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Clinical Nutrition (Edinburgh, Scotland) Jun 2022Vitamin B6 status and mortality risk are inversely associated in different patient groups, while prospective studies in the general population are lacking. Here, for the...
BACKGROUND & AIMS
Vitamin B6 status and mortality risk are inversely associated in different patient groups, while prospective studies in the general population are lacking. Here, for the first time, we evaluated the association between biomarkers of vitamin B6 status and mortality risk in a large population-based study.
METHODS
The vitamin B6 vitamers pyridoxal-5'-phosphat (PLP) and 4-pyridoxic acid (4-PA) were measured by high-performance liquid chromatography in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. Participants' vital status and causes of death were recorded until December 2015. Multivariable Cox regression analyses were carried out to estimate Hazard Ratios (HRs) and 95% confidence intervals (CIs) of mortality across quintiles of PLP, 4-PA, and the ratio of 4-PA and PLP.
RESULTS
Out of 15,304 study participants aged between 20 and 85 years at baseline, 1666 (7.7%) died during a median follow-up time of 7.8 years. An inverse association between PLP and mortality was found in a multivariable model adjusted for socioeconomic and lifestyle factors but became statistically non-significant upon adjustment for routine biomarkers (C-reactive protein, creatinine, albumin, and alkaline phosphatase). There was a significant linear trend for a positive association between 4-PA levels and mortality risk in the fully adjusted regression model, although a comparison of extreme quintiles (quintile 5 vs. quintile 1) did not show a significant difference (HR (95% CI): 1.19 (0.93, 1.51), p = 0.02). A positive association between the 4-PA/PLP ratio and all-cause mortality was observed in the multivariable model, with an HRs of 1.45 (95% CI: 1.14, 1.85; p<0.0001). There were no significant associations between the biomarkers and cardiovascular or cancer mortality. The association between 4-PA/PLP and mortality risk was heterogeneous across age groups, and only statistically significant among participants older than 65 years at baseline (HR (95% CI): 1.72 (1.29, 2.29), p<0.0001). In this group, 4-PA/PLP was also associated with cancer mortality, with an HR of 2.16 (1.20, 3.90), p = 0.02).
CONCLUSION
Increased vitamin B6 turnover, as indicated by a higher 4-PA/PLP ratio, was associated with all-cause and cancer mortality among the older U.S. general population. Intervention trials are needed to assess whether older individuals with a high 4-PA/PLP ratio would benefit from increased vitamin B6 intake.
Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Humans; Middle Aged; Neoplasms; Nutrition Surveys; Prospective Studies; Pyridoxal Phosphate; Vitamin B 6; Young Adult
PubMed: 35588551
DOI: 10.1016/j.clnu.2022.04.023 -
The Korean Journal of Gastroenterology... Feb 2020Optimal bowel preparation is essential for a more accurate, comfortable, and safe colonoscopy. The majority of postcolonoscopy colorectal cancers can be explained by... (Review)
Review
Optimal bowel preparation is essential for a more accurate, comfortable, and safe colonoscopy. The majority of postcolonoscopy colorectal cancers can be explained by procedural factors, mainly missed polyps or inadequate examination. Therefore the most important goal of optimal bowel preparation is to reduce the incidence of colorectal cancer. Although adequate preparation should be achieved in 85-90% or more of all colonoscopy as a quality indicator, unfortunately 20-30% shows inadequate preparation. Laxatives for oral colonoscopy bowel preparation can be classified into polyethylene glycol (PEG)-electrolyte lavage solution, osmotic laxatives, stimulant laxatives, and divided into high-volume solution (≥3 L) and low-volume solution (<3 L). The updated 2019 European Society of Gastrointestinal Endoscopy (ESGE) guideline is broadly similar to the 2014 American Society for Gastrointestinal Endoscopy (ASGE) recommendations and reaffirms the importance of split-dosing. However, new ESGE guideline, unlike the 2014 ASGE recommendation, suggests the use of high volume or low volume PEG-based regimens as well as that of non-PEG based agents that have been clinically validated for most outpatient scenarios. For effective, safe, and highly adherent bowel preparation, physicians who prescribe and implement colonoscopy should properly know the advantages and limitations, the dosing, and the timing of regimens. Recently many studies have attempted to find the most ideal regimens, and more convenient, effective, and safe regimens have been developed by reducing the dosing volume and improving the taste. The high tolerability and acceptability of the new low-volume regimens suggest us how we should use it to increase the participation of the national colorectal cancer screening program.
