Publications by authors named "Annelies Ham"

26 Publications

  • Page 1 of 1

Genetic variants modify the associations of concentrations of methylmalonic acid, vitamin B-12, vitamin B-6, and folate with bone mineral density.

Am J Clin Nutr 2021 May 8. Epub 2021 May 8.

Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.

Background: Elevated plasma homocysteine has been found to be associated with an increased risk of osteoporosis, especially hip and vertebral fractures. The plasma concentration of homocysteine is dependent on the activities of several B vitamin-dependent enzymes, such as methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), and cystathionine β-synthase (CBS).

Objectives: We investigated whether genetic variants in some of the genes involved in 1 carbon metabolism modify the association of B vitamin-related measures with bone mineral density (BMD) and strength.

Methods: We measured several B vitamins and biomarkers in participants of the Framingham Offspring Study, and performed analyses of methylmalonic acid (MMA) continuously and <210 nmol/L; pyridoxal-5'-phosphate; vitamin B-12 continuously and ≥258 pmol/L; and folate. The outcomes of interest included areal and volumetric BMD, measured by DXA and quantitative computed tomography (QCT), respectively. We evaluated associations between the bone measures and interactions of single nucleotide polymorphism with a B vitamin or biomarker in Framingham participants (n = 4310 for DXA and n = 3127 for QCT). For analysis of DXA, we validated the association results in the B-PROOF cohort (n = 1072). Bonferroni-corrected locus-wide significant thresholds were defined to account for multiple testing.

Results: The interactions between rs2274976 and vitamin B-12 and rs34671784 and MMA <210 nmol/L were associated with lumbar spine BMD, and the interaction between rs6586281 and vitamin B-12 ≥258 pmol/L was associated with femoral neck BMD. For QCT-derived traits, 62 interactions between genetic variants and B vitamins and biomarkers were identified.

Conclusions: Some genetic variants in the 1-carbon methylation pathway modify the association of B vitamin and biomarker concentrations with bone density and strength.  These interactions require further replication and functional validation for a mechanistic understanding of the role of the 1-carbon metabolism pathway on BMD and risks of fracture.
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http://dx.doi.org/10.1093/ajcn/nqab093DOI Listing
May 2021

Explaining integration and differentiation by identifying the rules and coordination mechanisms in a hospital's logistical system.

J Health Organ Manag 2021 Feb;35(9):66-84

Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre+, Maastricht, The Netherlands.

Purpose: Integration, that is, the coordination and alignment of tasks, is widely promoted as a means to improve hospital performance. A previous study examined integration and differentiation, that is, the extent to which tasks are segmented into subsystems, in a hospital's social network. The current study carries this research further, aiming to explain integration and differentiation by studying the rules and coordination mechanisms that agents in a hospital network use.

Design/methodology/approach: The current case study deepens the analysis of the social network in a hospital. All planning tasks and tasks for surgery performance were studied, using a naturalistic inquiry approach and a mixed method.

Findings: Of the 314 rules found, 85% predominantly exist in people's minds, 31% are in documents and 7% are in the information system. In the early planning stages for a surgery procedure, mutual adjustment based on hospital-wide rules is dominant. Closer to the day of surgery, local rules are used and open loops are closed through mutual adjustment, thus achieving integration. On the day of surgery, there is mainly standardization of work and output, based on hospital-wide rules. The authors propose topics for future research, focusing on increasing the hospital's robustness and stability.

Originality/value: This exploratory case study provides an overview of the rules and coordination mechanisms that are used for organizing hospital-wide logistics for surgery patients. The findings are important for future research on how integration and differentiation are effectively achieved in hospitals.
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http://dx.doi.org/10.1108/JHOM-06-2020-0236DOI Listing
February 2021

Identifying integration and differentiation in a Hospital's logistical system: a social network analysis of a case study.

BMC Health Serv Res 2020 Sep 11;20(1):857. Epub 2020 Sep 11.

Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University/Maastricht University Medical Centre+, P.O. Box 616, 6200, Maastricht, MD, The Netherlands.

Background: Integration, the coordination and alignment of tasks, has been promoted widely in order to improve the performance of hospitals. Both organization theory and social network analysis offer perspectives on integration. This exploratory study research aims to understand how a hospital's logistical system works, and in particular to what extent there is integration and differentiation. More specifically, it first describes how a hospital organizes logistical processes; second, it identifies the agents and the interactions for organizing logistical processes, and, third, it establishes the extent to which tasks are segmented into subsystems, which is referred to as differentiation, and whether these tasks are coordinated and aligned, thus achieving integration.

Methods: The study is based on case study research carried out in a hospital in the Netherlands. All logistical tasks that are executed for surgery patients were studied. Using a mixed method, data were collected from the Hospital Information System (HIS), documentation, observations and interviews. These data were used to perform a social network analysis and calculate the network metrics of the hospital network.

Results: This paper shows that 23 tasks are executed by 635 different agents who interact through 31,499 interaction links. The social network of the hospital demonstrates both integration and differentiation. The network appears to function differently from what is assumed in literature, as the network does not reflect the formal organizational structure of the hospital, and tasks are mainly executed across functional silos. Nurses and physicians perform integrative tasks and two agents who mainly coordinate the tasks in the network, have no hierarchical position towards other agents. The HIS does not seem to fulfill the interactional needs of agents.

Conclusions: This exploratory study reveals the network structure of a hospital. The cross-functional collaboration, the integration found, and position of managers, coordinators, nurses and doctors suggests a possible gap between organizational perspectives on hospitals and reality. This research sets a basis for further research that should focus on the relation between network structure and performance, on how integration is achieved and in what way organization theory concepts and social network analysis could be used in conjunction with one another.
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http://dx.doi.org/10.1186/s12913-020-05514-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7488445PMC
September 2020

Identifying logistical parameters in hospitals: Does literature reflect integration in hospitals? A scoping study.

Health Serv Manage Res 2019 08 21;32(3):158-165. Epub 2018 Nov 21.

CAPHRI School for Public Health and Primary Care, Maastricht University Maastricht, Netherlands.

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http://dx.doi.org/10.1177/0951484818813488DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7324119PMC
August 2019

No independent associations between preconception paternal dietary patterns and embryonic growth; the Predict Study.

Clin Nutr 2019 10 24;38(5):2333-2341. Epub 2018 Oct 24.

Department of Obstetrics and Gynecology, Erasmus MC, University Medical Centre Rotterdam, PO Box 2040, 3000 CA Rotterdam, the Netherlands. Electronic address:

Background & Aim: Several studies show the importance of periconceptional maternal dietary patterns on human embryonic growth. Healthy paternal nutrition has been associated with better semen quality and fecundability, however, evidence on the impact on pregnancy outcome is limited. Therefore, the aim of this study was to investigate the association between preconception paternal dietary patterns and first trimester embryonic growth using the parameters longitudinal crown-rump length (CRL) and embryonic volume (EV).

Methods: A total of 638 couples were enrolled in the Rotterdam Periconceptional Cohort and received longitudinal three dimensional transvaginal ultrasound scans from 7 up to 12 weeks of gestation. Virtual reality software was used to perform offline measurements of the embryonic CRL and EV. Food frequency questionnaires (FFQ) were used to estimate habitual food intake in couples. Principal component analysis (PCA) was performed to identify paternal and maternal dietary patterns. Linear mixed models adjusted for potential confounders were applied to analyze associations between paternal and maternal dietary patterns and embryonic growth parameters.

Results: The paternal dietary patterns retrieved were identified as "Whole wheat grains and Vegetables", "Sauces and Snacks Refined Grains", "Fish and Legumes" and explained 27.5% of the total variance of the dietary intake. No significant additional effects, independent of maternal dietary patters and other maternal and paternal potential confounders, were shown of these paternal dietary patterns on embryonic growth in spontaneous or IVF/ICSI pregnancies.

