The role of hyperhomocysteinemia as well as folate, vitamin B(6) and B(12) deficiencies in osteoporosis: a systematic review

A randomized trial alerting authors, with or without coauthors or editors, that research they cited in systematic reviews and guidelines has been retracted

Retracted clinical trials may be influential in citing systematic reviews and clinical guidelines. We assessed the influence of 27 retracted trials on systematic reviews and clinical guidelines (citing publications), then alerted authors to these retractions. Citing publications were randomized to up to three e-mails to contact author with/without up to two coauthors, with/without the editor. After one year we assessed corrective action. We included 88 citing publications; 51% (45/88) had findings likely to change if retracted trials were removed, 87% (39/45) likely substantially. 51% (44/86) of contacted citing publications replied. Including three authors rather than the contact author alone was more likely to elicit a reply (P = 0.03). Including the editor did not increase replies (P = 0.66). Whether findings were judged likely to change, and size of the likely change, had no effect on response rate or action taken. One year after e-mails were sent only nine publications had published notifications. E-Mail alerts to authors and editors are inadequate to correct the impact of retracted publications in citing systematic reviews and guidelines. Changes to bibliographic and referencing systems, and submission processes are needed. Citing publications with retracted citations should be marked until authors resolve concerns.

The injection of maternal B complex vitamin during the transition period: The impact on performance, thyroid hormones levels and immunological parameters in the Sannen goats and their kids, as well as the faeces status of newborn kids

BACKGROUND

It is proven that B vitamins through promote a wide range of metabolic pathways in animals as cofactors improve animal performance.

OBJECTIVES

This study was conducted to investigate the impacts of maternal B complex vitamin injection on performance and plasma parameters in goats and their offspring, as well as the faeces status of newborn kids.

METHODS

In this research, the pregnant goats (3 years old) were randomly divided into two groups: the control group (without B complex vitamin injection) and the B complex vitamin group (5 mL B complex vitamin injection per animal). The animals were injected with 5 mL B complex vitamin twice during the transition period (5 weeks pre- and 5 weeks post-kidding). The goats during the transition period and kids on days 10, 20 and 30 were weighed. Feed intake by goats and consumption of milk and starter in kids were recorded daily. The dry matter digestibility by kids was tested by collecting samples of faeces and feed for 5 days in the last week. Chemical analysis was determined using the AOAC method. The kids' faeces were prepared daily during the study. The blood samples of goats and newborn kids were taken 7 days after kidding. Then, levels of B group vitamin, as well as concentrations of liver enzymes, thyroid hormones and immunological parameters, were determined in plasma of goat and their offspring. In addition, concentrations of glucose and insulin were measured in goat plasma (Asadi et al., 2024).

RESULTS

According to results, the performances of goats and their offspring, as well as kids' faeces status, were improved by maternal B complex vitamin injection (p < 0.0001). The levels of cobalamin, pyridoxine, thiamine, folic acid, nicotinic, pantothenic and unconjugated pteridine increased in the plasma of goats and their kids in the B complex vitamin group compared with the control group during the transition period (p < 0.0001). Injection of maternal B complex vitamin raised the plasma levels of triiodothyronine and tetraiodothyronine, immunoglobulin G and immunoglobulin M in goats and their offspring (p < 0.0001). Higher levels of glucose and lower levels of insulin were determined in the goats injected with B complex vitamin (p < 0.0001).

CONCLUSIONS

These results suggest that maternal B complex vitamin injection is required for the improvement of performance, health status and the blood plasma parameters in pregnant goats and their kids.

Hair and Serum Trace Element and Mineral Levels Profiles in Women with Premenopausal and Postmenopausal Osteoporosis

The objective of the present study was to evaluate serum and hair trace element and mineral levels in women with osteoporosis, as well as to estimate the impact of menopausal status on the profile of trace element and mineral status in women with osteoporosis. 207 women with diagnosed osteoporosis 22-85 years-of-age, and 197 healthy women of the respective age participated in the present study. Analysis of the levels of mineral and trace element in hair and serum samples was performed by inductively-coupled plasma mass-spectrometry (ICP-MS). Women with osteoporosis were characterized by significantly lower hair Ca, Mg, Co, I, Li, and Mn levels, as well as serum Ca, Mg, Co, Fe, V, and Zn concentrations compared to women in the control group. After additional grouping according to menopausal status, the lowest hair Ca and Mg content was observed in postmenopausal osteoporotic women, whereas serum Ca and Mg concentrations were the lowest in premenopausal osteoporotic women. Hair Co, Mn, and Zn levels in postmenopausal osteoporotic women were lower than in healthy postmenopausal women. The lowest circulating Zn levels were observed in osteoporotic postmenopausal women. Taken together, decreased hair and serum levels in osteoporotic women are indicative of increased risk of Ca, Mg, Co, and Zn deficiency in women with osteoporosis. In turn, alterations in hair trace element and mineral levels in osteoporosis are more profound in postmenopausal women. Hypothetically, improvement in trace element and mineral metabolism especially in postmenopausal women may be considered as a potential strategy for mitigating osteoporosis.

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.

Associations of total homocysteine and kidney function with all-cause and cause-specific mortality in hypertensive patients: a mediation and joint analysis

Plasma total homocysteine (tHcy) and kidney function are both associated with mortality risk, but the degree to which kidney function modifies the impact of tHcy on mortality remains unknown. This prospective cohort study included a total of 14,225 hypertensive adults. Cox proportional hazard regression was used to analyze the separate and combined association of tHcy and estimated glomerular filtration rate (eGFR) with all-cause and cause-specific mortality. Mediation analysis was conducted to explore the mediating effect of eGFR. During a median follow-up of 4.0 years, 805 deaths were identified, including 397 deaths from cardiovascular disease (CVD). There were significant, positive relationships of tHcy with all-cause mortality (per 5 μmol/L; HR: 1.09; 95% CI: 1.07, 1.11), CVD mortality (HR: 1.11; 95% CI: 1.08, 1.13), and non-CVD mortality (HR: 1.07; 95% CI: 1.04, 1.10). The proportions of eGFR mediating these relationships were 39.1%, 35.7%, and 49.7%, respectively. There were additive interactions between tHcy and eGFR. Compared with those with low tHcy (<15 μmol/L) and high eGFR (≥90 mL·min-1·1.73 m-2), participants with high tHcy (≥20 μmol/L) and low eGFR (<60 mL·min-1·1.73 m-2) had the highest risk of all-cause mortality (HR: 4.89; 95% CI: 3.81, 6.28), CVD mortality (HR: 5.80; 95% CI: 4.01, 8.40), and non-CVD mortality (HR: 4.25; 95% CI: 3.02, 5.97). In conclusion, among Chinese hypertensive adults, high tHcy and impaired kidney function were independently and jointly associated with higher risks of all-cause and cause-specific mortality. Importantly, kidney function explained most (nearly 40%) of the increased risk of mortality conferred by high tHcy.

Association between dietary folate intake and bone mineral density in a diverse population: a cross-sectional study

BACKGROUND

Osteoporosis is a major public health problem, yet the association between dietary folate intake and bone health has been rarely studied. This study aimed to investigate the relationship between dietary folate intake and bone mineral density (BMD) in the general population of the USA.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey, dietary folate intake was gauged through 24-h dietary recall and BMD was determined via dual-energy X-ray absorptiometry. Multivariate linear regression models and generalized additive models were employed for correlation analysis.

