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Movement Disorders Clinical Practice Feb 2019Clinical, neurophysiological, and pathological evidence suggest an association between Parkinson's disease (PD) and peripheral neuropathy (PNP), with a possible... (Review)
Review
BACKGROUND
Clinical, neurophysiological, and pathological evidence suggest an association between Parkinson's disease (PD) and peripheral neuropathy (PNP), with a possible causative role of levodopa metabolic products, such as homocysteine and methylmalonic acid.
METHODS
We conducted a systematic review of studies reporting cases of PNP in l-dopa-treated PD patients indexed in PubMed between January 1990 and March 2018.
RESULTS
We identified 38 articles reporting cases of PNP in PD patients treated with oral l-dopa or with l-dopa/carbidopa intestinal gel infusion (LCIG). Prevalence of PNP was 30.2% in the former group and 42.1% in the latter. Oral l-dopa was mostly associated with slowly progressive PNP, whereas LCIG showed an acute or subacute onset in 35.7% of cases. In both groups, there was an association between PNP and higher l-dopa doses, as well as with the following biochemical alterations: increased homocysteine; reduced vitamin B12; increased methylmalonic acid; and reduced vitamin B6. A skin biopsy was performed in 181 patients, showing signs of small fibers neuropathy in 169 (93.4%). Positive, yet preliminary, results were observed in patients receiving periodic vitamin supplementation.
CONCLUSIONS
Over one third of PD patients in treatment with l-dopa may develop PNP, with a significantly higher prevalence of acute and subacute forms in those receiving LCIG. Pathogenic mechanisms remain unclear, but possibly related to a complex interplay between peripheral neurodegenerative processes and l-dopa neurotoxic metabolites. Prospective, randomized, clinical trials are required to identify factors associated with the onset and progression of PD-associated PNP and clarify the protective role of B-group vitamin supplementation.
PubMed: 30838307
DOI: 10.1002/mdc3.12688 -
Patient Safety in Surgery 2015The importance of vitamin D for musculoskeletal health has long been recognized, and awareness of significant extra-skeletal effects in health and disease is rapidly... (Review)
Review
The importance of vitamin D for musculoskeletal health has long been recognized, and awareness of significant extra-skeletal effects in health and disease is rapidly emerging. Although it has been possible for many decades to quantify serum markers of vitamin D deficiency, and to correct deficiency at low cost and with high safety, the influence of vitamin D status on post-surgical outcomes has only recently been identified as a research topic of interest. To the present, these data have not been the subject matter of formal review. Accordingly, we conducted a systematic review to assess the association between perioperative vitamin D status and outcomes after surgery. The databases of PubMed, Ovid MEDLINE, EMBASE, AMED, CINAHL (EBSCOHost), The Cochrane Databases of Systematic Review, and PROSPERO were searched through December, 2014 for studies relating to vitamin D and surgery. The initial search yielded 90 manuscripts. After applying exclusion criteria, 31 studies were eligible for inclusion. Fifteen studies employed prospective observational designs, 3 used prospective randomized protocols, and 13 report retrospective database interrogations. The main finding of the present review is that 26 of 31 studies (84%) report at least one statistically significant worse outcome in patients with low vitamin D status. Five of 31 studies (16%) found no association. In conclusion, this review supports the hypothesis that hypovitaminosis D is associated with adverse outcomes after diverse surgical procedures. Future studies should focus on additional surgeries and outcomes, and on the role of vitamin D supplementation in the improvement of patient safety in participants with low vitamin D status at the time of surgery.
PubMed: 25926889
DOI: 10.1186/s13037-015-0060-y -
Developmental Medicine and Child... Nov 2022We performed a systematic review and network meta-analysis (NMA) to obtain comparative effectiveness estimates and rankings of non-surgical interventions used to treat... (Meta-Analysis)
Meta-Analysis Review
AIM
We performed a systematic review and network meta-analysis (NMA) to obtain comparative effectiveness estimates and rankings of non-surgical interventions used to treat infantile spasms.
METHOD
All randomized controlled trials (RCTs) including children 2 months to 3 years of age with infantile spasms (with hypsarrhythmia or hypsarrhythmia variants on electroencephalography) receiving appropriate first-line medical treatment were included. Electroclinical and clinical remissions within 1 month of starting treatment were analyzed.