Topics: Citrates; Colonoscopy; Colorectal Neoplasms; Dose-Response Relationship, Drug; Humans; Laxatives; Organometallic Compounds; Picolines; Polyethylene Glycols; Sulfates; Vomiting
PubMed: 32098459
DOI: 10.4166/kjg.2020.75.2.65 -
Nutrients Jun 2022Previous evidence suggests a potential dual impact of aging and vitamin B6 (B6) deficiency on polyunsaturated fatty acid (PUFA) metabolism; gender may influence PUFA...
Previous evidence suggests a potential dual impact of aging and vitamin B6 (B6) deficiency on polyunsaturated fatty acid (PUFA) metabolism; gender may influence PUFA biosynthesis. Perturbation of PUFA compositions during B6 deficiency could be linked to age-related health outcomes. However, little is known about the interrelationships between vitamin B6, PUFA, and gender in the older population. Therefore, we investigated whether gender-specific associations of B6 intake and plasma pyridoxal 5’-phosphate (PLP) concentration, respectively, with plasma PUFA concentrations and ratios (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, and (EPA + DHA)/AA) existed in older adults. We further examined the relationships of adequate B6 status (PLP ≥ 20 nmol/L) with high (above median) plasma PUFA relative to deficient B6 status. This cross-sectional study analyzed 461 participants aged ≥60 years from NHANES 2003−2004. Nutrient intakes were assessed using two 24-h recalls and supplement questionnaires. PLP and PUFA concentrations were measured. Multivariate linear regression assessed the association of B6 intake and PLP with PUFA; multivariate logistic regression evaluated the relationship of adequate B6 status with high plasma PUFA, adjusting for demographic, socioeconomic, and dietary factors; physical activity; smoking; alcohol; medication; and BMI. There were interactions between gender and B6 intake on EPA (P-interaction = 0.008) and AA (P-interaction = 0.004) only, whereas no interaction existed between gender and PLP on PUFA. PLP was directly associated with EPA (β = 0.181, P = 0.002), DHA (β = 0.109, P = 0.005), EPA + DHA (β = 0.14, P = 0.002), EPA/AA (β = 0.186, P = 0.004), and (EPA + DHA)/AA (β = 0.13, P = 0.026). The odds of having high plasma EPA (adjusted (a) OR: 2.03, P = 0.049) and EPA/AA (aOR: 3.83, P < 0.0001) were greater in those with adequate B6 status compared to those with deficient B6 status. In conclusion, in US older adults, a higher PLP level was associated with a greater level of EPA, DHA, EPA + DHA, EPA/AA, and (EPA + DHA)/AA. Adequate B6 status was associated with high EPA and EPA/AA status. These findings suggest that sufficient vitamin B6 status may positively influence PUFA metabolism in older adults.
Topics: Aged; Arachidonic Acid; Cross-Sectional Studies; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Humans; Nutrition Surveys; Phosphates; Pyridoxal Phosphate; Vitamin B 6
PubMed: 35684138
DOI: 10.3390/nu14112336 -
Bioorganic & Medicinal Chemistry May 2017This study measured the antiplasmodial activity of nine zinc-dipicolylamine (ZnDPA) complexes against three strains of Plasmodium falciparum, the causative parasite of...
This study measured the antiplasmodial activity of nine zinc-dipicolylamine (ZnDPA) complexes against three strains of Plasmodium falciparum, the causative parasite of malaria. Growth inhibition assays showed significant activity against all tested strains, with 50% inhibitory concentrations between 5 and 600nM and almost no toxic effect against host cells including healthy red blood cells. Fluorescence microscopy studies with a green-fluorescent ZnDPA probe showed selective targeting of infected red blood cells. The results suggest that ZnDPA coordination complexes are promising antiplasmodial agents with potential for targeted malaria treatment.
