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1.
Am J Med Sci ; 361(6): 791-794, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958192

RESUMO

Pyridoxine is an important co-factor for many biochemical reactions in cellular metabolism related to the synthesis and catabolism of amino acids, fatty acids, neurotransmitters. Deficiency of pyridoxine results in impaired transcellular signaling between neurons and presents with muscular convulsions, hyperirritability, and peripheral neuropathy. Deficiency of pyridoxine is usually found in association with other vitamin B deficiencies such as folate (vitamin B9) and cobalamin (vitamin B12). Isolated pyridoxine deficiency is extremely rare. We present the case of a 59-year old female with type 2 diabetes who complained of painful muscle spasms. Her muscle spasms involved in both feet, which have spread proximally to her legs. She also experienced intermittent muscle spasms in her left arm, which is not alleviated by baclofen, cyclobenzaprine. Her plasma pyridoxal 5-phosphate confirmed pyridoxine deficiency. Vitamins B1, B3, B12, and folate were within normal limits. The patient received standard-dose intramuscular pyridoxine injections for three weeks followed by oral supplements for 3 months and her symptoms resolved. This case illustrates the rare instance of isolated pyridoxine deficiency in type 2 diabetes patient manifesting as myoclonic muscle spasms involving the legs and arms in the absence of objective polyneuropathy. Pyridoxine level should, therefore, be assessed in patients with type 2 diabetes, including newly diagnosed patients.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Piridoxina/sangue , Espasmo/sangue , Deficiência de Vitamina B 6/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Piridoxina/administração & dosagem , Piridoxina/deficiência , Espasmo/diagnóstico , Espasmo/tratamento farmacológico , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/tratamento farmacológico
2.
Nutrients ; 12(9)2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899820

RESUMO

BACKGROUND: a large number of studies have linked vitamin B6 to inflammation and cardiovascular disease in the general population. However, it remains uncertain whether vitamin B6 is associated with cardiovascular outcome independent of inflammation. METHODS: we measured plasma pyridoxal 5'-phosphate (PLP), as an indicator of vitamin B6 status, at baseline in a population-based prospective cohort of 6249 participants of the Prevention of Renal and Vascular End-stage Disease (PREVEND) study who were free of cardiovascular disease. As indicators of low-grade systemic inflammation, we measured high-sensitivity C-reactive protein and GlycA; Results: median plasma PLP was 37.2 (interquartile range, 25.1-57.0) nmol/L. During median follow-up for 8.3 (interquartile range, 7.8-8.9) years, 409 non-fatal and fatal cardiovascular events (composite outcome) occurred. In the overall cohort, log transformed plasma PLP was associated with the composite outcome, independent of adjustment for age, sex, smoking, alcohol consumption, body mass index (BMI), estimated glomerular filtration rate (eGFR), total cholesterol:high-density lipoprotein (HDL)-cholesterol ratio, and blood pressure (adjusted hazard ratio per increment of log plasma PLP, 0.66; 95% confidence interval (CI), 0.47-0.93). However, adjustment for high-sensitivity C-reactive protein and GlycA increased the hazard ratio by 9% and 12% respectively, to non-significant hazard ratios of 0.72 (95% confidence interval, 0.51-1.01) and 0.74 (95% confidence interval, 0.53-1.05). The association of plasma PLP with cardiovascular risk was modified by gender (adjusted Pinteraction = 0.04). When stratified according to gender, in women the prospective association with cardiovascular outcome was independent of age, smoking, alcohol consumption, high-sensitivity C-reactive protein, and GlycA (adjusted hazard ratio, 0.50, 95% confidence interval, 0.27-0.94), while it was not in men (adjusted hazard, 0.99, 95% confidence interval, 0.65-1.51). CONCLUSIONS: in this population-based cohort, plasma PLP was associated with cardiovascular outcome, but this association was confounded by traditional risk factors and parameters of inflammation. Notably, the association of low plasma PLP with high risk of adverse cardiovascular outcome was modified by gender, with a stronger and independent association in women.


Assuntos
Doenças Cardiovasculares/epidemiologia , Estado Nutricional , Deficiência de Vitamina B 6/complicações , Vitamina B 6/sangue , Adulto , Idoso , Proteína C-Reativa/análise , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Glicoproteínas/sangue , Fatores de Risco de Doenças Cardíacas , Humanos , Inflamação , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/etiologia , Falência Renal Crônica/prevenção & controle , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fosfato de Piridoxal/sangue , Fatores Sexuais , Deficiência de Vitamina B 6/sangue
3.
Clin Nutr ; 39(9): 2824-2831, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31883613