RESULTS

The study incorporated 9839 participants (48.88% males, aged 20-85 years, mean age: 47.62 ± 16.22). The average dietary folate intake stood at 401.1 ± 207.9 μg/day. And the average total femur, femoral neck, trochanter, intertrochanter, and lumbar BMD were 0.98 ± 0.16 g/cm2, 0.84 ± 0.15 g/cm2, 0.73 ± 0.13 g/cm2, 1.16 ± 0.19 g/cm2, and 1.03 ± 0.15 g/cm2, respectively. The higher quartiles of dietary folate intake directly correlated with increased total femoral, femoral neck, intertrochanteric, and lumbar BMD (P for trend = 0.003, 0.016, < 0.001, and 0.033, respectively). A consistent positive association between folate intake and BMD across age groups was observed, with significant findings for individuals over 80 years and non-Hispanic whites. Physical activity level and serum 25-hydroxyvitamin D levels influenced the association, with an optimal daily folate intake of 528-569 µg recommended for postmenopausal women.

CONCLUSION

In summary, our study reveals a significant positive association between dietary folate intake and BMD, across different age groups and particularly among individuals over 80 years old. Non-Hispanic whites benefit the most from increased folate intake. Physical activity level and serum 25-hydroxyvitamin D levels interact with this association. Screening and early intervention for osteoporosis may be essential for individuals with low dietary folate intake.

Effect of Vitamin B6 on Osteoporosis Fracture

Osteoporosis is a medical condition that causes bones to become weak and brittle, making them more likely to break or fracture. This condition occurs when the body loses too much bone, makes too little bone, or both. Bones are living tissues that are constantly being broken down and rebuilt. However, as we age, this process slows down, and our bodies may be unable to replace bone as quickly as it is broken down. This can lead to a loss of bone density, making bones weaker and more prone to fracture. Unfortunately, osteoporosis often has no symptoms until a bone is broken, so taking steps to prevent this condition is essential. This may include getting enough calcium and vitamin D, engaging in weight-bearing exercise, quitting smoking, limiting alcohol intake, and taking medication if prescribed by a doctor. Vitamin B6, also known as pyridoxine, is a water-soluble vitamin that plays a vital role in various bodily functions. It is part of the B-vitamin complex and is essential for metabolizing proteins, carbohydrates, and fats. Vitamin B6 produces neurotransmitters such as serotonin, which helps regulate mood, and dopamine, which is involved in motivation and reward. Several previous studies have found that women with higher intakes of vitamin B6 have higher bone mineral density (BMD) of the hips and spine than women with lower intakes. Another study found that men and women with higher blood levels of vitamin B6 had higher BMD in the hips and spine.

Postoperative Osteoporosis in Subjects with Morbid Obesity Undergoing Bariatric Surgery with Gastric Bypass or Sleeve Gastrectomy

Obesity has become a worldwide epidemic accompanied by adverse health effects. The limited efficiency of traditional weight reduction regimens has led to a substantial increase in the use of bariatric surgery. Today, sleeve gastrectomy (SG) and Roux-en-Y-gastric bypass (RYGB) are the most used procedures. The present narrative review focuses on the risk of developing postoperative osteoporosis and summarizes some of the most relevant micronutrient deficiencies associated with RYGB and SG. Preoperatively, the dietary habits of obese individuals might lead to precipitated deficiencies in vitamin D and other nutrients affecting bone mineral metabolism. Bariatric surgery with SG or RYGB can aggravate these deficiencies. The various surgical procedures appear to affect nutrient absorption differently. Being purely restrictive, SG may particularly affect the absorption of vitamin B12 and also vitamin D. In contrast, RYGB has a more profound impact on the absorption of fat-soluble vitamins and other nutrients, although both surgical methods induce only a mild protein deficiency. Despite adequate supplementation of calcium and vitamin D, osteoporosis may still occur after the surgery. This might be due to deficiencies in other micronutrients, e.g., vitamin K and zinc. Regular follow-ups with individual assessments and nutritional advice are indispensable to prevent osteoporosis and other adverse postoperative issues.

Intermediate role of gut microbiota in vitamin B nutrition and its influences on human health

Vitamin B consists of a group of water-soluble micronutrients that are mainly derived from the daily diet. They serve as cofactors, mediating multiple metabolic pathways in humans. As an integrated part of human health, gut microbiota could produce, consume, and even compete for vitamin B with the host. The interplay between gut microbiota and the host might be a crucial factor affecting the absorbing processes of vitamin B. On the other hand, vitamin B supplementation or deficiency might impact the growth of specific bacteria, resulting in changes in the composition and function of gut microbiota. Together, the interplay between vitamin B and gut microbiota might systemically contribute to human health. In this review, we summarized the interactions between vitamin B and gut microbiota and tried to reveal the underlying mechanism so that we can have a better understanding of its role in human health.

Folate ameliorates homocysteine-induced osteoblast dysfunction by reducing endoplasmic reticulum stress-activated PERK/ATF-4/CHOP pathway in MC3T3-E1 cells

INTRODUCTION

Homocysteine (Hcy) is considered a newly identified risk factor for osteoporosis. Nevertheless, the underlying mechanism of folate (FA), a key factor in the metabolism of Hcy, in protection against osteoblast dysfunction remains unclear. The purpose of this study was to investigate the mechanism by which FA attenuates Hcy-induced osteoblast damage.

MATERIALS AND METHODS

The Hcy-induced MC3T3-E1 cells were treated with different concentrations of FA. Cell morphology, cell density, cell proliferation ability, alkaline phosphatase (ALP) activity and mineralization capacity were observed and determined; the gene expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX) and ERS-associated factors, including glucose-regulated protein 78 (GRP-78), activating transcription factor 4 (ATF-4) and growth arrest and DNA damage inducible gene 153 (CHOP/GADD153), were assessed by RT-PCR; and protein levels of GRP-78 and ATF-4 were analyzed by western blotting.

RESULTS

Hcy suppressed the proliferation, differentiation and mineralization ability of MC3T3-E1 cells in a concentration-dependent manner and activated the ERS signaling pathway. After intervention with different concentrations of FA, the cell viability and density, ALP activity, number of mineralized nodules, calcium content and Bcl-2 gene expression were all significantly increased, whereas the gene expression of GRP-78, CHOP/GADD153, ATF-4 and Bax was markedly downregulated, and protein levels of GRP-78 and ATF-4 were also markedly decreased.

CONCLUSION

The adverse effects of Hcy on osteoblast differentiation are dose dependent. FA not only protects against osteoblasts apoptosis but also has a direct osteogenic effect on Hcy-induced osteoblasts, which could be partially mediated by inhibition of the PERK-activated ERS pathway.

Homocysteine Levels and Osteoporotic Fracture in a Population Aged 55 Years Over in Medan District Indonesia

BACKGROUND: Osteoporosis is a chronic, progressive, systemic, skeletal, multifactorial disorder characterized by low bone mass, microarchitectural deterioration of bone tissues that increased the risk of fragility fracture. The increased prevalence of early osteoporosis in homocystinuria illustrates that homocysteine metabolism is involved in the process of osteoporosis. AIM: This study was aimed to look for the relationship between homocysteine levels in the blood and the occurrence of osteoporotic fractures in the population above 55 years old. METHODS: This is a descriptive study with cross-sectional approach, total sixty-five patients aged 55 years or older with osteoporotic fracture and as a control group without osteoporotic fracture. Blood pressure, heart rate, and body weight were recorded, bone density was measured using central dual-energy x-ray absorptiometry (DXA) machine/DXA and homocysteine plasma levels were measured using the enzyme-linked immunoassay method. RESULTS: Total of 65 samples with age range between 55 and 88 years, they were 38 peoples with osteoporosis, which 12 got the osteoporotic fracture. Among the 16 samples in osteopenia group, two got the fracture, among 11 samples with normal bone density, one got the osteoporotic fracture. There was statistical significant between fracture and bone mineral density (p = 0.00) and no statistical significant between bone density and gender (p = 0.08), bone density and body mass index (BMI) (p = 0.11). There was statistical significant correlation between homocysteine and age (p = 0.02), age and bone density (p = 0.002) but no statistical significant correlation between homocysteine and BMI (p = 0.07), homocysteine and osteoporotic fracture (p = 0.87). CONCLUSIONS: Homocysteine level did not increased the incidence of osteoporotic fracture, however homocysteine increased with aging and correlated with bone mineral density.

