Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Nutr Rev ; 76(2): 108-116, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29228399

RESUMO

Context: Glucose is the main energy source for the brain, and as such, manipulation of glucose supply may affect brain function. It has been suggested that a change in blood glucose may influence mood. Objective: The aim of this review was to investigate the potential effects of glucose and sucrose, compared with placebo, on mood. Data Sources: The electronic databases PubMed and Scopus were searched. Reference lists of selected articles were checked manually. Data Extraction: Randomized controlled trials or crossover trials comparing the effects of glucose or sucrose on mood that were published up to May 2017 were eligible. Potentially eligible articles were selected independently by 2 reviewers. Results: In total, 19 studies were found. Thirteen studies investigated the effects of glucose consumption compared with placebo on mood. Seven of these 13 studies found no effect of glucose on mood. The other 6 studies found small and partial effects that may also be due to other factors like palatability and expectation. Seven of the 19 studies investigated the effects of sucrose ingestion versus placebo on mood. None of these studies found a positive effect on mood, and 1 study observed an adverse effect. One of the studies investigated the effects of both glucose and sucrose. Conclusions: The results from this review show limited effects of glucose ingestion on mood and no effect of sucrose on mood.


Assuntos
Afeto/efeitos dos fármacos , Sacarose Alimentar/administração & dosagem , Glucose/administração & dosagem , Estudos Cross-Over , Ingestão de Alimentos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Br J Clin Pharmacol ; 83(10): 2292-2302, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28589543

RESUMO

AIMS: To investigate the association between use of ß-blockers and ß-blocker characteristics - selectivity, lipid solubility, intrinsic sympathetic activity (ISA) and CYP2D6 enzyme metabolism - and fall risk. METHODS: Data from two prospective studies were used, including community-dwelling individuals, n = 7662 (the Rotterdam Study) and 2407 (B-PROOF), all aged ≥55 years. Fall incidents were recorded prospectively. Time-varying ß-blocker use was determined using pharmacy dispensing records. Cox proportional hazard models adjusted for age and sex were applied to determine the association between ß-blocker use, their characteristics - selectivity, lipid solubility, ISA and CYP2D6 enzyme metabolism - and fall risk. The results of the studies were combined using meta-analyses. RESULTS: In total 2917 participants encountered a fall during a total follow-up time of 89 529 years. Meta-analysis indicated no association between use of any ß-blocker, compared to nonuse, and fall risk, hazard ratio (HR) = 0.97 [95% confidence interval (CI) 0.88-1.06]. Use of a selective ß-blocker was also not associated with fall risk, HR = 0.92 (95%CI 0.83-1.01). Use of a nonselective ß-blocker was associated with an increased fall risk, HR = 1.22 (95%CI 1.01-1.48). Other ß-blocker characteristics including lipid solubility and CYP2D6 enzyme metabolism were not associated with fall risk. CONCLUSION: Our study suggests that use of a nonselective ß-blocker, contrary to selective ß-blockers, is associated with an increased fall risk in an older population. In clinical practice, ß-blockers have been shown effective for a variety of cardiovascular indications. However, fall risk should be considered when prescribing a ß-blocker in this age group, and the pros and cons for ß-blocker classes should be taken into consideration.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Antagonistas Adrenérgicos beta/farmacologia , Citocromo P-450 CYP2D6/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Bradicardia/induzido quimicamente , Bradicardia/complicações , Débito Cardíaco/efeitos dos fármacos , Citocromo P-450 CYP2D6/genética , Tontura/induzido quimicamente , Tontura/complicações , Feminino , Humanos , Hipotensão/induzido quimicamente , Hipotensão/complicações , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Sistema Nervoso Simpático/efeitos dos fármacos
3.
J Am Med Dir Assoc ; 18(1): 88.e1-88.e15, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27889507

