Self-reported caffeine consumption miss-matched consumption measured by plasma levels of caffeine and its metabolites: results from two population-based studies

Nermine Laaboub; Setareh Ranjbar; Marie-Pierre F Strippoli; Pedro Marques-Vidal; Sandrine Estoppey-Younes; Belen Ponte; Menno Pruijm; Bruno Vogt; Nicolas Ansermot; Séverine Crettol; Frederik Vandenberghe; Peter Vollenweider; Martin Preisig; Murielle Bochud; Chin B Eap

doi:10.1007/s00394-024-03351-9

Self-reported caffeine consumption miss-matched consumption measured by plasma levels of caffeine and its metabolites: results from two population-based studies

Eur J Nutr. 2024 May 4. doi: 10.1007/s00394-024-03351-9. Online ahead of print.

Authors

Nermine Laaboub¹, Setareh Ranjbar², Marie-Pierre F Strippoli², Pedro Marques-Vidal³, Sandrine Estoppey-Younes⁴, Belen Ponte⁵, Menno Pruijm⁶, Bruno Vogt⁷, Nicolas Ansermot¹, Séverine Crettol¹, Frederik Vandenberghe¹, Peter Vollenweider³, Martin Preisig², Murielle Bochud⁴, Chin B Eap^{8

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Affiliations

¹ Unit of Pharmacogenetics and Clinical Psychopharmacology, Department of Psychiatry, Centre for Psychiatric Neuroscience, Lausanne University Hospital, University of Lausanne, Prilly, Switzerland.
² Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital, University of Lausanne, Prilly, Switzerland.
³ Department of Internal Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
⁴ Centre for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland.
⁵ Division of Nephrology, Geneva University Hospitals, Geneva, Switzerland.
⁶ Service of Nephrology and Hypertension, University Hospital of Lausanne and University of Lausanne, Lausanne, Switzerland.
⁷ Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
⁸ Unit of Pharmacogenetics and Clinical Psychopharmacology, Department of Psychiatry, Centre for Psychiatric Neuroscience, Lausanne University Hospital, University of Lausanne, Prilly, Switzerland. chin.eap@chuv.ch.
⁹ School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland. chin.eap@chuv.ch.
¹⁰ Center for Research and Innovation in Clinical Pharmaceutical Sciences, University of Lausanne, Hôpital de Cery, Prilly, Lausanne, 1008, Switzerland. chin.eap@chuv.ch.
¹¹ Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, University of Lausanne, Geneva, Switzerland. chin.eap@chuv.ch.

PMID: 38703227
DOI: 10.1007/s00394-024-03351-9

Abstract

Importance and objective: Self-reported caffeine consumption has been widely used in research while it may be subject to bias. We sought to investigate the associations between self-reported caffeine consumption and plasma levels of caffeine and its two main metabolites (paraxanthine and theophylline) in the community.

Methods: Data from two population-based studies (SKIPOGH1 and 2 (N = 1246) and CoLaus|PsyCoLaus (N = 4461)) conducted in Switzerland were used. Self-reported caffeine consumption was assessed using questionnaires. Plasma levels of caffeine and its metabolites were quantified by ultra-high performance liquid chromatography coupled to a tandem quadrupole mass spectrometer.

Results: In both studies, mean log plasma levels of caffeine and its two metabolites were over 6.48 (plasma levels = 652 ng/ml) when no caffeine consumption was reported. Subsequently, nonlinear associations between log plasma levels and self-reported caffeine consumption were observed in SKIPOGH, with a change of the slope at 3-5 cups of espresso per day in SKIPOGH1 but not SKIPOGH2. In CoLaus|PsyCoLaus, increased daily consumption of caffeinated beverages was associated with increased log plasma levels with a change of the slope at 3 cups. In both studies, declared caffeine consumption higher than 3-5 cups per day was not associated with higher plasma levels of caffeine and its metabolites.

Conclusion: Self-reports of no or low caffeine consumption and consumption of more than 3-5 cups of coffee should be interpreted with caution, with possible under- or over-estimation. Quantifying plasma levels of caffeine and its metabolites may contribute to a better estimation of caffeine intake.

Keywords: Caffeine; Paraxanthine; Plasma levels; Questionnaire; Self-reporting; Theophylline.