Advanced Search

Study Preview



Study Title and Description

Caffeine-induced uncoupling of cerebral blood flow and oxygen metabolism: a calibrated BOLD fMRI study.



Key Questions Addressed
1 For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on cardiovascular outcomes?
  • Comments Comments (
    0
    ) |

Primary Publication Information
  • Comments Comments (
    0
    ) |
TitleData
Title Caffeine-induced uncoupling of cerebral blood flow and oxygen metabolism: a calibrated BOLD fMRI study.
Author JE Perthen,AE Lansing,J Liau,TT Liu,RB Buxton,
Country
Year 2008
Numbers

Secondary Publication Information
There are currently no secondary publications defined for this study.


Extraction Form: Cardiovascular Design
Design Details
Question... Follow Up Answer Follow-up Answer
What outcome is being evaluated in this paper? Cardiovascular
  • Comments Comments (
    0
    ) |
What is the objective of the study (as reported by the authors)? In this study, we implemented a quantitative R2* approach for assessing the BOLD response to improve the stability of repeated measurements, in combination with the calibrated-BOLD method, to examine the CBF and CMRO2 responses to caffeine ingestion.
  • Comments Comments (
    0
    ) |
Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods) Subjects: Data were acquired on 10 healthy adults (5 males; mean age 33 years, standard deviation 7 years; mean weight 154 pounds, standard deviation 32 pounds). All subjects reported a moderate daily caffeine intake of between 100 and 250 mg, and abstained from caffeine consumption for at least 12 hours prior to participating in the study. Eight of the 10 subjects (3 males; mean age 35 years, standard deviation 6 years) also took part in an additional study investigating R2* and CBF baseline stability. All studies were performed at approximately the same time of day between 8 am and noon). Imaging Protocol: Each imaging protocol consisted of two sessions, between which the subject ingested an over-the-counter tablet containing 200 mg caffeine and remained outside the scanner for approximately 30 mins to allow the caffeine to take effect before returning to the scanner for the post-dose session. Care was taken when positioning each subject: the laser landmark and stationary landmarks on the head coil were used to ensure that the positioning of the subject for the post-dose scan was as closely matched as possible to their pre-dose scan. The impact of errors in this alignment is discussed in later sections and further addressed in the stability study. Throughout scanning, cardiac pulse and respiratory effort data were monitored using a pulse oximeter (InVivo) and a respiratory effort transducer (BIOPAC), respectively. Scanner TTL pulse data were also recorded to synchronize the physiological data to the acquired images. Baseline measurement stability protocol: The stability experiments were designed to assess the stability of the baseline R2* and CBF measurements between the pre and post-dose sessions, i.e. to quantify the variability in R2* and CBF caused by removing the subject from the scanner between sessions. The protocol was identical to that described above, but no caffeine was administered in the 30 minute break between the two imaging sessions. In addition, no hypercapnia scans were acquired.
  • Comments Comments (
    0
    ) |
How many outcome-specific endpoints are evaluated? 2
  • Comments Comments (
    0
    ) |
What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Cerebral metabolic rate of oxygen (CRMO2)
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately). 2 Cerebral blood flow (CBF)
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).3
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).4
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).5
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).6
  • Comments Comments (
    0
    ) |
Clinical, physiological, other Physiological
  • Comments Comments (
    0
    ) |
What is the study design? Controlled Trial
  • Comments Comments (
    0
    ) |
Randomized or Non-Randomized? NCT
  • Comments Comments (
    0
    ) |
What were the diagnostics or methods used to measure the outcome? Objective
  • Comments Comments (
    0
    ) |
Optional: Name of Method or short description All data were acquired on a GE Signa Excite 3T whole body system with a body transmit coil and an 8-channel receive-only head coil.
  • Comments Comments (
    0
    ) |
Caffeine (general) Caffeine (general)
  • Comments Comments (
    0
    ) |
Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other?
  • Comments Comments (
    0
    ) |
Measured or self reported? Measured
  • Comments Comments (
    0
    ) |
Children, adolescents, adults, or pregnant included? Adults
  • Comments Comments (
    0
    ) |
What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) Subjects served as their own controls. Scans were taken before caffeine administration; subjects rested outside the scanners; then re-entered the scanners to be scanned again post-exposure. Authors stated that "Care was taken when positioning each subject: the laser landmark and stationary landmarks on the head coil were used to ensure that the positioning of the subject for the post-dose scan was as closely matched as possible to their pre-dose scan."
  • Comments Comments (
    0
    ) |
What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models.  Copy from methods) Gender, weight, baseline CBF, and mean daily caffeine intake.
  • Comments Comments (
    0
    ) |
What conflicts of interest were reported? None reported.
  • Comments Comments (
    0
    ) |
Refid 18191583
  • Comments Comments (
    0
    ) |
What were the sources of funding? This work was supported by NIH grants NS-36722, NS-42069, and NS-51661.
  • Comments Comments (
    0
    ) |




Results & Comparisons

No Results found.