RESUMO

OBJECTIVE: To investigate whether the CYP2C9*2 and *3 variants modify benzodiazepine-related fall risk. DESIGN: Three prospective studies; the Rotterdam Study, B-PROOF, and LASA. SETTING: Community-dwelling individuals living in or near five Dutch cities. PARTICIPANTS: There were 11,485 participants aged ≥55 years. MEASUREMENTS: Fall incidents were recorded prospectively. Benzodiazepine use was determined using pharmacy dispensing records or interviews. Cox proportional hazard models adjusted for age and sex were applied to determine the association between benzodiazepine use and fall risk stratified for CYP2C9 genotype and comparing benzodiazepine users to nonusers. The results of the three studies were combined applying meta-analysis. Within benzodiazepine users, the association between genotypes and fall risk was also assessed. RESULTS: Three thousand seven hundred five participants (32%) encountered a fall during 91,996 follow-up years, and 4% to 15% (depending on the study population) used benzodiazepines. CYP2C9 variants had frequencies of 13% for the *2 allele and 6% for the *3 allele. Compared to nonusers, current benzodiazepine use was associated with an 18% to 36% increased fall risk across studies with a combined hazard ratio (HR) = 1.26 (95% confidence interval [CI], 1.13; 1.40). CYP2C9*2 or *3 allele variants modified benzodiazepine-related fall risk. Compared to nonusers, those carrying a CYP2C9*2 or *3 allele and using benzodiazepines had a 45% increased fall risk (HR, 1.45 95% CI, 1.21; 1.73), whereas CYP2C9*1 homozygotes using benzodiazepines had no increased fall risk (HR, 1.14; 95% CI, 0.90; 1.45). Within benzodiazepine users, having a CYP2C9*2 or *3 allele was associated with an increased fall risk (HR, 1.35; 95% CI, 1.06; 1.72). Additionally, we observed an allele dose effect; heterozygous allele carriers had a fall risk of (HR = 1.30; 95% CI, 1.05; 1.61), and homozygous allele carriers of (HR = 1.91 95% CI, 1.23; 2.96). CONCLUSIONS: CYP2C9*2 and *3 allele variants modify benzodiazepine-related fall risk. Those using benzodiazepines and having reduced CYP2C9 enzyme activity based on their genotype are at increased fall risk. In clinical practice, genotyping might be considered for elderly patients with an indication for benzodiazepine use. However, because the exact role of CYP2C9 in benzodiazepine metabolism is still unclear, additional research is warranted.


Assuntos
Acidentes por Quedas , Benzodiazepinas/efeitos adversos , Citocromo P-450 CYP2C9/genética , Genótipo , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Países Baixos , Farmacogenética , Modelos de Riscos Proporcionais , Estudos Prospectivos
4.
Nutrients ; 9(1)2016 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-28029114

RESUMO

AIM: We investigated cross-sectional associations between circulating homocysteine, folate, biomarkers of vitamin B12 status and brain volumes. We furthermore compared brain volumes of participants who received daily folic acid and vitamin B12 supplementation with participants who did not. METHODS: Participants of the B-PROOF study (n = 2919) were assigned to 400 µg folic acid and 500 µg vitamin B12, or a placebo. After two years of intervention, T1-weighted magnetic resonance imaging (MRI) scans were made in a random subsample (n = 218) to obtain grey and white matter volume, and total brain volume (TBV). Plasma homocysteine, serum folate, vitamin B12, holotranscobalamin, and methylmalonic acid concentrations were measured. RESULTS: Multiple linear regression analyses showed inverse associations between plasma homocysteine with TBV (ß = -0.91, 95% CI -1.85-0.03; p = 0.06) and between serum folate and TBV (ß = -0.20, 95% CI -0.38, -0.02; p = 0.03). No significant associations were observed for serum vitamin B12 and holotranscobalamin. Fully adjusted ANCOVA models showed that the group that received B-vitamins had a lower TBV (adjusted mean 1064, 95% CI 1058-1069 mL) than the non-supplemented group (1072, 95% CI 1067-1078 mL, p = 0.03). CONCLUSIONS: Results were contradictory, with higher Hcy levels associated with lower TBV, but also with higher folate levels associated with lower TBV. In addition, the lack of a baseline measurement withholds us from giving recommendations on whether folic acid and vitamin B12 supplementation will be beneficial above and beyond normal dietary intake for brain health.


Assuntos
Encéfalo/anatomia & histologia , Ácido Fólico/sangue , Homocisteína/sangue , Vitamina B 12/sangue , Idoso , Biomarcadores/sangue , Índice de Massa Corporal , Estudos Transversais , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Ácido Metilmalônico/sangue , Estado Nutricional , Tamanho do Órgão , Espectrometria de Massas em Tandem , Transcobalaminas/análise
5.
Nutrients ; 8(11)2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27886078

RESUMO

Lowering elevated plasma homocysteine (Hcy) concentrations by supplementing vitamin B12 and folic acid may reduce depressive symptoms and improve health-related quality of life (HR-QoL) in older adults. This study aimed to test this hypothesis in a randomized controlled trial. Participants (N = 2919, ≥65 years, Hcy concentrations ≥12 µmol/L) received either 500 µg vitamin B12 and 400 µg folic acid daily or placebo for two years. Both tablets contained 15 µg vitamin D3. Depressive symptoms were measured with the Geriatric Depression Scale-15 (GDS-15). HR-QoL was assessed with the SF-12 Mental and Physical component summary scores and the EQ-5D Index score and Visual Analogue Scale. Differences in two-year change scores were analyzed with Analysis of Covariance (ANCOVA). Hcy concentrations decreased more in the intervention group, but two-year change scores of the GDS-15 and three of four HR-QoL measures did not differ between groups. The EQ-5D Index score declined less in the intervention group than in the placebo group (mean change 0.00 vs. -0.02, p = 0.004). In conclusion, two-year supplementation with vitamin B12 and folic acid in older adults with hyperhomocysteinemia showed that lowering Hcy concentrations does not reduce depressive symptoms, but it may have a small positive effect on HR-QoL.


