Study Title and Description
Coffee increases state anxiety in males but not in females.
Key Questions Addressed
|1||For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on behavior*?|
Primary Publication Information
|Title||Coffee increases state anxiety in males but not in females.|
|Author||P Botella,A Parra,|
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Behavior - Design Details - INCLUDED Studies
No arms have been defined in this extraction form.
|Question... Follow Up||Answer||Follow-up Answer|
|What outcome is being evaluated in this paper?||Behavior|
|What is the objective of the study (as reported by the authors)?||In the present study, the effects of coffee on anxiety and cardiovascular functioning were measured.|
|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)||Participants Participants were healthy volunteer students at the University of Valencia, Spain; 39 males and 60 females, ranging in age from 18 to 31 years (mean_x0001_ SD¼22.6_x0001_2.9 years). Subjects were not paid for participating. The inclusion criteria were: to be 18 years old or older; to be in good health as reported by the subjects themselves; and to have signed the informed consent form. The exclusion criteria were: being on any medication; having a history of mental disorders; having an irregular sleep pattern during the night before the experiment; and substance abuse. Moderate alcohol drinking and/or cigarette smoking were allowed. The mean daily caffeine intake for each subject was calculated according to Barone and Roberts (1996). As a result of this calculation, the placebo group of females appeared to consume more caffeine than their counterpart males [t23 = 3.12; p < 0.01], but this difference was not statistically significant in the remaining treatments. Other demographic characteristics for participants in this study can be seen in Table 1 of Botella et al. (2001). Dose manipulation The beverage was prepared from espresso coffee kept frozen at _x0002_20_x0003_C after boiling. The caffeine concentration of the coffee was determined with HPLC analysis. On the day of the test, the coffee was thawed and diluted with water to 75, 150 or 300 mg of caffeine in a volume of 100 ml. The placebo was decaffeinated coffee containing 3mg of caffeine. The beverage was served in a disposable opaque glass with 10 g of sucrose at 3_x0003_–5_x0003_C. Procedure Each subject arrived individually at the laboratory between 8:00 and 10:30 a.m. having had breakfast but no caffeine in the past 15 h. The groups were: placebo (decaffeinated coffee, P), 75, 150 or 300 mg of caffeine (C75, C150 and C300, respectively). All subjects were blind as to the caffeine content of their beverage until the end of their participation. Then 25–30 min after drinking the beverage, they completed the Spanish version of the state-trait anxiety inventory (STAI) (Spielberger et al., 1970); and 30–40 min after drinking the beverage, blood pressure and heart rate were recorded. After all the tests were completed, and before knowing the actual dose of caffeine in the coffee ingested, the subjects were asked for their subjective level of increased alertness with none, low, medium or high as responses. Then the subjects were informed about the doses employed in the study and asked to guess which one they had been given.|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||Anxiety|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|What is the study design?||Controlled Trial|
|Randomized or Non-Randomized?||RCT|
|What were the diagnostics or methods used to measure the outcome?||Subjective|
|Optional: Name of Method or short description||State-trait anxiety inventory (STAI)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||placebo group, decaffeinated coffee (3 mg caffeine) vs coffee with 75, 150 or 300 mg of caffeine|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||differences in daily caffeine consumption|
|Provide a general description of results (as reported by the authors).||Males showed a higher state anxiety than females in the STAI test (F(1, 91) = 12.76; p<0.001). This difference was due to the effect of the beverage because sex differences were not present in the placebo condition. The effect of the beverage was significant in males (F(3, 35) = 4.11; p<0.02) but not in females (F(3, 56) = 0.32; p=0.81). These and other state anxiety results are illustrated in Figure 1. As expected, the treatment was not statistically significant in the trait anxiety variable.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||The observed results in state anxiety, with males being dose-dependently sensitive to caffeinated coffee and with females showing no effect, seem to be well grounded.|
|What were the author's conclusions?||The observed results in state anxiety, with males being dose-dependently sensitive to caffeinated coffee and with females showing no effect, seem to be well grounded. There are two reasons for this statement: first, the differences should not be attributed to differences in daily caffeine consumption because the reported ANOVAs were also performed as analyses of covariance, with daily caffeine intake as a covariate, and the results of such analyses showed no relevant discrepancy from the ANOVAs; second, the differences should not be attributed to differences in the availability of caffeine in the brain because the amounts of caffeine measured in saliva were almost identical in males and females (see Botella et al., 2001). We think that the observed differences are due to differences in the sensitivity to caffeine or other substances contained in coffee.|
|What were the sources of funding?||None listed.|
|What conflicts of interest were reported?||N/A|
|Does the exposure (dose) need to be standardized to the SR?||No|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).|
|List all the endpoint(s) followed by the dose (mg) which will be used in comparison to Nawrot. Characterize value as LOAEL/NOAEL, etc. if possible.||Anxiety (state) - NOAEL = 75 mg; LOAEL = 150 mg (males) Anxiety (state) - NOAEL = 300 mg (females)|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||This endpoint was significant only for males, not females. Trait anxiety was not affected by caffeine.|
|What is the importance of the study with respect to the adverseness of the outcome?||Important|
No baseline characteristics have been defined for this extraction form.
Results & Comparisons
No Results found.
|Arm or Total||Title||Description||Comments|
No quality dimensions were specified.
No quality rating data was found.