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 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.

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

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.

Higher Serum 25-Hydroxyvitamin D and Lower Plasma Glucose Are Associated with Larger Gray Matter Volume but Not with White Matter or Total Brain Volume in Dutch Community-Dwelling Older Adults.

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.

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.

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.

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

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.

Vitamin B12 intake and status and cognitive function in elderly people.

Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 µg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimer's disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status.

EURRECA-Principles and future for deriving micronutrient recommendations.

The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence (NoE) explored an approach for setting micronutrient recommendations, which would address the variation in recommendations across Europe. Therefore, a framework for deriving and using micronutrient Dietary Reference Values (DRVs) has been developed. This framework comprises four stages (defining the problem-monitoring and evaluating-deriving dietary reference values-using dietary reference values in policy making). The aim of the present paper is to use this framework to identify specific research gaps and needs related to (1) knowledge available on specific micronutrients (folate, iodine, iron, selenium, vitamin B12, vitamin D, and zinc) and (2) the methodology presented in the framework. Furthermore, the paper describes the different outputs that support the process like protocols, guidelines, systematic review databases, and peer-reviewed publications, as well as the principal routes of dissemination of these outputs to ensure their optimal uptake in policy, practice, and research collaborations. The importance of ensuring transparency in risk assessment and risk management, systematic searching the literature, and taking into account policy options is highlighted. [Supplementary materials are available for this article. Go to the publisher's online edition of Critical Reviews in Food Science and Nutrition for the following free supplemental files: Additional tables.].

EURRECA-Evidence-based methodology for deriving micronutrient recommendations.

The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence explored the process of setting micronutrient recommendations to address the variance in recommendations across Europe. Work centered upon the transparent assessment of nutritional requirements via a series of systematic literature reviews and meta-analyses. In addition, the necessity of assessing nutritional requirements and the policy context of setting micronutrient recommendations was investigated. Findings have been presented in a framework that covers nine activities clustered into four stages: stage one "Defining the problem" describes Activities 1 and 2: "Identifying the nutrition-related health problem" and "Defining the process"; stage two "Monitoring and evaluating" describes Activities 3 and 7: "Establishing appropriate methods," and "Nutrient intake and status of population groups"; stage three "Deriving dietary reference values" describes Activities 4, 5, and 6: "Collating sources of evidence," "Appraisal of the evidence," and "Integrating the evidence"; stage four "Using dietary reference values in policy making" describes Activities 8 and 9: "Identifying policy options," and "Evaluating policy implementation." These activities provide guidance on how to resolve various issues when deriving micronutrient requirements and address the methodological and policy decisions, which may explain the current variation in recommendations across Europe. [Supplementary materials are available for this article. Go to the publisher's online edition of Critical Reviews in Food Science and Nutrition for the following free supplemental files: Additional text, tables, and figures.].

Association between vitamin B12 intake and EURRECA's prioritized biomarkers of vitamin B12 in young populations: a systematic review.

OBJECTIVE: To review evidence on the associations between vitamin B12 intake and its biomarkers, vitamin B12 intake and its functional health outcomes, and vitamin B12 biomarkers and functional health outcomes. DESIGN: A systematic review was conducted by searching electronic databases, until January 2012, using a standardized strategy developed in the EURRECA network. Relevant articles were screened and sorted based on title and abstract, then based on full text, and finally included if they met inclusion criteria. A total of sixteen articles were included in the review. SETTING: Articles covered four continents: America (n 4), Europe (n 8), Africa (n 1) and Asia (n 3). SUBJECTS: Population groups included healthy infants, children and adolescents, and pregnant and lactating women. RESULTS: From the total number of 5815 papers retrieved from the initial search, only sixteen were eligible according to the inclusion criteria: five for infants, five for children and adolescents, and six for pregnant and lactating women. CONCLUSIONS: Only one main conclusion could be extracted from this scarce number of references: a positive association between vitamin B12 intake and serum vitamin B12 in the infant group. Other associations were not reported in the eligible papers or the results were not provided in a consistent manner. The low number of papers that could be included in our systematic review is probably due to the attention that is currently given to research on vitamin B12 in elderly people. Our observations in the current systematic review justify the idea of performing well-designed studies on vitamin B12 in young populations.

Systematic review on daily vitamin B12 losses and bioavailability for deriving recommendations on vitamin B12 intake with the factorial approach.

