Association of homocysteine, vitamin B12, and folate with bone mineral density in postmenopausal women: a meta-analysis

B vitamins and bone health: a meta-analysis with trial sequential analysis of randomized controlled trials

Our study showed that B vitamins did not have significant effect on fracture incidence, bone mineral density, and bone turnover markers. However, the research data of B vitamins on bone mineral density and bone turnover markers are limited, and more clinical trials are needed to draw sufficient conclusions.

PURPOSE

The objective of this study was to identify the efficacy of B vitamin (VB) (folate, B6, and B12) supplements on fracture incidence, bone mineral density (BMD), and bone turnover markers (BTMs).

METHODS

A comprehensive search was performed in PubMed, MEDLINE, EMBASE, Cochrane databases, and ClinicalTrials.gov up to September 4, 2023. The risk of bias was assessed according to Cochrane Handbook and the quality of evidence was assessed according to the GRADE system. We used trial sequential analysis (TSA) to assess risk of random errors and Stata 14 to conduct sensitivity and publication bias analyses.

RESULTS

Data from 14 RCTs with 34,700 patients were extracted and analyzed. The results showed that VBs did not significantly reduce the fracture incidence (RR, 1.06; 95% CI, 0.95 - 1.18; p = 0.33; I2 = 40%) and did not affect BMD in lumbar spine and femur neck. VBs had no significant effect on bone specific alkaline phase (a biomarker for bone formation), but could increase the serum carboxy-terminal peptide (a biomarker for bone resorption) (p = 0.009; I2 = 0%). The TSA showed the results of VBs on BMD and BTMs may not be enough to draw sufficient conclusions due to the small number of sample data included and needed to be demonstrated in more clinical trials. The inability of VBs to reduce fracture incidence has been verified by TSA as sufficient. Sensitivity analysis and publication bias assessment proved that our meta-analysis results were stable and reliable, with no significant publication bias.

CONCLUSIONS

Available evidence from RCTs does not support VBs can effectively influence osteoporotic fracture risk, BMD, and BTMs.

TRIAL REGISTRATION

PROSPERO registration number: CRD42023427508.

Relationship Between Plasma Homocysteine and Bone Density, Lean Mass, Muscle Strength and Physical Function in 1480 Middle-Aged and Older Adults: Data from NHANES

Hyperhomocysteinemia induces oxidative stress and chronic inflammation (both of which are catabolic to bone and muscle); thus, we examined the association between homocysteine and body composition and physical function in middle-aged and older adults. Data from the National Health and Nutrition Examination Survey was used to build regression models. Plasma homocysteine (fluorescence immunoassay) was used as the exposure and bone mineral density (BMD; dual-energy X-ray absorptiometry; DXA), lean mass (DXA), knee extensor strength (isokinetic dynamometer; newtons) and gait speed (m/s) were used as outcomes. Regression models were adjusted for confounders (age, sex, race/Hispanic origin, height, fat mass %, physical activity, smoking status, alcohol intakes, cardiovascular disease, diabetes, cancer and vitamin B12). All models accounted for complex survey design by using sampling weights provided by NHANES. 1480 adults (median age: 64 years [IQR: 56, 73]; 50.3% men) were included. In multivariable models, homocysteine was inversely associated with knee extensor strength (β = 0.98, 95% CI 0.96, 0.99, p = 0.012) and gait speed (β = 0.85, 95% CI 0.78, 0.94, p = 0.003) and borderline inversely associated with femur BMD (β = 0.84, 95% CI 0.69, 1.03, p = 0.086). In the sub-group analysis of older adults (≥ 65 years), homocysteine was inversely associated with gait speed and femur BMD (p < 0.05) and the slope for knee extensor strength and whole-body BMD were in the same direction. No significant associations were observed between homocysteine and total or appendicular lean mass in the full or sub-group analysis. We found inverse associations between plasma homocysteine and muscle strength/physical function, and borderline significant inverse associations for femur BMD.

Associations between Plasma Folate and Vitamin B12, Blood Lead, and Bone Mineral Density among Adults and Elderly Who Received a Health Examination

This study hypothesized that plasma folate and vitamin B₁₂ levels modified the association between blood lead and cadmium and total urinary arsenic levels and bone loss. A total of 447 study subjects who received a physical examination at the Wanfang Hospital Medical Center were recruited. Bone loss was defined as a calcaneus bone mineral density T-score less than -1. Blood cadmium and lead concentrations were measured by ICP-MS. Urinary arsenic species were determined using HPLC-HG-AAS. A SimulTRAC-SNB radioassay was used to measure plasma folate, vitamin B₁₂, and homocysteine levels. Total urinary arsenic and blood lead concentration were positively correlated with the odds ratio (OR) for bone loss in a dose-response manner. The OR and 95% confidence interval (CI) for bone loss in participants with blood lead concentrations > 56.14 versus ≤33.82 μg/dL were 1.82 and 1.10-3.01. No correlation between plasma folate and vitamin B₁₂ levels alone and bone loss was observed. However, this study is the first observational study to find that blood lead concentrations tend to increase the OR of bone loss in a low plasma folate and plasma vitamin B₁₂ group with multivariate ORs (95% CI) of 2.44 (0.85-6.96).