Assuntos
Afeto , Depressão/prevenção & controle , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Homocisteína/sangue , Hiper-Homocisteinemia/tratamento farmacológico , Qualidade de Vida , Vitamina B 12/administração & dosagem , Fatores Etários , Idoso , Biomarcadores/sangue , Depressão/diagnóstico , Depressão/etiologia , Depressão/psicologia , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/diagnóstico , Masculino , Países Baixos , Escalas de Graduação Psiquiátrica , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Regulação para Cima
6.
Calcif Tissue Int ; 98(1): 18-27, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26412463

RESUMO

Elevated homocysteine concentrations are associated with a decline in physical function in elderly persons. Homocysteine-lowering therapy may slow down this decline. This study aimed to examine the effect of a 2-year intervention of vitamin B12 and folic acid supplementation on physical performance, handgrip strength, and risk of falling in elderly subjects in a double-blind, randomized placebo-controlled trial. Participants aged ≥65 years with elevated plasma homocysteine concentrations [12-50 µmol/L (n = 2919)] were randomly assigned to daily supplementation of 500 µg vitamin B12, 400 µg folic acid, and 600 IU vitamin D3, or to placebo with 600 IU vitamin D3. Physical performance (range 0-12) and handgrip strength (kg) were measured at baseline and after 2 years. Falls were reported prospectively on a research calendar. Intention-to-treat (primary) and per-protocol (secondary) analyses were performed. Physical performance level and handgrip strength significantly decreased during the follow-up period, but this decline did not differ between groups. Moreover, time to first fall was not significantly different (HR: 1.0, 95% CI 0.9-1.2). Secondary analyses on a per-protocol base identified an interaction effect with age on physical performance. In addition, the treatment was associated with higher follow-up scores on the walking test (cumulative OR: 1.3, 95% CI 1.1-1.5). Two-year supplementation of vitamin B12 and folic acid was neither effective in reducing the age-related decline in physical performance and handgrip strength, nor in the prevention of falling in elderly persons. Despite the overall null-effect, the results provide indications for a positive effect of the intervention on gait, as well as on physical performance among compliant persons >80 years. These effects should be further tested in future studies.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Ácido Fólico/administração & dosagem , Força da Mão/fisiologia , Atividade Motora/efeitos dos fármacos , Vitamina B 12/administração & dosagem , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Suplementos Nutricionais , Feminino , Homocisteína/sangue , Humanos , Masculino , Fraturas por Osteoporose/epidemiologia , Aptidão Física
7.
J Steroid Biochem Mol Biol ; 164: 168-176, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26275945

RESUMO

BACKGROUND/OBJECTIVES: The prevalence of vitamin D deficiency among seniors is high. Whereas sun exposure, vitamin D intake, genes, demographics, and lifestyle have been identified as being important determinants of vitamin D status, the impact of these factors is expected to differ across populations. To improve current prevention and treatment strategies, this study aimed to explore the main determinants of vitamin D status and its relative importance in a population of community-dwelling Dutch older adults. METHODS/SUBJECTS: Serum 25-hydroxyvitamin D (25(OH)D) was measured in 2857 adults aged ≥65 years. Sun exposure was assessed with a structured questionnaire (n=1012), vitamin D intake using a Food Frequency Questionnaire (n=596), and data on genetic variation that may affect 25(OH)D status was obtained for 4 genes, DHCR7 (rs12785878), CYP2R1 (rs10741657), GC (rs2282679), and CYP24A1 (rs6013897) (n=2530). RESULTS: Serum 25(OH)D concentrations <50nmol/L were observed in 45% of the population; only 6% of these participants used vitamin D supplements. Sun exposure (being outside daily during summer: 66±25nmol/L vs not being outside daily during summer: 58±27nmol/L, P=0.02) and vitamin D intake (per unit µg/day during winter/spring: 3.1±0.75nmol/L, P<0.0001) were associated with higher 25(OH)D concentrations. Major allele carriers of SNPs related to DHCR7, CYP24A1, and GC, as well as CYP2R1 minor allele carriers had the highest 25(OH)D concentrations. Together, sun (R2=0.29), vitamin D intake (R2=0.24), and genes (R2=0.28) explained 35% (R2=0.35) of the variation in 25(OH)D concentrations during summer/autumn period, when adjusted for age, sex, BMI, education, alcohol consumption, smoking, physical activity, and self-rated health status (n=185). CONCLUSION: The investigated determinants explained 35% of 25(OH)D status. Of the three main determinants under study, sun exposure still appeared to be an important determinant of serum 25(OH)D in older individuals, closely followed by genes, and vitamin D intake. Given the low frequency of vitamin D supplement use in this population, promoting supplement use may be an inexpensive, easy, and effective strategy to fight vitamin D deficiency.