RESUMO

BACKGROUND: Plasma concentrations of most vitamins decrease as part of the systemic inflammatory response (SIR). Thus low plasma values do not necessarily indicate deficiency. Vitamin B6 status is usually assessed by measurement of pyridoxal phosphate (PLP) in plasma, although vitamin concentrations in blood cells tend to be better markers of cellular stores. In health, plasma PLP appears to be determined primarily by intake, its binding to albumin, and its hydrolysis by alkaline phosphatase (ALP). OBJECTIVE: To examine, using in vitro studies, the effect of albumin concentration and ALP activity on PLP concentration in plasma and red blood cells of healthy subjects (HS) and critically ill patients (CI). DESIGN: Heparin and EDTA (ALP inhibited) whole blood samples from HS (n = 8) and CI (n = 26) were incubated with PLP. Concentration of PLP in plasma and red cells was measured. Albumin and ALP levels were determined in plasma. RESULTS: In PLP incubated heparin samples, there was a strong direct relationship between albumin in the concentration range 10-44 g/L and increase in plasma PLP concentration (rs = 0.93, P < 0.001) and an inverse relationship with increase in red cell PLP concentration (rs = -0.90, P < 0.001). In contrast, ALP activity was inversely associated with increase in plasma PLP concentration (rs = -0.42; P = 0.013) and directly associated with red cell PLP concentration (rs = 0.49; P = 0.003). CONCLUSIONS: Plasma albumin concentration and to a lesser extent ALP activity influences PLP concentration in plasma and red cells. In conditions associated with low albumin (e.g. SIR) or altered ALP activity, red cell PLP measurements are more likely to be reliable than plasma measurements in differentiating true from apparent vitamin B6 deficiency and to guide vitamin B6 supplementation.


Assuntos
Fosfatase Alcalina/sangue , Eritrócitos/química , Fosfato de Piridoxal/sangue , Albumina Sérica/análise , Deficiência de Vitamina B 6/sangue , Vitamina B 6/sangue , Adulto , Idoso , Coleta de Amostras Sanguíneas/métodos , Estado Terminal , Humanos , Inflamação/sangue , Pessoa de Meia-Idade , Estado Nutricional
4.
Int J Hematol ; 110(5): 543-549, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31407257

RESUMO

Vitamin B6 (VB6) deficiency contributes to oncogenesis and tumor progression in certain cancers, and is prevalent in cancer patients in general. VB6 is also an essential element of heme synthesis, and deficiency can lead to anemia. Primary myelofibrosis (PMF) and secondary myelofibrosis (sMF) are myeloproliferative neoplasms often presenting with anemia along with other cytopenias. We performed a prospective study to determine whether PMF and sMF patients suffer from VB6 deficiency, and whether VB6-deficient patients show improvement of anemias with VB6 supplementation. Twelve PMF patients and 11 sMF patients were analyzed. A total of 16 of 23 patients (69.6%) were found to have VB6 deficiency, but VB6 supplementation with pyridoxal phosphate hydrate did not elevate hemoglobin levels in deficient patients. None of the patients presented with vitamin B12, iron, or copper deficiencies. Four patients showed serum folate levels below the lower limit of normal and eight patients showed serum zinc levels below the lower limit of normal; however, these deficiencies were marginal and unlikely to contribute to anemia. Compared to VB6-sufficient patients, VB6-deficient patients showed significantly lower serum folate levels and higher serum copper levels. Studies elucidating the relationship of VB6 deficiency and etiology of PMF/sMF are warranted.


Assuntos
Mielofibrose Primária/sangue , Deficiência de Vitamina B 6/sangue , Adulto , Anemia , Cobre/sangue , Feminino , Ácido Fólico/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Mielofibrose Primária/etiologia , Estudos Prospectivos , Fosfato de Piridoxal/uso terapêutico , Deficiência de Vitamina B 6/tratamento farmacológico
5.
J Nutr ; 149(5): 770-775, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31050750

RESUMO

BACKGROUND: A frequent observation in inflammatory conditions, including rheumatoid arthritis (RA), is low circulating amounts of pyridoxal 5'-phosphate (PLP), the metabolically active form of vitamin B-6. Recently, a functional marker of vitamin B-6 status, the ratio of 3-hydroxykynurenine (HK): xanthurenic acid (XA) in plasma (HK: XA), was proposed. OBJECTIVE: We investigated vitamin B-6 status in patients with RA before and after established treatment with TNFα inhibitors. METHODS: We performed a longitudinal study of RA patients (n = 106, 36% men, median age 54 y) starting first treatment with a TNFα inhibitor (infliximab, etanercept, adalimumab, golimumab, or certolizumab). Clinical assessment (Disease Activity Score for 28 standard joints, DAS28), joint ultrasonography, and blood draw were performed at baseline and after 3 mo treatment. Plasma concentrations of PLP, HK, and XA were measured by liquid chromatography-tandem mass spectrometry. Associations of changes in vitamin B-6 markers with change in DAS28 were assessed by generalized additive models regression and with European League Against Rheumatism (EULAR) response categories by linear regression. RESULTS: At baseline PLP was inversely correlated with CRP (ρ = -0.27, P = 0.007), whereas HK: XA correlated with DAS28 (ρ = 0.46, P < 0.001), CRP (ρ = 0.36, P < 0.001), and ultrasonography scores (ρ = 0.29-0.35, P ≤ 0.003). After 3 mo treatment, the change (a 33% overall reduction) in DAS28 was related to changes in both PLP (ß = -0.28, P = 0.01) and HK: XA (ß = 0.33, P < 0.001). Good responders (45%) according to EULAR criteria experienced a 31% increase in PLP (P = 0.003) and an 11% decrease in HK: XA (P = 0.1), whereas nonresponders (24%) experienced a 25% increase in HK: XA (P = 0.02). CONCLUSION: Two independent measures of vitamin B-6 status confirm an association with disease activity in RA patients. The association of HK: XA with disease activity may also imply perturbations in kynurenine metabolism in RA. This trial was registered at helseforskning.etikkom.no as 2011/490.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Estado Nutricional , Inibidores do Fator de Necrose Tumoral/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Deficiência de Vitamina B 6/complicações , Vitamina B 6/sangue , Adulto , Artrite Reumatoide/sangue , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Feminino , Humanos , Cinurenina/análogos & derivados , Cinurenina/sangue , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fosfato de Piridoxal/sangue , Resultado do Tratamento , Fator de Necrose Tumoral alfa/sangue , Deficiência de Vitamina B 6/sangue , Xanturenatos/sangue
6.
J Nutr Sci Vitaminol (Tokyo) ; 65(1): 94-101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30814419