Oral manifestations associated with inherited hyperhomocysteinemia: A first case description

Hyperhomocysteinemia is a rare disease caused by nutritional deficiencies or genetic impairment of cysteine metabolism. To date, no oral manifestations of hyperhomocysteinemia have been described in humans. Therefore, to our knowledge, the present case report is the first description of a hyperhomocysteinemic patient showing oral tissue alterations leading to both early tooth loss and failed implant osseointegration. The patient presented with a methylenetetrahydrofolate reductase gene mutation (677T polymorphism) leading to mild hyperhomocysteinemia. The radiologic analysis showed hyperdense lesions scattered in the maxillae. The histologic observations indicated alterations in both collagen and elastic networks in the gingiva and dermis. Interestingly, the presence of ectopic mineralized inclusions was noted in both periodontal ligament and gingiva. Strong osteoclastic activity was associated with abnormal calcification of trabecular spaces. Uneven oral tissue remodeling due to high tissue levels of homocysteine could explain the pathologic manifestations observed in this case.

Maternal vitamin B12 in mice positively regulates bone, but not muscle mass and strength in post-weaning and mature offspring

Vitamin B₁₂ deficiency has been shown to affect bone mass in rodents and negatively impact bone formation in humans. In this study using mouse models, we define the effect of B₁₂ supplementation in the wild-type mother and B₁₂ deficiency in a mouse genetic model (Gif^−/− mice) during gestation on bone and muscle architecture and mechanical properties in the offspring. Analysis of bones from 4-wk-old offspring of the wild-type mother following vehicle or B₁₂ supplementation during gestation (from embryonic day 0.5 to 20.5) showed an increase in bone mass caused by an isolated increase in bone formation in the B₁₂-supplemented group compared with vehicle controls. Analysis of the effect of B₁₂ deficiency in the mother in a mouse genetic model (Gif^−/− mice) on the long bone architecture of the offspring showed a compromised cortical and trabecular bone mass, which was completely prevented by a single injection of B₁₂ in the B₁₂-deficient Gif^−/− mothers. Biomechanical analysis of long bones of the offspring born from B₁₂-supplemented wild-type mothers showed an increase in bone strength, and conversely, offspring born from B₁₂-deficient Gif^−/− mothers revealed a compromised bone strength, which could be rescued by a single injection of B₁₂ in the B₁₂-deficient Gif^−/− mother. Muscle structure and function analysis however revealed no significant effect on muscle mass, structure, and grip strength of B₁₂ deficiency or supplementation in Gif^−/− mice compared with littermate controls. Together, these results demonstrate the beneficial effect of maternally derived B₁₂ in the regulation of bone structure and function in the offspring.

Observations on spindly leg syndrome in a captive population of Andinobates geminisae

Amphibian health problems of unknown cause limit the success of the growing number of captive breeding programs. Spindly leg syndrome (SLS) is one such disease, where affected individuals with underdeveloped limbs often require euthanization. We experimentally evaluated husbandry-related factors of SLS in a captive population of the critically endangered frog, Andinobates geminisae. SLS has been linked to tadpole nutrition, vitamin B deficiency, water filtration methods, and water quality, but few of these have been experimentally tested. We tested the effects of water filtration method and vitamin supplementation (2017) and the effects of tadpole husbandry protocol intensity (2018) on time to metamorphosis and the occurrence of SLS. We found that vitamin supplementation and reconstituted reverse osmosis filtration of tadpole rearing water significantly reduced SLS prevalence and that reduced tadpole husbandry delayed time to metamorphosis. A fortuitous accident in 2018 resulted in a decrease in the phosphate content of rearing water, which afforded us an additional opportunity to assess the influence of phosphate on calcium sequestration. We found that tadpoles that had more time to sequester calcium for ossification during development had decreased the prevalence of SLS. Taken together, our results suggest that the qualities of the water used to rear tadpoles plays an important role in the development of SLS. Specifically, filtration method, vitamin supplementation, and calcium availability of tadpole rearing water may play important roles. Focused experiments are still needed, but our findings provide important information for amphibian captive rearing programs affected by high SLS prevalence.

Association of homocysteine with ankylosing spondylitis: a systematic review and meta-analysis

Background

Hyperhomocysteinemia is associated with autoimmune diseases such as ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). Current findings regarding plasma/serum homocysteine (HCY) levels in AS patients are inconsistent. This study aims to systematically evaluate the association between circulating HCY levels and AS.

Methods

Online electronic databases (PubMed, Web of Science, Embase, ScienceDirect, China National Knowledge Infrastructure (CNKI), and Wanfang data) were used to retrieve all relevant articles published up to May 7, 2020. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated using the random-effect model, Stata16 software.

Results

Nine articles containing 778 AS patients and 522 controls were included in this meta-analysis. No significant differences in HCY levels were found between AS and control groups (pooled SMD = 0.46, 95% CI = − 0.30 to 1.23, P = 0.23). However, subgroup analysis suggested that HCY levels were significantly higher (P < 0.05) in the AS group treated with methotrexate (MTX) compared with the control group. In contrast, HCY levels were significantly (P < 0.05) lower in the AS group receiving anti-TNF-α treatment compared with the control group. No significant differences were detected between HCY levels and disease activity scores (Bath AS disease activity index, BASDAI), and methylenetetrahydrofolate reductase (MTHFR) C677T genotype.

Conclusion

This meta-analysis indicates that HCY levels are similar between AS and controls, and do not correlate with disease activity. However, different medical treatments cause fluctuations of circulating HCY levels in AS patients. Further and larger-scale studies are needed to confirm these findings.

Trial registration

This study was registered at international prospective register of systematic reviews (PROSPERO), registration number: CRD42020184426.

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.

[Neuroendocrine and metabolic impairments in patients with Parkinson's disease]

ABSRACT

Neuroendocrine and neurometabolic disorders, although occasionally noted in Parkinson's disease (PD), existed in the shadow of motor and non-motor symptoms (hypokinesia, rigidity, tremor, depression, constipation, etc.). In recent years, they are increasingly being diagnosed and are the subject of special research. These include, in particular, disorders of carbohydrate metabolism, changes in body weight, metabolic disorders in bone tissue, secretion, as well as the secretion of neurohormones, such as melatonin. They are associated with other non-motor symptoms, negatively affect patients' general condition and quality of life, but can be treatable. At the same time, treatment of neuroendocrine and neurometabolic disorders can favorably influence the rate of progression of the disease as a whole. This review discusses the pathophysiological mechanisms, clinical consequences, as well as pharmacological and non-pharmacological approaches to the treatment of neuroendocrine and neurometabolic disorders arising in PD, which have been relatively rarely covered in literature.

Serum homocysteine and folate concentrations in early pregnancy and subsequent events of adverse pregnancy outcome: the Sichuan Homocysteine study

Background

Hyperhomocysteinemia may be a risk factor for endothelial dysfunction. Folate and vitamin B12 regulate the homocysteine metabolic process. This study aimed to evaluate the associations between subsequent events of adverse pregnancy outcome and early variables of homocysteine, folate, and vitamin B12 in pregnant women.