Assuntos
Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/genética , Vitamina D/uso terapêutico , Vitaminas/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Colestanotriol 26-Mono-Oxigenase/genética , Estudos Transversais , Família 2 do Citocromo P450/genética , Suplementos Nutricionais , Feminino , Humanos , Masculino , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Polimorfismo de Nucleotídeo Único , Estações do Ano , Luz Solar , Vitamina D/análogos & derivados , Vitamina D/sangue , Vitamina D/genética , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/prevenção & controle , Vitamina D3 24-Hidroxilase/genética , Vitaminas/genética
8.
J Hypertens ; 33(9): 1897-906; discussion 1906, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26147383

RESUMO

INTRODUCTION: Hyperhomocysteinemia is an important cardiovascular risk indicator in the oldest old, and is associated with elevated arterial stiffness in this age group. Since several intervention trials reported a lack of benefit of B-vitamin supplementation on cardiovascular outcomes, we aimed to investigate the effect of B-vitamin supplementation on arterial stiffness and atherosclerosis in hyperhomocysteinemic elderly patients. METHODS: The B-PROOF study is a double-blind, randomized controlled trial, including 2919 elderly aged at least 65 years, with hyperhomocysteinemia (12-50  µmol/l), treated with B-vitamins (500  µg vitamin B12 and 400  µg folic acid) or placebo for 2 years. In a subgroup (n = 569), the effect of B-vitamins on pulse wave velocity (PWV) was investigated as a measurement of arterial stiffness. To measure atherosclerosis, carotid intima-media thickness (IMT) measures had been used. Incidents of cardiovascular and cerebrovascular events were determined via structured questionnaires, and blood pressure was also measured. RESULTS: Compared to placebo, B-vitamin supplementation lowered serum homocysteine by 3.6  µmol/l (P < 0.001). Analysis of covariance showed no effect of supplementation on PWV levels, and this was not different for patients without increased arterial stiffness at baseline. Furthermore, no effect on carotid IMT was observed. DISCUSSION: Vitamin B12 and folic acid supplementation in hyperhomocysteinemic elderly patients have no effect on PWV or carotid IMT. Further research will still be necessary to unravel the effects and pathways of homocysteine-lowering treatment on cardiovascular outcomes.


Assuntos
Aterosclerose/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Doenças Cardiovasculares/fisiopatologia , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Hiper-Homocisteinemia/fisiopatologia , Rigidez Vascular/efeitos dos fármacos , Vitamina B 12/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/mortalidade , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/mortalidade , Espessura Intima-Media Carotídea , Método Duplo-Cego , Feminino , Humanos , Hiper-Homocisteinemia/mortalidade , Masculino , Análise de Onda de Pulso , Fatores de Risco , Resultado do Tratamento , Rigidez Vascular/fisiologia
9.
J Nutr ; 145(8): 1817-23, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26136594

RESUMO

BACKGROUND: Previous studies have shown beneficial associations between 25-hydroxyvitamin D [25(OH)D] status and cognitive performance, but results are inconclusive. Studies on 25(OH)D status and brain volumetric measures may provide more insight in the potential role of vitamin D in cognitive performance. OBJECTIVES: The aims of this study were to cross-sectionally investigate the association between vitamin D status and brain tissue volumes in 217 Dutch community-dwelling older adults aged ≥65 y and to examine whether surrogate markers of glucose homeostasis act as modifiers in these associations. METHODS: Serum 25(OH)D, plasma glucose, and plasma insulin were analyzed, serving as exposure measures. Estimates of total brain volume, gray matter volume, and white matter volume were obtained using MRI, serving as outcome measures. Associations of serum 25(OH)D, plasma glucose, and plasma insulin concentrations with brain tissue volumes were evaluated using multiple linear regression analyses. Potential effect modification by glucose homeostasis in the association between 25(OH)D and brain volumetric measures was examined by stratification and testing for interaction. RESULTS: After full adjustment, higher serum 25(OH)D concentrations and lower plasma glucose concentrations were associated with larger gray matter volume, [ß ± SE: 0.20 ± 0.08 mL (P = 0.02) and -3.26 ± 1.59 mL (P = 0.04), respectively]. There were no associations between serum 25(OH)D and plasma insulin concentrations with total brain volume and white matter volume. Furthermore, there was no evidence for a mediation or modification effect of plasma glucose on the associations between serum 25(OH)D and brain tissue volumes. CONCLUSION: Higher serum 25(OH)D and lower plasma glucose are associated with larger gray matter volume, but not white matter or total brain volume, in a population of Dutch adults aged ≥65 y. This trial was registered at clinicaltrials.gov as NCT00696514.