RESULTS
Twenty-two RCTs comparing first-line treatments for infantile spasms were reviewed; of these, 17 were included in the NMA. Both frequentist and Bayesian network rankings for electroclinical remission showed that high dose adrenocorticotropic hormone (ACTH), methylprednisolone, low dose ACTH and magnesium sulfate (MgSO ) combination, low dose ACTH, and high dose prednisolone were most likely to be the 'best' interventions, although these were not significantly different from each other. For clinical remission, low dose ACTH/MgSO combination, high dose ACTH (with/without vitamin B ), high dose prednisolone, and low dose ACTH were 'best'.
INTERPRETATION
Treatments including ACTH and high dose prednisolone are more effective in achieving electroclinical and clinical remissions for infantile spasms.
WHAT THIS PAPER ADDS
Adrenocorticotropic hormone and high dose prednisolone are more effective than other medications for infantile spasms. Symptomatic etiology decreases the likelihood of remission even after adjusting for treatment lag.
Topics: Adrenocorticotropic Hormone; Anticonvulsants; Child; Humans; Infant; Magnesium Sulfate; Methylprednisolone; Network Meta-Analysis; Spasms, Infantile; Treatment Outcome; Vitamins
PubMed: 35765990
DOI: 10.1111/dmcn.15330 -
Journal of the American Heart... Dec 2023Cardiovascular calcification, characterized by deposition of calcium phosphate in the arterial wall and heart valves, is associated with cardiovascular morbidity and...
BACKGROUND
Cardiovascular calcification, characterized by deposition of calcium phosphate in the arterial wall and heart valves, is associated with cardiovascular morbidity and mortality and is commonly seen in aging, diabetes, and chronic kidney disease. Whether evidence-based interventions could significantly attenuate cardiovascular calcification progression remains uncertain.
METHODS AND RESULTS
We conducted a systematic review of randomized controlled trials involving interventions, compared with placebo, another comparator, or standard of care, to attenuate cardiovascular calcification. Included clinical trials involved participants without chronic kidney disease, and the outcome was cardiovascular calcification measured using radiological methods. Quality of evidence was determined by the Cochrane risk of bias and Grading of Recommendations, Assessment, Development, and Evaluations assessment. Forty-nine randomized controlled trials involving 9901 participants (median participants 104, median duration 12 months) were eligible for inclusion. Trials involving aged garlic extract (n=6 studies) consistently showed attenuation of cardiovascular calcification. Trials involving 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (n=14), other lipid-lowering agents (n=2), hormone replacement therapies (n=3), vitamin K (n=5), lifestyle measures (n=4), and omega-3 fatty acids (n=2) consistently showed no attenuation of cardiovascular calcification with these therapies. Trials involving antiresorptive (n=2), antihypertensive (n=2), antithrombotic (n=4), and hypoglycemic agents (n=3) showed mixed results. Singleton studies involving salsalate, folate with vitamin B6 and 12, and dalcetrapib showed no attenuation of cardiovascular calcification. Overall, Cochrane risk of bias was moderate, and the Grading of Recommendations, Assessment, Development, and Evaluations assessment for a majority of analyses was moderate certainty of evidence.
CONCLUSIONS
Currently, there are insufficient or conflicting data for interventions evaluated in clinical trials for mitigation of cardiovascular calcification. Therapy involving aged garlic extract appears most promising, but evaluable studies were small and of short duration.
Topics: Humans; Antioxidants; Diabetes Mellitus; Disease Progression; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic; Vascular Calcification; Garlic; Phytotherapy; Plant Extracts
PubMed: 38014685
DOI: 10.1161/JAHA.123.031676 -
The Cochrane Database of Systematic... Jun 2015Vitamin B6 plays vital roles in numerous metabolic processes in the human body, such as nervous system development and functioning. It has been associated with some... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin B6 plays vital roles in numerous metabolic processes in the human body, such as nervous system development and functioning. It has been associated with some benefits in non-randomised studies, such as higher Apgar scores, higher birthweights, and reduced incidence of pre-eclampsia and preterm birth. Recent studies also suggest a protection against certain congenital malformations.
OBJECTIVES
To evaluate the clinical effects of vitamin B6 supplementation during pregnancy and/or labour.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 March 2015) and reference lists of retrieved studies.
SELECTION CRITERIA
We included randomised controlled trials comparing vitamin B6 administration in pregnancy and/or labour with: placebos, no supplementations, or supplements not containing vitamin B6.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. For this update, we assessed methodological quality of the included trials using risk of bias and the GRADE approach.