Causal effects of homocysteine levels on the changes of bone mineral density and risk for bone fracture: A two-sample mendelian randomization study

BACKGROUND & AIMS

Observational studies have demonstrated the relations of homocysteine (HCY) with bone mineral density (BMD) and bone fracture risk, but yielding contradictory results. The present study was conducted to evaluate whether the genetically predicted plasma HCY levels were causally associated with the change of BMD and the risk of bone fracture.

METHODS

Genetic summary statistics were extracted from genome-wide association study (GWAS) meta-analysis of plasma HCY levels (n = 44,147), GWAS meta-analyses of measured forearm (FA), femoral neck (FN) and lumbar spine (LS) BMD (n = up to 32,735), UK Biobank estimated heel BMD (eBMD) (n = 426,824) and fracture (n = 426,795) GWAS data. Two Sample Mendelian Randomization (TSMR) analysis was performed to assess the causal effects of genetically determined plasma HCY on the BMD and bone fractures.

RESULTS

The MR analysis indicated that, genetically decreased plasma HCY was associated with the increased FA-BMD based on the inverse variance weighting (IVW) method (standard deviation [SD] = 0.348, 95% CI: 0.146 to 0.550, P = 7 × 10^-4). However, there were no significant associations of genetically decreased plasma HCY with FN-BMD, LS-BMD, eBMD and the risk for bone fracture (SD = -0.041, 95% CI: -0.189 to 0.106, P = 0.582; SD = -0.053, 95% CI: -0.238 to 0.131, P = 0.572; SD = -0.030, 95% CI: -0.090 to 0.030, P = 0.328, odds ratio [OR]: 1.03, 95% CI: 0.94 to 1.13, P = 0.562, respectively). Moreover, the results also found that genetically determined HCY increase was not correlated with the changes of BMD and the risk for bone fracture.

CONCLUSION

Our study revealed that genetically decreased plasma HCY was associated with increase of FA-BMD.

Osteoporosis and the effect of dysregulation of the transsulfuration pathway via taurine on intracellular calcium homeostasis, vitamin D absorption and vitamin K absorption

BACKGROUND & AIMS

In this article we connect the dysregulation of the transsulfuration pathway to bone dysregulations and propose a novel treatment for osteoporosis. Current treatments for osteoporosis are very frequently inadequate. In osteoporosis, the risk of fractures increases with increased homocysteine (Hcy).

METHODS

Here, we conduct a review on the relationship between osteoporosis and the dysregulation of the transsulfuration pathway.

RESULTS

we show that the transsulfuration pathway metabolizes Hcy to L-cysteine. Increased Hcy levels point to the transsulfuration pathway being dysregulated. With the transsulfuration pathway dysregulated, there will be decreased levels of L-cysteine and decreased levels of taurine, which is synthesized from L-cysteine. Taurine levels are decreased in patients with osteoporosis. Taurine regulates intracellular calcium homeostasis. Taurine, also, when conjugated with bile acids assists with absorption of fats and fat-soluble vitamins such as vitamin D and vitamin K. Dysregulated calcium homeostasis, decreased calcium absorption and decreased absorption of vitamin D and vitamin K due to low levels of taurine negatively affect bone mineral density (BMD) leading to osteoporosis and fractures.

CONCLUSIONS

In this article, we propose that a combination of taurine, calcium, vitamin D and vitamin K, could increase BMD reducing number of years spent in disability and reducing deaths due to fractures in patients with osteoporosis.

Associations of serum vitamins levels with bone mineral density in the different race-ethnicities US adults

BACKGROUND

The conclusions on the associations of specific vitamin levels with bone mineral density (BMD) were controversial. Therefore, the aims of this study were to examine the associations of serum vitamins levels with BMD and the modified effect of race/ ethnicity on these associations in the US adults.

METHODS

This study was from the third National Health and Nutrition Examination Survey. All participants aged ≥18 years with complete data were eligible. Serum vitamins A, B9, B12, C, and E levels were assayed using the Quantaphase II Radioassay Kit (Bio-Rad). Dual-energy X-ray absorptiometry was employed to measure BMD, including femur neck and the total hip.

