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Study Title and Description

The association of caffeinated beverages with blood pressure in adolescents.



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 The association of caffeinated beverages with blood pressure in adolescents.
Author MR Savoca,CD Evans,ME Wilson,GA Harshfield,DA Ludwig,
Country
Year 2004
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 present study was to examine the association between the consumption of caffeinated beverages and blood pressure in a sample of both African American and white adolescents.
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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) Data for this investigation were obtained in the course of an ongoing research program to examine hemodynamic responses to competitive stress in healthy adolescents. Subjects were volunteers throughout the public and private high schools in Richmond County and Columbia County, Georgia. Subjects were recruited according to their interest in participating via school announcements, flyers, and handouts to 1 high school (900 students) and through word of mouth from subjects who had already participated in similar research projects. Inclusion criteria were African American or white ethnicity, aged 15 to 19 years, not taking any medications including contraceptives, and having no food allergies by parental and self-report as well as the ability to meet the dietary and testing requirements of the protocol. Of 194 potential participants, 35 were excluded before testing as a result of exceeding the age requirement between consent and their availability for testing, rescheduling owing to conflicts, relocation out of the area, pregnancy as determined by urine pregnancy testing, illness on test day, failure to comply with the dietary protocol (determined by daily overnight urine samples), or withdrawal of parental consent or subject assent. Trained research assistants measured blood pressure levels using a mercury manometer. Normotensive status and values used in subsequent statistical analyses were determined using the mean of 3 successive blood pressure readings. The subjects received a sodium-controlled diet for 3 days. After the research assistants obtained blood pressure readings and weight and height measurements, subjects planned their meals by selecting foods and beverages from a menu that included a wide array of breakfast, lunch, dinner, snack, and beverage items. Of the 15 beverage choices, 6 contained caffeine. There were also 10 chocolate-containing items with small amounts of caffeine. Controlling mean±SD sodium intake to 4000±200 mg/d was the only selection criterion. The preselected meals were packed into coolers. Subjects were required to return any uneaten food as well as the packaging from the foods and beverages that were eaten. The amount of each food returned was recorded. The total amount of foods and beverages selected minus the amount returned was used to determine subjects’ dietary intake during the 3 days. Caffeine content for all foods and beverages on the menu was determined using the University of Minnesota nutrient database. The amount of caffeine consumed during the 3 days was calculated for each subject based on the amount of caffeine in each food and the quantity of each food consumed by that subject. Caffeine intake was treated as a categorical variable by stratifying subjects into 3 caffeine-intake categories based on their mean daily caffeine intake. A general linear model (multiple regression including both continuous and categorical variables) was used to assess the effects of race and category of caffeine intake on systolic and diastolic blood pressure and determine if the association between caffeine intake and blood pressure varied by race. Sex and body mass index were controlled for in the model. The amount of variance explained (R2) by the model and the unique contribution of each variable in the model are provided. We used t tests to compute individual pairwise comparisons of least squares regression means in the model. Differences between least squares regression means were reported using mean differences and 95% confidence intervals (CIs).
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How many outcome-specific endpoints are evaluated? 1
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What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Blood pressure (SBP and DBP)
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List additional health endpoints (separately). 2
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List additional health endpoints (separately).3
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List additional health endpoints (separately).4
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List additional health endpoints (separately).5
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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? NCT
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What were the diagnostics or methods used to measure the outcome? Objective
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Optional: Name of Method or short description Trained research assistants measured blood pressure levels using a mercury manometer.
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Caffeine (general) Caffeine (general)
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Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other? chocolate, soda, tea
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Measured or self reported? Measured
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Children, adolescents, adults, or pregnant included? Adolescents
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What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) High vs. low consumptions
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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) race, sex, body mass index
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What conflicts of interest were reported? No information provided
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Refid 15123481
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What were the sources of funding? This study was supported by grants HL-59954 and HL-64225 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md.
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Results & Comparisons

No Results found.