Aged Arteries and B-vitamins

__Abstract__ Cardiovascular disease is a very common condition, especially among elderly. Cardiovascular risk prediction via the Framingham risk score is the most commonly used risk prediction. However, the Framingham risk score has only been validated until the age of 75 and the power of the classical risk factors have been shown to decline with advancing age. A strong predictor of cardiovascular disease in older populations is arterial stiffness. Arterial stiffness is involved in the pathogenesis of cardiovascular disease, with pulse wave velocity being the major marker for cardiovascular risk. Over the years, arterial stiffness have been shown to be an important pre-clinical stage of cardiovascular disease of interest for research, mainly based on preventive strategies. Arterial stiffness is associated with many lifestyle factors and disorders, among others smoking, vitamin D deficiency, physical functioning, renal failure, diabetes and constructive obstructive pulmonary disease (COPD)

Serum vitamin D levels are associated with structural and functional properties of the carotid artery in older men and women

Background and aims: This cross-sectional study aimed to assess the relationship between serum vitamin D levels and carotid and brachial artery distensibility in patients older than 55 years, referred to the outpatient clinic of the department of internal medicine and geriatric medicine of the Erasmus Medical Center, in Rotterdam. Methods and results: From April to July 2006 we consecutively enrolled 49 elder patients (21 men and 28 women, mean age 78 ± 8 years) without a cardiovascular event within 6 weeks before the visit. Carotid and brachial artery distensibility coefficients and serum 25(OH)D levels (mean 50 ± 28.8 nmol/L) were assessed. Multivariate analysis (with linear regression model) was performed to investigate the relation between these parameters: carotid artery distensibility coefficient was associated with serum 25(OH)D levels (β = 0.112; 95% CI 0.053 0.172; p = 0.001). Moreover, a negative association was also observed between carotid artery distensibility coefficient and mean arterial pressure (β = −0.279; 95% CI, −0.339 −0.159; p = 0.0001). On the contrary, brachial artery distensibility has shown no association with 25(OH)D levels, being negatively linked to LDL-cholesterol levels and heart rate. An association was also observed between serum 25(OH)D level and carotid artery intima–media thickness. Conclusion: Our results revealed that serum 25(OH)D levels of older men and women were associated with both structural and functional properties of the carotid artery. No association was found with the brachial artery distensibility

A Randomized Controlled Trial to Examine the Effect of 2-Year Vitamin B12 and Folic Acid Supplementation on Physical Performance, Strength, and Falling: Additional Findings from the B-PROOF Study

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 I

Low vitamin D status is associated with more depressive symptoms in Dutch older adults

Purpose: The existence of vitamin D receptors in the brain points to a possible role of vitamin D in brain function. We examined the association of vitamin D status and vitamin D-related genetic make-up with depressive symptoms amongst 2839 Dutch older adults aged ≥65 years. Methods: 25-Hydroxyvitamin D (25(OH)D) was measured, and five ‘vitamin D-related genes’ were selected. Depressive symptoms were measured with the 15-point Geriatric Depression Scale. Results were expressed as the relative risk of the score of depressive symptoms by quartiles of 25(OH)D concentration or number of affected alleles, using the lowest quartile or minor allele group as reference. Results: A clear cross-sectional and pr

Effect of Vitamin B<inf>12</inf> and Folic Acid Supplementation on Bone Mineral Density and Quantitative Ultrasound Parameters in Older People with an Elevated Plasma Homocysteine Level: B-PROOF, a Randomized Controlled Trial

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 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

Discovery and functional prioritization of Parkinson's disease candidate genes from large-scale whole exome sequencing.

BACKGROUND: Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models. RESULTS: Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication. CONCLUSIONS: By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies

Long-term effects of folic acid and vitamin-B12 supplementation on fracture risk and cardiovascular disease: Extended follow-up of the B-PROOF trial

Background & aims: In the initial B-proof, we found inconsistent results of B vitamin supplementation. However, the debate regarding the effects of B vitamins on age-related diseases continues. Therefore, our aim was to investigate the long-term effects (5–7 years follow-up) of an intervention with folic acid and vitamin-B12 supplementation on fracture and cardiovascular disease risk. Methods: Extended follow-up of the B-PROOF trial, a multi-center, double-blind randomized placebo-controlled trial designed to assess the effect of 2–3 years daily supplementation with folic acid (400 μg) and vitamin-B12 (500 μg) versus placebo (n = 2,919). Primary outcome was verified self-reported fracture incidence and secondary outcomes were self-reported cardiovascular endpoints, which were collected through a follow-up questionnaires Proportional hazard analyses was used for the effect of the intervention on risk of fracture(s) and logistic regression for the effect of the intervention on risk of cardiovascular disease. Results: A total of 1,298 individuals (44.5%) participated in the second follow-up round with median of 54 months [51–58], (n = 662 and n = 636, treatment versus placebo group). Median age at baseline was 71.0 years [68.0–76.0] for both groups. No effect was observed of the intervention on osteoporotic fracture or any fracture risk after a follow-up (HR: 0.99, 95% CI: 0.62–1.59 and HR: 0.77; 95% CI: 0.50–1.19, respectively), nor on cardiovascular or cerebrovascular disease risk (OR: 1.05; 95%CI: 0.80–1.44 and OR: 0.85; 95%CI: 0.50–1.45, respectively). Potential interaction by baseline homocysteine concentration was observed for osteoporotic- and any fracture (p = 0.10 and 0.06 respectively), which indicated a significantly lower risk of any fracture in the treatment group with higher total homocysteine concentrations (>15.1 μmol/l). No age-dependent effects were present. Conclusions: This study supports and extends previous null-findings of the B-PROOF trial and shows that supplementation of folic acid and vitamin-B12 has no effect on fracture risk, nor on cardiovascular disease in older individuals over a longer follow-up period. However, B-vitamin supplementation may be beneficial in reducing fractures in individuals with high total homocysteine concentrations, a finding which needs to be replicated

Beta-blocker use and fall risk in older individuals: Original results from two studies with meta-analysis

Aims: To investigate the association between use of β-blockers and β-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 β-blocker use was determined using pharmacy dispensing records. Cox proportional hazard models adjusted for age and sex were applied to determine the association between β-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 β-blocker, compared to nonuse, and fall risk, hazard ratio (HR) = 0.97 [95% confidence interval (CI) 0.88–1.06]. Use of a selective β-blocker was also not associated with fall risk, HR = 0.92 (95%CI 0.83–1.01). Use of a nonselective β-blocker was associated with an increased fall risk, HR = 1.22 (95%CI 1.01–1.48). Other β-blocker characteristics including lipid solubility and CYP2D6 enzyme metabolism were not associated with fall risk. Conclusion: Our study suggests that use of a nonselective β-blocker, contrary to selective β-blockers, is associated with an increased fall risk in an older population. In clinical practice, β-blockers hav