RESULTS

There were 6023 participants included in the final analysis. Serum folate, vitamins A and C levels were positively associated with BMD. No significant associations of serum vitamins B12 and E levels with BMD were observed. There were positive associations of serum folate level (β = 0.00027 and 0.00032; and 95% CI: 0.00002-0.00057 and 0.00002-0.00063, respectively), vitamin A level (β = 0.01132 and 0.01115; and 95% CI: 0.00478-0.01787 and 0.00430-0.01799, respectively), and vitamin C level (β = 0.00027 and 0.00029; and 95% CI: 0.00012-0.00042 and 0.00013-0.00045, respectively) with BMD at femur neck and the total hip only in the Not Hispanic participants.

CONCLUSION

Elevated serum folate, vitamins A and C levels were associated with a higher BMD. Furthermore, sex and race/ ethnicity modified the associations of serum vitamins levels with BMD.

Correlation of oxidative stress-related biomarkers with postmenopausal osteoporosis: a systematic review and meta-analysis

Oxidative stress (OS) is implicated in postmenopausal osteoporosis (PO). Results show an imbalance between antioxidative and oxidative markers in PO. Thus, monitoring of OS-related biomarkers and keeping balance between reactive oxygen species and antioxidant system are beneficial to the diagnosis and prognosis of PO.

PURPOSE

Oxidative stress (OS) has been implicated in postmenopausal osteoporosis (PO). However, the relations between OS-related markers and PO are controversial. This study aimed to quantitatively and comprehensively assess the roles of OS-related biomarkers in PO.

METHODS

Relevant articles were retrieved from electronic databases. All OS-associated biomarkers with at least 2 independent study outcomes were meta-analyzed. The pooled standardized mean differences (SMD) with its 95% confidence intervals (CI) were presented.

RESULTS

A total of 36 studies involving 16 OS-related biomarkers were investigated. The overall results showed that total oxidant status (TOS), superoxide dismutase (SOD), hydroperoxides (HY), paraoxonase (PON1), nitric oxide (NO), and homocysteine (Hcy) were not statistically different between the PO and control groups, whereas significantly increased levels of oxidative stress index (OSI), malondialdehyde (MDA), advanced oxidation protein products (AOPP), and vitamin B12, along with decreased total antioxidant status (TAS), total antioxidant power (TAP), catalase (CAT), glutathione peroxidase (GPx), uric acid (UA), and folate, were detected in the PO group. Subgroup analysis based on biological samples displayed significantly elevated NO in erythrocyte and Hcy in serum, along with decreased SOD in serum.

CONCLUSION

Monitoring of certain OS-related biomarkers might be beneficial to the diagnosis and prognosis of PO.

Effect of Vitamin B12 Injection on the Vocal Performance of Professional Singers: A Randomized, Double-blind, Placebo-Controlled, Crossover Trial

Importance

One-third of singers and vocal professionals report experiencing a benefit from empirical vitamin B12 injections for improvement of mild singing-related symptoms (eg, reduced stamina, vocal fatigue, and effort). However, there is no objective evidence to support or refute these claims.

Objective

To assess the presence and magnitude of the effect of empirical vitamin B12 injection on the vocal performance of singers.

Design, Setting, and Participants

A randomized, double-blind, placebo-controlled, crossover trial was conducted from November 7, 2017, to November 30, 2018, at an academic voice center among 20 active adult singers without dysphonia but with mild vocal symptoms. Individuals with known or suspected vitamin B12 deficiency or active or recent vitamin B12 treatment were excluded. Analysis was on a per-protocol basis.

Interventions

Participants were randomized to receive an intramuscular (deltoid) injection of either vitamin B12 (1000 μg of cyanocobalmin) or placebo (0.9% sodium chloride). After a washout period of at least 4 weeks, participants were crossed over to receive the opposite injection. Both the investigators and participants were blinded to the order of injections.

Main Outcomes and Measures

The participants completed the Singing Voice Handicap Index-10 (SVHI-10), the Voice Fatigue Index (VFI), and the Evaluation of the Ability to Sing Easily (EASE) before each injection and at intervals of 1 hour, 3 hours, 24 hours, 72 hours, and 1 week after the injection. The primary time point assessment was 72 hours after injection, and the SVHI-10 score was the primary outcome measure.