AIMS: To systematically review the literature on daily losses and bioavailability of vitamin B12. These estimates could be used for deriving recommendations on vitamin B12 intake for adults and elderly. METHODS: We identified publications on daily vitamin B12 losses (July 2011) and publications on the bioavailability of vitamin B12 from foods or diets (June 2010) in MEDLINE, EMBASE and the Cochrane Library. RESULTS: A pooled analysis of five studies (52 subjects) showed that 0.13 ± 0.03% of the total body store is lost per day. Absorption of vitamin B12 ranged from 4.5 (dose of 38 µg from consumption of liver) to 83% (dose of 3.0 µg from consumption of mutton meat). Data from eight studies including 83 subjects suggested that the amount of vitamin B12 absorbed from food (Ai) increased with increasing doses of vitamin B12 (Di) as described by the equation: ln(Ai) = 0.7694 * ln(Di) - 0.9614. CONCLUSION: Daily vitamin B12 losses in apparently healthy adults and elderly probably range from 1.4 to 5.1 µg. Vitamin B12 intakes needed to compensate for these losses seem to range from 3.8 to 20.7 µg. More evidence is needed on the relationships between biochemical markers of vitamin B12 status, vitamin B12 body store and long-term health outcomes to evaluate whether current recommendations on vitamin B12 intake (1.4-3 µg) need to be changed.

Explaining the variability in recommended intakes of folate, vitamin B12, iron and zinc for adults and elderly people.

OBJECTIVE: To signal key issues for harmonising approaches for establishing micronutrient recommendations by explaining observed variation in recommended intakes of folate, vitamin B12, Fe and Zn for adults and elderly people. DESIGN: We explored differences in recommended intakes of folate, vitamin B12, Fe and Zn for adults between nine reports on micronutrient recommendations. Approaches used for setting recommendations were compared as well as eminence-based decisions regarding the selection of health indicators indicating adequacy of intakes and the consulted evidence base. RESULTS: In nearly all reports, recommendations were based on the average nutrient requirement. Variation in recommended folate intakes (200-400 µg/d) was related to differences in the consulted evidence base, whereas variation in vitamin B12 recommendations (1.4-3.0 µg/d) was due to the selection of different CV (10-20 %) and health indicators (maintenance of haematological status or basal losses). Variation in recommended Fe intakes (men 8-10 mg/d, premenopausal women 14.8-19.6 mg/d, postmenopausal women 7.5-10.0 mg/d) was explained by different assumed reference weights and bioavailability factors (10-18 %). Variation in Zn recommendations (men 7-14 mg/d, women 4.9-9.0 mg/d) was also explained by different bioavailability factors (24-48 %) as well as differences in the consulted evidence base. CONCLUSIONS: For the harmonisation of approaches for setting recommended intakes of folate, vitamin B12, Fe and Zn across European countries, standardised methods are needed to (i) select health indicators and define adequate biomarker concentrations, (ii) make assumptions about inter-individual variation in requirements, (iii) derive bioavailability factors and (iv) collate, select, interpret and integrate evidence on requirements.

The process of setting micronutrient recommendations: a cross-European comparison of nutrition-related scientific advisory bodies.

OBJECTIVE: To examine the workings of the nutrition-related scientific advisory bodies in Europe, paying particular attention to the internal and external contexts within which they operate. DESIGN: Desk research based on two data collection strategies: a questionnaire completed by key informants in the field of micronutrient recommendations and a case study that focused on mandatory folic acid (FA) fortification. SETTING: Questionnaire-based data were collected across thirty-five European countries. The FA fortification case study was conducted in the UK, Norway, Denmark, Germany, Spain, Czech Republic and Hungary. RESULTS: Varied bodies are responsible for setting micronutrient recommendations, each with different statutory and legal models of operation. Transparency is highest where there are standing scientific advisory committees (SAC). Where the standing SAC is created, the range of expertise and the terms of reference for the SAC are determined by the government. Where there is no dedicated SAC, the impetus for the development of micronutrient recommendations and the associated policies comes from interested specialists in the area. This is typically linked with an ad hoc selection of a problem area to consider, lack of openness and transparency in the decisions and over-reliance on international recommendations. CONCLUSIONS: Even when there is consensus about the science behind micronutrient recommendations, there is a range of other influences that will affect decisions about the policy approaches to nutrition-related public health. This indicates the need to document the evidence that is drawn upon in the decisions about nutrition policy related to micronutrient intake.