Assuntos
Glicemia , Substância Cinzenta/anatomia & histologia , Vitamina D/análogos & derivados , Substância Branca/anatomia & histologia , Idoso , Envelhecimento , Feminino , Homeostase , Humanos , Masculino , Países Baixos , Vitamina D/sangue
10.
Nutr Rev ; 73(2): 92-105, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26024496

RESUMO

Glucose is the main fuel for the brain, and manipulation of the glucose supply may consequently affect brain function. The present review was conducted to provide an overview of studies that investigated the acute effects of glucose load on memory and other cognitive functions in elderly people. The effects of sucrose on cognition and suggested mechanisms were also explored. A total of twenty studies met the inclusion criteria. In the majority of studies, episodic memory was investigated and a beneficial role for glucose in that specific cognitive domain was suggested. Other cognitive domains, i.e., working memory, semantic memory, visual memory, information-processing speed, attention, executive function, and visual/spatial function, have been studied less frequently and evidence for a beneficial effect of glucose was equivocal. Mechanisms are suggested to be mainly related to the human body's need for glucose as a metabolic substrate for physiological mechanisms in both central and peripheral processes.


Assuntos
Cognição/efeitos dos fármacos , Glucose/farmacologia , Idoso , Atenção/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Função Executiva/efeitos dos fármacos , Humanos , Memória/efeitos dos fármacos , Processamento Espacial/efeitos dos fármacos , Sacarose/farmacologia
11.
Calcif Tissue Int ; 96(5): 401-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25712255

RESUMO

High plasma homocysteine (Hcy) levels are associated with increased osteoporotic fracture incidence. However, the mechanism remains unclear. We investigated the effect of Hcy-lowering vitamin B12 and folic acid treatment on bone mineral density (BMD) and calcaneal quantitative ultrasound (QUS) parameters. This randomized, double-blind, placebo-controlled trial included participants aged ≥65 years with plasma Hcy levels between 12 and 50 µmol/L. The intervention comprised 2-year supplementation with either a combination of 500 µg B12, 400 µg folic acid, and 600 IU vitamin D or placebo with 600 IU vitamin D only. In total, 1111 participants underwent repeated dual-energy X-ray assessment and 1165 participants underwent QUS. Femoral neck (FN) BMD, lumbar spine (LS) BMD, calcaneal broadband ultrasound attenuation (BUA), and calcaneal speed of sound (SOS) were assessed. After 2 years, FN-BMD and BUA had significantly decreased, while LS-BMD significantly increased (all p < 0.01) and SOS did not change in either treatment arm. No statistically significant differences between the intervention and placebo group were present for FN-BMD (p = 0.24), LS-BMD (p = 0.16), SOS (p = 0.67), and BUA (p = 0.96). However, exploratory subgroup analyses revealed a small positive effect of the intervention on BUA at follow-up among compliant persons >80 years (estimated marginal mean 64.4 dB/MHz for the intervention group and 61.0 dB/MHz for the placebo group, p = 0.04 for difference). In conclusion, this study showed no overall effect of treatment with vitamin B12 and folic acid on BMD or QUS parameters in elderly, mildly hyperhomocysteinemic persons, but suggests a small beneficial effect on BUA in persons >80 years who were compliant in taking the supplement.


Assuntos
Densidade Óssea/efeitos dos fármacos , Ácido Fólico/uso terapêutico , Homocisteína/sangue , Osteoporose/prevenção & controle , Vitamina B 12/uso terapêutico , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Calcâneo/diagnóstico por imagem , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Colo do Fêmur/diagnóstico por imagem , Humanos , Masculino , Osteoporose/sangue , Ultrassonografia
12.
Age Ageing ; 44(1): 136-42, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25038832

RESUMO

BACKGROUND: several studies have been pointing towards a non-linear relationship between serum 25(OH)D and cardiovascular disease. Next to vitamin D deficiency, also higher levels of 25(OH)D have been reported to be associated with increased cardiovascular risk. We aimed to investigate the nature of the relationship between serum 25(OH)D and measures of arterial stiffness and arteriosclerosis in an elderly population. DESIGN: cross-sectional. SETTING/SUBJECTS: a subgroup of the B-PROOF study was included to determine associations between serum 25(OH)D and arterial stiffness and atherosclerosis (n = 567, 57% male, age 72.6 ± 5.6 years, mean serum 25(OH)D 54.6 ± 24.1 nmol/l). METHODS: carotid intima media thickness (IMT) was assessed using ultrasonography and pulse wave velocity (PWV) was determined with applanation tonometry. Associations were tested using multivariable restricted cubic spline functions and stratified linear regression analysis. RESULTS: the associations between serum 25(OH)D and carotid IMT or PWV were non-linear. Spline functions demonstrated a difference between 25(OH)D deficient and sufficient individuals. In serum 25(OH)D sufficient participants (≥50 nmol/l; n = 287), a positive association with IMT and serum 25(OH)D was present (ß 1.24; 95%CI [0.002; 2.473]). PWV levels were slightly lower in vitamin D deficient individuals, but the association with 25(OH)D was not significant. CONCLUSION: our study demonstrates that associations of serum 25(OH)D and PWV and IMT in an elderly population are not linear. In particular from serum 25(OH)D levels of 50 nmol/l and up, there is a slight increase of IMT with increasing 25(OH)D levels.