Results

Twenty singers (10 men; median age, 22 years [range, 19-42 years]) were enrolled. The improvements after either placebo or vitamin B12 injections were comparable to each other. At 72 hours after the vitamin B12 injection, the median difference in the SVHI-10 score was 1 (95% CI, -1 to 2) compared with 3 (95% CI, 0-4) after placebo. The median difference between differences at 72 hours between placebo and vitamin B12 injections were 1.5 (95% CI, -2 to 5) for the SVHI-10, 1 (95% CI, -9 to 9) for the VFI, and -1 (95% CI, -3 to 2) for the EASE. The improvements after both injections failed to reach the estimated minimal clinically important difference. Of the 20 participants, 4 (20%) reached the estimated minimal clinically important difference in their SVHI-10 score after 72 hours for both vitamin B12 and placebo injections.

Conclusions and Relevance

This randomized, double-blind, placebo-controlled, crossover trial found that after empirical vitamin B12 injection to improve mild voice-related symptoms, the improvement in self-reported voice measures in singers shows no meaningful difference compared with placebo.

Trial Registration

ClinicalTrials.gov Identifier: NCT03437824.

Hyperhomocysteinemia is Associated with Inflammation, Bone Resorption, Vitamin B12 and Folate Deficiency and MTHFR C677T Polymorphism in Postmenopausal Women with Decreased Bone Mineral Density

Osteoporosis is an age-related bone disease, affecting mainly postmenopausal women, characterized by decreased bone mineral density (BMD) and consequent risk of fractures. Homocysteine (Hcy), a sulfur-aminoacid whose serum level is regulated by methylenetrahydrofolate reductase (MTHFR) activity and vitamin B12 and folate as cofactors, is a risk factor for inflammatory diseases. Literature data concerning the link between Hcy and osteoporosis are still debated. The aim of our study was to assess the relationship among Hcy and BMD, inflammation, vitamin status and bone turnover in postmenopausal osteoporosis. In 252 postmenopausal women, BMD was measured by dual-energy X-ray absorptiometry (DXA). In addition to serum Hcy, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and bone turnover markers (bone alkaline phosphatase-BAP, osteocalcin-OC, C-terminal telopeptide of type I collagen (CTX), vitamin deficiencies and MTHFR-C677T polymorphism were evaluated. Hcy, inflammation, bone resorption markers and prevalence of C677T polymorphism were higher, whereas vitamin D, B12, folate, and bone formation markers were lower in women with decreased BMD compared to those with normal BMD. Our results suggest a significant association between Hcy, BMD and inflammation in postmenopausal osteoporosis. The regulation of Hcy overproduction and the modulation of the inflammatory substrate could represent additional therapeutic approaches for osteoporosis prevention.

Gene interactions observed with the HDL-c blood lipid, intakes of protein, sugar and biotin in relation to circulating homocysteine concentrations in a group of black South Africans

Background

Elevated homocysteine (Hcy) is associated with several pathologies. Gene–diet interactions related to Hcy might be used to customize dietary advice to reduce disease incidence. To explore this possibility, we investigated interactions between anthropometry, biochemical markers and diet and single-nucleotide polymorphisms (SNPs) in relation to Hcy concentrations. Five SNPs of Hcy-metabolizing enzymes were analyzed in 2010 black South Africans.

Results

Hcy was higher with each additional methylenetetrahydrofolate reductase (MTHFR) C677T minor allele copy, but was lower in methionine synthase (MTR) 2756AA homozygotes than heterozygotes. Individuals harboring cystathionine β synthase (CBS) 833 T/844ins68 had lower Hcy concentrations than others. No interactive effects were observed with any of the anthropometrical markers. MTHFR C677T and CBS T833C/844ins68 homozygote minor allele carriers presented with lower Hcy as high density lipoprotein cholesterol (HDL-c) increased. Hcy concentrations were negatively associated with dietary protein and animal protein intake in the TT and TC genotypes, but positively in the CC genotype of CBS T833C/844ins68. Hcy was markedly higher in TT homozygotes of MTHFR C677T as added sugar intake increased. In CBS T833C/844ins68 major allele carriers, biotin intake was negatively associated with Hcy; but positively in those harboring the homozygous minor allele.

Conclusions

The Hcy–SNP associations are modulated by diet and open up the possibility of invoking dietary interventions to treat hyperhomocysteinemia. Future intervention trials should further explore the observed gene–diet and gene–blood lipid interactions.