Methods

This multicenter, retrospective, case–control study involved 563 pregnant women with adverse pregnancy outcome and 600 controls. Adverse pregnancy outcomes included one or more of the following events: preeclampsia, preterm birth, low birth weight, and stillbirth. The associations between subsequent events of adverse pregnancy outcome and early variables of homocysteine, folate, and vitamin B12; metabolic parameters; inflammatory markers; anthropometrics; and lifestyle habits at 11–12 weeks of gestation were analyzed using the logistic regression model.

Results

Compared to the lower quartile homocysteine concentrations, the upper quartile homocysteine concentrations were associated with preeclampsia, preterm birth and low birth weight. On the contrary, the lower quartile folate concentrations were associated with preeclampsia, preterm birth and low birth weight compared with the upper quartile folate concentrations. The incidence of adverse pregnancy outcome increased progressively from the first to fourth homocysteine quartiles but decreased progressively from the first to fourth folate quartiles. After adjusting for confounding factors, multivariate logistic regression analysis showed that besides systolic blood pressure, diastolic blood pressure, body mass index and age, homocysteine (IV vs I quartile, aOR 5.89, 95% CI 4.08–8.51, P < 0.001), folate (IV vs I quartile, aOR 0.35, 95% CI 0.25–0.50, P < 0.001), folate supplementation (yes vs no, aOR 0.55, 95% CI 0.35–0.86, P = 0.010) during early pregnancy were independently associated with subsequent events of adverse pregnancy outcome, and vitamin B12 was rejected. Of these, the homocysteine revealed the highest odds ratio in all risk variables, and folate showed the lowest odds ratio in all protective variables.

Conclusions

Higher homocysteine concentration and lower folate level during early pregnancy were associated with adverse pregnancy outcome. However, no association was found between vitamin B12 and adverse pregnancy outcome. Supplementation with folate in early pregnancy may reduce adverse pregnancy outcome.

Circulating amino acids are associated with bone mineral density decline and ten-year major osteoporotic fracture risk in older community-dwelling adults

With aging, poor bone mineral density (BMD) and accelerated decrease in BMD are strong risk factors for fracture. Reports of the associations of dietary protein intake with bone strength are inconsistent, possibly owing to differences in protein sources and amino acid (AA) composition. We examined the associations of serum AA with 4-year hip BMD loss and subsequent fracture risk within 10 years in older community-dwelling adults, and further addressed whether lifestyle, dietary protein intake and its source, and body composition would affect the associations. In 1424 men and 1573 women (mean age 72 years), using binary logistic regression, higher serum valine, leucine, isoleucine and tryptophan concentrations were associated (or approaching a borderline significance in case of the last three ones) with less hip BMD decline (defined as BMD loss ≥ 2.8 times the precision error of the BMD measurement at femoral neck) in 4 years later, with the OR (95%CI) /SD of AA increase, ranging from 0.83 (0.75, 0.91) to 0.92 (0.87, 0.98) after multiple adjustments for baseline age, gender, BMI, BMD, estimated glomerular filtration rate (eGFR), dietary protein intake (animal- and plant-derived protein intakes), calcium intake, established lifestyles (physical activity level, smoking and alcohol drinking status), osteoporosis medications, and changes of body fat and lean muscle mass. Higher serum total homocysteine (tHcy) concentration was independently associated with BMD decline 4 years later (OR (95%CI) /SD of 1.16 (1.05, 1.27)). Using multivariate Cox regression, higher serum tryptophan concentration potentially predicted low risk of incident major osteoporotic fractures (MOFs) (HR/SD (95%CI)=0.86 (0.75, 0.98)) after multiple adjustments. Higher serum tHcy was associated with MOFs (HR/SD (95%CI)=1.29 (1.12, 1.50)) risk after multiple adjustments in men. These findings suggest that a specific AA profile correlates with greater BMD and lower subsequent fracture risk, independent of diet and lifestyle factors.

An investigation into the impact and implications of published papers from retracted research: systematic search of affected literature

OBJECTIVE

Analyses of the impact of a body of clinical trial reports subject to research misconduct have been few. Our objective was to examine the impact on clinically relevant research of a group of researchers' trial reports ('affected trial reports') affected by research misconduct, and whether identification of misconduct invoked a reappraisal.

DESIGN

In 2016, we used five databases and search engines to identify 'citing publications', that is, guidelines, systematic and other reviews, and clinical trials citing any of 12 affected trial reports, published 1998-2011, eventually retracted for research misconduct. The affected trial reports were assessed more likely to have had impact because they had hip fracture outcomes and were in journals with impact factor >4. Two authors assessed whether findings of the citing publications would change if the affected trial reports were removed. In 2018, we searched for evidence that the citing publications had undertaken a reassessment as a result of the potential influence of the affected trial reports.

RESULTS

By 2016 the affected trial reports were cited in 1158 publications, including 68 systematic reviews, meta-analyses, narrative reviews, guidelines and clinical trials. We judged that 13 guidelines, systematic or other reviews would likely change their findings if the affected trial reports were removed, and in another eight it was unclear if findings would change. By 2018, only one of the 68 citing publications, a systematic review, appeared to have undertaken a reassessment, which led to a correction.

CONCLUSIONS

We found evidence that this group of affected trial reports distorted the evidence base. Correction of these distortions is slow, uncoordinated and inconsistent. Unless there is a rapid, systematic, coordinated approach by bibliographic databases, authors, journals and publishers to mitigate the impact of known cases of research misconduct, patients, other researchers and their funders may continue to be adversely affected.

Biomarkers of Osteoporosis: An Update

Background:

Osteoporosis, characterized by compromised bone quality and strength is associated with bone fragility and fracture risk. Biomarkers are crucial for the diagnosis or prognosis of a disease as well as elucidating the mechanism of drug action and improve decision making.

Objective:

An exhaustive description of traditional markers including bone mineral density, vitamin D, alkaline phosphatase, along with potential markers such as microarchitectural determination, trabecular bone score, osteocalcin, etc. is provided in the current piece of work. This review provides insight into novel pathways such as the Wnt signaling pathway, neuro-osseous control, adipogenic hormonal imbalance, gut-bone axis, genetic markers and the role of inflammation that has been recently implicated in osteoporosis.

Methods:

We extensively reviewed articles from the following databases: PubMed, Medline and Science direct. The primary search was conducted using a combination of the following keywords: osteoporosis, bone, biomarkers, bone turnover markers, diagnosis, density, architecture, genetics, inflammation.

Conclusion:

Early diagnosis and intervention delay the development of disease and improve treatment outcome. Therefore, probing for novel biomarkers that are able to recognize people at high risk for developing osteoporosis is an effective way to improve the quality of life of patients and to understand the pathomechanism of the disease in a better way.

Association of dietary folate and vitamin B-12 intake with genome-wide DNA methylation in blood: a large-scale epigenome-wide association analysis in 5841 individuals

BACKGROUND

Folate and vitamin B-12 are essential micronutrients involved in the donation of methyl groups in cellular metabolism. However, associations between intake of these nutrients and genome-wide DNA methylation levels have not been studied comprehensively in humans.

OBJECTIVE

The aim of this study was to assess whether folate and/or vitamin B-12 intake are asssociated with genome-wide changes in DNA methylation in leukocytes.

METHODS

A large-scale epigenome-wide association study of folate and vitamin B-12 intake was performed on DNA from 5841 participants from 10 cohorts using Illumina 450k arrays. Folate and vitamin B-12 intakes were calculated from food-frequency questionnaires (FFQs). Continuous and categorical (low compared with high intake) linear regression mixed models were applied per cohort, controlling for confounders. A meta-analysis was performed to identify significant differentially methylated positions (DMPs) and regions (DMRs), and a pathway analysis was performed on the DMR annotated genes.

