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Study Title and Description

Acute effect of caffeine intake on hemodynamics after resistance exercise in young non-hypertensive subjects.



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?
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Primary Publication Information
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TitleData
Title Acute effect of caffeine intake on hemodynamics after resistance exercise in young non-hypertensive subjects.
Author D Souza,J Casonatto,R Poton,J Willardson,M Polito,
Country
Year 2014
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
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What is the objective of the study (as reported by the authors)? The purpose of the current study was to examine the effect of caffeine intake on cardiovascular and hemodynamic variables after a resistance exercise session.
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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 sample consisted of 15 healthy, non-smoking volunteers (12 male, three female) who had recreational resistance training experience, were non-hypertensive (SBP and DBP lower than 140/90 mmHg, respectively), had no orthopedic problems, and used no substances or medications with cardiovascular effects. Post-resistance exercise hypotension (Queiroz et al., 2013) and cardiovascular response related to caffeine intake (MacDougall, Musante, Castillo, & Acevedo, 1988) are similar in men and women. Subjects were instructed not to drink any caffeinated beverages, perform strenuous physical exertion, or consume alcohol for 72 hours before the start of data collection and throughout the experiment. Experimental design: The study was conducted on two non-consecutive days, a minimum of 72 hours apart, between 8:00 and 9:00 in the morning. Upon arrival at the testing site, subjects remained comfortably seated and quiet for 10 minutes. Immediately thereafter, baseline BP was measured using an automatic device (Omron HEM 742 INT). The baseline BP value was the calculated mean of three consecutive measurements. After the baseline BP measurements were complete, subjects ingested either a capsule containing 4 mg caffeine per kg of body weight or a placebo capsule (talc). Forty-five minutes following the ingestion of caffeine or placebo, systolic blood pressure (SBP), diastolic BP (DBP), mean arterial pressure (MAP), HR, stroke volume (SV), cardiac output (CO) and peripheral vascular resistance (PVR) were continuously and non-invasively monitored with beat-to-beat measurements (Finometer PRO, Finapres Medical Systems). Later, subjects underwent a resistance exercise session consisting of three sets of 10 repetitions each (70% 1RM; 90 seconds rest between sets) of the following exercises: lat pull down, knee flexion, chest press, knee extension, biceps curl, leg press 45°, and triceps curl. Subjects performed a 5-minute warm-up before each experimental session. Fifteen minutes after the end of the exercise session, the subjects’ SBP, DBP, MAP, HR, SV, CO and PVR were again continuously and non-invasively measured with beat-to-beat measurements. Next, an ambulatory blood pressure monitoring device (SpaceLabs 90207) was placed on the right arm of each subject to monitor their BP at 30-minute intervals for the succeeding 9 hours. The MAP was calculated by the equation: MAP = (2Å~DBP + SBP) ÷ 3.
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How many outcome-specific endpoints are evaluated? 5
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What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Heart rate
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List additional health endpoints (separately). 2 Blood pressure (diastolic, systolic, mean arterial)
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List additional health endpoints (separately).3 Stroke volume
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List additional health endpoints (separately).4 Cardiac output
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List additional health endpoints (separately).5 Peripheral vascular resistance
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List additional health endpoints (separately).6
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Clinical, physiological, other Physiological
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What is the study design? Controlled Trial
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Randomized or Non-Randomized? RCT
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What were the diagnostics or methods used to measure the outcome?
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Optional: Name of Method or short description BP was measured using an automatic device (Omron HEM 742 INT). Systolic blood pressure (SBP), diastolic BP (DBP), mean arterial pressure (MAP), HR, stroke volume (SV), cardiac output (CO) and peripheral vascular resistance (PVR) were continuously and non-invasively monitored with beat-to-beat measurements (Finometer PRO, Finapres Medical Systems). Ambulatory blood pressure monitoring device (SpaceLabs 90207) also used.
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Caffeine (general) Caffeine (general)
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Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other?
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Measured or self reported? Measured
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Children, adolescents, adults, or pregnant included? Adults
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What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) 4 mg/kg caffeine or placebo + exercise
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What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models.  Copy from methods) The comparison of resting variables before and after the intake of caffeine or placebo was performed using a two-way analysis of variance (ANOVA). The same statistical procedures were used for comparison of the caffeine/placebo conditions at the post-exercise time point (i.e. 15 minutes after exercise) as well as the mean values during the 9 hours of ambulatory monitoring. Tukey’s post-hoc tests were utilized when necessary. To analyze the period of ambulatory monitoring, multiple comparisons were performed using a repeated measures ANOVA, followed by Bonferroni post-hoc tests, when necessary, to identify the differences.
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What conflicts of interest were reported? Not discussed.
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Refid 24950113
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What were the sources of funding? Not discussed.
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