MAIN RESULTS
Four trials (1646 women) were included. The method of randomisation was unclear in all four trials and allocation concealment was reported in only one trial. Two trials used blinding of participants and outcomes. Vitamin B6 as oral capsules or lozenges resulted in decreased risk of dental decay in pregnant women (capsules: risk ratio (RR) 0.84; 95% confidence interval (CI) 0.71 to 0.98; one trial, n = 371, low quality of evidence; lozenges: RR 0.68; 95% CI 0.56 to 0.83; one trial, n = 342, low quality of evidence). A small trial showed reduced mean birthweights with vitamin B6 supplementation (mean difference -0.23 kg; 95% CI -0.42 to -0.04; n = 33; one trial). We did not find any statistically significant differences in the risk of eclampsia (capsules: n = 1242; three trials; lozenges: n = 944; one trial), pre-eclampsia (capsules n = 1197; two trials, low quality of evidence; lozenges: n = 944; one trial, low-quality evidence) or low Apgar scores at one minute (oral pyridoxine: n = 45; one trial), between supplemented and non-supplemented groups. No differences were found in Apgar scores at five minutes, or breastmilk production between controls and women receiving oral (n = 24; one trial) or intramuscular (n = 24; one trial) loading doses of pyridoxine at labour. Overall, the risk of bias was judged as unclear. The quality of the evidence using GRADE was low for both pre-eclampsia and dental decay. The other primary outcomes, preterm birth before 37 weeks and low birthweight, were not reported in the included trials.
AUTHORS' CONCLUSIONS
There were few trials, reporting few clinical outcomes and mostly with unclear trial methodology and inadequate follow-up. There is not enough evidence to detect clinical benefits of vitamin B6 supplementation in pregnancy and/or labour other than one trial suggesting protection against dental decay. Future trials assessing this and other outcomes such as orofacial clefts, cardiovascular malformations, neurological development, preterm birth, pre-eclampsia and adverse events are required.
Topics: Birth Weight; Dental Caries; Dietary Supplements; Eclampsia; Female; Humans; Infant, Newborn; Labor, Obstetric; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Pyridoxine; Randomized Controlled Trials as Topic; Vitamin B Complex
PubMed: 26039815
DOI: 10.1002/14651858.CD000179.pub3 -
International Journal of Molecular... May 2024The published data on the vitamin status of patients with phenylketonuria (PKU) is contradictory; therefore, this systematic review and meta-analysis evaluated the... (Meta-Analysis)
Meta-Analysis Review
The published data on the vitamin status of patients with phenylketonuria (PKU) is contradictory; therefore, this systematic review and meta-analysis evaluated the vitamin status of PKU patients. A comprehensive search of multiple databases (PubMed, Web of Sciences, Cochrane, and Scopus) was finished in March 2024. The included studies compared vitamin levels between individuals diagnosed with early-treated PKU and healthy controls while excluding pregnant and lactating women, untreated PKU or hyperphenylalaninemia cases, control groups receiving vitamin supplementation, PKU patients receiving tetrahydrobiopterin or pegvaliase, and conference abstracts. The risk of bias in the included studies was assessed by the Newcastle-Ottawa scale. The effect sizes were expressed as standardised mean differences. The calculation of effect sizes with 95% CI using fixed-effects models and random-effects models was performed. A -value < 0.05 was considered statistically significant. The study protocol was registered in the PROSPERO database (CRD42024519589). Out of the initially identified 11,086 articles, 24 met the criteria. The total number of participants comprised 770 individuals with PKU and 2387 healthy controls. The meta-analyses of cross-sectional and case-control studies were conducted for vitamin B12, D, A, E, B6 and folate levels. PKU patients demonstrated significantly higher folate levels (random-effects model, SMD: 1.378, 95% CI: 0.436, 2.320, = 0.004) and 1,25-dihydroxyvitamin D concentrations (random-effects model, SMD: 2.059, 95% CI: 0.250, 3.868, = 0.026) compared to the controls. There were no significant differences in vitamin A, E, B6, B12 or 25-dihydroxyvitamin D levels. The main limitations of the evidence include a limited number of studies and their heterogeneity and variability in patients' compliance. Our findings suggest that individuals with PKU under nutritional guidance can achieve a vitamin status comparable to that of healthy subjects. Our study provides valuable insights into the nutritional status of PKU patients, but further research is required to confirm these findings and explore additional factors influencing vitamin status in PKU.