RESUMO

Despite previous studies suggesting that choline and betaine ameliorate lipid accumulation in rat livers, the relative effectiveness of the two nutrients is unclear. We examined the efficacy of dietary supplementation with choline or betaine in ameliorating lipid accumulation induced by vitamin B6 (B6) deficiency in the rat liver. Male Wistar rats were fed control, B6-deficient, choline-supplemented B6-deficient, betaine-supplemented B6-deficient, or both choline and betaine-supplemented B6-deficient diets (all containing 9 g of l-methionine (Met)/kg) for 35 d. Two experiments were performed, i.e., one using 17 mmol/kg diet choline bitartrate, betaine anhydrous, and the combination and another using 8.5 mmol/kg diet. Rats fed a B6-deficient diet developed lipid accumulation in the liver with a reduction of plasma lipids induced by the disruption of Met metabolism. However, the addition of 17 mmol/kg diet choline or betaine was sufficient to ameliorate the disruptions of lipid and Met metabolism. Additionally, 8.5 mmol/kg diet choline ameliorated liver lipid deposition, while the same amount of betaine had no significant effects on liver or plasma lipid profiles. Supplementation with choline resulted in a higher liver betaine than that found using the same amount of betaine alone, although the overall liver betaine content was reduced in B6-deficient rats. Our findings indicate that choline is more effective than betaine in ameliorating B6 deficiency-related disruptions in Met metabolism and liver lipid accumulation by increasing liver betaine levels.


Assuntos
Betaína/administração & dosagem , Colina/administração & dosagem , Suplementos Nutricionais , Dislipidemias/prevenção & controle , Deficiência de Vitamina B 6/complicações , Animais , Dislipidemias/etiologia , Lipídeos/sangue , Fígado/metabolismo , Masculino , Proteínas Proto-Oncogênicas c-met/metabolismo , Ratos , Ratos Wistar , Resultado do Tratamento , Deficiência de Vitamina B 6/sangue
7.
Nutr Neurosci ; 22(9): 625-636, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29338677

RESUMO

Background: Low vitamin B-6 status has been linked to depressive symptomatology. We examined the longitudinal association of vitamin B-6 status with depressive symptomatology across 3-time points over ∼5-7 years in a cohort of older Hispanic adults. Methods: We used two-level hierarchical linear regression models for continuous outcomes. Vitamin B-6 status was associated with depressive symptomatology across these time points. Results: Plasma pyridoxyl-5-phosphate (PLP) concentration, a time-varying predictor, was significantly associated with depressive symptomatology. Study participants with PLP deficiency, vs. optimal PLP, had higher baseline depressive symptoms (Center for Epidemiologic Studies-Depression Scale (CES-D) score of 22 ± 14, vs. 20 ± 13); this differential remained constant over time and persisted after controlling for age, sex, education, body mass index, smoking and alcohol use, other relevant nutritional factors, perceived stress, stressful life events, allostatic load, and use of antidepressant medication. However, PLP concentration was not associated with the rate of change in depressive symptomatology over time. Conclusions: Suboptimal plasma PLP is associated with higher depressive symptomatology in older Hispanic of Puerto Rican descent and this appears to persist over time. Our data suggest that identification and treatment of vitamin B-6 deficiency may be a useful preventive approach in this population.