Conclusion: No significant effects of paternal dietary patterns independent of maternal dietary patters and other parental potential confounders on embryonic growth parameters could be established in spontaneous or IVF/ICSI pregnancies. The biological importance of paternal nutrition on semen quality, however, supports the need of periconceptional tailored nutritional counselling of couples trying to conceive.
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http://dx.doi.org/10.1016/j.clnu.2018.10.011DOI Listing
October 2019

Life-Course Genome-wide Association Study Meta-analysis of Total Body BMD and Assessment of Age-Specific Effects.

Am J Hum Genet 2018 01;102(1):88-102

MRC Epidemiology Unit, University of Cambridge, Cambridge CB2 0QQ, UK.

Bone mineral density (BMD) assessed by DXA is used to evaluate bone health. In children, total body (TB) measurements are commonly used; in older individuals, BMD at the lumbar spine (LS) and femoral neck (FN) is used to diagnose osteoporosis. To date, genetic variants in more than 60 loci have been identified as associated with BMD. To investigate the genetic determinants of TB-BMD variation along the life course and test for age-specific effects, we performed a meta-analysis of 30 genome-wide association studies (GWASs) of TB-BMD including 66,628 individuals overall and divided across five age strata, each spanning 15 years. We identified variants associated with TB-BMD at 80 loci, of which 36 have not been previously identified; overall, they explain approximately 10% of the TB-BMD variance when combining all age groups and influence the risk of fracture. Pathway and enrichment analysis of the association signals showed clustering within gene sets implicated in the regulation of cell growth and SMAD proteins, overexpressed in the musculoskeletal system, and enriched in enhancer and promoter regions. These findings reveal TB-BMD as a relevant trait for genetic studies of osteoporosis, enabling the identification of variants and pathways influencing different bone compartments. Only variants in ESR1 and close proximity to RANKL showed a clear effect dependency on age. This most likely indicates that the majority of genetic variants identified influence BMD early in life and that their effect can be captured throughout the life course.
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http://dx.doi.org/10.1016/j.ajhg.2017.12.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5777980PMC
January 2018

Use of Selective Serotonin Reuptake Inhibitors and Bone Mineral Density Change: A Population-Based Longitudinal Study in Middle-Aged and Elderly Individuals.

J Clin Psychopharmacol 2017 Oct;37(5):524-530

From the Departments of *Internal Medicine, †Epidemiology, ‡Psychiatry, and §Child and Adolescent Psychiatry, Erasmus MC-University Medical Center Rotterdam, Rotterdam; ∥Department of Internal Medicine, Section of Geriatric Medicine, Academic Medical Center, Amsterdam; ¶Apotheek Haagse Ziekenhuizen-HAGA, The Hague; and #Inspectorate of Health Care, Utrecht, the Netherlands.

Background: Longitudinal studies showed conflicting results regarding the association between use of selective serotonin reuptake inhibitors (SSRIs) and bone mineral density (BMD). Therefore, we investigate the association between-duration of-SSRI use and BMD, and change in BMD ([INCREMENT]BMD).

Methods: Data from the population-based Rotterdam Study cohort (1991-2008) were used. In total, 4915 men and 5831 postmenopausal women, aged 45 years and older, were included, having measurement visits at 4- to 5-year intervals. Multivariable linear mixed models were applied to examine the association between SSRI use, based on pharmacy records, duration of SSRI use, and repeated measures of BMD, and changes in BMD, compared with nonuse. Femoral neck BMD (grams per centimeters squared) was measured at 4 visits, comprising 19,861 BMD measurements. Three [INCREMENT]BMD periods were examined, comprising 7897 [INCREMENT]BMD values. Change in BMD was expressed in the annual percentage [INCREMENT]BMD between 2 consecutive visits.

