Advanced Search

Study Preview



Study Title and Description

Coffee consumption and CYP1A2 genotype in relation to bone mineral density of the proximal femur in elderly men and women: A cohort 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 bone and calcium balance outcomes?
  • Comments Comments (
    0
    ) |

Primary Publication Information
  • Comments Comments (
    0
    ) |
TitleData
Title Coffee consumption and CYP1A2 genotype in relation to bone mineral density of the proximal femur in elderly men and women: A cohort study
Author H. Hallstrom, H. Melhus, A. Glynn, L. Lind, A. C. Syvanen and K. Michalsson
Country
Year 2010
Numbers

Secondary Publication Information
There are currently no secondary publications defined for this study.


Extraction Form: Bone & Calcium Outcomes
Design Details
Question... Follow Up Answer Follow-up Answer
Refid 10190
  • Comments Comments (
    0
    ) |
What outcome is being evaluated in this paper? Bone and Calcium
  • Comments Comments (
    0
    ) |
What is the objective of the study (as reported by the authors)? The principal aim of this study was to investigate the relation between consumption of coffee and BMD of the proximal femur in a population-based cohort of 70- year-old Swedish men and women. A secondary aim was to study whether the relation between consumption of coffee and BMD in the cohort was modified by the participants’ genotype for cytochrome P450 1A2 (CYP1A2).
  • 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: 70-year-old individuals residing in Uppsala, Sweden, in 2001-2004; randomly selected. 50% of those invited participated in study. Each subject was examined for blood pressure and anthropometry, blood sampling after overnight fast, routine medical history, and assessment of BMD using dual-energy X-ray absorptiometery (DXA) Dietary assessments: Dietary habits were registered in 850 (84%) of the participants. Each participant recorded his or her food consumption during 7 consecutive days using a pre-coded food diary after instructions from a dietician. The questionnaire has been validated. The daily intake of energy, caffeine, alcohol and selected nutrients including calcium, vitamin D and A, was calculated using a computerized program and information about energy and nutrient contents of foods from a database from the National Food Administration. One cup of filtered coffee (150 mL) was estimated to contain approximately 100 mg caffeine. One cup of tea (200 mL) was estimated to contain about 50 mg of caffeine. No analyses of caffeine content of the consumed coffee and tea were performed. Measurement of bone mineral density at the proximal femur: On average, 2 years after the baseline investigation, 898 of 1,016 cohort members agreed to undergo measurements of BMD (g/cm2 ) for total proximal femur, femoral neck and trochanteric regions of the proximal femur by DXA. Two main fracture categories were included - the femoral neck and the trochanteric femoral fracture; when applicable, both extremities were used in the calculation. By triple measurements in 15 participants, the precision error of the DXA measurements of total proximal femur in our laboratory has been calculated to be about 0.7%. Genotyping of CYP1A2: Evaluated SNP rs11854147, which is in linkage disequilibrium with rs762551 (R2 = 0.886). The SNP rs11854147 was genotyped at the SNP Technology Platform at Uppsala University, Sweden using the Illumina BeadStation 500GX and the 384-plex Illumina Golden Gate assay. The sample success rate was 98.8% and the reproducibility 100% according to duplicate analysis of 2.4% of the genotypes. The genotype distribution was in Hardy-Weinberg equilibrium. Statistical analyses: Authors had the possibility to include 717 genotyped participants with both dietary assessment and BMD measurement in our analysis. All statistical calculations were performed using SAS (SAS 9.1; SAS Institute Inc., Cary, NC). The relation between coffee consumption as a continuous variable and BMD was primarily analyzed by ordinary linear regression models. Coffee intake was categorized by quartiles (0-2 cups/day, 3 cups/day, 4 cups/day and more than 4 cups/day), and the least square means of BMD for each quartile was estimated on the basis of the regression estimates using the General Linear Model (GLM). All estimates were ageadjusted (at time of the DXA measurement) or adjusted by a multivariable model. The multivariable model included age, height, weight, total caloric intake; intakes of vitamin D, vitamin A, calcium, alcohol and tea (all continuous). Categorized variables included in the model were smoking (never, current, former) and levels of leisure physical activity (low, medium, high). The hypothesis that the participants’ CYP1A2 genotype could potentially modify the relation between coffee intake and BMD was tested in high consumers (both sexes) of coffee (4 cups or more per day). " Slow" metabolizers were defined as participants with genotypes C/T (40.6%) or T/T (10.7%) while " rapid" metabolizers were those with genotype C/C (48.7%). Average multivariableadjusted BMD values of " slow" and " rapid" metabolizers were compared. To eliminate potential inducing effects of smoking on CYP1A2 the analyses were repeated in nonsmoking participants only. Authors additionally analyzed whether there existed a difference in adjusted mean BMD values in men and women with a high consumption of coffee (4 cups or more per day) according to their calcium intake: low (<600 mg/day), intermediate (600-1200 mg/day) and high (>1200 mg/day) total calcium intake (including diet and supplements).
  • Comments Comments (
    0
    ) |
How many outcome-specific endpoints are evaluated? 1
  • Comments Comments (
    0
    ) |
What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Bone mineral density
  • Comments Comments (
    0
    ) |
Clinical, physiological, other Physiological
  • Comments Comments (
    0
    ) |
What is the study design? Cohort
  • 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 DXA
  • Comments Comments (
    0
    ) |
Caffeine (general) Caffeine (general)
  • Comments Comments (
    0
    ) |
Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other? coffee, tea
  • 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.) Various analyses conducted based on (1) Quartiles based on coffee consumption: 0-2, 3, 4 and >4 cups/day; (2) in genotype high consumers (4 or more cups/day) - slow and fast metabolizers based on genotype
  • 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) The multivariable model included age, height, weight, total caloric intake; intakes of vitamin D, vitamin A, calcium, alcohol and tea (all continuous). Categorized variables included in the model were smoking (never, current, former) and levels of leisure physical activity (low, medium, high).
  • Comments Comments (
    0
    ) |
What were the sources of funding? This study was supported by grants from the Swedish Research Council. The SNP genotyping was supported by the Knut and Alice Wallenberg foundation and Uppsala University
  • Comments Comments (
    0
    ) |
What conflicts of interest were reported? The authors declare that they have no competing interests.
  • Comments Comments (
    0
    ) |




Results & Comparisons

No Results found.