The Relationship between Nutrient Patterns and Bone Mineral Density in Postmenopausal Women

In women, the menopausal transition is characterized by acid-base imbalance, estrogen deficiency and rapid bone loss. Research into nutritional factors that influence bone health is therefore necessary. In this study, the relationship between nutrient patterns and nutrients important for bone health with bone mineral density (BMD) was explored. In this cross-sectional analysis, 101 participants aged between 54 and 81 years were eligible. Body composition and BMD analyses were performed using dual-energy X-ray absorptiometry (DXA). Nutrient data were extracted from a 3-day diet diary (3-DDD) using Foodworks 9 and metabolic equivalent (MET-minutes) was calculated from a self-reported New Zealand physical activity questionnaire (NZPAQ). Significant positive correlations were found between intakes of calcium (p = 0.003, r = 0.294), protein (p = 0.013, r = 0.246), riboflavin (p = 0.020, r = 0.232), niacin equivalent (p = 0.010, r = 0.256) and spine BMD. A nutrient pattern high in riboflavin, phosphorus and calcium was significantly positively correlated with spine (p < 0.05, r = 0.197) and femoral neck BMD (p < 0.05, r = 0.213), while the nutrient pattern high in vitamin E, α-tocopherol, β-carotene and omega 6 fatty acids was negatively correlated with hip (p < 0.05, r = −0.215) and trochanter BMD (p < 0.05, r = −0.251). These findings support the hypothesis that a nutrient pattern high in the intake of vitamin E, α-tocopherol and omega 6 fatty acids appears to be detrimental for bone health in postmenopausal women.

Homocysteine-lowering exercise effect is greater in hyperhomocysteinemic people living with HIV: a randomized clinical trial

Elevated concentration of homocysteine has been identified as an independent risk factor for the development of cardiovascular disease and is frequently associated with oxidative stress. Moreover, studies have shown that people living with human immunodeficiency virus (PLHIV) present elevated concentration of homocysteine and oxidative stress compared with people without HIV. Our purpose was to describe blood homocysteine and oxidative stress markers in PLHIV and those without HIV infection, and to examine the effects of a 16-week combined training exercise program (CTE) on oxidative stress and homocysteine concentrations of PLHIV. We included 49 PLHIV (21 men, 28 women) and 33 people without HIV infection (13 men, 20 women). After baseline evaluations, 30 PLHIV were randomized to either CTE (trained group, n = 18) or the control group (n = 12); CTE consisted of aerobic and strength exercise sessions during 16 weeks, 3 times a week. Plasma homocysteine, oxidative damage markers, folate, and vitamin B₁₂ were assessed pre- and post-training and by hyperhomocysteinemia (homocysteine ≥ 15 μmol/L) status. At baseline, PLHIV had higher levels of homocysteine and malondialdehyde, as well as reduced circulating folate when compared with people without HIV infection. CTE resulted in a 32% reduction (p < 0.05) in homocysteine concentration and a reduction in lipid hydroperoxide in PLHIV with hyperhomocysteinemia, which was not observed in those without hyperhomocysteinemia. Hyperhomocysteinemic participants experienced a 5.6 ± 3.2 μmol/L reduction in homocysteine after CTE. In summary, 16 weeks of CTE was able to decrease elevated homocysteine concentration and enhance redox balance of PLHIV with hyperhomocysteinemia, which could improve their cardiovascular risk.

Relation of Bone Mineral Density with Homocysteine and Cathepsin K levels in Postmenopausal Women

BACKGROUND

Homocysteine (HCY) interferes with collagen cross-linking in bones and stimulates osteoclast activity. The activated osteoclasts secrete cathepsin K (CathK), a cysteine protease, in eminent quantity during bone resorption. Hyperhomocysteinemia may effect bone mineral density (BMD) through CathK. We, therefore, examined the relation between HCY and BMD along with CathK, 25-hydroxyvit-D (25[OH]D), intact parathyroid hormone (iPTH), and Vitamin B12.

MATERIALS AND METHODS

We recruited a total of 93 postmenopausal women between the age group of 45-60 years, attending the Endocrinology outpatient department at King George's Medical University, Lucknow. BMD was done by DXA scan using Hologic QDR1000 system. Based on the WHO criteria, patients were segregated into three groups as follows; normal bone mass, osteopenia, and osteoporosis. All women underwent routine biochemical laboratory parameters, HCY, Vitamin B12, and CathK levels.

RESULTS

Among 93 postmenopausal women, 56% (52) had osteoporosis. Nineteen percent (18) had normal BMD (mean age, 53.22 ± 8.5 years) and 23 (25%) had osteopenia (mean age 52.86 ± 6.67 years). The mean age in the osteoporetic group was 56.2 ± 6.9 years. The median (interquartile range) levels of HCY in the three groups were 14.5 μmol/L (12.2-24.7), 15.05 μmol/L (12.1-19.9) and 13.2 μmol/L (10.3-17.0), respectively. CathK levels were similar in three groups 7.6 ng/ml (7.0-80.5), 8.3 ng/ml (7.3-8.5), and 8.6 ng/ml (7.2-8.9). Both HCY and CathK were found positively associated with serum phosphorus (r = 0.584, P < 2.01 and r = 0.249, P < 0.05, respectively). Levels of HCY positively correlate with PTH (r = 0.303, P < 0.01) and inversely with Vitamin B12 (r = -0.248, P < 0.05). No significant association was seen between CathK level and 25(OH) D, iPTH, serum calcium.