Topics: Phenylketonurias; Humans; Vitamins; Vitamin D; Folic Acid; Vitamin B 12; Vitamin A
PubMed: 38791104
DOI: 10.3390/ijms25105065 -
Nutrients Jul 2023Nutritional deficiencies during pregnancy can have serious consequences for the health of the (unborn) child. This systematic review provides an updated overview of the... (Review)
Review
Nutritional deficiencies during pregnancy can have serious consequences for the health of the (unborn) child. This systematic review provides an updated overview of the available food and nutrient intake data for pregnant women in The Netherlands and an evaluation based on the current recommendations. Embase, MEDLINE, and national institute databases were used. Articles were selected if they had been published since 2008 and contained data on food consumption, nutrient intake, or the status of healthy pregnant women. A qualitative comparison was made with the 2021 Dutch Health Council recommendations and reference values. A total of 218 reports were included, representing 54 individual studies. Dietary assessments were primarily performed via food frequency questionnaires. Protein, vitamin A, thiamin, riboflavin, vitamin B, folate, vitamin B, vitamin C, iron, calcium, and magnesium intakes seemed to be adequate. For folate and vitamin D, supplements were needed to reach the recommended intake. The reasons for concern are the low intakes of fruits, vegetables, and (fatty) fish, and the intakes of alcohol, sugary drinks, and salt. For several foods and nutrients, no or limited intake data were found. High-quality, representative, and recent data are needed to evaluate the nutrient intake of pregnant women in order to make accurate assessments and evaluations, supporting scientific-based advice and national nutritional policies.
Topics: Animals; Female; Pregnancy; Humans; Pregnant Women; Netherlands; Energy Intake; Eating; Vitamins; Folic Acid; Diet
PubMed: 37447397
DOI: 10.3390/nu15133071 -
Cells Aug 2023There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients... (Meta-Analysis)
Meta-Analysis Review
There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients with chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis of the association between circulating metabolites within the arginine (arginine, citrulline, ornithine, asymmetric, ADMA, and symmetric, SDMA dimethylarginine), transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B, and vitamin B) metabolic pathways and COPD. We searched electronic databases from inception to 30 June 2023 and assessed the risk of bias and the certainty of evidence. In 21 eligible studies, compared to healthy controls, patients with stable COPD had significantly lower methionine (standardized mean difference, SMD = -0.50, 95% CI -0.95 to -0.05, = 0.029) and folic acid (SMD = -0.37, 95% CI -0.65 to -0.09, = 0.009), and higher homocysteine (SMD = 0.78, 95% CI 0.48 to 1.07, < 0.001) and cysteine concentrations (SMD = 0.34, 95% CI 0.02 to 0.66, = 0.038). Additionally, COPD was associated with significantly higher ADMA (SMD = 1.27, 95% CI 0.08 to 2.46, = 0.037), SDMA (SMD = 3.94, 95% CI 0.79 to 7.08, = 0.014), and ornithine concentrations (SMD = 0.67, 95% CI 0.13 to 1.22, = 0.015). In subgroup analysis, the SMD of homocysteine was significantly associated with the biological matrix assessed and the forced expiratory volume in the first second to forced vital capacity ratio, but not with age, study location, or analytical method used. Our study suggests that the presence of significant alterations in metabolites within the arginine, transsulfuration, and folic acid pathways can be useful for assessing nitric oxide dysregulation and oxidative stress and identifying novel treatment targets in COPD. (PROSPERO registration number: CRD42023448036.).
Topics: Humans; Cysteine; Nitric Oxide; Metabolomics; Arginine; Methionine; Racemethionine; Folic Acid; Homocysteine; Vitamins
PubMed: 37681911
DOI: 10.3390/cells12172180 -
Systematic Reviews May 2020Development of cognitive decline represents substantial issues in today's society, steadily gaining importance with increasing life expectancy. One potential approach to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Development of cognitive decline represents substantial issues in today's society, steadily gaining importance with increasing life expectancy. One potential approach to preventing cognitive decline is to lower homocysteine by administering vitamin B. In this systematic review and meta-analysis, we address this topic and investigate whether oral supplementation of vitamin B can successfully prevent cognitive decline in cognitively unimpaired individuals.
METHODS
A computerized systematic literature search was conducted using the electronic databases PubMed, Embase, and the Cochrane Library. Eligibility criteria included oral supplementation with vitamin B (B, B, folic acid, and B) and the absence of cognitive impairment. A meta-analysis was conducted with "global cognition" as the primary outcome of this review. Secondary outcomes were changes in cognitive function in other cognitive domains reported in the included studies. Risk of bias was assessed according to the Cochrane Risk of Bias tool and the GRADE approach to establish the overall certainty of the evidence.