Assuntos
Arteriosclerose/etiologia , Rigidez Vascular , Vitamina D/análogos & derivados , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Arteriosclerose/sangue , Arteriosclerose/diagnóstico , Arteriosclerose/fisiopatologia , Biomarcadores/sangue , Espessura Intima-Media Carotídea , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Manometria , Análise Multivariada , Dinâmica não Linear , Análise de Onda de Pulso , Fatores de Risco , Vitamina D/sangue
13.
Neurology ; 83(23): 2158-66, 2014 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-25391305

RESUMO

OBJECTIVE: We investigated the effects of 2-year folic acid and vitamin B12 supplementation on cognitive performance in elderly people with elevated homocysteine (Hcy) levels. METHODS: This multicenter, double-blind, randomized, placebo-controlled trial included 2,919 elderly participants (65 years and older) with Hcy levels between 12 and 50 µmol/L. Participants received daily either a tablet with 400 µg folic acid and 500 µg vitamin B12 (B-vitamin group) or a placebo tablet. Both tablets contained 15 µg vitamin D3. Data were available for global cognitive functioning assessed by Mini-Mental State Examination (n = 2,556), episodic memory (n = 2,467), attention and working memory (n = 759), information processing speed (n = 731), and executive function (n = 721). RESULTS: Mean age was 74.1 (SD 6.5) years. Hcy concentrations decreased 5.0 (95% confidence interval -5.3 to -4.7) µmol/L in the B-vitamin group and 1.3 (-1.6 to -0.9) µmol/L in the placebo group. Cognitive domain scores did not differ over time between the 2 groups, as determined by analysis of covariance. Mini-Mental State Examination score decreased with 0.1 (-0.2 to 0.0) in the B-vitamin group and 0.3 (-0.4 to -0.2) in the placebo group (p = 0.05), as determined by an independent t test. CONCLUSIONS: Two-year folic acid and vitamin B12 supplementation did not beneficially affect performance on 4 cognitive domains in elderly people with elevated Hcy levels. It may slightly slow the rate of decline of global cognition, but the reported small difference may be attributable to chance. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that 2-year supplementation with folic acid and vitamin B12 in hyperhomocysteinemic elderly people does not affect cognitive performance.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Cognição/efeitos dos fármacos , Ácido Fólico/uso terapêutico , Memória/efeitos dos fármacos , Vitamina B 12/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Suplementos Nutricionais , Método Duplo-Cego , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Vitamina B 12/administração & dosagem
14.
Am J Clin Nutr ; 100(6): 1578-86, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25411293

RESUMO

BACKGROUND: Elevated plasma homocysteine concentrations are a risk factor for osteoporotic fractures. Lowering homocysteine with combined vitamin B-12 and folic acid supplementation may reduce fracture risk. OBJECTIVE: This study [B-vitamins for the PRevention Of Osteoporotic Fractures (B-PROOF)] aimed to determine whether vitamin B-12 and folic acid supplementation reduces osteoporotic fracture incidence in hyperhomocysteinemic elderly individuals. DESIGN: This was a double-blind, randomized, placebo-controlled trial in 2919 participants aged ≥65 y with elevated homocysteine concentrations (12-50 µmol/L). Participants were assigned to receive daily 500 µg vitamin B-12 plus 400 µg folic acid or placebo supplementation for 2 y. Both intervention and placebo tablets also contained 600 IU vitamin D3. The primary endpoint was time to first osteoporotic fracture. Exploratory prespecified subgroup analyses were performed in men and women and in individuals younger than and older than age 80 y. Data were analyzed according to intention-to-treat and per-protocol principles. RESULTS: Osteoporotic fractures occurred in 61 persons (4.2%) in the intervention group and 75 persons (5.1%) in the placebo group. Osteoporotic fracture risk was not significantly different between groups in the intention-to-treat analyses (HR: 0.84; 95% CI: 0.58, 1.21) or per-protocol analyses (HR: 0.81; 95% CI: 0.54, 1.21). For persons aged >80 y, in per-protocol analyses, osteoporotic fracture risk was lower in the intervention group than in the placebo group (HR: 0.27; 95% CI: 0.10, 0.74). The total number of adverse events (including mortality) did not differ between groups. However, 63 and 42 participants in the intervention and placebo groups, respectively, reported incident cancer (HR: 1.56; 95% CI: 1.04, 2.31). CONCLUSIONS: These data show that combined vitamin B-12 and folic acid supplementation had no effect on osteoporotic fracture incidence in this elderly population. Exploratory subgroup analyses suggest a beneficial effect on osteoporotic fracture prevention in compliant persons aged >80 y. However, treatment was also associated with increased incidence of cancer, although the study was not designed for assessing cancer outcomes. Therefore, vitamin B-12 plus folic acid supplementation cannot be recommended at present for fracture prevention in elderly people. The B-PROOF study was registered with the Netherlands Trial Register (trialregister.nl) as NTR1333 and at clinicaltrials.gov as NCT00696414.