Assuntos
Depressão/sangue , Depressão/complicações , Fosfato de Piridoxal/sangue , Deficiência de Vitamina B 6/complicações , Idoso , Biomarcadores/sangue , Feminino , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Fatores de Tempo , Deficiência de Vitamina B 6/sangue
8.
Psychiatr Danub ; 30(3): 310-316, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30267523

RESUMO

BACKGROUND: In our study, we aimed to evaluate the serum homocysteine levels, pyridoxine, folate and vitamin B12 levels in children with attention deficit hyperactivity disorders (ADHD). SUBJECTS AND METHODS: This study included 30 newly diagnosed drug-naive children with ADHD (23 males and 7 female, mean age 9.3±1.8 years) and 30 sex-and age matched healthy controls. The diagnosis of ADHD was made according to DSM-V criteria. Children and adolescents were administered the Schedule for Affective Disorders and Schizophrenia for School Aged Children, Present and Lifetime Version, the Conners' Parent Rating Scale-Revised, Long Form, the Conners' Teacher Rating Scale and the Wechsler Intelligence Scale for Children Revised (WISC-R) for all participants. Homocysteine, pyridoxine, folate and vitamin B12 levels were measured with enzyme-linked immunosorbent assay. RESULTS: Homocysteine, pyridoxine, folate and vitamin B12 levels were significantly lower in children with ADHD compared with their controls (p<0.05). A positive significant correlation was observed between the all WISC-R scores and vitamin B12 level in patients (r=0.408, p=0.025). CONCLUSIONS: The results obtained in this study showed that reduced homocysteine, pyridoxine, folate and vitamin B12 levels could be a risk factor in the etiology of ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/sangue , Ácido Fólico/sangue , Homocisteína/sangue , Piridoxina/sangue , Vitamina B 12/sangue , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Escala de Avaliação Comportamental , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/diagnóstico , Homocisteína/deficiência , Humanos , Masculino , Valores de Referência , Fatores de Risco , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/diagnóstico , Escalas de Wechsler
9.
Pediatr Nephrol ; 33(11): 2161-2165, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30128792

RESUMO

OBJECTIVES: We investigated vitamin B6 blood concentrations in children on long-term dialysis at our centre. METHODS: Retrospective cross-sectional review of vitamin B6 blood concentrations in children on maintenance dialysis [peritoneal dialysis (PD), intermittent haemodialysis (IHD)]. RESULTS: We reviewed 28 children (16 boys), 15 IHD and 13 PD with median (interquartile range, IQR) age of 9.4 (2.4, 14.3) years. The median (IQR) vitamin B6 concentration was 223.4 (74.2, 392.8) nmol/L measured a median (IQR) of 9 (4, 16.5) months following commencement of dialysis. None of the children had vitamin B6 deficiency. Vitamin B6 concentrations were raised in 17 (61%), eight of these received a supplement. Nineteen (68%) received vitamin B6 and/or a supplement containing vitamin B6 whilst 11 (39%) received an enteral feed and a supplement. In those with normal vitamin B6 concentrations who were not receiving an enteral feed or an oral nutritional supplement (n = 6), all achieved normal concentrations without need for vitamin B6 supplementation. There were no differences between those on PD versus IHD (269.2 nmol/L vs. 130 nmol/L, P = 0.65). CONCLUSIONS: We report no children with vitamin B6 deficiency although > 50% had elevated vitamin B6 concentrations. We suggest if dietary assessment of vitamin B6 intake indicates insufficient intake, measurement of blood concentrations will help confirm if supplementation is required. Routine vitamin B6 supplementation and monitoring is currently not indicated in children on chronic dialysis.


Assuntos
Suplementos Nutricionais , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/terapia , Deficiência de Vitamina B 6/sangue , Vitamina B 6/sangue , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Insuficiência Renal Crônica/complicações , Estudos Retrospectivos , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/etiologia , Deficiência de Vitamina B 6/prevenção & controle
10.
Matern Child Nutr ; 14(1)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28544455

RESUMO

Vitamin B6 is important in fetal development, but little is known of the vitamin B6 status of pregnant women and newborns in North America and potential modifying factors. This prospective study determined maternal and cord plasma concentrations of pyridoxal 5' phosphate (PLP; an indicator of vitamin B6 status) in a convenience sample of 368 Canadian pregnant women and their newborns. The association of maternal intake of vitamin B6 and fetal genetic variants with cord plasma PLP and homocysteine concentrations was also examined. Dietary and supplemental intakes of vitamin B6 were assessed in early and mid to late pregnancy. PLP concentrations were measured in maternal plasma in early pregnancy and at delivery, and in cord plasma. Six fetal variants of the MTHFR and CßS genes were assessed for their association with cord plasma PLP and homocysteine concentrations. Geometric mean (95% CI) PLP concentrations were 107 (98, 116) nmol/L in early pregnancy and 58 (53, 62) nmol/L at delivery, respectively, and 296 (275, 319) nmol/L in cord blood (p < .0001). During early pregnancy and at delivery, 3.6% and 5.5% of women had plasma PLP concentrations <20 nmol/L, respectively. Ninety eight percent of the women with supplemental B6 intake of at least the recommended dietary allowance had PLP concentrations >20 nmol/L. Fetal genetic variants were not associated with cord PLP and homocysteine concentrations. Vitamin B6 deficiency is uncommon in a cohort of Canadian pregnant women due largely to prevalent vitamin B6 supplement use.


Assuntos
Dieta Saudável , Suplementos Nutricionais , Fenômenos Fisiológicos da Nutrição Materna , Cooperação do Paciente , Fosfato de Piridoxal/sangue , Saúde da População Urbana , Deficiência de Vitamina B 6/prevenção & controle , Adulto , Estudos de Coortes , Dieta Saudável/etnologia , Feminino , Sangue Fetal/química , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente/etnologia , Recém-Nascido , Masculino , Fenômenos Fisiológicos da Nutrição Materna/etnologia , Inquéritos Nutricionais , Ontário/epidemiologia , Cooperação do Paciente/etnologia , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/etnologia , Complicações na Gravidez/prevenção & controle , Prevalência , Fosfato de Piridoxal/deficiência , Saúde da População Urbana/etnologia , Vitamina B 6/uso terapêutico , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/epidemiologia , Deficiência de Vitamina B 6/etnologia , Adulto Jovem
11.
Biomed Res Int ; 2017: 7367831, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29082255

RESUMO

The purpose of this study was to investigate whether plasma pyridoxal 5'-phosphate (PLP) and homocysteine were dependent on or independent of each other in order to be associated with inflammatory markers in patients with chronic kidney disease (CKD) or those receiving hemodialysis treatment. This was a cross-sectional study. Sixty-eight stage 2-5 CKD patients and 68 hemodialysis patients had one time fasting blood drawn for measurements of plasma PLP, pyridoxal (PL), homocysteine, and several inflammatory markers. Early CKD stage (stages 2-3) patients showed significantly lower plasma PLP levels and homocysteine concentrations than patients in an advanced CKD stage (stages 4-5) and those undergoing hemodialysis. Plasma PLP significantly correlated with CRP levels (partial rs = -0.21, p < 0.05) and plasma PL significantly correlated with IL-10 levels (partial rs = -0.24, p < 0.01), while plasma PLP plus PL significantly correlated with both CRP levels (partial rs = -0.20, p < 0.05) and interleukin-1ß (partial rs = 0.22, p < 0.05) levels after adjusting for plasma homocysteine and other potential confounders. Plasma homocysteine displayed no significant correlations with any inflammatory markers. Vitamin B-6 status, rather than homocysteine, appeared to be a significant factor in relation to inflammatory responses for CKD and hemodialysis patients.


Assuntos
Inflamação/sangue , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/sangue , Deficiência de Vitamina B 6/sangue , Vitamina B 6/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Feminino , Ácido Fólico/sangue , Homocisteína/sangue , Humanos , Inflamação/complicações , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fosfato de Piridoxal/sangue , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/fisiopatologia , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/fisiopatologia
12.
Am J Clin Nutr ; 106(6): 1366-1374, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28978540

RESUMO

Background: Low plasma concentrations of pyridoxal 5'-phosphate (PLP) are common in renal transplant recipients (RTRs) and confer increased risk of long-term mortality. To our knowledge, it is not known whether low plasma PLP concentrations have functional (i.e., intracellular) consequences and, if so, whether such consequences are associated with increased risk of mortality.Objectives: We assessed the association of plasma PLP with functional vitamin B-6 status and explored the potential association of functional vitamin B-6 status with long-term mortality in RTRs.Design: In a longitudinal cohort of 678 stable RTRs with a median follow-up of 5.3 y (IQR: 4.8-6.1 y) and 297 healthy controls, PLP, plasma 3-hydroxykynurenine (3-HK), and xanthurenic acid (XA) were analyzed via validated assays. PLP was used as direct biomarker for vitamin B-6 status, and the 3-HK:XA ratio was used as functional biomarker of vitamin B-6 status with a higher ratio reflecting worse functional vitamin B-6 status.Results: Median PLP, 3-HK, and XA concentrations were 41 nmol/L (IQR: 29-60 nmol/L), 40.1 nmol/L (IQR: 33.0-48.0 nmol/L), and 19.1 nmol/L (IQR: 14.5-24.9 nmol/L), respectively, in healthy controls compared with 29 nmol/L (IQR: 17-50 nmol/L), 61.5 nmol/L (IQR: 45.6-86.5 nmol/L), and 25.5 nmol/L (IQR: 17.2-40.0 nmol/L), respectively, in RTRs (all P < 0.001). RTRs had a higher median 3-HK:XA ratio (2.38; IQR: 1.68-3.49) than did healthy controls (2.13; IQR: 1.63-2.71) (P < 0.05). In RTRs, the 3-HK:XA ratio was inversely associated with plasma PLP (ß = -0.21, P < 0.001). Moreover, a higher 3-HK:XA ratio was independently associated with increased risk of all-cause mortality (HR per SD increment: 1.30; 95% CI: 1.13, 1.49), cancer mortality (HR per SD increment: 1.47; 95% CI: 1.12, 1.95), and infectious disease mortality (HR per SD increment: 1.50; 95% CI: 1.21, 1.86) in RTRs.Conclusions: Vitamin B-6-deficient RTRs have a worse functional vitamin B-6 status than do healthy controls and vitamin B-6-sufficient RTRs. Worse functional vitamin B-6 status in RTRs is independently associated with an increased risk of mortality particularly because of cancer and infectious disease. This trial was registered at clinicaltrials.gov as NCT02811835.


Assuntos
Infecções/mortalidade , Transplante de Rim/efeitos adversos , Cinurenina/análogos & derivados , Neoplasias/mortalidade , Fosfato de Piridoxal/sangue , Deficiência de Vitamina B 6/complicações , Xanturenatos/sangue , Adulto , Idoso , Biomarcadores/sangue , Causas de Morte , Estudos de Coortes , Feminino , Humanos , Rim/cirurgia , Nefropatias/cirurgia , Cinurenina/sangue , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Fatores de Risco , Vitamina B 6/sangue , Deficiência de Vitamina B 6/sangue , Complexo Vitamínico B/sangue
13.
J Inherit Metab Dis ; 40(6): 883-891, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28801717

RESUMO

Pyridoxal 5'-phosphate (PLP), the metabolically active form of vitamin B6, plays an essential role in brain metabolism as a cofactor in numerous enzyme reactions. PLP deficiency in brain, either genetic or acquired, results in severe drug-resistant seizures that respond to vitamin B6 supplementation. The pathogenesis of vitamin B6 deficiency is largely unknown. To shed more light on the metabolic consequences of vitamin B6 deficiency in brain, we performed untargeted metabolomics in vitamin B6-deprived Neuro-2a cells. Significant alterations were observed in a range of metabolites. The most surprising observation was a decrease of serine and glycine, two amino acids that are known to be elevated in the plasma of vitamin B6 deficient patients. To investigate the cause of the low concentrations of serine and glycine, a metabolic flux analysis on serine biosynthesis was performed. The metabolic flux results showed that the de novo synthesis of serine was significantly reduced in vitamin B6-deprived cells. In addition, formation of glycine and 5-methyltetrahydrofolate was decreased. Thus, vitamin B6 is essential for serine de novo biosynthesis in neuronal cells, and serine de novo synthesis is critical to maintain intracellular serine and glycine. These findings suggest that serine and glycine concentrations in brain may be deficient in patients with vitamin B6 responsive epilepsy. The low intracellular 5-mTHF concentrations observed in vitro may explain the favourable but so far unexplained response of some patients with pyridoxine-dependent epilepsy to folinic acid supplementation.


Assuntos
Serina/metabolismo , Vitamina B 6/metabolismo , Encéfalo/metabolismo , Células Cultivadas , Glicina/sangue , Glicina/metabolismo , Humanos , Fosfato de Piridoxal/sangue , Fosfato de Piridoxal/metabolismo , Piridoxina/sangue , Serina/sangue , Vitamina B 6/sangue , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/metabolismo
14.
Am J Clin Nutr ; 105(6): 1344-1350, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28468895

RESUMO

Background: Previous studies have reported low circulating concentrations of pyridoxal-5-phospate (PLP) in renal transplant recipients (RTRs). It is unknown whether this is because of low intake or altered handling, and it is also unknown whether variation in circulating concentrations of PLP influences long-term outcome.Objective: We compared vitamin B-6 intake and circulating PLP concentrations of RTRs with those of healthy controls and investigated long-term clinical implications of vitamin B-6 deficiency in stable outpatient RTRs.Design: In a longitudinal cohort of 687 stable RTRs (57% male; mean ± SD age: 53 ± 13 y) with a median (IQR) follow-up of 5.3 y (4.8-6.1 y) and 357 healthy controls (47% male; age 54 ± 11 y), baseline vitamin B-6 was measured as plasma PLP by high-performance liquid chromatography (HPLC). Vitamin B-6 deficiency was defined as PLP <20 nmol/L, and insufficiency as PLP 20-30 nmol/L. Dietary intake was assessed by validated food-frequency questionnaires.Results: At inclusion [5.3 y (1.8-12.1 y) after transplantation], the mean vitamin B-6 intakes in RTRs and healthy controls were 1.77 ± 0.49 and 1.85 ± 0.56 mg/d, respectively (P = 0.23). In these groups, the median plasma PLP concentrations were 29 nmol/L (17-50 nmol/L) and 41 nmol/L (29-60 nmol/L), respectively (P < 0.001). Accordingly, deficiency was present in 30% of RTRs compared with 11% of healthy controls. PLP concentrations were inversely associated with glucose homeostasis variables and inflammation variables (all P < 0.01). During follow-up, 149 (21%) RTRs died and 82 (12%) developed graft failure. In RTRs, vitamin B-6 deficiency was associated with considerably higher mortality risk (HR 2.14; 95% CI: 1.48, 3.08) than a sufficient vitamin B-6 status, independent of potential confounders. No associations were observed for graft failure (P = 0.18).Conclusions: Vitamin B-6 deficiency is common in RTRs and does not seem to be a consequence of inadequate intake. In addition, this deficient state is clinically relevant and independently associated with an increased risk of mortality in RTRs. The cohort on which the study was based [TransplantLines Food and Nutrition Biobank and Cohort Study (TxL-FN)] was registered at clinicaltrials.gov as NCT02811835.