Topics: Animals; Antimalarials; CHO Cells; Cell Proliferation; Coordination Complexes; Cricetinae; Cricetulus; Erythrocytes; Hemolysis; Humans; Malaria; Microscopy, Fluorescence; Organometallic Compounds; Picolines; Plasmodium falciparum
PubMed: 28377170
DOI: 10.1016/j.bmc.2017.03.050 -
Cellular and Molecular Life Sciences :... Aug 2005The discovery that pyridoxamine (PM) can inhibit glycation reactions and the formation of advanced glycation end products (AGEs) stimulated new interest in this B6... (Review)
Review
The discovery that pyridoxamine (PM) can inhibit glycation reactions and the formation of advanced glycation end products (AGEs) stimulated new interest in this B6 vitamer as a prospective pharmacological agent for treatment of complications of diabetes. The mechanism of action of PM includes: (i) inhibition of AGE formation by blocking oxidative degradation of the Amadori intermediate of the Maillard reaction; (ii) scavenging of toxic carbonyl products of glucose and lipid degradation; and (iii) trapping of reactive oxygen species. The combination of these multiple activities along with PM safety posture it as a promising drug candidate for treatment of diabetic complications as well as other multifactorial chronic conditions in which oxidative reactions and carbonyl compounds confer pathogenicity.
Topics: Animals; Diabetes Complications; Glycation End Products, Advanced; Humans; Maillard Reaction; Oxidative Stress; Pyridoxamine; Reactive Oxygen Species
PubMed: 15905958
DOI: 10.1007/s00018-005-5082-7 -
Nutrition Journal Feb 2015Chromium (Cr) is a trace element involved in glucose homeostasis. We aim to evaluate and quantify the effects of Cr supplementation on A1C and FPG in patients with T2DM. (Meta-Analysis)
Meta-Analysis Review
AIMS
Chromium (Cr) is a trace element involved in glucose homeostasis. We aim to evaluate and quantify the effects of Cr supplementation on A1C and FPG in patients with T2DM.
MATERIALS AND METHODS
A systematic literature search of Pubmed, EMBASE and the Cochrane Library (from database inception to 11/2014) with no language restrictions sought RCTs or cohort studies evaluating Cr supplementation in T2DM vs control and reporting either change in glycated hemoglobin (A1C) or fasting plasma glucose (FPG). Meta-analysis was conducted on each subtype of Cr supplement separately, and was analyzed by random effects model to yield the weighted mean differences (WMD) and 95% confidence intervals (CIs). Heterogeneity was assessed by using the I(2) statistic.
RESULTS
A total of 14 RCTs (n=875 participants, mean age range: 30 to 83 years old, 8 to 24 weeks of follow-up) were identified (Cr chloride: n=3 study, Cr picolinate: n=5 study, brewer's yeast: n=4 study and Cr yeast: n=3 study). Compared with placebo, Cr yeast, brewer's yeast and Cr picolinate did not show statistically significant effects on A1C. Furthermore, compared to control, Cr chloride, Cr yeast and Cr picolinate showed no effect on FPG, however, brewer's yeast showed a statistically significant decrease in FPG -19.23 mg/dL (95% CI=-35.30 to -3.16, I(2)=21%, n=137).
CONCLUSIONS
Cr supplementation with brewer's yeast may provide marginal benefits in lowering FPG in patients with T2DM compared to placebo however it did not have any effect on A1C.
Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; Chlorides; Chromium; Chromium Compounds; Diabetes Mellitus, Type 2; Dietary Supplements; Fasting; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Picolinic Acids; Saccharomyces cerevisiae; Trace Elements; Treatment Outcome
PubMed: 25971249
DOI: 10.1186/1475-2891-14-14 -
Microbiology Spectrum Aug 2022Dicyandiamide (DCD) and nitrapyrin (NP) are nitrification inhibitors (NIs) used in agriculture for over 40 years. Recently, ethoxyquin (EQ) was proposed as a novel...
Dicyandiamide (DCD) and nitrapyrin (NP) are nitrification inhibitors (NIs) used in agriculture for over 40 years. Recently, ethoxyquin (EQ) was proposed as a novel potential NI, acting through its derivative quinone imine (QI). Still, the specific activity of these NIs on the different groups of ammonia-oxidizing microorganisms (AOM), and mostly their effects on other soil microbiota remain unknown. We determined the impact of QI, and comparatively of DCD and NP, applied at two doses (regular versus high), on the function, diversity, and dynamics of target (AOM), functionally associated (nitrite-oxidizing bacteria-NOB), and off-target prokaryotic and fungal communities in two soils mainly differing in pH (5.4 versus 7.9). QI was equally effective to DCD but more effective than NP in inhibiting nitrification in the acidic soil, while in the alkaline soil QI was less efficient than DCD and NP. This was attributed to the higher activity of QI toward AOA prevailing in the acidic soil. All NIs induced significant effects on the composition of the AOB community in both soils, unlike AOA, which were less responsive. Beyond on-target effects, we noted an inhibitory effect of all NIs on the abundance of NOB in the alkaline soil, with being more sensitive than . QI, unlike the other NIs, induced significant changes in the composition of the bacterial and fungal communities in both soils. Our findings have serious implications for the efficiency and future use of NIs on agriculture and provide unprecedented evidence for the potential off-target effects of NIs on soil microbiota. NIs could improve N use efficiency and decelerate N cycling. Still, we know little about their activity on the distinct AOM groups and about their effects on off-target soil microorganisms. Here, we studied the behavior of a new potent NI, QI, compared to established NIs. We show that (i) the variable efficacy of NIs across soils with different pH reflects differences in the inherent specific activity of the NIs to AOA and AOB; (ii) beyond AOM, NIs exhibit negative effects on other nitrifiers, like NOB; (iii) QI was the sole NI that significantly affected prokaryotic and fungal diversity. Our findings (i) highlight the need for novel NI strategies that consider the variable sensitivity of AOM groups to the different NIs (ii) identify QI as a potent AOA inhibitor, and (iii) stress the need for monitoring NIs' impact on off-target soil microorganisms to ensure sustainable N fertilizers use and soil ecosystem functioning.
Topics: Ammonia; Archaea; Bacteria; Guanidines; Imines; Microbiota; Nitrification; Oxidation-Reduction; Phylogeny; Picolines; Quinones; Soil; Soil Microbiology
PubMed: 35856708
DOI: 10.1128/spectrum.02403-21 -
Ecotoxicology and Environmental Safety Jul 2022The form of chromium (Cr) is an important factor that influences its bioavailability and potential toxicity, while the difference of Cr bioaccumulation between organic...
The form of chromium (Cr) is an important factor that influences its bioavailability and potential toxicity, while the difference of Cr bioaccumulation between organic and inorganic Cr has been rarely investigated. The present study compared the bioaccumulation of organic Cr (e.g., chromium picolinate (CrPic)) and inorganic Cr (e.g., trivalent (Cr(III)) and hexavalent (Cr(VI))) in juvenile coral trout (Plectropomus leopardus). The fish were exposed to a gradient level of different forms of dietary Cr for 66 days. Then the Cr bioaccumulation in fish were comparatively quantified between CrPic, Cr(VI) and Cr(III) groups. The results showed that the Cr bioaccumulation was form- and tissue-specific, dose- and time-dependent. Specifically, the newly bioaccumulated Cr in fish generally increased with the increasing dietary Cr level and exposure time, while the CrPic groups accumulated the highest Cr in most cases, followed by Cr(VI) and Cr(III) groups. The highest Cr content was observed in gut for CrPic groups, while it was highest in heart for Cr(VI) and Cr(III) groups, followed by kidney, skin, fin, liver, gill, bone, eyes and muscle in order. Overall, the results here firstly demonstrated that the dietary organic Cr(III) had significantly higher bioaccumulation than inorganic Cr (Cr(III) and Cr(VI)). Our findings suggested the complexity and variability of form-specific Cr bioavailability and toxicity should be cautiously evaluated in aquatic environments, which has been largely overlooked previously.
Topics: Animals; Anthozoa; Bioaccumulation; Chromium; Picolinic Acids; Trout
PubMed: 35636236
DOI: 10.1016/j.ecoenv.2022.113692 -
The American Journal of Clinical... Aug 2022Folate-mediated 1-carbon metabolism requires several nutrients, including vitamin B6. Circulating biomarker concentrations indicating high vitamin B6 status are...