Assuntos
Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Homocisteína/sangue , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/prevenção & controle , Vitamina B 12/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Seguimentos , Humanos , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/tratamento farmacológico , Incidência , Masculino , Atividade Motora , Países Baixos , Fatores de Risco , Resultado do Tratamento
15.
Drugs Aging ; 31(12): 917-27, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25398701

RESUMO

BACKGROUND: Medication use is a potentially modifiable risk factor for falling; psychotropic and cardiovascular drugs have been indicated as main drug groups that increase fall risk. However, evidence is mainly based on studies that recorded falls retrospectively and/or did not determine medication use at the time of the fall. Therefore, we investigated the associations indicated in the literature between medication use and falls, using prospectively recorded falls and medication use determined at the time of the fall. METHODS: Data from the B-PROOF (B-vitamins for the prevention of osteoporotic fractures) study were used, concerning community-dwelling elderly aged ≥65 years. We included 2,407 participants with pharmacy dispensing records. During the 2- to 3-year follow-up, participants recorded falls using a fall calendar. Cox proportional hazard models were applied, adjusting for potential confounders including age, sex, health status variables and concomitant medication use. RESULTS: During follow-up, 1,147 participants experienced at least one fall. Users of anti-arrhythmic medication had an increased fall risk (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.12-2.32) compared with non-users. Similarly, non-selective beta-blocker use was associated with an increased fall risk (HR 1.41 [95% CI 1.12-1.78]), while statin use was associated with a lower risk (HR 0.81 [95% CI 0.71-0.94]). Benzodiazepine use (HR 1.32 [95% CI 1.02-1.71]), and antidepressant use (HR 1.40 [95% CI 1.07-1.82]) were associated with an increased fall risk. Use of other cardiovascular and psychotropic medication was not associated with fall risk. CONCLUSION: Our results strengthen the evidence for an increased fall risk in community-dwelling elderly during the use of anti-arrhythmics, non-selective beta-blockers, benzodiazepines, and antidepressant medication. Clinicians should prescribe these drugs cautiously and if possible choose safer alternatives for older patients.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Antiarrítmicos/efeitos adversos , Benzodiazepinas/efeitos adversos , Feminino , Serviços de Saúde para Idosos , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/prevenção & controle , Humanos , Incidência , Vida Independente , Masculino , Países Baixos/epidemiologia , Modelos de Riscos Proporcionais , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
Drugs Aging ; 31(8): 611-21, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24993981

RESUMO

BACKGROUND: Elevated homocysteine levels are a risk indicator for cardiovascular disease, fractures and cognitive decline. Previous studies indicated associations between homocysteine levels and medication use, including antihypertensive, lipid-lowering and antidiabetic medication. However, results were often contradictory and inconclusive. Our objective was to study the associations established previously in more detail by sub-classifying medication groups, and investigate the potential mediating role of vitamin B12 and folate status. MATERIALS AND METHODS: Baseline data from the B-PROOF (B-vitamins for the PRevention Of Osteoporotic Fractures) study were used. We included 2,912 participants aged ≥65 years, with homocysteine levels of 12-50 µmol/L and creatinine levels ≤150 µmol/L, for whom self-reported medication data were available. We used multivariable linear regression models and analysis of covariance to assess the association between medication use and plasma homocysteine levels, and the potential mediation by serum vitamin B12 and folate. RESULTS: The mean age was 74 years (standard deviation, 6.5), 50 % were women, and median homocysteine levels were 14 µmol/L [interquartile range, 13-17 µmol/L]. Higher mean homocysteine levels were observed in users vs. non-users for diuretics (15.2 vs. 14.9, p = 0.043), high-ceiling sulphonamide diuretics (16.0 vs. 14.9, p < 0.001), medication acting via the renin-angiotensin system (15.2 vs. 14.9, p = 0.029) and metformin (15.6 vs. 15.1, p = 0.006). Non-selective ß-blocker use was associated with lower mean homocysteine levels (14.4 vs. 15.0, p = 0.019). Only this association was mediated by an underlying association with vitamin B12 and folate levels. CONCLUSION: The associations between homocysteine levels and medication use appear to be fairly modest. Our results suggest that medication use is unlikely to contribute to clinically relevant changes in plasma homocysteine levels.


Assuntos
Homocisteína/sangue , Deficiência de Vitamina B 12/sangue , Idoso , Diuréticos/administração & dosagem , Feminino , Ácido Fólico/administração & dosagem , Serviços de Saúde para Idosos , Humanos , Masculino , Metformina/administração & dosagem , Países Baixos , Osteoporose/epidemiologia , Vigilância da População , Vitamina B 12/administração & dosagem
17.
J Clin Exp Neuropsychol ; 36(5): 517-27, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24839862

RESUMO

In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (-0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.


