary supplements).<h4 ...[more]

PMID: 25833779

Similar Datasets

Project description:BackgroundCaffeine is the most frequently used psychoactive substance in the United States and >90% of reproductive-age women report some amount of intake daily. Despite biological plausibility, previous studies on caffeine and fecundability report conflicting results. Importantly, prior studies measured caffeine exposure exclusively by self-report, which is subject to measurement error and does not account for factors that influence caffeine metabolism.ObjectivesOur objective was to examine associations between preconception serum caffeine metabolites, caffeinated beverage intake, and fecundability.MethodsParticipants included 1228 women aged 18-40 y with a history of 1-2 pregnancy losses in the EAGeR (Effects of Aspirin in Gestation and Reproduction) trial. We prospectively evaluated associations of preconception caffeine metabolites (i.e., caffeine, paraxanthine, and theobromine) measured from 1191 serum samples untimed to a specific time of day, self-reported usual caffeinated beverage intakes at baseline, and time-varying cycle-average caffeinated beverage intake, with fecundability. Using Cox proportional hazards models, we estimated fecundability odds ratios (FORs) and 95% CIs according to each metabolite. Follow-up was complete for 89% (n = 1088) of participants.ResultsAt baseline, 85%, 73%, and 91% of women had detectable serum caffeine, paraxanthine, and theobromine, respectively. A total of 797 women became pregnant during ≤6 cycles of preconception follow-up. After adjusting for potential confounders, neither serum caffeine [tertile (T)3 compared with T1 FOR: 0.87; 95% CI: 0.71, 1.08], paraxanthine (T3 compared with T1 FOR: 0.92; 95% CI: 0.75, 1.14), nor theobromine (T3 compared with T1 FOR: 1.15; 95% CI: 0.95, 1.40) were associated with fecundability. Baseline intake of total caffeinated beverages was not associated with fecundability (>3 compared with 0 servings/d adjusted FOR: 0.99; 95% CI: 0.74, 1.34), nor was caffeinated coffee (>2 compared with 0 servings/d adjusted FOR: 0.93; 95% CI: 0.45, 1.92) or caffeinated soda (>2 servings/d adjusted FOR: 0.92; 95% CI: 0.71, 1.20).ConclusionsOur findings are reassuring that caffeine exposure from usual low to moderate caffeinated beverage intake likely does not influence fecundability.This trial was registered at clinicaltrials.gov as NCT00467363.

Project description:BackgroundLimited data are available on the accuracy of 24-h dietary recalls used to monitor US sodium and potassium intakes.ObjectiveWe examined the difference in usual sodium and potassium intakes estimated from 24-h dietary recalls and urine collections.DesignWe used data from a cross-sectional study in 402 participants aged 18-39 y (∼50% African American) in the Washington, DC, metropolitan area in 2011. We estimated means and percentiles of usual intakes of daily dietary sodium (dNa) and potassium (dK) and 24-h urine excretion of sodium (uNa) and potassium (uK). We examined Spearman's correlations and differences between estimates from dietary and urine measures. Multiple linear regressions were used to evaluate the factors associated with the difference between dietary and urine measures.ResultsMean differences between diet and urine estimates were higher in men [dNa - uNa (95% CI) = 936.8 (787.1, 1086.5) mg/d and dK - uK = 571.3 (448.3, 694.3) mg/d] than in women [dNa - uNa (95% CI) = 108.3 (11.1, 205.4) mg/d and dK - uK = 163.4 (85.3, 241.5 mg/d)]. Percentile distributions of diet and urine estimates for sodium and potassium differed for men. Spearman's correlations between measures were 0.16 for men and 0.25 for women for sodium and 0.39 for men and 0.29 for women for potassium. Urinary creatinine, total caloric intake, and percentages of nutrient intake from mixed dishes were independently and consistently associated with the differences between diet and urine estimates of sodium and potassium intake. For men, body mass index was also associated. Race was associated with differences in estimates of potassium intake.ConclusionsLow correlations and differences between dietary and urinary sodium or potassium may be due to measurement error in one or both estimates. Future analyses using these methods to assess sodium and potassium intake in relation to health outcomes may consider stratifying by factors associated with the differences in estimates from these methods. This trial was registered at clinicaltrials.gov as NCT01631240.

Dataset Information

Urine excretion of caffeine and select caffeine metabolites is common in the U.S. population and associated with caffeine intake.

Publications

Urine excretion of caffeine and select caffeine metabolites is common in the U.S. population and associated with caffeine intake.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets