RESUMEN
Metabolites of the cytochrome P450 (CYP) pathway may contribute to vasodilation of the vasculature. However, it is not known whether exercise affects their circulating concentrations. The authors determined effects of exercise intensity and duration on plasma concentrations of epoxy and dihydroxy metabolites of arachidonic acid. Their goal was to delineate the threshold workload, optimal workload, and duration required to produce increases in plasma concentrations of these vasoactive substances. Healthy volunteers (N = 14) performed maximal exercise testing on a bicycle ergometer during Visit 1. On separate days, subjects cycled for 20 min at 30%, 60%, and 80% of their maximal exercise intensity. The last day consisted of 40 min of exercise at 60% of maximal exercise intensity. Venous blood was obtained before, during, and after exercise for analysis. Compared with rest, increases were observed during the 80% workload at 20 min postexercise -14,15-DHET (0.77 ± 0.21 vs. 0.93 ± 0.27 nM) - and at 2 min postexercise: 11,12-DHET (0.64 ± 0.22 vs. 0.71 ± 0.24 nM; p < .05). Also compared with rest, 40-min values during the 60% workload were 14,15-DHET 0.79 ± 0.22 vs. 0.91 ± 0.31 nM and at 2 min post 14,15 EET 0.12 ± 0.06 vs. 0.21 ± 0.16 nM (p < .05). Results suggest the CYP metabolites (i.e., DHETs) are released during short-term high-intensity and long-term moderate-intensity exercise.
Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Ácido Araquidónico/metabolismo , Ciclismo/fisiología , Sistema Enzimático del Citocromo P-450/metabolismo , Compuestos Epoxi/metabolismo , Ejercicio Físico/fisiología , Ácido 8,11,14-Eicosatrienoico/metabolismo , Adulto , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esfuerzo Físico/fisiología , Descanso/fisiologíaRESUMEN
BACKGROUND: Low folate status is associated with poor cognitive function and dementia in the elderly. Since 1998, grain products in the United States have been fortified with folic acid, which has reduced the prevalence of folate deficiency and hyperhomocysteinemia. OBJECTIVE: We investigated whether folate status is associated with cognitive function and dementia in a cohort of elderly Latinos (aged >or= 60 y; n = 1789) exposed to folic acid fortification. DESIGN: Global cognitive function was assessed by the Modified Mini-Mental State Examination (3MSE) and specific cognitive functions by cross-culturally validated neuropsychological tests. Dementia was diagnosed according to the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised, and California Alzheimer Disease Diagnostic and Treatment criteria. Red blood cell (RBC) folate was measured by automated chemiluminescence and total plasma homocysteine by HPLC. RESULTS: The prevalence of folate deficiency (RBC folate Asunto(s)
Envejecimiento/fisiología
, Trastornos del Conocimiento/etnología
, Trastornos del Conocimiento/etiología
, Deficiencia de Ácido Fólico/complicaciones
, Hispánicos o Latinos
, Anciano
, Anciano de 80 o más Años
, Envejecimiento/etnología
, California/epidemiología
, Trastornos del Conocimiento/diagnóstico
, Estudios de Cohortes
, Estudios Transversales
, Demencia/diagnóstico
, Demencia/etnología
, Demencia/etiología
, Eritrocitos/química
, Femenino
, Ácido Fólico/administración & dosificación
, Deficiencia de Ácido Fólico/etnología
, Alimentos Fortificados
, Homocisteína/sangre
, Humanos
, Masculino
, Persona de Mediana Edad
, Estado Nutricional
, Análisis de Regresión
, Complejo Vitamínico B/administración & dosificación
RESUMEN
BACKGROUND: A relation between low folate status and depression has been recognized since the 1960s. Since 1998, flour in the United States has been fortified with folic acid, and the prevalence of folate deficiency has decreased dramatically. OBJECTIVE: We investigated whether, in this era of folic acid fortification, low folate status is a determinant of depressive symptoms in a cohort of elderly Latinos (aged >/=60 y) participating in the Sacramento Area Latino Study on Aging (SALSA). DESIGN: In a cross-sectional logistic regression analysis of data from SALSA (n = 627 M, 883 F), odds ratios (ORs) were ascertained for elevated depressive symptoms [Center for Epidemiologic Studies Depression Scale (CES-D) score >/=16] among tertiles of plasma folate. Depressive symptoms were assessed by using the CES-D. Plasma folate concentrations were determined by radioassay. RESULTS: The prevalence of folate deficiency (plasma folate