Results: In men and women, we observed no association between SSRI and BMD when compared with nonuse (women: mean difference, 0.007 g/cm; 95% confidence interval, -0.002 to 0.017; P = 0.123). We did not find an association between duration of SSRI use and [INCREMENT]BMD (women: annual percentage change, -0.081; 95% confidence interval, -0.196 to 0.033; P = 0.164).

Conclusions: In conclusion, use of SSRIs is not associated with BMD or [INCREMENT]BMD, after taking duration of treatment into account, in middle-aged and elderly individuals. Therefore, our results question previously raised concerns on the adverse effects of SSRIs on BMD.
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http://dx.doi.org/10.1097/JCP.0000000000000756DOI Listing
October 2017

Low-Frequency Synonymous Coding Variation in CYP2R1 Has Large Effects on Vitamin D Levels and Risk of Multiple Sclerosis.

Am J Hum Genet 2017 Aug 27;101(2):227-238. Epub 2017 Jul 27.

Department of Internal Medicine, Erasmus Medical Center, Rotterdam 3015 GE, the Netherlands.

Vitamin D insufficiency is common, correctable, and influenced by genetic factors, and it has been associated with risk of several diseases. We sought to identify low-frequency genetic variants that strongly increase the risk of vitamin D insufficiency and tested their effect on risk of multiple sclerosis, a disease influenced by low vitamin D concentrations. We used whole-genome sequencing data from 2,619 individuals through the UK10K program and deep-imputation data from 39,655 individuals genotyped genome-wide. Meta-analysis of the summary statistics from 19 cohorts identified in CYP2R1 the low-frequency (minor allele frequency = 2.5%) synonymous coding variant g.14900931G>A (p.Asp120Asp) (rs117913124[A]), which conferred a large effect on 25-hydroxyvitamin D (25OHD) levels (-0.43 SD of standardized natural log-transformed 25OHD per A allele; p value = 1.5 × 10). The effect on 25OHD was four times larger and independent of the effect of a previously described common variant near CYP2R1. By analyzing 8,711 individuals, we showed that heterozygote carriers of this low-frequency variant have an increased risk of vitamin D insufficiency (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.78-2.78, p = 1.26 × 10). Individuals carrying one copy of this variant also had increased odds of multiple sclerosis (OR = 1.4, 95% CI = 1.19-1.64, p = 2.63 × 10) in a sample of 5,927 case and 5,599 control subjects. In conclusion, we describe a low-frequency CYP2R1 coding variant that exerts the largest effect upon 25OHD levels identified to date in the general European population and implicates vitamin D in the etiology of multiple sclerosis.
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http://dx.doi.org/10.1016/j.ajhg.2017.06.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5544392PMC
August 2017

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

Br J Clin Pharmacol 2017 Oct 4;83(10):2292-2302. Epub 2017 Jul 4.

Department of Internal Medicine, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.

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 have been shown effective for a variety of cardiovascular indications. However, fall risk should be considered when prescribing a β-blocker in this age group, and the pros and cons for β-blocker classes should be taken into consideration.
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http://dx.doi.org/10.1111/bcp.13328DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595938PMC
October 2017

CYP2C9 Genotypes Modify Benzodiazepine-Related Fall Risk: Original Results From Three Studies With Meta-Analysis.

J Am Med Dir Assoc 2017 01 23;18(1):88.e1-88.e15. Epub 2016 Nov 23.

Department of Internal Medicine, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, the Netherlands; Department of Internal Medicine, Section of Geriatric Medicine, Academic Medical Centre, Amsterdam, the Netherlands. Electronic address:

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.
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http://dx.doi.org/10.1016/j.jamda.2016.09.021DOI Listing
January 2017

Effects of Two-Year Vitamin B and Folic Acid Supplementation on Depressive Symptoms and Quality of Life in Older Adults with Elevated Homocysteine Concentrations: Additional Results from the B-PROOF Study, an RCT.

Nutrients 2016 Nov 23;8(11). Epub 2016 Nov 23.

Division of Human Nutrition, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.