Rationale and design of the B-PROOF study, a randomized controlled trial on the effect of supplemental intake of vitamin B12 and folic acid on fracture incidence.

BACKGROUND: Osteoporosis is a major health problem, and the economic burden is expected to rise due to an increase in life expectancy throughout the world. Current observational evidence suggests that an elevated homocysteine concentration and poor vitamin B12 and folate status are associated with an increased fracture risk. As vitamin B12 and folate intake and status play a large role in homocysteine metabolism, it is hypothesized that supplementation with these B-vitamins will reduce fracture incidence in elderly people with an elevated homocysteine concentration. METHODS/DESIGN: The B-PROOF (B-Vitamins for the PRevention Of Osteoporotic Fractures) study is a randomized double-blind placebo-controlled trial. The intervention comprises a period of two years, and includes 2919 subjects, aged 65 years and older, independently living or institutionalized, with an elevated homocysteine concentration (≥ 12 µmol/L). One group receives daily a tablet with 500 µg vitamin B12 and 400 µg folic acid and the other group receives a placebo tablet. In both tablets 15 µg (600 IU) vitamin D is included. The primary outcome of the study is osteoporotic fractures. Measurements are performed at baseline and after two years and cover bone health i.e. bone mineral density and bone turnover markers, physical performance and physical activity including falls, nutritional intake and status, cognitive function, depression, genetics and quality of life. This large multi-center project is carried out by a consortium from the Erasmus MC (Rotterdam, the Netherlands), VUmc (Amsterdam, the Netherlands) and Wageningen University, (Wageningen, the Netherlands), the latter acting as coordinator. DISCUSSION: To our best knowledge, the B-PROOF study is the first intervention study in which the effect of vitamin B12 and folic acid supplementation on osteoporotic fractures is studied in a general elderly population. We expect the first longitudinal results of the B-PROOF intervention in the second semester of 2013. The results of this intervention will provide evidence on the efficacy of vitamin B12 and folate supplementation in the prevention of osteoporotic fractures. TRIAL REGISTRATION: The B-PROOF study is registered with the Netherlands Trial (NTR NTR1333) and with ClinicalTrials.gov (NCT00696514).

EURRECA's approach for estimating micronutrient requirements.

In Europe, micronutrient dietary reference values have been established by (inter)national committees of experts and are used by public health policy decision-makers to monitor and assess the adequacy of diets within population groups. The approaches used to derive dietary reference values (including average requirements) vary considerably across countries, and so far no evidence-based reason has been identified for this variation. Nutrient requirements are traditionally based on the minimum amount of a nutrient needed by an individual to avoid deficiency, and is defined by the body's physiological needs. Alternatively the requirement can be defined as the intake at which health is optimal, including the prevention of chronic diet-related diseases. Both approaches are confronted with many challenges (e. g., bioavailability, inter and intra-individual variability). EURRECA has derived a transparent approach for the quantitative integration of evidence on Intake-Status-Health associations and/or Factorial approach (including bioavailability) estimates. To facilitate the derivation of dietary reference values, EURopean micronutrient RECommendations Aligned (EURRECA) is developing a process flow chart to guide nutrient requirement-setting bodies through the process of setting dietary reference values, which aims to facilitate the scientific alignment of deriving these values.

Vitamin B(12) deficiency stimulates osteoclastogenesis via increased homocysteine and methylmalonic acid.

The risk of nutrient deficiencies increases with age in our modern Western society, and vitamin B(12) deficiency is especially prevalent in the elderly and causes increased homocysteine (Hcy) and methylmalonic acid (MMA) levels. These three factors have been recognized as risk factors for reduced bone mineral density and increased fracture risk, though mechanistic evidence is still lacking. In the present study, we investigated the influence of B(12), Hcy, and MMA on differentiation and activity of bone cells. B(12) deficiency did not affect the onset of osteoblast differentiation, maturation, matrix mineralization, or adipocyte differentiation from human mesenchymal stem cells (hMSCs). B(12) deficiency caused an increase in the secretion of Hcy and MMA into the culture medium by osteoblasts, but Hcy and MMA appeared to have no effect on hMSC osteoblast differentiation. We further studied the effect of B(12), Hcy, and MMA on the formation of multinucleated tartrate-resistant acid phosphatase-positive osteoclasts from mouse bone marrow. We observed that B(12) did not show an effect on osteoclastogenesis. However, Hcy as well as MMA were found to induce osteoclastogenesis in a dose-dependent manner. On the basis of these results, we conclude that B(12) deficiency may lead to decreased bone mass by increased osteoclast formation due to increased MMA and Hcy levels.

