Advanced Search

Study Preview



Study Title and Description

Chronic coffee consumption has a detrimental effect on aortic stiffness and wave reflections.



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 Chronic coffee consumption has a detrimental effect on aortic stiffness and wave reflections.
Author C Vlachopoulos,D Panagiotakos,N Ioakeimidis,I Dima,C Stefanadis,
Country
Year 2005
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)? The present study was undertaken to investigate whether chronic coffee consumption affects aortic stiffness and wave reflections in healthy subjects.
  • 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 The study population consisted of a total of 228 clinically healthy subjects: 141 men (mean +/- SD: 41 +/- 8 y old) and 87 women (41 +/- 9 y old). The subjects were randomly selected from the employees’ records of 2 large industries located in the Athens, Greece, area and represented various socioeconomic categories. Based on a detailed clinical interview and examination, none of the patients had any evidence of cardiovascular disease, hypertension, hypercholesterolemia, diabetes mellitus, or any chronic disease. Furthermore, lipid and fasting blood sugar concentrations were measured in blood samples. Women taking oral contraceptives were excluded from the study. Modifying factors included cigarette smoking, body mass index, and physical activity. All subjects were studied in the morning after fasting overnight in a quiet, air-conditioned room. After a 15-min rest, arterial blood pressure was measured 3 times on the right arm with a sphygmomanometer. Subsequently, arterial function was measured. Coffee Intake Assessment All participants were asked to report their usual frequency of coffee consumption during the past year on a food-frequency questionnaire, which was validated by the Unit of Nutrition, Athens Medical School (22). All reported types of coffee (instant, "Greek" type, filtered, espresso, or cappuccino) were adjusted for 1 cup (150 mL) of coffee and a caffeine concentration of 80 mg. According to the distribution of coffee consumption, we categorized usual coffee consumption as none, low (<200 mL/d), moderate (200–450 mL/d), or high (>450 mL/d). Included in the analysis were the following dummy variables: consumption of decaffeinated coffee, tea, and caffeine-containing drinks (cola types) and chocolate. Evaluation of Aortic Elastic Properties and Wave Reflection Carotid-femoral pulse wave velocity (PWV) was calculated from measurements of pulse transit time and the distance traveled between 2 recording sites (pulse wave velocity = distance [meters]/transit time [seconds]) with a validated noninvasive device (Complior; Artech Medical, Pantin, France). The pressure waveform recorded at any site of the arterial tree is the sum of the forward traveling waveform, which is the waveform generated by pump ejection, and the backward traveling, which is the "echo" of the incident wave reflected at peripheral sites. The merging point of the incident and the reflected wave can be identified on the pressure waveform as an inflection point, which divides the systole into an early and late systolic phase in most people. Augmentation index (AIx), augmented pressure (AP), and delta-t of the central (aortic) pressure waveform was measured as an index of wave reflection. Because AIx and AP are influenced by changes in heart rate, this index was included as a covariate in the analysis. AIx was measured by using a validated, commercially available system (SphygmoCor, AtCor Medical, Sydney, Australia). Waveforms of radial pressure were calibrated according to sphygmomanometric systolic and diastolic pressure measured in the brachial artery. Statistical Analysis Continuous variables are presented as means +/- SD, whereas qualitative variables are presented as absolute and relative frequencies. Associations between coffee consumption groups and sex were tested by use of contingency tables and the calculation of chi-squared tests. Correlations between variables were evaluated by calculating Pearson’s correlation coefficient for the normally distributed variables and Spearman’s correlation coefficients for skewed variables. Comparisons between normally distributed continuous variables and coffee-consuming groups were performed by analysis of variance. Differences in arterial function indexes and arterial pressures between particular subgroups, according to coffee consumption, were tested by using post hoc analysis after correction of the P value for multiple comparisons with the Bonferroni correction. All reported P values were based on two-sided tests. SPSS software (version 11.0, 2002; SPSS Inc, Chicago, IL) was used for all of the statistical calculations.
  • Comments Comments (
    0
    ) |
How many outcome-specific endpoints are evaluated? 5
  • Comments Comments (
    0
    ) |
What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Blood pressure (central [aortic] and peripheral [brachial] SBP, DBP, MP, PP
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately). 2 Heart rate
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).3 Aortic stiffness (pulse wave velocity [PWV])
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).4 Wave reflection (augmentation index [AIx], augmented pressure [AP], time from beginning of aortic waveform to inflection point [delta-t])
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).5 Serum cholesterol (total cholesterol [TC], low density lipoproteins [LDL])
  • Comments Comments (
    0
    ) |
List additional health endpoints (separately).6
  • Comments Comments (
    0
    ) |
Clinical, physiological, other Physiological
  • Comments Comments (
    0
    ) |
What is the study design? Cross-sectional
  • Comments Comments (
    0
    ) |
Randomized or Non-Randomized?
  • 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 Arterial blood pressure was measured 3 times on the right arm with a sphygmomanometer. Carotid-femoral pulse wave velocity (PWV) was calculated from measurements of pulse transit time and the distance traveled between 2 recording sites with a validated noninvasive device (Complior; Artech Medical, Pantin, France). AIx was measured by using a validated, commercially available system (SphygmoCor, AtCor Medical, Sydney, Australia). Waveforms of radial pressure were calibrated according to sphygmomanometric systolic and diastolic pressure measured in the brachial artery.
  • Comments Comments (
    0
    ) |
Caffeine (general)
  • Comments Comments (
    0
    ) |
Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other? Coffee
  • Comments Comments (
    0
    ) |
Measured or self reported? Self-report
  • 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.) No coffee consumption group vs. consumption estimated in mL/day
  • 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) Age, sex, smoking habits, body mass index or height, physical activity, total cholesterol, LDL cholesterol, triacylglycerols, blood glucose concentrations, and heart rate [NOTE: confounders assessed via linear regression only; therefore, results could not be used.
  • Comments Comments (
    0
    ) |
What conflicts of interest were reported? No information provided
  • Comments Comments (
    0
    ) |
Refid 15941880
  • Comments Comments (
    0
    ) |
What were the sources of funding? No information provided
  • Comments Comments (
    0
    ) |




Results & Comparisons

No Results found.