Lowering elevated plasma homocysteine (Hcy) concentrations by supplementing vitamin B 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 ( = 2919, ≥65 years, Hcy concentrations ≥12 µmol/L) received either 500 µg vitamin B 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, = 0.004). In conclusion, two-year supplementation with vitamin B 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.
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http://dx.doi.org/10.3390/nu8110748DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5133130PMC
November 2016

Effect of vitamin B12 and folic acid supplementation on biomarkers of endothelial function and inflammation among elderly individuals with hyperhomocysteinemia.

Vasc Med 2016 Apr 15;21(2):91-8. Epub 2016 Jan 15.

Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands Department of Internal Medicine and Institute for Cardiovascular Research ICaR-VU, VU University Medical Center, Amsterdam, The Netherlands.

B-vitamin trials failed to demonstrate beneficial effects on cardiovascular outcomes, but hyperhomocysteinemia still stands out as an independent cardiovascular risk factor, particularly in elderly individuals. B-vitamins may influence early vascular dysfunction, such as endothelial dysfunction, or may have adverse effects, for example on inflammation. We investigated the effect of B-vitamins on endothelial function and inflammation within an interventional study. This study was conducted within the framework of the B-PROOF trial, which included 2919 hyperhomocysteinemic elderly individuals, who received daily vitamin B12 (500 μg) and folic acid (400 μg) or placebo for 2 years. Using an electrochemiluminescence platform, we measured intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), serum amyloid A (SAA), vascular endothelial growth factor (VEGF) and C-reactive protein (CRP) at baseline and follow-up in a subsample of 522 participants (271 intervention group; 251 placebo). Treatment effects were analyzed with ANCOVA. The participants had a mean age of 72 years, and 55% of them were male. At the 2-year follow-up, B-vitamins did not change the ICAM-1 (+36% change in the intervention group versus +32% change in the placebo group; p = 0.72), VCAM-1 (+27% vs +25%; p = 0.39), VEGF (-1% vs +4%; p = 0.40), SAA (+34% vs +38%; p = 0.85) or CRP levels (+26% vs +36%; p = 0.70) as compared to placebo. In conclusion, in elderly patients with hyperhomocysteinemia, vitamin B12 and folic acid are unlikely to influence either endothelial function or low-grade systemic inflammation. ClinicalTrials.gov Identifier: NCT00696514.
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http://dx.doi.org/10.1177/1358863X15622281DOI Listing
April 2016

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.

PLoS Genet 2015 Oct 1;11(10):e1005378. Epub 2015 Oct 1.

HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States of America.

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.
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http://dx.doi.org/10.1371/journal.pgen.1005378DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4591371PMC
October 2015

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.

Calcif Tissue Int 2016 Jan 28;98(1):18-27. Epub 2015 Sep 28.

Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.

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.
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http://dx.doi.org/10.1007/s00223-015-0059-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703626PMC
January 2016

Relative importance of summer sun exposure, vitamin D intake, and genes to vitamin D status in Dutch older adults: The B-PROOF study.

J Steroid Biochem Mol Biol 2016 11 11;164:168-176. Epub 2015 Aug 11.

Division of Human Nutrition, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.

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 (R=0.29), vitamin D intake (R=0.24), and genes (R=0.28) explained 35% (R=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.
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http://dx.doi.org/10.1016/j.jsbmb.2015.08.008DOI Listing
November 2016

Effects of 2-year vitamin B12 and folic acid supplementation in hyperhomocysteinemic elderly on arterial stiffness and cardiovascular outcomes within the B-PROOF trial.

J Hypertens 2015 Sep;33(9):1897-906; discussion 1906

aErasmus MC, Department of Internal Medicine, Rotterdam bVU University Medical Center, EMGO Institute for Health and Care Research, Department of Epidemiology and Biostatistics, Amsterdam cWageningen University, Division of Human Nutrition, Wageningen dVU University Medical Center, Department of Clinical Chemistry eVU University Medical Center, Department of Internal Medicine, Amsterdam fNetherlands Consortium for Healthy Ageing, Rotterdam, Leiden gVU University Medical Center, Institute for Cardiovascular Research ICaR-VU hAcademic Medical Center, Department of Internal Medicine, Section of Geriatrics, Amsterdam, the Netherlands.