CONCLUSION

Low bone mass by DXA is a significant problem in postmenopausal females. HCY and CathK do not reliably correlate with bone loss in postmenopausal women although phosphorus metabolism may play a role.

S-adenosylhomocysteine hydrolase over-expression does not alter S-adenosylmethionine or S-adenosylhomocysteine levels in CBS deficient mice

Elevated plasma total homocysteine (tHcy) is associated with a number of human diseases including coronary artery disease, stroke, osteoporosis and dementia. It is highly correlated with intracellular S-adenosylhomocysteine (SAH). Since SAH is a strong inhibitor of methyl-transfer reactions involving the methyl-donor S-adenosylmethionine (SAM), elevation in SAH could be an explanation for the wide association of tHcy and human disease. Here, we have created a transgenic mouse (Tg-hAHCY) that expresses human S-adenosylhomocysteine hydrolase (AHCY) from a zinc-inducible promoter in the liver and kidney. Protein analysis shows that human AHCY is expressed well in both liver and kidney, but elevated AHCY enzyme activity (131% increase) is only detected in the kidney due to the high levels of endogenous mouse AHCY expression in liver. Tg-hAHCY mice were crossed with mice lacking cystathionine β-synthase activity (Tg-I278T Cbs^−/−) to explore the effect to AHCY overexpression in the context of elevated serum tHcy and elevated tissue SAM and SAH. Overexpression of AHCY had no significant effect on the phenotypes of Tg-I278T Cbs^−/− mice or any effect on the steady state concentrations of methionine, total homocysteine, SAM, SAH, and SAM/SAH ratio in the liver and kidney. Furthermore, enhanced AHCY activity did not lower serum and tissue tHcy or methionine levels. Our data suggests that enhancing AHCY activity does not alter the distribution of methionine recycling metabolites, even when they are greatly elevated by Cbs mutations.

The Singer's and the Clinician's Perspective on Vitamin B12 Treatment for Vocal Benefits

INTRODUCTION

There is a belief among vocalists that there are voice benefits from vitamin B₁₂ treatment. Yet there are no previous reports regarding vitamin B₁₂ effects on voice.

OBJECTIVES

To assess the prevalence of vitamin B₁₂ use among singers and their beliefs regarding vitamin B₁₂ therapy.

METHODS

Anonymous online survey administered to singers, singing-teachers, speech-language pathologists, and laryngologists.

RESULTS

A total of 192 participants completed the surveys; 128 singers (68 singing-teachers, 30 speech-language pathologists) and 64 laryngologists. Among singers, 12% have perceived voice benefits from vitamin B₁₂ treatment taken for any reason. Four percent used vitamin B₁₂ for voice benefits; all perceived voice benefits as a result. The leading voice benefits were improved stamina, reduced effort, confidence, and control. Nineteen percent of the singers would recommend vitamin B₁₂ treatment to a friend; 15% of the singing-teachers would recommend it to a student. Among laryngologists, 33% been asked by a singer to prescribe vitamin B₁₂ for voice benefits; 9% have prescribed it in the past. Yet only 3% would you recommend it to a patient. When asked "Do you believe vitamin B₁₂ therapy improves vocal performance?" 31% of the singers responded "Yes," compared with none in the laryngologists. When asked "Do you think the singing community believes vitamin B₁₂ therapy improves vocal performance?" 26% of the singers responded "Yes," compared with 53% of the laryngologists (P = 0.0002).

CONCLUSIONS

There is a discrepancy between the singers' and the laryngologists' beliefs regarding vocal benefits perceived by vitamin B₁₂. Blinded randomized trials are required to verify or refute this belief.

Oxidative Stress-Related Biomarkers in Postmenopausal Osteoporosis: A Systematic Review and Meta-Analyses

Numerous studies suggested that oxidative stress (OS) played a central role in the onset and development of postmenopausal osteoporosis (PO); however, conflicting results were obtained as to the association of OS-related biomarkers and PO. This meta-analysis aimed to identify the association between these markers and PO, and explore factors that may explain the inconsistencies in these results. A systematic literature search was conducted in relevant database. Search terms and selection criteria were priorly determined to identify and include all studies that detected markers of OS in PO patients. We pooled data with a random effects meta-analysis with standardized mean differences and 95% confidence interval. Total 17 studies including 12 OS markers were adopted. The results showed that superoxide dismutase (SOD) in erythrocytes, catalase (CAT), total antioxidant status (TAS), hydroperoxides (HY), advanced oxidation protein products (AOPP), malondialdehyde (MDA), and vitamin B12 (VB₁₂) in plasma/serum were not statistically different between the PO and control group, whereas significantly increased level of homocysteine (Hcy) and nitric oxide (NO), along with decreased SOD, glutathione peroxidase (GPx), folate, and total antioxidant power (TAP) in plasma/serum were obtained in the PO group. In summary, OS might serve as potential biomarkers in the etiopathophysiology and clinical course of PO.

