Study Title and Description
Coffee, tea and caffeine intake and the risk of severe depression in middle-aged Finnish men: the Kuopio Ischaemic Heart Disease Risk Factor 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 behavior*?|
Primary Publication Information
|Title||Coffee, tea and caffeine intake and the risk of severe depression in middle-aged Finnish men: the Kuopio Ischaemic Heart Disease Risk Factor Study.|
|Author||A Ruusunen,SM Lehto,T Tolmunen,J Mursu,GA Kaplan,S Voutilainen,|
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)?||Only a few cross-sectional studies have assessed the association between coffee, tea and caffeine and the risk of depression. Our aim was to determine the association in a population-based cohort study.|
|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)||The Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) is an ongoing population-based cohort study designed to investigate risk factors for CVD and other chronic diseases in middle-aged men from Eastern Finland. The study population (n 2232) included those men who were not found to be depressive at the baseline examinations and had no previously diagnosed psychiatric disorder. Depressive symptoms were assessed with the eighteen-item Human Population Laboratory (HPL) Depression Scale at baseline. The scale consists of items dealing with mood disturbance, negative self-concept, loss of energy, problems with eating and sleeping, trouble with concentration and psychomotor retardation or agitation. Those who scored five or more at baseline (n 271, 10.9% of participants) were considered depressed, and were thus excluded from the analysis. We used severe depression diagnosed by a physician as an outcome. Data included participants who received a discharge diagnosis of depressive disorder during the follow-up until the end of December 2006. The dietary intake of foods and beverages was quantitatively assessed by a 4 d food recording at the KIHD study baseline. Participants filled the instructed and nutritionist checked 4 d food recording by using conventional household measures, including cups of coffee and tea. Nutrient intakes were calculated using the Finnish Nutrica_x0002_R software (The Social Insurance Institution of Finland, Turku, Finland), which is mainly compiled using Finnish values for the nutrient composition of foods. Coffee and tea are the main sources of caffeine in our study population, since it was very uncommon to use other sources of caffeine in Finland in the late 1980s. We calculated the caffeine intake of participants from these most important sources of caffeine. In these calculations, we assumed that 100 ml of coffee and tea contain 100mg and 40mg of caffeine, respectively. The participants were divided into quartiles according to coffee drinking: non-drinkers, light drinkers (,375 ml/d), moderate drinkers (375–813 ml/d) and heavy drinkers (.813 ml/d). Because of the low amount of tea consumed by the tea drinkers (mean intake: 105 ml/d), participants were categorized into tea drinkers and non-drinkers. The cohort was also divided into quartiles based on caffeine intake: ,425 mg/d, 425–594 mg/d, 595–781 mg/d and .781 mg/d. All statistical analyses were conducted using the Statistical Package for the Social Sciences statistical software package version 14.0 for Windows (SPSS Inc., Chicago, IL, USA).|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||Relative Risk (RR) of severe depression|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|What is the study design?||Cohort|
|Randomized or Non-Randomized?|
|What were the diagnostics or methods used to measure the outcome?||Subjective|
|Optional: Name of Method or short description||Diagnosis by physician|
|Caffeine (general)||Caffeine (general)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||lowest caffeine intake (<425 mg/d) vs highest caffeine intake (>781 mg/d)|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||The relative risk (RR) of depression was examined using the Cox proportional hazards model adjusted for age and examination years (Model 1) and for socio-economic status, smoking, alcohol consumption, maximal oxygen uptake, BMI and daily intakes of folate and PUFA (Model 2). Further adjustment for marital status, medical comorbidity (hypertension, diabetes and heart disease), leisure time activity, energy intake, the energy-adjusted daily intakes of eicosapentaenoic and docosahexaenoic acids, and use of dairy products did not appreciably change the associations (data not shown). We also repeated the analyses substituting the intake of PUFA with MUFA and SFA, which did not attenuate the results (data not shown). Model 3 included covariates in Model 2 plus HPL Depression Scale scores. To investigate the consistency of coffee drinking habits, we examined the correlation of coffee consumption between the KIHD baseline and 11-year follow-up examinations using Pearson’s correlation coefficient.|
|Provide a general description of results (as reported by the authors).||When comparing coffee drinkers (n 2150) and nondrinkers (n 82), there was a trend towards decreased risk of depression after adjustment for age and examination years (RR=0.41, 95% CI 0.14, 1.12, P=0.081). Further adjustments (Models 2 and 3) did not alter the association. Tea drinking or caffeine intake was not associated with the risk of depression. Table 3 presents the risks of severe depression in tea drinkers v. non-drinkers and in quartiles of caffeine intake. The results remained similar when caffeine intake groups were categorized as medians (RR=1.31; 95% CI 0.74, 2.31; P=0.355) or tertiles (highest tertile v. lowest tertile; RR=1.14; 95% CI 0.53, 2.44; P=0.744).|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||No|
|What were the authors's observations re: trend analysis?|
|What were the author's conclusions?||Coffee consumption, but not tea consumption or caffeine intake, may be associated with the decreased risk of severe depression in middle-aged or older Finnish men. Further studies are required to investigate the mechanisms behind these observations.|
|What were the sources of funding?||The present study was supported by the Finnish Graduate School of Psychiatry, the Juho Vainio Foundation and the Yrjo Jahnsson Foundation.|
|What conflicts of interest were reported?||None of the authors had any personal or financial conflict of interest.|
|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.||Severe depression NOAEL = >781 mg/d|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||Cohort was also divided into coffee and tea drinkers, NOAEL reported is for total caffeine intake quartiles. An insignificant decrease was reported for RR of sever depression when comparing the highest quartile group to the lowest quartile.|
|What is the importance of the study with respect to the adverseness of the outcome?||Critcal|
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.