RESULTS
The meta-analysis did not yield a significant overall effect of supplementation with vitamin B on cognitive function (Z = 0.87; p = 0.39; SMD, 0.02; 95% CI, - 0.034, 0.08). A sensitivity analysis focusing on specific risk factors did not alter this result. Some studies reported isolated significant effects of the intervention on secondary outcomes. However, these findings were outnumbered by the number of cognitive tests that did not yield significant effects.
DISCUSSION
We found no overall evidence that oral vitamin B supplementation prevented cognitive decline. The isolated significant effects that were reported could be attributed to methodological issues. The results of this review do not provide evidence that population groups with certain risk factors would profit more from the intervention than others. Our findings do not apply to forms of administration other than oral supplementation nor do they offer information regarding the treatment of cognitively impaired individuals via the administration of vitamin B.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42017071692.
Topics: Cognitive Dysfunction; Dietary Supplements; Folic Acid; Humans; Vitamin B 12; Vitamin B Complex
PubMed: 32414424
DOI: 10.1186/s13643-020-01378-7 -
The Cochrane Database of Systematic... May 2016People with end-stage kidney disease (ESKD) have high rates of cardiovascular events. Randomised controlled trials (RCTs) of homocysteine-lowering therapies have not... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
People with end-stage kidney disease (ESKD) have high rates of cardiovascular events. Randomised controlled trials (RCTs) of homocysteine-lowering therapies have not shown reductions in cardiovascular event rates in the general population. However, people with kidney disease have higher levels of homocysteine and may have different mechanisms of cardiovascular disease. We performed a systematic review of the effect of homocysteine-lowering therapies in people with ESKD.
OBJECTIVES
To evaluate the benefits and harms of established homocysteine lowering therapy (folic acid, vitamin B6, vitamin B12) on all-cause mortality and cardiovascular event rates in patients with ESKD.
SEARCH METHODS
We searched Cochrane Kidney and Transplant's Specialised Register to 25 January 2016 through contact with the Information Specialist using search terms relevant to this review.
SELECTION CRITERIA
Studies conducted in people with ESKD that reported at least 100 patient-years of follow-up and assessed the effect of therapies that are known to have homocysteine-lowering properties were included.
DATA COLLECTION AND ANALYSIS
Two authors independently extracted data using a standardised form. The primary outcome was cardiovascular mortality. Secondary outcomes included all-cause mortality, incident cardiovascular disease (fatal and nonfatal myocardial infarction and coronary revascularisation), cerebrovascular disease (stroke and cerebrovascular revascularisation), peripheral vascular disease (lower limb amputation), venous thromboembolic disease (deep vein thrombosis and pulmonary embolism), thrombosis of dialysis access, and adverse events. The effects of homocysteine-lowering therapies on outcomes were assessed with meta-analyses using random-effects models. Prespecified subgroup and sensitivity analyses were conducted.
MAIN RESULTS
We included six studies that reported data on 2452 participants with ESKD. Interventions investigated were folic acid with or without other vitamins (vitamin B6, vitamin B12). Participants' mean age was 48 to 65 years, and proportions of male participants ranged from 50% to 98%.Homocysteine-lowering therapy probably leads to little or no effect on cardiovascular mortality (4 studies, 1186 participants: RR 0.93, 95% CI 0.70 to 1.22). There was no evidence of heterogeneity among the included studies (I² = 0%). Homocysteine-lowering therapy had little or no effect on all-cause mortality or any other of this review's secondary outcomes. All prespecified subgroup and sensitivity analyses demonstrated little or no difference. Reported adverse events were mild and there was no increase in the incidence of adverse events from homocysteine-lowering therapies (3 studies, 1248 participants: RR 1.12, 95% CI 0.51 to 2.47; I(2) = 0%). Overall, studies were assessed as being at low risk of bias and there was no evidence of publication bias.
AUTHORS' CONCLUSIONS
Homocysteine-lowering therapies were not found to reduce mortality (cardiovascular and all-cause) or cardiovascular events among people with ESKD.
Topics: Aged; Cardiovascular Diseases; Cause of Death; Female; Folic Acid; Homocysteine; Humans; Hyperhomocysteinemia; Kidney Failure, Chronic; Male; Middle Aged; Myocardial Infarction; Renal Dialysis; Stroke; Venous Thrombosis; Vitamin B 12; Vitamin B 6; Vitamin B Complex
PubMed: 27243372
DOI: 10.1002/14651858.CD004683.pub4