RESULTS

The categorical model resulted in 6 DMPs, which are all negatively associated with folate intake, annotated to FAM64A, WRAP73, FRMD8, CUX1, and LCN8 genes, which have a role in cellular processes including centrosome localization, cell proliferation, and tumorigenesis. Regional analysis showed 74 folate-associated DMRs, of which 73 were negatively associated with folate intake. The most significant folate-associated DMR was a 400-base pair (bp) spanning region annotated to the LGALS3BP gene. In the categorical model, vitamin B-12 intake was associated with 29 DMRs annotated to 48 genes, of which the most significant was a 1100-bp spanning region annotated to the calcium-binding tyrosine phosphorylation-regulated gene (CABYR). Vitamin B-12 intake was not associated with DMPs.

CONCLUSIONS

We identified novel epigenetic loci that are associated with folate and vitamin B-12 intake. Interestingly, we found a negative association between folate and DNA methylation. Replication of these methylation loci is necessary in future studies.

Association between serum vitamin B6 concentration and risk of osteoporosis in the middle-aged and older people in China: a cross-sectional study

OBJECTIVE

To determine the relationship between serum vitamin B₆ (Vit B₆) concentration and the status of bone mineral density and identify the relationship between serum Vit B6 and bone metabolism parameters in middle-aged and older people in China.

DESIGN

The present study was a cross-sectional study within the framework of an ongoing prospective population-based cohort study.

SETTING AND PARTICIPANTS

A total of 1829 residents (men ≥50 years and women ≥45 years) from two subdistricts were recruited from July 2015 to February 2016 in Shanghai, China.

MEASURES

Recruited residents were grouped (control, osteopenia and osteoporosis) according to their lumbar spine bone mineral density, measured through dual-energy X-ray absorptiometry. Serum Vit B₆ concentrations, bone turnover marker concentrations and calcium and phosphorus metabolism parameters were assessed.

RESULTS

No significant linear trend between serum Vit B₆ concentrations and lumbar bone mass was observed in the men. In the women, the average osteoporosis risk was 61% higher at serum Vit B₆ concentrations of <19.2 μg/L than at those of >26.9 μg/L (OR 1.61, 95% CI 1.00 to 2.58). However, there was no significance after controlling of serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration, respectively. In the osteoporotic women, the serum Vit B₆ concentration was significantly negatively correlated to concentrations of bone turnover marker including N-terminal propeptide of type I collagen, β-C-terminal telopeptide of type I collagen and osteocalcin. It was also positively related to the serum 25-hydroxy-vitamin D concentration and inversely related to the serum parathyroid hormone concentration.

CONCLUSIONS

A relatively low serum Vit B₆ concentration, even in the normal range, may be a risk factor for osteoporosis in postmenopausal women, which is dependent on serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration.

TRIAL REGISTRATION NUMBER

NCT02958020; Post-results.

Proton Pump Inhibitors and Fracture Risk: A Review of Current Evidence and Mechanisms Involved

The number of patients with gastroesophageal problems taking proton pump inhibitors (PPIs) is increasing. Several studies suggested a possible association between PPIs and fracture risk, especially hip fractures, but the relationship remains contentious. This review aimed to investigate the longitudinal studies published in the last five years on the relationship between PPIs and fracture risk. The mechanism underlying this relationship was also explored. Overall, PPIs were positively associated with elevated fracture risk in multiple studies (n = 14), although some studies reported no significant relationship (n = 4). Increased gastrin production and hypochlorhydria are the two main mechanisms that affect bone remodeling, mineral absorption, and muscle strength, contributing to increased fracture risk among PPI users. As a conclusion, there is a potential relationship between PPIs and fracture risks. Therefore, patients on long-term PPI treatment should pay attention to bone health status and consider prophylaxis to decrease fracture risk.

Association of High Intakes of Vitamins B6 and B12 From Food and Supplements With Risk of Hip Fracture Among Postmenopausal Women in the Nurses' Health Study

IMPORTANCE

Vitamin supplementation far exceeding recommended doses is popular in segments of the population. However, adverse effects can occur. In a previous secondary analysis of combined data from 2 double-blind randomized clinical trials (RCTs), an unexpected increased risk of hip fracture was found among those treated with high doses of vitamin B6 in combination with vitamin B12.

OBJECTIVES

To study if high intakes of vitamins B6 and B12 from food and supplements were associated with a risk of hip fracture in the Nurses' Health Study and to investigate whether combined high intakes of both vitamins conferred a particularly increased fracture risk.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort study, 75 864 postmenopausal women in the United States were followed up from June 1984 through May 2014. The dates of analysis were July 2016 to June 2018. Information on hip fracture and a wide range of potential confounders was collected at baseline and with biennial follow-up questionnaires. Extensive dietary information was collected approximately every 4 years with a semiquantitative food frequency questionnaire. Relative risks (RRs) were calculated by Cox proportional hazards regression, with cumulative average intakes of vitamins B6 and B12 as main exposures, adjusting for potential confounders.

MAIN OUTCOME AND MEASURE

Hip fracture.

RESULTS

During follow-up, 2304 of 75 864 women had a hip fracture. Among the women with hip fractures, the median (range) age at hip fracture was 75.8 (46.7-93.0) years and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 24.3 (4.6). Median (interquartile range) cumulative average intakes of total vitamins B6 and B12 were 3.6 (4.8) mg/d and 12.1 (11.7) μg/d, respectively. Both vitamin B6 (RR, 1.29; 95% CI, 1.04-1.59 for an intake of ≥35 vs <2 mg/d; P = .06 for linear trend) and vitamin B12 (RR, 1.25; 95% CI, 0.98-1.58 for an intake of ≥30 vs <5 μg/d; P = .02 for linear trend) were associated with increased fracture risk. Risk was highest in women with a combined high intake of both vitamins (B6 ≥35 mg/d and B12 ≥20 μg/d), exhibiting an almost 50% increased risk of hip fracture (RR, 1.47; 95% CI, 1.15-1.89) compared with women with a low intake of both vitamins (B6 <2 mg/d and B12 <10 μg/d).

CONCLUSIONS AND RELEVANCE

In this cohort study, a combined high intake of vitamins B6 and B12 was associated with an increased risk of hip fracture. The intakes were far higher than the recommended dietary allowances. These findings add to previous studies suggesting that vitamin supplements should be used cautiously because adverse effects can occur.

Comparison of ESI-MS/MS and APCI-MS methods for the quantification of folic acid analogs in C. elegans

Folic acid (FA) plays a vital role in central metabolism, including the one carbon cycle, nucleotide, and amino acid biosynthesis. The development of sensitive, accurate analytical methods to measure FA intermediates in tissues is critical to understand their biological roles in diverse physiological and pathological contexts. Here, we developed a highly sensitive method for the simultaneous quantification of FA intermediates in the nematode Caenorhabditis elegans as a model to dissect metabolic networks. The method was further validated by analyzing the worm folate pool upon RNAi knockdown of the dihydrofolate reductase gene dhfr-1. Comparative mass spectrometry behavior of the FA analogs using two different ion sources, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), revealed ESI-MS/MS to be more sensitive, but APCI-MS provided more detailed structure inferences, which can elucidate chemical investigation and synthesis of FA analogs. Finally, we report on the use of in vitro oxidation coupled with high-resolution mass spectrometry as a tool to discover new endogenous FA derivatives in the nematode.