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.
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http://dx.doi.org/10.1097/HJH.0000000000000647DOI Listing
September 2015

Cognitive Performance: A Cross-Sectional Study on Serum Vitamin D and Its Interplay With Glucose Homeostasis in Dutch Older Adults.

J Am Med Dir Assoc 2015 Jul 30;16(7):621-7. Epub 2015 Mar 30.

Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.

Objectives: First, the association between serum 25-hydroxyvitamin D (25[OH]D) and cognitive performance was examined. Second, we assessed whether there was evidence for an interplay between 25(OH)D and glucose homeostasis in the association with cognitive performance.

Design, Setting, And Participants: Associations were studied using cross-sectional data of 776 (3 domains) up to 2722 (1 domain) Dutch community-dwelling older adults, aged 65 years or older.

Measurements: Serum 25(OH)D, plasma glucose, and insulin concentrations were obtained. Cognitive performance was assessed with an extensive cognitive test battery. Prevalence ratios (PRs) were calculated to quantify the association between 25(OH)D and cognition; poor performance was defined as the worst 10% of the distribution of the cognitive scores.

Results: The overall median MMSE score was 29 (IQR 28-30). Higher serum 25(OH)D was associated with better attention and working memory, PR 0.50 (95% CI 0.29-0.84) for the third serum 25(OH)D tertile, indicating a 50% lower probability of being a poor performer than participants in the lowest tertile. Beneficial trends were shown for 25(OH)D with executive function and episodic memory. Serum 25(OH)D was not associated with plasma glucose or insulin. Plasma insulin only modified the association between serum 25(OH)D and executive function (P for interaction: .001), suggesting that the improvement in executive function with high 25(OH)D concentrations is stronger in participants with high plasma insulin concentrations compared with those with low plasma insulin concentrations.

Conclusion: Higher 25(OH)D concentrations significantly associated with better attention and working memory performance. This study does not demonstrate an interplay between serum 25(OH)D and glucose homeostasis in the association with cognitive performance.
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http://dx.doi.org/10.1016/j.jamda.2015.02.013DOI Listing
July 2015

Effect of Vitamin B12 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.

Calcif Tissue Int 2015 May 25;96(5):401-9. Epub 2015 Feb 25.

Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.

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.
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http://dx.doi.org/10.1007/s00223-015-9968-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4415946PMC
May 2015

Effect of daily vitamin B-12 and folic acid supplementation on fracture incidence in elderly individuals with an elevated plasma homocysteine concentration: B-PROOF, a randomized controlled trial.

Am J Clin Nutr 2014 Dec 1;100(6):1578-86. Epub 2014 Oct 1.

From the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands (JPvW, RAMD-R, EMB-B, NLvdZ, and LCPGMdG); the Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research (KMAS, ES, NMvS, JB, and PL) and the Department of Internal Medicine, Endocrine Section (PL), VU University Medical Center, Amsterdam, The Netherlands; the Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands (AWE, SCvD, ACH, JBJvM, MCZ, NvdV, and AGU); and the Department of Internal Medicine, Section of Geriatric Medicine, Academic Medical Center, Amsterdam, The Netherlands (NvdV).

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.
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http://dx.doi.org/10.3945/ajcn.114.090043DOI Listing
December 2014

Medication-related fall incidents in an older, ambulant population: the B-PROOF study.

Drugs Aging 2014 Dec;31(12):917-27

Section of Geriatrics, Department of Internal Medicine, Erasmus MC, University Medical Centre Rotterdam, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.

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.
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http://dx.doi.org/10.1007/s40266-014-0225-xDOI Listing
December 2014

Results of 2-year vitamin B treatment on cognitive performance: secondary data from an RCT.