Surplus vitamin B12 use does not reduce fatigue in patients with Irritable Bowel Syndrome or inflammatory bowel disease: A randomized double-blind placebo-controlled trial.

OBJECTIVE: In non-conventional care, high doses of vitamin B12 supplementation are used for the treatment of fatigue even in case of normal vitamin B12 blood levels. We performed a randomized placebo controlled trial to investigate the effect of surplus oral vitamin B12 supplementation on fatigue in patients with IBS or IBD. METHODS: This randomized double-blind, placebo-controlled trial included 95 out-clinic IBS and IBD patients with deactivating fatigue and normal vitamin B12 blood levels (≥150 pmol/l) aged 18-65 years. Participants were randomly assigned to receive 1000 µg vitamin B12 daily or a placebo supplement for 8 weeks. The primary outcome measure was fatigue (Checklist Individual Strength (CIS)). In addition, measures of quality of life and depression were examined. RESULTS: No significant difference in scores of the CIS subscale 'subjective fatigue' was observed between the intervention group and the control group with changes in scores of -8.1 ± 9.5 and -8.3 ± 10.6 (95% CI -11.65 to 6.71), respectively. The scores on the CIS subscale 'motivation' improved with a significant change in scores of -2.2 ± 4.6 (95% CI -4.4 to -0.04). No significantly increased scores were observed for depression or quality of life in the intervention group compared to the control group. CONCLUSION: This study did not confirm the expected effect of non-conventional surplus vit B12 supplementation on fatigue in IBS or IBD patients. In addition, no positive effect was observed on depression or quality of life. We conclude that surplus treatment with vitamin B12 in IBS and IBD patients suffering from fatigue has no beneficial clinical effect.

Homocysteine levels and the risk of osteoporotic fracture.

BACKGROUND: Very high plasma homocysteine levels are characteristic of homocystinuria, a rare autosomal recessive disease accompanied by the early onset of generalized osteoporosis. We therefore hypothesized that mildly elevated homocysteine levels might be related to age-related osteoporotic fractures. METHODS: We studied the association between circulating homocysteine levels and the risk of incident osteoporotic fracture in 2406 subjects, 55 years of age or older, who participated in two separate prospective, population-based studies. In the Rotterdam Study, there were two independent cohorts: 562 subjects in cohort 1, with a mean follow-up period of 8.1 years; and 553 subjects in cohort 2, with a mean follow-up period of 5.7 years. In the Longitudinal Aging Study Amsterdam, there was a single cohort of 1291 subjects, with a mean follow-up period of 2.7 years. Multivariate Cox proportional-hazards regression models were used for analysis of the risk of fracture, with adjustment for age, sex, body-mass index, and other characteristics that may be associated with the risk of fracture or with increased homocysteine levels. RESULTS: During 11,253 person-years of follow-up, osteoporotic fractures occurred in 191 subjects. The overall multivariable-adjusted relative risk of fracture was 1.4 (95 percent confidence interval, 1.2 to 1.6) for each increase of 1 SD in the natural-log-transformed homocysteine level. The risk was similar in all three cohorts studied, and it was also similar in men and women. A homocysteine level in the highest age-specific quartile was associated with an increase by a factor of 1.9 in the risk of fracture (95 percent confidence interval, 1.4 to 2.6). The associations between homocysteine levels and the risk of fracture appeared to be independent of bone mineral density and other potential risk factors for fracture. CONCLUSIONS: An increased homocysteine level appears to be a strong and independent risk factor for osteoporotic fractures in older men and women.

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

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.

Large meta-analysis of genome-wide association studies identifies five loci for lean body mass.

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p < 5 × 10-8) or suggestively genome wide (p < 2.3 × 10-6). Replication in 63,475 (47,227 of European ancestry) individuals from 33 cohorts for whole body lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass.Lean body mass is a highly heritable trait and is associated with various health conditions. Here, Kiel and colleagues perform a meta-analysis of genome-wide association studies for whole body lean body mass and find five novel genetic loci to be significantly associated.