Homocysteine-Lowering Treatment and the Risk of Fracture: Secondary Analysis of a Randomized Controlled Trial and an Updated Meta-Analysis

High plasma homocysteine is a risk factor for osteoporotic fractures. Several studies have assessed the possible preventive effect of homocysteine-lowering B-vitamin treatment on the risk of fracture with inconclusive results. In the current study, we include new results from the Aspirin Folate Polyp Prevention Study (AFPPS) together with an updated meta-analysis of randomized controlled trials (RCTs). Our objective was to determine whether there is an association between homocysteine-lowering B-vitamin treatment and the risk of fracture. The AFPPS trial was performed between 1994 and 2004 in nine clinical centers in the United States, and 1021 participants were randomized to a daily folic acid dose of 1 mg (n = 516) or placebo (n = 505). The main outcome was fracture of any type. In addition, we analyzed the risk of hip fracture. In the meta-analysis, studies were identified following a search strategy in electronic database and by hand searching. Risk ratio with 95% confidence interval (CI) was chosen for pooled analyses. In the AFPPS, no statistically significant association was found between folic acid treatment and fractures of any type (risk ratio [RR] = 0.95; 95% CI 0.61-1.48) or hip fracture (RR = 0.98; 95% CI 0.25-3.89). In the meta-analysis, six RCTs were included with a total of 36,527 participants. For interventions including folic acid and/or vitamin B12, the pooled RR for treatment was 0.97 (95% CI 0.87-1.09) for fractures of any type (n = 1199) and 1.00 (95% CI 0.81-1.23) for hip fractures (n = 335). In conclusion, no association was found between homocysteine-lowering treatment with B vitamins (folic acid and vitamin B12) and the risk of fracture. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

B Vitamins and Hip Fracture: Secondary Analyses and Extended Follow-Up of Two Large Randomized Controlled Trials

Elevated plasma homocysteine levels are associated with increased risk of fractures in observational studies. However, it is unsettled whether homocysteine-lowering treatment affects fracture risk. The aim of this study was to investigate the effect of an intervention with B vitamins on the risk of hip fracture in a secondary analysis of combined data from two large randomized controlled trials originally designed to study cardiovascular diseases. Both trials had identical design, intervention, and primary objective. Based on a two-by-two factorial design, the intervention consisted of a daily capsule with either (1) folic acid (0.8 mg) plus vitamin B₁₂ (0.4 mg) and vitamin B₆ (40 mg); (2) folic acid (0.8 mg) plus vitamin B₁₂ (0.4 mg); (3) vitamin B₆ alone (40 mg); or (4) placebo. The participants were followed with respect to hip fracture during the trial or during an extended follow-up (from the trial start for each patient until the end of 2012). No statistically significant association was found between folic acid plus vitamin B₁₂ treatment and the risk of hip fracture, neither during the trial (median 3.3 years; hazard ratio [HR] 0.87; 95% confidence interval [CI], 0.48 to 1.59) nor during the extended follow-up (median 11.1 years; HR 1.08; 95% CI, 0.84 to 1.40). Nor were there significant differences in the risk of hip fracture between groups receiving versus not receiving vitamin B₆ during the trial (HR 1.42; 95% CI, 0.78 to 2.61). However, during the extended follow-up, those receiving vitamin B₆ showed a significant 42% higher risk of hip fracture (HR 1.42; 95% CI, 1.09 to 1.83) compared to those not receiving vitamin B₆ . In conclusion, treatment with folic acid plus vitamin B₁₂ was not associated with the risk of hip fracture. Treatment with a high dose of vitamin B₆ was associated with a slightly increased risk of hip fracture during the extended follow-up (in-trial plus post-trial follow-up). © 2017 American Society for Bone and Mineral Research.

Association between Homocysteine Levels and All-cause Mortality: A Dose-Response Meta-Analysis of Prospective Studies

Plasma homocysteine (Hcy) levels may be associated with all-cause mortality risk. However, the results of this association are conflicting and the dose-response relationship between them has not been clearly defined. In this meta-analysis, we conducted a systematic literature search of the PubMed, Embase, Web of Science and Cochrane Library for the relevant articles dated up to February 2017. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the estimates, and the dose-response relationship was estimated using a restricted cubic spline model. Eleven prospective studies (4,110 deaths among 27,737 individuals) were included. The summary RR of all-cause mortality for the highest Hcy category vs. the lowest Hcy category was 1.80 (95% CI: 1.51, 2.14) with the random effects model. In dose-response meta-analysis, Hcy levels were significantly associated with all-cause mortality risk in a linear fashion (p_nonlinearity = 0.255), and the risk of all-cause mortality increased by 33.6% for each 5 µmol/L increase in Hcy levels (RR = 1.336, 95% CI: 1.254–1.422, p < 0.001). Findings from this dose-response meta-analysis suggest that Hcy levels are linearly and positively associated with risk of all-cause mortality.

Neuroendocrine abnormalities in Parkinson's disease

Neuroendocrine abnormalities are common in Parkinson's disease (PD) and include disruption of melatonin secretion, disturbances of glucose, insulin resistance and bone metabolism, and body weight changes. They have been associated with multiple non-motor symptoms in PD and have important clinical consequences, including therapeutics. Some of the underlying mechanisms have been implicated in the pathogenesis of PD and represent promising targets for the development of disease biomarkers and neuroprotective therapies. In this systems-based review, we describe clinically relevant neuroendocrine abnormalities in Parkinson's disease to highlight their role in overall phenotype. We discuss pathophysiological mechanisms, clinical implications, and pharmacological and non-pharmacological interventions based on the current evidence. We also review recent advances in the field, focusing on the potential targets for development of neuroprotective drugs in Parkinson's disease and suggest future areas for research.

Comparison of parameters of bone profile and homocysteine in physically active and non-active postmenopausal females

BACKGROUND AND OBJECTIVES

Optimal physical activity is important in attaining a peak bone mass. Physically active women have better bone mineral density and reduce fracture risk as compared to females living a sedentary life. The objective of this study was to compare parameters of bone profile and serum homocysteine levels in physically active and non-active postmenopausal females.

METHODS

In this cross sectional study postmenopausal females between 50-70 years of age were recruited and divided into two groups: Physically inactive (n=133) performing light physical activity and Physically active (n=34) performing moderate physical activity. Physical activity (in metabolic equivalents), bone mineral density and serum homocysteine levels were assessed. Spearman's rho correlation was applied to observe correlations. Two independent sample t test and Mann Whitney U test were applied to compare groups. P-value ≤ 0.05 was taken statistically significant.

RESULTS

Parameters of bone profile were significantly higher and serum homocysteine levels were significantly lower in postmenopausal females performing moderate physical activity as compared to females performing light physical activity. Homocysteine was not significantly related to T-score and Z-score in both groups.

CONCLUSION

Improving physical activity could be beneficial for improving the quality of bone, decreasing fracture risk and decreasing serum homocysteine levels.

Homocysteine and cognition: A systematic review of 111 studies

BACKGROUND

Elevated plasma homocysteine ​​(Hcy) levels have been associated with cognitive dysfunction in a wide range of conditions. The aim of this review is to establish which cognitive domains and populations are the most affected.

METHODS

We systematically review the literature and consider all articles that showed any relationship between plasma Hcy levels and scores achieved on cognitive performance tests in both, the general population and patients suffering from central nervous system disorders and other diseases. When effect sizes were available and combinable, several meta-analyses were performed.

RESULTS

We found 111 pertinent articles. There were 24 cohort studies, 18 randomized trials, 21 case-control studies, and 48 cross-sectional studies. This review reveals a positive trend between cognitive decline and increased plasma Hcy concentrations in general population and in patients with cognitive impairments. Results from the meta-analyses also confirm this trend. Treatment with vitamin supplementation fails to show a reduction in cognitive decline.

DISCUSSION

Further investigations are warranted to clarify this relationship. Earlier detection of the elevated Hcy levels may be an effective intervention to prevent cognitive impairment and dementia.

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.