Assuntos
Transplante de Rim , Rim/cirurgia , Estado Nutricional , Fosfato de Piridoxal/sangue , Deficiência de Vitamina B 6/complicações , Vitamina B 6/sangue , Adulto , Idoso , Glicemia/metabolismo , Estudos de Coortes , Feminino , Humanos , Inflamação/sangue , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Vitamina B 6/administração & dosagem , Deficiência de Vitamina B 6/sangue
15.
Int J Dermatol ; 56(9): 952-956, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28436021

RESUMO

BACKGROUND: Burning mouth syndrome (BMS) is a disorder characterized by chronic mouth pain in the absence of objective clinical abnormalities. Vitamin or mineral deficiencies may have a role in BMS, but data regarding the prevalence and relevance of hematinic deficiencies are conflicting. We aimed to determine the frequency of specific laboratory abnormalities in patients with BMS. METHODS: We retrospectively reviewed the results of screening blood tests in patients with BMS at our institution between January 2003 and December 2013. RESULTS: Among 659 patients with BMS, the most common decreased values or deficiencies were vitamin D3 (15%), vitamin B2 (15%), vitamin B6 (5.7%), zinc (5.7%), vitamin B1 (5.3%), thyrotropin (TSH) (3.2%), vitamin B12 (0.8%), and folic acid (0.7%). Laboratory values for fasting blood glucose and TSH were increased in 23.7% and 5.2%, respectively. CONCLUSIONS: In patients with symptoms of BMS, our results suggest it is reasonable to screen for fasting blood glucose, vitamin D (D2 and D3 ), vitamin B6 , zinc, vitamin B1 , and TSH. Deficiencies of vitamin B12 and folic acid were rare (<1% abnormal).


Assuntos
Deficiência de Vitaminas/sangue , Síndrome da Ardência Bucal/sangue , Síndrome da Ardência Bucal/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Deficiência de Vitaminas/complicações , Glicemia/metabolismo , Colecalciferol/sangue , Colecalciferol/deficiência , Feminino , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Deficiência de Riboflavina/sangue , Deficiência de Riboflavina/complicações , Deficiência de Tiamina/sangue , Deficiência de Tiamina/complicações , Tireotropina/sangue , Tireotropina/deficiência , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Adulto Jovem , Zinco/sangue , Zinco/deficiência
16.
J Immunol Res ; 2017: 2197975, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28367454

RESUMO

The immune system is critical in preventing infection and cancer, and malnutrition can weaken different aspects of the immune system to undermine immunity. Previous studies suggested that vitamin B6 deficiency could decrease serum antibody production with concomitant increase in IL4 expression. However, evidence on whether vitamin B6 deficiency would impair immune cell differentiation, cytokines secretion, and signal molecule expression involved in JAK/STAT signaling pathway to regulate immune response remains largely unknown. The aim of this study is to investigate the effects of vitamin B6 deficiency on the immune system through analysis of T lymphocyte differentiation, IL-2, IL-4, and INF-γ secretion, and SOCS-1 and T-bet gene transcription. We generated a vitamin B6-deficient mouse model via vitamin B6-depletion diet. The results showed that vitamin B6 deficiency retards growth, inhibits lymphocyte proliferation, and interferes with its differentiation. After ConA stimulation, vitamin B6 deficiency led to decrease in IL-2 and increase in IL-4 but had no influence on IFN-γ. Real-time PCR analysis showed that vitamin B6 deficiency downregulated T-bet and upregulated SOCS-1 transcription. This study suggested that vitamin B6 deficiency influenced the immunity in organisms. Meanwhile, the appropriate supplement of vitamin B6 could benefit immunity of the organism.


Assuntos
Citocinas/genética , Linfócitos T/imunologia , Linfócitos T/fisiologia , Deficiência de Vitamina B 6/imunologia , Animais , Diferenciação Celular , Dieta , Regulação para Baixo , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Ativação Linfocitária , Camundongos , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/sangue , Proteína 1 Supressora da Sinalização de Citocina/genética , Proteínas com Domínio T/genética , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/metabolismo , Xanturenatos/sangue
17.
Am J Clin Nutr ; 105(4): 897-904, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28275126

RESUMO

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.


Assuntos
Neoplasias Colorretais/etiologia , Cinurenina/análogos & derivados , Estado Nutricional , Deficiência de Vitamina B 6/complicações , Vitamina B 6/sangue , Xanturenatos/sangue , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Neoplasias Colorretais/sangue , Neoplasias Colorretais/prevenção & controle , Feminino , Humanos , Inflamação/sangue , Inflamação/etiologia , Cinurenina/sangue , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estresse Oxidativo , Estudos Prospectivos , Piridoxal/sangue , Fosfato de Piridoxal/sangue , Ácido Piridóxico/sangue , Suécia , Deficiência de Vitamina B 6/sangue
18.
Biosci Biotechnol Biochem ; 81(2): 316-322, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27696964

