Central and peripheral effects of sustained caffeine use: Tolerance is incomplete
Authors: Watson, J., Deary, I. and Kerr, D.
Journal: British Journal of Clinical Pharmacology
Volume: 54
Issue: 4
Pages: 400-406
ISSN: 0306-5251
DOI: 10.1046/j.1365-2125.2002.01681.x
Abstract:Aims: It is widely held that tolerance develops to the effects of sustained caffeine consumption. This study was designed to investigate the effects of chronic, staggered caffeine ingestion on the responses of an acute caffeine challenge, during euglycaemia. Methods: Twelve healthy volunteers were randomized using a double-blind, crossover design to take either 200 mg caffeine (C-replete) or placebo (C-naïve) twice daily for 1 week. Following baseline measurements being made, the responses to 200 mg caffeine (blood-pressure, middle cerebral artery velocity, mood and cognitive performance) were examined over the subsequent 120 min. Blood glucose was not allowed to fall below 4.0 mmol l-1. Results: After the caffeine challenge, middle cerebral artery blood velocity decreased in both conditions but was greater in the C-naïve condition (-8.0 [-10.0, -6.1] cm s-1 vs -4.9 [-6.8, -2.9] cm s-1 C-replete, P < 0.02). Systolic blood pressure rise was not significantly different in C-naïve, although this rise was more sustained over time (P < 0.04). Mood was adversely affected by regular caffeine consumption with tense aspect of mood significantly higher at baseline in C-replete 11.6 ± 0.6 C-naïve vs 16.3 ± 1.6 C-replete, P < 0.01). Cognitive performance was not affected by previous caffeine exposure. Conclusions: Overall these results suggest that tolerance is incomplete with respect to both peripheral or central effects of caffeine.
Source: Scopus
Central and peripheral effects of sustained caffeine use: tolerance is incomplete.
Authors: Watson, J., Deary, I. and Kerr, D.
Journal: Br J Clin Pharmacol
Volume: 54
Issue: 4
Pages: 400-406
ISSN: 0306-5251
DOI: 10.1046/j.1365-2125.2002.01681.x
Abstract:AIMS: It is widely held that tolerance develops to the effects of sustained caffeine consumption. This study was designed to investigate the effects of chronic, staggered caffeine ingestion on the responses of an acute caffeine challenge, during -euglycaemia. METHODS: Twelve healthy volunteers were randomized using a double-blind, cross-over design to take either 200 mg caffeine (C-replete) or placebo (C-naïve) twice daily for 1 week. Following baseline measurements being made, the responses to 200 mg caffeine (blood-pressure, middle cerebral artery velocity, mood and cognitive performance) were examined over the subsequent 120 min. Blood glucose was not allowed to fall below 4.0 mmol l-1. RESULTS: After the caffeine challenge, middle cerebral artery blood velocity decreased in both conditions but was greater in the C-naïve condition (-8.0 [-10.0, -6.1] cm s-1 vs -4.9 [-6.8, -2.9] cm s-1 C-replete, P < 0.02). Systolic blood pressure rise was not significantly different in C-naïve, although this rise was more sustained over time (P < 0.04). Mood was adversely affected by regular caffeine consumption with tense aspect of mood significantly higher at baseline in C-replete 11.6 +/- 0.6 C-naïve vs 16.3 +/- 1.6 C-replete, P < 0.01). Cognitive performance was not affected by previous caffeine exposure. CONCLUSIONS: Overall these results suggest that tolerance is incomplete with respect to both peripheral or central effects of caffeine.
Source: PubMed
Central and peripheral effects of sustained caffeine use: tolerance is incomplete
Authors: Watson, J., Deary, I. and Kerr, D.
Journal: BRITISH JOURNAL OF CLINICAL PHARMACOLOGY
Volume: 54
Issue: 4
Pages: 400-406
ISSN: 0306-5251
DOI: 10.1046/j.1365-2125.2002.01681.x
Source: Web of Science (Lite)
Central and peripheral effects of sustained caffeine use: tolerance is incomplete
Authors: Watson, J., Deary, I.A. and Kerr, D.
Journal: British Journal of Clinical Pharmacology
Volume: 54
Pages: 400-406
ISSN: 0144-6657
DOI: 10.1046/j.1365-2125.2002.01681.x
Abstract:Aims It is widely held that tolerance develops to the effects of sustained caffeine consumption. This study was designed to investigate the effects of chronic, staggered caffeine ingestion on the responses of an acute caffeine challenge, during euglycaemia.
Methods Twelve healthy volunteers were randomized using a double-blind, cross-over design to take either 200 mg caffeine (C-replete) or placebo (C-naïve) twice daily for 1 week. Following baseline measurements being made, the responses to 200 mg caffeine (blood-pressure, middle cerebral artery velocity, mood and cognitive performance) were examined over the subsequent 120 min. Blood glucose was not allowed to fall below 4.0 mmol l−1.
Results After the caffeine challenge, middle cerebral artery blood velocity decreased in both conditions but was greater in the C-naïve condition (−8.0 [-10.0, −6.1] cm s−1 vs −4.9 [-6.8, −2.9] cm s−1 C-replete, P < 0.02). Systolic blood pressure rise was not significantly different in C-naïve, although this rise was more sustained over time (P < 0.04). Mood was adversely affected by regular caffeine consumption with tense aspect of mood significantly higher at baseline in C-replete 11.6 ± 0.6 C-naïve vs 16.3 ± 1.6 C-replete, P < 0.01). Cognitive performance was not affected by previous caffeine exposure.
Conclusions Overall these results suggest that tolerance is incomplete with respect to both peripheral or central effects of caffeine.
Source: Manual
Preferred by: David Kerr
Central and peripheral effects of sustained caffeine use: tolerance is incomplete.
Authors: Watson, J., Deary, I. and Kerr, D.
Journal: British journal of clinical pharmacology
Volume: 54
Issue: 4
Pages: 400-406
eISSN: 1365-2125
ISSN: 0306-5251
DOI: 10.1046/j.1365-2125.2002.01681.x
Abstract:Aims
It is widely held that tolerance develops to the effects of sustained caffeine consumption. This study was designed to investigate the effects of chronic, staggered caffeine ingestion on the responses of an acute caffeine challenge, during -euglycaemia.Methods
Twelve healthy volunteers were randomized using a double-blind, cross-over design to take either 200 mg caffeine (C-replete) or placebo (C-naïve) twice daily for 1 week. Following baseline measurements being made, the responses to 200 mg caffeine (blood-pressure, middle cerebral artery velocity, mood and cognitive performance) were examined over the subsequent 120 min. Blood glucose was not allowed to fall below 4.0 mmol l-1.Results
After the caffeine challenge, middle cerebral artery blood velocity decreased in both conditions but was greater in the C-naïve condition (-8.0 [-10.0, -6.1] cm s-1 vs -4.9 [-6.8, -2.9] cm s-1 C-replete, P < 0.02). Systolic blood pressure rise was not significantly different in C-naïve, although this rise was more sustained over time (P < 0.04). Mood was adversely affected by regular caffeine consumption with tense aspect of mood significantly higher at baseline in C-replete 11.6 +/- 0.6 C-naïve vs 16.3 +/- 1.6 C-replete, P < 0.01). Cognitive performance was not affected by previous caffeine exposure.Conclusions
Overall these results suggest that tolerance is incomplete with respect to both peripheral or central effects of caffeine.Source: Europe PubMed Central