| 1. |
- Eussen, Simone J. P. M., et al.
(författare)
-
North-south gradients in plasma concentrations of B-vitamins and other components of one-carbon metabolism in Western Europe: results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study
- 2013
-
Ingår i: British Journal of Nutrition. - 1475-2662 .- 0007-1145. ; 110:2, s. 363-374
-
Tidskriftsartikel (refereegranskat)abstract
- Different lifestyle patterns across Europe may influence plasma concentrations of B-vitamins and one-carbon metabolites and their relation to chronic disease. Comparison of published data on one-carbon metabolites in Western European regions is difficult due to differences in sampling procedures and analytical methods between studies. The present study aimed, to compare plasma concentrations of one-carbon metabolites in Western European regions with one laboratory performing all biochemical analyses. We performed the present study in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort among 5446 presumptively healthy individuals. Quantile regression was used to compare sex-specific median concentrations between Northern (Denmark and Sweden), Central (France, Germany, The Netherlands and United Kingdom) and Southern (Greece, Spain and Italy) European regions. The lowest folate concentrations were observed in Northern Europe (men, 10.4 nmol/l; women, 10.7 nmol/l) and highest concentrations in Central Europe. Cobalamin concentrations were slightly higher in Northern Europe (men, 330 pmol/l; women, 352 pmol/l) compared with Central and Southern Europe, but did not show a clear north-south gradient. Vitamin B-2 concentrations were highest in Northern Europe (men, 22.2 nmol/l; women, 26.0 nmol/l) and decreased towards Southern Europe (P-trend < 0.001). Vitamin B-6 concentrations were highest in Central Europe in men (77.3 nmol/l) and highest in the North among women (70.4 nmol/l), with decreasing concentrations towards Southern Europe in women (P-trend < 0.001). In men, concentrations of serine, glycine and sarcosine increased from the north to south. In women, sarcosine increased from Northern to Southern Europe. These findings may provide relevant information for the study of regional differences of chronic disease incidence in association with lifestyle.
|
|
| 2. |
- Gylling, Björn, 1978-, et al.
(författare)
-
One-carbon metabolite ratios as functional B-vitamin markers and in relation to colorectal cancer risk
- 2019
-
Ingår i: International Journal of Cancer. - : John Wiley & Sons. - 0020-7136 .- 1097-0215. ; 144:5, s. 947-956
-
Tidskriftsartikel (refereegranskat)abstract
- Background: One-carbon metabolism biomarker are easily measured in plasma, but analyzing them one at a time in relation to disease does not take into account the interdependence of the many factors involved. The relative dynamics of major one-carbon metabolism branches can be assessed by relating the functional B-vitamin marker total homocysteine (tHcy) to transsulfuration (total cysteine) and methylation (creatinine) outputs.Objective: We validated the ratios of tHcy to total cysteine (Hcy:Cys), tHcy to creatinine (Hcy:Cre), and tHcy to cysteine to creatinine (Hcy:Cys:Cre) as functional markers of B-vitamin status. We also calculated the associations of these ratios to colorectal cancer (CRC) risk.Design: The relative contribution of potential confounders to the variance of the ratio-based B-vitamin markers was calculated by linear regression in a nested case-control study of 613 CRC cases and 1211 matched controls. Total B-vitamin status was represented by a summary score comprising Z-standardized plasma concentrations of folate, cobalamin, betaine, pyridoxal 5´-phosphate, and riboflavin. Associations with CRC risk were estimated using conditional logistic regression.Results: The ratio-based B-vitamin markers all outperformed tHcy as markers of total B-vitamin status, in both CRC cases and controls. Associations with CRC risk were similar for the ratio-based B-vitamin markers and total B-vitamin status (approximately 25% lower risk for high versus low B-vitamin status).Conclusions: Ratio-based B-vitamin markers were good predictors of total B-vitamin status, and displayed similar associations with CRC risk. Since tHcy and creatinine are routinely clinically analyzed, Hcy:Cre could be easily implemented in clinical practice to aid interpretation of tHcy results.
|
|
| 3. |
- Gylling, Björn, et al.