Neurology 2014 Dec 12;83(23):2158-66. Epub 2014 Nov 12.

From the Division of Human Nutrition (N.L.v.d.Z., R.A.M.D.-R., J.P.v.W., E.M.B.-B., O.v.d.R., P.H.I.t.V., L.C.P.G.M.d.G.), Wageningen University; Department of Internal Medicine (A.W.E., S.C.v.D., A.C.H., N.v.d.V., T.J.M.v.d.C., A.G.U.), Erasmus University Medical Center, Rotterdam; Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research (K.M.A.S., N.M.v.S., P.L.), and Department of Internal Medicine, Endocrine Section (P.L.), VU University Medical Center, Amsterdam; Radboud Alzheimer Center (R.P.C.K.) and Department of Medical Psychology (R.P.C.K.), Radboud University Medical Center, Nijmegen; and Donders Institute for Brain, Cognition and Behavior (R.P.C.K.), Radboud University Nijmegen, the Netherlands.

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.
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http://dx.doi.org/10.1212/WNL.0000000000001050DOI Listing
December 2014

Non-linear associations between serum 25-OH vitamin D and indices of arterial stiffness and arteriosclerosis in an older population.

Age Ageing 2015 Jan 19;44(1):136-42. Epub 2014 Jul 19.

Department of Internal Medicine, Section of Geriatrics, Erasmus MC, PO Box 2040, Rotterdam 3000 CA, The Netherlands.

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 (β 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.
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http://dx.doi.org/10.1093/ageing/afu095DOI Listing
January 2015

Associations between medication use and homocysteine levels in an older population, and potential mediation by vitamin B12 and folate: data from the B-PROOF Study.

Drugs Aging 2014 Aug;31(8):611-21

Department of Internal Medicine, Erasmus MC, Geriatric Section, University Medical Centre Rotterdam, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.

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 β-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.
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http://dx.doi.org/10.1007/s40266-014-0192-2DOI Listing
August 2014

Homocysteine level is associated with aortic stiffness in elderly: cross-sectional results from the B-PROOF study.

J Hypertens 2013 May;31(5):952-9

Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.

Objective: Homocysteine has been shown to be a more accurate predictor of cardiovascular mortality in very old persons than models based on classical risk factors. Arterial stiffening is a structural abnormality involved in the pathway of cardiovascular disease. We expect this underlying pathophysiology to be a possible explanation for the association between homocysteine and cardiovascular risk, particularly in older populations.

Methods: Baseline cross-sectional data of the B-PROOF study were used to determine associations between homocysteine and outcomes of vascular function and structure. The cardiovascular subgroup of the B-PROOF study was included [n = 560, 58% men, age 72.6 ± 5.5 years, median homocysteine level 14.2 μmol/l (IQR 13.0-16.6)]. We assessed carotid distensibility coefficient, carotid compliance coefficient, aortic pulse wave velocity (aPWV), augmentation index (AIx) and aortic pulse pressure (aortic PP). Associations were tested using linear regression analysis and ANCOVA and were adjusted for possible confounders including age, sex, renal function, mean arterial pressure and heart rate.

Results: Ln-homocysteine was strongly associated with aPWV [β 0.005 95% confidence interval (0.001-0.009)]. Furthermore, this association was shown to be age-dependent (P = 0.02) and it was most strong in the upper tertile of age (77-98 years). No significant associations with ln-homocysteine were observed for AIx, carotid distensibility coefficient and compliance coefficient and aortic PP. Sex stratification shows the association between ln-homocysteine and aPWV is only significant in men.

Conclusion: In older persons, homocysteine is associated with aortic stiffness, predominantly in the oldest old. This suggests that the strong association between homocysteine and cardiovascular mortality in the elderly may be mediated by aortic stiffness.
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http://dx.doi.org/10.1097/HJH.0b013e32835eb6b9DOI Listing
May 2013