B-vitamins and bone health--a review of the current evidence

Because of ongoing global ageing, there is a rapid worldwide increase in incidence of osteoporotic fractures and the resultant morbidity and mortality associated with these fractures are expected to create a substantial economic burden. Dietary modification is one effective approach for prevention of osteoporosis in the general population. Recently, B vitamins have been investigated for their possible roles in bone health in human studies. In this review, we provide different lines of evidence and potential mechanisms of individual B vitamin in influencing bone structure, bone quality, bone mass and fracture risk from published peer-reviewed articles. These data support a possible protective role of B vitamins, particularly, B2, B6, folate and B12, in bone health. However, results from the clinical trials have not been promising in supporting the efficacy of B vitamin supplementation in fracture reduction. Future research should continue to investigate the underlying mechanistic pathways and consider interventional studies using dietary regimens with vitamin B enriched foods to avoid potential adverse effects of high-dose vitamin B supplementation. In addition, observational and interventional studies conducted in Asia are limited and thus require more attention due to a steep rise of osteoporosis and hip fracture incidence projected in this part of the world.

Recent genetic discoveries in osteoporosis, sarcopenia and obesity

Osteoporosis is a skeletal disorder characterized by low bone mineral density (BMD) and an increased susceptibility to fractures. Evidence from genetic studies indicates that BMD, a complex quantitative trait with a normal distribution, is genetically controlled. Genome-wide association studies (GWAS) as well as studies using candidate gene approaches have identified single-nucleotide polymorphisms (SNPs) that are associated with BMD, osteoporosis and osteoporotic fractures. These SNPs have been mapped close to or within genes including those encoding WNT/β-catenin signaling proteins. Understanding the genetics of osteoporosis will help to identify novel candidates for diagnostic and therapeutic targets. Genetic factors are also important for the development of sarcopenia, which is characterized by a loss of lean body mass, and obesity, which is characterized by high fat mass. Hence, in this review, we discuss the genetic factors, identified by genetic studies, which regulate the body components related to osteoporosis, sarcopenia, and obesity.

Relationship of homocysteine and homocysteine-related vitamins to bone mineral density in Japanese patients with type 2 diabetes

Aims/Introduction:  To estimate nutritional risk factors for osteoporosis in patients with type 2 diabetes, bone mineral density, homocysteine level, and intakes and levels of Hcy‐related vitamins including folate, vitamin B₆ and vitamin B₁₂ were analyzed in a cross‐sectional study.

Materials and Methods:  Lumbar spine and femoral neck bone mineral density, serum concentrations of vitamin B₆, vitamin B₁₂, and folate and plasma homocysteine levels were measured in 125 Japanese patients with type 2 diabetes. Nutrient intake values were evaluated using a food frequency questionnaire.

Results:  Homocysteine was inversely correlated with bone mineral density, and with both dietary intake and serum concentration of folate. Intake of green vegetables was correlated with intake and level of folate and homocysteine levels. When the population was analyzed across the quartiles, bone mineral density, serum folate concentration, folate intake and intake of green vegetables were lowest in the highest homocysteine group.

Conclusions:  In patients with type 2 diabetes, the nutritional status of folate might affect the homocysteine level, a putative risk factor for osteoporosis. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00088.x, 2011)

Association between Helicobacter pylori Infection and Risk of Osteoporosis in Elderly Taiwanese Women with Upper Gastrointestinal Diseases: A Retrospective Patient Record Review

Introduction. Helicobacter pylori (H. pylori) infection could lead to chronic local and systemic immune response. The resulting increase in proinflammatory cytokines could affect bone resorption and might increase the risk of osteoporosis. This study aimed to investigate the association between H. pylori infection and osteoporosis in elderly female patients with upper gastrointestinal diseases. Methods. A retrospective patient record review study was conducted in a regional teaching hospital in south Taiwan. Relevant information on female patients aged 65 and over who were diagnosed with diseases of esophagus, gastric ulcer, or duodenal ulcer during January 2008 to December 2010 were abstracted. Association between H. pylori infection and osteoporosis was evaluated using multivariate logistic regression analysis. Results. Of the 365 patients with a mean age of 77.3 years, 77 (21.1%) had H. pylori infection and 101 (27.7%) had been diagnosed with osteoporosis. Multivariate logistic regression analysis revealed that osteoporosis was significantly associated with H. pylori infection (adjusted odds ratio = 2.03, 95% confidence interval = 1.14-3.62) after adjusting for age group, body mass index group, and use of proton pump inhibitor. Conclusion. Osteoporosis was found to be associated with H. pylori infection in Taiwanese female patients with upper gastrointestinal diseases. Further studies with information on potential confounders are needed to confirm the association.

Association between dietary intake and seasonal variations in postmenopausal women

Background

Evidence supports that increasing number of postmenopausal women are suffering from one or more chronic diseases. Dietary patterns have a pivotal role in maintaining human health. The aim of this study was to characterize the nutrients and energy intake in postmenopausal women, with the special focus on seasonal variation effect in their food intake.

Methods

The study population consisted of 30 postmenopausal women referred to Dr. Shariati Hospital, Tehran (Iran). Socio-demographic characteristics and BMI were registered. Dietary assessment was performed by a 3 day food records in each season through one year, allowing the estimation of energy, protein, carbohydrate, total fat, monounsaturated fatty acid (MUFA), polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) intake. The mean of nutrient intake in each season was adjusted for energy intake. The effect of season on energy and nutrients intake was assessed based on the General linear model (GLM).

Results

The mean of daily intake of vitamin C, B, B2, B12, iron, zinc, phosphorus and chromium was significantly higher than Recommended Dietary Allowance (RDAs ) (p < 0.05). The mean of vitamin D, E, B6, B5, folate, calcium, magnesium, potassium and selenium consumption was significantly less than RDAs (p < 0.05). All the participants meet the goal for vitamins A, K and B3 from food. The mean of energy intake was not different between seasons. However, the mean intake of fat, vitamin C, vitamin K and folate was significantly different between seasons.

Conclusion

These findings highlight some nutrients deficiency in postmenopausal women and therefore suggest nutritional education with emphasis on seasonal variation effect.

B-vitamins and bone in health and disease: the current evidence

Osteoporosis, a metabolic skeletal disease characterised by decreased bone mass and increased fracture risk, is a growing public health problem. Among the various risk factors for osteoporosis, calcium and vitamin D have well-established protective roles, but it is likely that other nutritional factors are also implicated. This review will explore the emerging evidence supporting a role for certain B-vitamins, homocysteine and the 677 C → T polymorphism in the gene encoding the folate-metabolising enzyme methylenetetrahydrofolate reductase, in bone health and disease. The evidence, however, is not entirely consistent and as yet no clear mechanism has been defined to explain the potential link between B-vitamins and bone health. Coeliac disease, a common condition of malabsorption, induced by gluten ingestion in genetically susceptible individuals, is associated with an increased risk both of osteoporosis and inadequate B-vitamin status. Given the growing body of evidence linking low bone mineral density and/or increased fracture risk with low B-vitamin status and elevated homocysteine, optimal B-vitamin status may play an important protective role against osteoporosis in coeliac disease; to date, no trial has addressed this possible link.

Low holotranscobalamin and cobalamins predict incident fractures in elderly men: the MrOS Sweden

In a population-based study on cobalamin status and incident fractures in elderly men (n = 790) with an average follow-up of 5.9 years, we found that low levels of metabolically active and total cobalamins predict incident fractures, independently of body mass index (BMI), bone mineral density (BMD), plasma total homocysteine (tHcy), and cystatin C.

INTRODUCTION

Cobalamin deficiency in elderlies may affect bone metabolism. This study aims to determine whether serum cobalamins or holotranscobalamin (holoTC; the metabolic active cobalamin) predict incident fractures in old men.

METHODS

Men participating in the Gothenburg part of the population-based Osteoporotic Fractures in Men (MrOS) Sweden cohort and without ongoing vitamin B medication were included in the present study (n = 790; age range, 70-81 years).