RESUMO

We investigated the efficacy of supplementing the diet with choline or betaine in ameliorating lipid accumulation induced by vitamin B6 (B6) deficiency in rat liver. Male Wistar rats were fed a control, B6-deficient, choline-supplemented (2, 4, or 6 g choline bitartrate/kg diet) B6-deficient diet or betaine-supplemented (1, 2, or 4 g betaine anhydrous/kg diet) B6-deficient diet for 35 d; all diets contained 9 g L-methionine (Met)/kg diet. Choline or betaine supplementation attenuated liver lipid deposition and restored plasma lipid profiles to control levels. These treatments restored the disruptions in Met metabolism and the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio induced by B6 deficiency in liver microsomes. These results suggest that choline and betaine ameliorated liver lipid accumulation induced by B6 deficiency via recovery of Met metabolism and very low-density lipoprotein secretion by restoring the supply of PC derived from PE.


Assuntos
Betaína/farmacologia , Colina/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Deficiência de Vitamina B 6/metabolismo , Animais , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Homocisteína/sangue , Homocisteína/metabolismo , Masculino , Fosfatidilcolinas/biossíntese , Fosfatidilcolinas/sangue , Fosfatidilcolinas/metabolismo , Ratos , Ratos Wistar , Vitamina B 6/sangue , Vitamina B 6/metabolismo , Deficiência de Vitamina B 6/sangue
19.
PLoS One ; 11(9): e0162346, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27598005

RESUMO

AIM: In this work we estimated the contribution of the fluorescence of 4-pyridoxic acid (4-PA) to the total fluorescence of spent dialysate with the aim of evaluating the on-line monitoring of removal of this vitamin B-6 metabolite from the blood of patients with end-stage renal disease (ESRD). METHODS: Spectrofluorometric analysis of spent dialysate, collected from hemodialysis and hemodiafiltration sessions of 10 patients receiving regularly pyridoxine injections after dialysis treatment, was performed in the range of Ex/Em 220-500 nm. 4-PA in dialysate samples was identified and quantified using HPLC with fluorescent and MS/MS detection. RESULTS: Averaged HPLC chromatogram of spent dialysate had many peaks in the wavelength region of Ex320/Em430 nm where 4-PA was the highest peak with contribution of 42.2±17.0% at the beginning and 47.7±18.0% in the end of the dialysis. High correlation (R = 0.88-0.95) between 4-PA concentration and fluorescence intensity of spent dialysate was found in the region of Ex310-330/Em415-500 nm, respectively. CONCLUSION: 4-PA elimination from the blood of ESRD patients can be potentially followed using monitoring of the fluorescence of the spent dialysate during dialysis treatments.


Assuntos
Hemodiafiltração , Falência Renal Crônica/sangue , Ácido Piridóxico/sangue , Deficiência de Vitamina B 6/sangue , Vitamina B 6/sangue , Idoso , Biotransformação , Cromatografia Líquida de Alta Pressão , Soluções para Diálise , Feminino , Fluorescência , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Espectrometria de Fluorescência , Vitamina B 6/administração & dosagem , Vitamina B 6/farmacocinética , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/diagnóstico , Deficiência de Vitamina B 6/terapia
20.
Nutrients ; 8(9)2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27598193

RESUMO

Low periconceptional vitamin B6 (B6) status has been associated with an increased risk of preterm birth and early pregnancy loss. Given many pregnancies are unplanned; it is important for women to maintain an adequate B6 status throughout reproductive years. There is limited data on B6 status in Canadian women. This study aimed to assess the prevalence of B6 deficiency and predictors of B6 status in young adult women in Metro Vancouver. We included a convenience sample of young adult non-pregnant women (19-35 years; n = 202). Vitamin B6 status was determined using fasting plasma concentrations of pyridoxal 5'-phosphate (PLP). Mean (95% confidence interval) plasma PLP concentration was 61.0 (55.2, 67.3) nmol/L. The prevalence of B6 deficiency (plasma PLP < 20 nmol/L) was 1.5% and that of suboptimal B6 status (plasma PLP = 20-30 nmol/L) was 10.9%. Body mass index, South Asian ethnicity, relative dietary B6 intake, and the use of supplemental B6 were significant predictors of plasma PLP. The combined 12.4% prevalence of B6 deficiency and suboptimal status was lower than data reported in US populations and might be due to the high socioeconomic status of our sample. More research is warranted to determine B6 status in the general Canadian population.


Assuntos
Fosfato de Piridoxal/sangue , Saúde da População Urbana , Deficiência de Vitamina B 6/epidemiologia , Saúde da Mulher , Adulto , Fatores Etários , Biomarcadores/sangue , Colúmbia Britânica/epidemiologia , Estudos Transversais , Feminino , Nível de Saúde , Inquéritos Epidemiológicos , Humanos , Modelos Lineares , Análise Multivariada , Prevalência , Fatores de Risco , Fatores Sexuais , Deficiência de Vitamina B 6/sangue , Deficiência de Vitamina B 6/diagnóstico , Adulto Jovem
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