Asunto(s)
Depresión/sangre , Dieta , Deficiencia de Ácido Fólico/complicaciones , Deficiencia de Ácido Fólico/epidemiología , Ácido Fólico/sangre , Aculturación , Anciano , Envejecimiento/sangre , California/epidemiología , Estudios Transversales , Depresión/diagnóstico , Depresión/etnología , Depresión/etiología , Femenino , Ácido Fólico/administración & dosificación , Deficiencia de Ácido Fólico/sangre , Deficiencia de Ácido Fólico/etnología , Alimentos Fortificados , Hispánicos o Latinos , Homocisteína/sangre , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores Sexuales , Vitamina B 12/sangreRESUMEN
BACKGROUND: Elevated plasma homocysteine (hyperhomocysteinemia), an independent risk factor for vascular disease, has been reported to be inversely correlated with objective measures of cognitive function in patients with Alzheimer disease and in community-dwelling older adults. OBJECTIVE: We evaluated the cross-sectional relation between total plasma homocysteine concentration and cognitive function in elderly Latinos (aged > or = 60 y; n = 1789) participating in the Sacramento Area Latino Study on Aging. DESIGN: Global cognitive function was assessed by using the Modified Mini-Mental State Examination, and specific cognitive functions were assessed by using 6 instruments developed for cross-cultural and multilingual neuropsychological evaluation of older persons. Associations between the cognitive function scores and total plasma homocysteine concentrations were then measured by multiple regression analysis with control for potential confounding by nutrient status (red blood cell folate, plasma vitamin B-12), kidney function (serum creatinine), demographic variables (age, sex, education, acculturation), and depressive symptoms. RESULTS: Modest inverse associations were found between homocysteine concentrations and several indexes of cognitive function, including the global Modified Mini-Mental State Examination assessment and the picture-association, verbal attention-span, and pattern-recognition tests (P < or = 0.05). Demographic variables, particularly age and education, were more strongly associated with cognitive function scores than was homocysteine. CONCLUSIONS: Homocysteine is a modest independent predictor of cognitive function in community-dwelling elderly Latinos. Reducing plasma homocysteine concentrations by administering B-vitamin supplements may provide some protection against cognitive decline in this and other elderly populations, but the effect may be limited.
Asunto(s)
Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/epidemiología , Factores de Edad , Anciano , Biomarcadores/sangre , California/epidemiología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/prevención & control , Estudios de Cohortes , Estudios Transversales , Escolaridad , Femenino , Hispánicos o Latinos , Homocisteína/sangre , Humanos , Hiperhomocisteinemia/diagnóstico , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Factores de Riesgo , Factores Sexuales , Vitamina B 12/administración & dosificaciónRESUMEN
A common polymorphism (775G>C) in the vitamin B12 transport protein, transcobalamin II (TCII), has been identified in which proline replaces arginine at codon 259. We determined the influence of TCII genotype on indices of B12 status, including total serum B12, the amount of B12 bound to TCII (holoTCII), methylmalonic acid, and homocysteine, in 128 healthy older adults (ages 40-88 years). Mean total B12 and homocysteine concentrations were not significantly different among the 3 genotypes. Mean holoTCII concentration was significantly higher in those subjects homozygous for the proline form of TCII (PP) compared with those homozygous for the arginine form (RR) and heterozygotes (PR) (P Asunto(s)
Polimorfismo de Nucleótido Simple
, Transcobalaminas/genética
, Vitamina B 12/sangre
, Adulto
, Anciano
, Anciano de 80 o más Años
, Biomarcadores/sangre
, Femenino
, Homocisteína/metabolismo
, Humanos
, Masculino
, Ácido Metilmalónico/metabolismo
, Persona de Mediana Edad
, Vitamina B 12/metabolismo
, Deficiencia de Vitamina B 12/genética