BACKGROUND
Folate-mediated 1-carbon metabolism requires several nutrients, including vitamin B6. Circulating biomarker concentrations indicating high vitamin B6 status are associated with a reduced risk of colorectal cancer (CRC). However, little is known about the effect of B6 status in relation to clinical outcomes in CRC patients.
OBJECTIVES
We investigated survival outcomes in relation to vitamin B6 status in prospectively followed CRC patients.
METHODS
A total of 2031 patients with stage I-III CRC participated in 6 prospective patient cohorts in the international FOCUS (folate-dependent 1-carbon metabolism in colorectal cancer recurrence and survival) Consortium. Preoperative blood samples were used to measure vitamin B6 status by the direct marker pyridoxal 5'-phosphate (PLP), as well as the functional marker HK-ratio (HKr)[3'-hydroxykynurenine: (kynurenic acid + xanthurenic acid + 3'-hydroxy anthranilic acid + anthranilic acid)]. Using Cox proportional hazards regression, we examined associations of vitamin B6 status with overall survival (OS), disease-free survival (DFS), and risk of recurrence, adjusted for patient age, sex, circulating creatinine concentrations, tumor site, stage, and cohort.
RESULTS
After a median follow-up of 3.2 y for OS, higher preoperative vitamin B6 status as assessed by PLP and the functional marker HKr was associated with 16-32% higher all-cause and disease-free survival, although there was no significant association with disease recurrence (doubling in PLP concentration: HROS, 0.68; 95% CI: 0.59, 0.79; HRDFS, 0.84; 95% CI: 0.75, 0.94; HRRecurrence, 0.96; 95% CI: 0.84, 1.09; HKr: HROS, 2.04; 95% CI: 1.67, 2.49; HRDFS, 1.56; 95% CI: 1.31, 1.85; HRRecurrence, 1.21; 95% CI: 0.96,1. 52). The association of PLP with improved OS was consistent across colorectal tumor site (right-sided colon: HROS, 0.75; 95% CI: 0.59, 0.96; left-sided colon: HROS, 0.71; 95% CI: 0.55, 0.92; rectosigmoid junction and rectum: HROS, 0.61; 95% CI: 0.47, 0.78).
CONCLUSION
Higher preoperative vitamin B6 status is associated with improved OS among stage I-III CRC patients.
Topics: Biomarkers; Carbon; Colorectal Neoplasms; Folic Acid; Humans; Neoplasm Recurrence, Local; Prospective Studies; Pyridoxal Phosphate; Vitamin B 6
PubMed: 35394006
DOI: 10.1093/ajcn/nqac090 -
Clinical Chemistry and Laboratory... Mar 2013Although vitamin B6 and its metabolite, pyridoxal 5'-phosphate (PLP), have been shown to exert beneficial effects in ischemic heart disease, the mechanisms of their... (Review)
Review
Although vitamin B6 and its metabolite, pyridoxal 5'-phosphate (PLP), have been shown to exert beneficial effects in ischemic heart disease, the mechanisms of their action are not fully understood. Some studies have shown that ventricular arrhythmias and mortality upon the occlusion of coronary artery were attenuated by pretreatment of animals with PLP. Furthermore, ischemia-reperfusion-induced abnormalities in cardiac performance and defects in sarcoplasmic reticular Ca2+-transport activities were decreased by PLP. The increase in cardiac contractile activity of isolated heart by ATP was reduced by PLP, unlike propranolol, whereas that by isoproterenol was not depressed by PLP. ATP-induced increase in [Ca2+]i, unlike KCl-induced increase in [Ca2+]i in cardiomyocytes was depressed by PLP. Both high- and low-affinity sites for ATP binding in sarcolemmal membranes were also decreased by PLP. These observations support the view that PLP may produce cardioprotective effects in ischemic heart disease by attenuating the occurrence of intracellular Ca2+ overload due to the blockade of purinergic receptors.
Topics: Animals; Cardiotonic Agents; Heart; Myocardial Ischemia; Pyridoxal Phosphate; Reperfusion Injury; Vitamin B 6; Vitamin B 6 Deficiency
PubMed: 23314545
DOI: 10.1515/cclm-2012-0553