B-vitamin status and bone mineral density and risk of lumbar osteoporosis in older females in the United States

BACKGROUND

Previous data suggest that elevated serum total homocysteine (tHcy) may be a risk factor for bone fracture and osteoporosis. Nutritional causes of elevated tHcy are suboptimal B-vitamin status. To our knowledge, this is the first nationally representative report on the relation of B vitamins and bone health from a population with folic acid fortification.

OBJECTIVE

The purpose of this analysis was to examine the relation between B-vitamin status biomarkers and bone mineral density (BMD), risk of osteoporosis, and biomarkers of bone turnover.

DESIGN

We examined the relation of tHcy, methylmalonic acid (MMA), and serum/red blood cell folate and total-body and lumbar spine BMD in women aged ≥50 y participating in the NHANES 1999-2004 (n = 2806), a nationally representative cross-sectional survey. These are the only years with concurrent measurement of tHcy and whole-body dual-energy X-ray absorptiometry. We also examined B-vitamin biomarkers relative to bone turnover markers, bone alkaline phosphatase, and urinary N-terminal cross-linked telopeptide of type I collagen in a 1999-2002 subset with available data (n = 1813).

RESULTS

In comparison with optimal concentrations, women with elevated tHcy were older with lower serum vitamin B-12, red blood cell folate, and dietary micronutrient intakes and had significantly higher mean ± SE markers of bone turnover (bone alkaline phosphatase: 15.8 ± 0.59 compared with 14.0 ± 0.25 μg/L; urinary N-terminal cross-linked telopeptide of type I collagen: 48.2 ± 2.9 compared with 38.9 ± 0.90 nmol bone collagen equivalents per mmol creatinine/L). Elevated MMA (OR: 1.88; 95% CI: 1.10, 3.18) and tHcy (OR: 2.17; 95% CI: 1.14, 4.15) were related to increased risk of lumbar osteoporosis. When examined as a continuous variable, tHcy was negatively associated, serum folates were positively associated, and MMA and vitamin B-12 were not significantly associated with lumbar and total-body BMD.

CONCLUSION

In this nationally representative population of older US women with high exposure to B vitamins through food fortification and dietary supplements, only elevated tHcy and MMA were independently associated with risk of lumbar spine osteoporosis.

Elevated homocysteine levels in human immunodeficiency virus-infected patients under antiretroviral therapy: A meta-analysis

AIM: To evaluate the association between the levels of homocysteine (Hcy), folate, vitamin B12 in human immunodeficiency virus (HIV)-infected patients who were treated with antiretroviral therapy (ART) or not treated with ART.

METHODS: The PubMed and Scielo databases were searched. Eligible studies regarding plasma Hcy level in HIV-infected patients were firstly identified. After careful analysis by two independent researches, the identified articles were included in the review according to two outcomes (1) Hcy, folate and vitamin B12 blood concentration in HIV-infected subjects vs health controls and; (2) Hcy blood concentration in HIV-infected subjects under ART vs not treated with ART. RevMan (version 5.2) was employed for data synthesis.

RESULTS: A total of 12 studies were included in outcome 1 (1649 participants, 932 cases and 717 controls). Outcome 1 meta-analysis demonstrated higher plasma Hcy (2.05 µmol/L; 95%CI: 0.10 to 4.00, P < 0.01) and decreased plasma folate concentrations (-2.74 ng/mL; 95%CI: -5.18 to -0.29, P < 0.01) in HIV-infected patients compared to healthy controls. No changes in vitamin B12 plasma concentration were observed between groups. All studies included in the outcome 2 meta-analysis (1167 participants; 404 HIV-infected exposed to ART and 757 HIV-infected non-ART patients) demonstrated higher mean Hcy concentration in subjects HIV-infected under ART compared to non-ART HIV subjects (4.13 µmol/L; 95%CI: 1.34 to 6.92, P < 0.01).

CONCLUSION: This meta-analysis demonstrated that the levels of Hcy and folate, but not vitamin B12, were associated with HIV infection. In addition, Hcy levels were higher in HIV-infected patients who were under ART compared to HIV-infected patients who were not exposed to ART. Our results suggest that hyperhomocysteinemia should be included among the several important metabolic disturbances that are associated with ART in patients with HIV infection.