Assuntos
Afeto/efeitos dos fármacos , Cognição/efeitos dos fármacos , Glucose/farmacologia , Sacarose/farmacologia , Idoso , Idoso de 80 Anos ou mais , Atenção/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Masculino , Memória/efeitos dos fármacos , Testes Neuropsicológicos , Tempo de Reação/efeitos dos fármacos
18.
Mech Ageing Dev ; 136-137: 85-93, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24374288

RESUMO

Physical activity has been proposed as one of the most effective strategies to prevent cognitive decline. Protein supplementation may exert an additive effect. The effect of resistance-type exercise training with or without protein supplementation on cognitive functioning in frail and pre-frail elderly people was assessed in a secondary analysis. Two 24-week, double-blind, randomized, placebo-controlled intervention studies were carried out in parallel. Subjects performed a resistance-type exercise program of two sessions per week (n=62) or no exercise program (n=65). In both studies, subjects were randomly allocated to either a protein (2×15 g daily) or a placebo drink. Cognitive functioning was assessed with a neuropsychological test battery focusing on the cognitive domains episodic memory, attention and working memory, information processing speed, and executive functioning. In frail and pre-frail elderly, resistance-type exercise training in combination with protein supplementation improved information processing speed (changes in domain score 0.08±0.51 versus -0.23±0.19 in the non-exercise group, p=0.04). Exercise training without protein supplementation was beneficial for attention and working memory (changes in domain scores 0.35±0.70 versus -0.12±0.69 in the non-exercise group, p=0.02). There were no significant differences among the intervention groups on the other cognitive tests or domain scores.


Assuntos
Transtornos Cognitivos/prevenção & controle , Cognição , Proteínas Alimentares/uso terapêutico , Suplementos Nutricionais , Treinamento Resistido , Idoso , Idoso de 80 Anos ou mais , Atenção , Dieta , Método Duplo-Cego , Feminino , Idoso Fragilizado , Humanos , Masculino , Memória de Curto Prazo , Projetos de Pesquisa
19.
Eur J Nutr ; 53(3): 803-12, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24045855

RESUMO

PURPOSE: Maintenance of cognitive abilities is important for elderly to stay independent. With the aging of the population, the call for modifiable factors is emerging. Dietary protein might improve cognitive performance; however, this has hardly been studied. Therefore, we studied the impact of 24-week dietary protein supplementation on cognitive performance in pre-frail and frail elderly people. METHODS: Pre-frail and frail elderly subjects, according to the Fried criteria, randomly received a protein drink containing 15 g protein or a placebo drink twice a day. Cognitive performance was measured at baseline and after 24 weeks by means of a sensitive neuropsychological test battery. In addition, reaction time was assessed after both 12 and 24 weeks of intervention. Domain scores were calculated for the domains episodic memory, attention and working memory, information processing speed, and executive functioning. Analyses of covariance were used to determine differences between groups. Linear mixed models were used to determine differences in reaction time over time and per treatment. RESULTS: In total, 65 subjects (79 ± 8 years) with a median Mini-Mental State Examination score of 28 (interquartile range 26-30) were included. Reaction time improved more in the protein group (68 ms) than in the placebo group (18 ms, P = 0.03). Dietary protein had no significant effect on any of the cognitive domain scores. CONCLUSIONS: Protein supplementation might improve reaction time performance in pre-frail and frail elderly, but did not improve other cognitive functions.


Assuntos
Envelhecimento , Bebidas , Cognição , Disfunção Cognitiva/prevenção & controle , Proteínas do Leite/uso terapêutico , Tempo de Reação , Idoso , Idoso de 80 Anos ou mais , Atenção , Método Duplo-Cego , Função Executiva , Feminino , Idoso Fragilizado , Avaliação Geriátrica , Humanos , Masculino , Refeições , Memória , Países Baixos , Testes Neuropsicológicos
20.
J Am Med Dir Assoc ; 14(11): 852.e9-17, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23921196

RESUMO

OBJECTIVES: The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH]D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria. MEASUREMENTS: Associations of 25(OH)D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression. RESULTS: No associations were observed for 25(OH)D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH)D was positively associated with executive functioning (ß 0.007, P = .01) and tended to be associated with information-processing speed (ß 0.006, P = .06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression. CONCLUSION: This cross-sectional study suggests an association of serum 25(OH)D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated.


Assuntos
Glicemia/metabolismo , Transtornos Cognitivos/sangue , Depressão/sangue , Função Executiva , Idoso Fragilizado , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Antropometria , Estudos Transversais , Dieta , Feminino , Humanos , Masculino , Países Baixos , Luz Solar , Vitamina D/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...