| 1. |
- Aleksandrova, Krasimira, et al.
(författare)
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Biomarker patterns of inflammatory and metabolic pathways are associated with risk of colorectal cancer : results from the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2014
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 29:4, s. 261-275
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Tidskriftsartikel (refereegranskat)abstract
- A number of biomarkers of inflammatory and metabolic pathways are individually related to higher risk of colorectal cancer (CRC); however, the association between biomarker patterns and CRC incidence has not been previously evaluated. Our study investigates the association of biomarker patterns with CRC in a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC). During median follow-up time of 7.0 (3.7-9.4) years, 1,260 incident CRC cases occurred and were matched to 1,260 controls using risk-set sampling. Pre-diagnostic measurements of C-peptide, glycated hemoglobin, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), C-reactive protein (CRP), reactive oxygen metabolites (ROM), insulin-like growth factor 1, adiponectin, leptin and soluble leptin receptor (sOB-R) were used to derive biomarker patterns from principal component analysis (PCA). The relation with CRC incidence was assessed using conditional logistic regression models. We identified four biomarker patterns 'HDL-C/Adiponectin fractions', 'ROM/CRP', 'TG/C-peptide' and 'leptin/sOB-R' to explain 60 % of the overall biomarker variance. In multivariable-adjusted logistic regression, the 'HDL-C/Adiponectin fractions', 'ROM/CRP' and 'leptin/sOB-R' patterns were associated with CRC risk [for the highest quartile vs the lowest, incidence rate ratio (IRR) = 0.69, 95 % CI 0.51-0.93, P-trend = 0.01; IRR = 1.70, 95 % CI 1.30-2.23, P-trend = 0.002; and IRR = 0.79, 95 % CI 0.58-1.07; P-trend = 0.05, respectively]. In contrast, the 'TG/C-peptide' pattern was not associated with CRC risk (IRR = 0.75, 95 % CI 0.56-1.00, P-trend = 0.24). After cases within the first 2 follow-up years were excluded, the 'ROM/CRP' pattern was no longer associated with CRC risk, suggesting potential influence of preclinical disease on these associations. By application of PCA, the study identified 'HDL-C/Adiponectin fractions', 'ROM/CRP' and 'leptin/sOB-R' as biomarker patterns representing potentially important pathways for CRC development.
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| 2. |
- Baltar, Valéria Troncoso, et al.
(författare)
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A structural equation modelling approach to explore the role of B vitamins and immune markers in lung cancer risk
- 2013
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 28:8, s. 677-688
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Tidskriftsartikel (refereegranskat)abstract
- The one-carbon metabolism (OCM) is considered key in maintaining DNA integrity and regulating gene expression, and may be involved in the process of carcinogenesis. Several B-vitamins and amino acids have been implicated in lung cancer risk, via the OCM directly as well as immune system activation. However it is unclear whether these factors act independently or through complex mechanisms. The current study applies structural equations modelling (SEM) to further disentangle the mechanisms involved in lung carcinogenesis. SEM allows simultaneous estimation of linear relations where a variable can be the outcome in one equation and the predictor in another, as well as allowing estimation using latent variables (factors estimated by correlation matrix). A large number of biomarkers have been analysed from 891 lung cancer cases and 1,747 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Four putative mechanisms in the OCM and immunity were investigated in relation to lung cancer risk: methionine-homocysteine metabolism, folate cycle, transsulfuration, and mechanisms involved in inflammation and immune activation, all adjusted for tobacco exposure. The hypothesized SEM model confirmed a direct and protective effect for factors representing methionine-homocysteine metabolism (p = 0.020) and immune activation (p = 0.021), and an indirect protective effect of folate cycle (p = 0.019), after adjustment for tobacco smoking. In conclusion, our results show that in the investigation of the involvement of the OCM, the folate cycle and immune system in lung carcinogenesis, it is important to consider complex pathways (by applying SEM) rather than the effects of single vitamins or nutrients (e.g. using traditional multiple regression). In our study SEM were able to suggest a greater role of the methionine-homocysteine metabolism and immune activation over other potential mechanisms.
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| 3. |
- Bamia, Christina, et al.
(författare)
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Mediterranean diet and colorectal cancer risk: results from a European cohort
- 2013
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Ingår i: European Journal of Epidemiology. - Dordrecht : Springer Science and Business Media LLC. - 1573-7284 .- 0393-2990. ; 28:4, s. 317-328
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Tidskriftsartikel (refereegranskat)abstract
- The authors investigated the association of adherence to Mediterranean diet with colorectal cancer (CRC) risk in the European Prospective Investigation into Cancer and nutrition study. Adherence to Mediterranean diet was expressed through two 10-unit scales, the Modified Mediterranean diet score (MMDS) and the Centre-Specific MMDS (CSMMDS). Both scales share the same dietary components but differ in the cut-off values that were used for these components in the construction of the scales. Adjusted hazard ratios (HR) for the associations of these scales with CRC incidence were estimated. After 5,296,617 person-years of follow-up, 4,355 incident CRC cases were identified. A decreased risk of CRC, of 8 and 11 % was estimated when comparing the highest (scores 6-9) with the lowest (scores 0-3) adherence to CSMMDS and MMDS respectively. For MMDS the HR was 0.89 (95 % confidence interval (CI): 0.80, 0.99). A 2-unit increment in either Mediterranean scale was associated with a borderline statistically significant 3 to 4 % reduction in CRC risk (HR for MMDS: 0.96; 95 % CI: 0.92, 1.00). These associations were somewhat more evident, among women, were mainly manifested for colon cancer risk and their magnitude was not altered when alcohol was excluded from MMDS. These findings suggest that following a Mediterranean diet may have a modest beneficial effect on CRC risk.
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| 4. |
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| 5. |
- Peters, Tricia, et al.
(författare)
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Validity of a short questionnaire to assess physical activity in 10 European countries
- 2012
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Ingår i: European Journal of Epidemiology. - Dordrecht : Springer Netherlands. - 0393-2990 .- 1573-7284. ; 27:1, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) was measured in 1,941 healthy individuals from 10 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the short EPIC-PAQ, which refers to past year's activity. Pearson (r) and Spearman (sigma) correlation coefficients were calculated for each country, and random effects meta-analysis was used to calculate the combined correlation across countries to estimate the validity of two previously- and one newly-derived ordered, categorical PA indices ("Cambridge index", "total PA index", and "recreational index") that categorized individuals as inactive, moderately inactive, moderately active, or active. The strongest associations with PAEE and MVPA were observed for the Cambridge index (r = 0.33 and r = 0.25, respectively). No significant heterogeneity by country was observed for this index (I-2 = 36.3%, P = 0.12; I-2 = 0.0%, P = 0.85), whereas heterogeneity was suggested for other indices (I-2 > 48%, P < 0.05, I-2 > 47%, P < 0.05). PAEE increased linearly across self-reported PA categories (P for trend < 0.001), with an average difference of approximately 460 kJ/d for men and 365 kJ/d for women, between categories of the Cambridge index. The EPIC-PAQ is suitable for categorizing European men and women into four distinct categories of overall physical activity. The difference in PAEE between categories may be useful when estimating effect sizes from observational research.
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