RESULTS

During an average follow-up of 5.9 years, 110 men sustained X-ray-verified fractures including 45 men with clinical vertebral fractures. The risk of fracture (adjusted for age, smoking, BMI, BMD, falls, prevalent fracture, tHcy, cystatin C, 25-OH-vitamin D, intake of calcium, and physical activity (fully adjusted)), increased per each standard deviation decrease in cobalamins (hazard ratio (HR), 1.38; 95% confidence intervals (CI), 1.11-1.72) and holoTC (HR, 1.26; 95% CI, 1.03-1.54), respectively. Men in the lowest quartile of cobalamins and holoTC (fully adjusted) had an increased risk of all fracture (cobalamins, HR = 1.67 (95% CI, 1.06-2.62); holoTC, HR = 1.74 (95% CI, 1.12-2.69)) compared with quartiles 2-4. No associations between folate or tHcy and incident fractures were seen.

CONCLUSIONS

We present novel data showing that low levels of holoTC and cobalamins predicting incident fracture in elderly men. This association remained after adjustment for BMI, BMD, tHcy, and cystatin C. However, any causal relationship between low cobalamin status and fractures should be explored in a prospective treatment study.

Polymorphism of SLC25A32, the folate transporter gene, is associated with plasma folate levels and bone fractures in Japanese postmenopausal women

AIM

Elevation of homocysteine is associated with an increased risk for bone fractures. We previously reported that the methylenetetrahydrofolate reductase (MTHFR) gene polymorphism is associated with homocysteine levels and fracture. The association between the fracture and folate levels or their related gene polymorphisms is not completely clear. We speculated that the SLC25A32 gene, the mitochondrial inner membrane folate transporter, also could be implicated in the regulation of folate metabolism and fracture.

METHODS

A total of 851 Japanese postmenopausal women participated in the association study between the single nucleotide polymorphism genotype and plasma homocysteine or folate. We also tested the association between the candidate single nucleotide polymorphism and 663 postmenopausal women.

RESULTS

The AA genotype of rs2241777 single nucleotide polymorphism at the 3'UTR region in the SLC25A32 gene was associated with lower plasma folate concentration compared with the other genotypes in 851 postmenopausal women. A total of 674 postmenopausal ambulatory Japanese women were followed up for 5.5 ± 0.1 years (mean ± SE). The AA genotype groups also showed an apparently higher rate and earlier onset of incident fractures than the other genotypes. A total of 407 participants had >70% young-adult mean bone mineral density at the start of the observation.

CONCLUSIONS

These results show that the SLC25A32 gene polymorphism could be a risk factor for lower folate concentration and future fracture.

Nutriepigenetic regulation by folate-homocysteine-methionine axis: a review

Although normally folic acid is given during pregnancy, presumably to prevent neural tube defects, the mechanisms of this protection are unknown. More importantly it is unclear whether folic acid has other function during development. It is known that folic acid re-methylates homocysteine (Hcy) to methionine by methylene tetrahydrofolate reductase-dependent pathways. Folic acid also generates high-energy phosphates, behaves as an antioxidant and improves nitric oxide (NO) production by endothelial NO synthase. Interestingly, during epigenetic modification, methylation of DNA/RNA generate homocysteine unequivocally. The enhanced overexpression of methyl transferase lead to increased yield of Hcy. The accumulation of Hcy causes vascular dysfunction, reduces perfusion in the muscles thereby causing musculopathy. Another interesting fact is that children with severe hyperhomocysteinaemia (HHcy) have skeletal deformities, and do not live past teenage. HHcy is also associated with the progeria syndrome. Epilepsy is primarily caused by inhibition of gamma-amino-butyric-acid (GABA) receptor, an inhibitory neurotransmitter in the neuronal synapse. Folate deficiency leads to HHcy which then competes with GABA for binding on the GABA receptors. With so many genetic and clinical manifestations associated with folate deficiency, we propose that folate deficiency induces epigenetic alterations in the genes and thereby results in disease.

Poststroke hip fracture: prevalence, clinical characteristics, mineral-bone metabolism, outcomes, and gaps in prevention

Objective. To assess the prevalence, clinical and laboratory characteristics, and short-term outcomes of poststroke hip fracture (HF). Methods. A cross-sectional study of 761 consecutive patients aged ≥60 years (82.3 ± 8.8 years; 75% females) with osteoporotic HF. Results. The prevalence of poststroke HF was 13.1% occurring on average 2.4 years after the stroke. The poststroke group compared to the rest of the cohort had a higher proportion of women, subjects with dementia, history of TIA, hypertension, coronary artery disease, secondary hyperparathyroidism, higher serum vitamin B12 levels (>350 pmol/L), walking aid users, and living in residential care facilities. The majority of poststroke HF patients had vitamin D insufficiency (68%) and excess bone resorption (90%). This group had a 3-fold higher incidence of postoperative myocardial injury and need for institutionalisation. In multivariate analysis, independent indicators of poststroke HF were female sex (OR 3.6), history of TIA (OR 5.2), dementia (OR 4.1), hypertension (OR 3.2), use of walking aid (OR 2.5), and higher vitamin B12 level (OR 2.3). Only 15% of poststroke patients received antiosteoporotic therapy prior to HF. Conclusions. Approximately one in seven HFs occurs in older stroke survivors and are associated with poorer outcomes. Early implementation of fracture prevention strategies is needed.

The effect of homocysteine-lowering with B-vitamins on osteoporotic fractures in patients with cerebrovascular disease: substudy of VITATOPS, a randomised placebo-controlled trial

BACKGROUND

Homocysteine has been postulated as a novel, potentially reversible risk factor for osteoporosis and related fractures. We evaluated whether homocysteine-lowering therapy with B-vitamins in patients with symptomatic cerebrovascular disease reduced the incidence of osteoporotic fractures.

METHODS

VITAmins To Prevent Stroke (VITATOPS) was a prospective randomised double-blind placebo-controlled trial in which 8,164 patients with recent (within 7 months) stroke or transient ischemic attack were randomly allocated to double-blind treatment with one tablet daily of either placebo (n = 4,075) or B-vitamins (folic acid 2 mg, vitamin B6 25 mg, vitamin B12 500 μg; n = 4,089). Patients were reviewed every six months. Any osteoporotic fracture and osteoporotic hip fractures were secondary outcome events, and were reviewed by a masked adjudication committee. Analysis was by intention to treat. Logistic regression was used to identify independent predictors of fracture.

RESULTS

Participants had a mean age of 62.6 years (SD 12.5 years) and 64% were male, 42% of Western European descent and 75% were functionally independent (Oxford Handicap Scale of two or less). After a median duration of 2.8 years therapy and 3.4 years follow-up, there was no significant difference in the incidence of any osteoporotic fracture between participants assigned B-vitamins (67 [1.64%]) and placebo (78 [1.91%]; risk ratio [RR] 0.86, 95% confidence interval [CI] 0.62-1.18) or the incidence of hip fractures (34 [0.83%] B-vitamins vs. 36 [0.88%] placebo; RR 0.94, 95% CI 0.59-1.5). There was no significant impact of B-vitamin therapy on time to first fracture. Baseline homocysteine levels did not predict any osteoporotic fracture (p =0.43). Independent predictors of any osteoporotic fracture were female sex, age > 64 years, Western European ethnicity and use of anti-osteoporosis medication at randomization (all p < 0.01).

CONCLUSIONS

Once daily treatment with B-vitamins had no effect on incidence of osteoporotic fractures during a median of 3.4 years follow-up in patients with cerebrovascular disease. A modest effect of B-vitamin therapy is not excluded due to the low numbers of fracture outcome events.