(författare)
-
Vitamin B-6 and colorectal cancer risk : a prospective population-based study using 3 distinct plasma markers of vitamin B-6 status
- 2017
-
Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 105:4, s. 897-904
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Higher plasma concentrations of the vitamin B-6 marker pyridoxal 5#-phosphate (PLP) have been associated with reduced colorectal cancer (CRC) risk. Inflammatory processes, including vitamin B-6 catabolism, could explain such findings. Objective: We investigated 3 biomarkers of vitamin B-6 status in relation to CRC risk. Design: This was a prospective case-control study of 613 CRC cases and 1190 matched controls nested within the Northern Sweden Health and Disease Study (n = 114,679). Participants were followed from 1985 to 2009, and the median follow-up from baseline to CRC diagnosis was 8.2 y. PLP, pyridoxal, pyridoxic acid (PA), 3-hydroxykynurenine, and xanthurenic acids (XAs) were measured in plasma with the use of liquid chromatography-tandem mass spectrometry. We calculated relative and absolute risks of CRC for PLP and the ratios 3-hydroxykynurenine: XA (HK: XA), an inverse marker of functional vitamin B-6 status, and PA:(PLP + pyridoxal) (PAr), a marker of inflammation and oxidative stress and an inverse marker of vitamin B-6 status. Results: Plasma PLP concentrations were associated with a reduced CRC risk for the third compared with the first quartile and for PLP sufficiency compared with deficiency [OR: 0.60 (95% CI: 0.44, 0.81) and OR: 0.55 (95% CI: 0.37, 0.81), respectively]. HK: XA and PAr were both associated with increased CRC risk [OR: 1.48 (95% CI: 1.08, 2.02) and OR: 1.50 (95% CI: 1.10, 2.04), respectively] for the fourth compared with the first quartile. For HK: XA and PAr, the findings were mainly observed in study participants with,10.5 y of follow-up between sampling and diagnosis. Conclusions: Vitamin B-6 deficiency as measured by plasma PLP is associated with a clear increase in CRC risk. Furthermore, our analyses of novel markers of functional vitamin B-6 status and vitamin B-6-associated oxidative stress and inflammation suggest a role in tumor progression rather than initiation.
|
|
| 4. |
|
|
| 5. |
- Riedel, Bettina M., et al.
(författare)
-
Transcobalamin polymorphism 67A-> G, but not 776C-> G, affects serum holotranscobalamin in a cohort of healthy middle-aged men and women
- 2011
-
Ingår i: Journal of Nutrition. - Bethesda, Md. : Elsevier BV. - 0022-3166 .- 1541-6100. ; 141:10, s. 1784-1790
-
Tidskriftsartikel (refereegranskat)abstract
- Two polymorphic variants in the gene coding for transcobalamin II (TCN2), TCN2 776C-> G and TCN2 67A-> G, may alter serum holotranscobalamin (holoTC), which in turn may affect cellular uptake of cobalamin (Cbl) and thereby Cbl status indicators. We studied the effects of TCN2 776C- > G and TCN2 67A- > G on blood concentrations of holoTC, Cbl, methylmalonic acid (MMA), and total homocysteine (tHcy) in 2411 individuals (50-64 y) that had been selected on the basis of these TCN2 genotypes from 10601 Norwegian inhabitants. The serum holoTC concentration was lower in TCN2 67AG (55 +/- 0.75 pmol/L) and 67GG (48 +/- 2.14 pmol/L) than in 67AA (62 +/- 0.67 pmol/L) (P < 0.001) but did not differ among TCN2 776C-> G genotypes. The polymorphisms interacted as serum holoTC determinants (P= 0.001) and the presence of TCN2 67AG and GG in strata of 776CC and CG, but not 776GG, increased the risk of having serum holoTC <45.6 pmol/L [tertile 1 vs. tertiles 2 and 3: OR = 2.5(95% CI 1.8-3.5) for 67AG; OR = 5.7 (95% Cl 3.5-9.1) for 67GG in 776CC; OR = 2.1 195% Cl 1.6-2.9) for 67AG; and OR = 4.5 (95% Cl 2.4-8.2) for 67GG in 776CG; all P < 0.0011. Plasma MMA, tHcy, and Cbl were not affected by either polymorphism. In summary, serum holoTC, but not plasma Cbl, MMA, or tHcy, varied according to TCN2 67A-> G genotypes. It remains to be determined whether this polymorphic effect on serum holoTC alters its diagnostic utility as Cbl status indicator.
|
|
| 6. |
|
|
| 7. |
|
|