Osteoporosis and cardiovascular disease: an update

Osteoporosis (OP) and cardiovascular diseases (CVD) are the most important causes of mortality and morbility in the elderly. Lots of studies showed a correlation between bone loss and cardiovascular risk mediated by the vascular calcification. The relationship between OP and CVD could be firstly explained by their common risk factors such as age, smoking, alcohol consumption, physical activity and menopause. However, other different hypotheses were proposed to clarify this link. Multiple factors, for example bone morphogenetic proteins, osteoprotegerin, receptor activator of nuclear factor κB ligand, parathyroid hormone, phosphate, oxidized lipids and vitamins D and K seemed to be involved in both conditions, indicating a possible common pathophysiologic mechanism. We review and discuss the available data describing this association. Further studies are necessary to better investigate similarities between OP and CVD.

Vertebral fractures on routine chest computed tomography: relation with arterial calcifications and future cardiovascular events

Osteoporosis and cardiovascular disease often coexist. Vertebral fractures incidentally imaged in the course of routine care might be able to contribute to the prediction of cardiovascular events. Following a case-cohort design, 5,679 patients undergoing chest CT were followed for a median duration of 4.4 years. Cases were defined as patients who subsequently developed a cardiovascular event (n = 493). The presence and severity of vertebral fractures, as well as aortic, coronary and valvular calcifications on CT were investigated. Cases were more likely to be male (69 vs 60 %) and older (66 vs 61 years old). Prevalent vertebral fractures conferred an elevated risk of cardiovascular events after adjustment for age and gender [hazard ratio (HR) of 1.28, 95 % confidence interval (CI) 1.07 to 1.54]. This effect remained moderate after correction for cardiovascular calcifications (HR 1.20, CI 0.99-1.44). However, in terms of discrimination, vertebral fractures did not have substantial incremental prognostic value after correction (C-index was 0.683 vs 0.682 for models with and without vertebral fractures respectively). Prevalent vertebral fractures on routine clinical chest CT are related to future cardiovascular events but do not have additional prognostic value to models that already include age, gender and cardiovascular calcifications.

HDL-Associated Paraoxonase 1 as a Bridge between Postmenopausal Osteoporosis and Cardiovascular Disease

The association of postmenopausal osteoporosis (PMOP) with both atherosclerosis and vascular/valvular calcification is well known. Recently, ample evidence has suggested a common etiologic factor, namely, reduced HDL-associated paraoxonase 1 (PON1) activity, as a causative factor in the development of PMOP and cardiovascular disease (CVD). This common etiologic factor not only contributes to atherosclerotic diseases but also to PMOP following an almost identical mechanism including dysfunctional HDL and lipid oxidation. According to recent studies, lipid oxidation might improve osteoblastic transformation of vascular cells and obstruct such transformation in bone cells. The primary objective of this current review was to summarize the evidence revealing the role of HDL-associated PON1 enzyme in PMOP. Additionally, the review aimed to address some of the subjects that need further investigation in order to define whether hyperhomocysteinemia and sensitivity to lipid oxidation may be risk factors for PMOP.

Secondary confounders of osteoporotic hip fractures in patients admitted to a geriatric acute care department

BACKGROUND

With respect to the pathogenesis of osteoporosis, primary and secondary forms of the disease can be distinguished. It has been recognized that the incidence of primary and secondary osteoporosis differs in women and men.

OBJECTIVE

The aim of the present study was to assess the incidence and gender distribution of factors contributing to osteoporosis in older hip fracture patients.

METHODS

In this cross-sectional study 404 patients with hip fractures and controls referred to an acute geriatric care department over a period of 15 months were included. The medical history was recorded and blood samples were analyzed for routine laboratory parameters.

RESULTS

A total of 249 patients with hip fractures and 155 matched controls were studied. The Tinetti test and the Barthel index were found to show highly significant differences in both groups mainly because of the postoperative state of patients with fractures. Vitamin D deficiency was found in 94.1% of male fracture patients and 94.6% of female fracture patients. On average 2.4 secondary contributors of osteoporosis were present in male fracture patients versus 2.9 in male controls and 2.3 in female fracture patients versus 2.3 in female controls. For most parameters no significant gender differences of possible secondary contributors to osteoporosis were found. Secondary osteoporosis was diagnosed in all male fracture patients and in 56.2% of all female fracture patients.

CONCLUSION

Based on the findings of this study it is recommended that hip fracture patients should be assessed for secondary contributors of osteoporosis. Although the overall distribution of secondary contributors was similar in women and men, the prevalence of secondary osteoporosis was higher in men.