Folic acid and plasma lipids: Interactions and effect of folate supplementation.

Dyslipidaemia and hyperhomocysteinemia are known risk factors for cardiovascular disease. While it is evident that optimization of plasma lipid is associated with low risk of cardiovascular disease in the general population, it is not yet fully clear whether reduction of homocysteinemia is associated with an improvement in risk in all subjects. The aim of our narrative review is to highlight eventual effects of folate supplementation on LDL-C levels, LDL-C oxidation and atherosclerosis-related complications. A comprehensive literature search was done in electronic database, including PubMed, Web of Science, Cochrane, and Scopus from inception up to January 2024. Based on the available evidence, epidemiological data, pathophysiological observations and meta-analyses of randomized clinical trials suggest that folic acid supplementation may modestly but significantly improve plasma lipid levels, lipid atherogenicity, and atherosclerosis-related early vascular damage, and that folic acid supplementation may significantly reduce the risk of cerebrovascular disease. Considering the low-cost and high safety profile of folic acid, its long-term supplementation could be considered for dyslypidaemic patients in secondary prevention for cardiovascular disease.

RBC Folate and Serum Folate, Vitamin B-12, and Homocysteine in Chinese Couples Prepregnancy in the Shanghai Preconception Cohort.

BACKGROUND: The protective effects of maternal folate on neural tube defects are well-established. Emerging evidence has shown paternal folate also is related to pregnancy outcome and offspring health. OBJECTIVES: This study aimed to assess the status of red blood cell (RBC) folate and serum folate, vitamin B-12, and homocysteine (Hcy) and their associated factors in a cohort of pregnancy-preparing couples. METHODS: This was a cross-sectional study involving 14,178 participants from the extension of the Shanghai Preconception Cohort conducted in 2018-2021. Circulating biomarker concentrations were measured, and the prevalence of abnormal status was reported. Linear and logistic regression analyses were conducted to examine associations of demographic factors (age, education, and income), lifestyle factors (smoking, drinking, and folic acid supplement use), and BMI with concentrations of the folate-related biomarkers, abnormal status of folate (deficiency and insufficiency) and vitamin B-12 (deficiency and marginal deficiency), and hyperhomocysteinemia. RESULTS: The geometric mean (95% CI) concentrations of RBC folate, serum folate, vitamin B-12, and Hcy were 490 nmol/L (485, 496 nmol/L), 20.1 nmol/L (19.8, 20.3 nmol/L), 353 pmol/L (350, 357 pmol/L), and 7.54 µmol/L (7.48, 7.60 µmol/L) in females, respectively, and 405 nmol/L (401, 409 nmol/L), 13.5 nmol/L (13.4, 13.7 nmol/L), 277 pmol/L (274, 279 pmol/L), and 12.0 µmol/L (11.9, 12.2 µmol/L) in males, respectively. Prevalence of abnormal status was higher in males than females for the 4 folate-related biomarkers: RBC folate deficiency (<340 nmol/L, 32.2% compared with 18.9%), serum folate deficiency (<10.0 nmol/L, 26.5% compared with 7.3%), RBC folate insufficiency (<906 nmol/L, 96.6% compared with 90.1%), serum folate insufficiency (<15.9 nmol/L, 65.5% compared with 31.4%), vitamin B-12 marginal deficiency (148-221 pmol/L, 21.4% compared with 8.8%), and hyperhomocysteinemia (>15.0 µmol/L, 22.1% compared with 2.5%). CONCLUSIONS: Most pregnancy-preparing couples failed to achieve the optimal RBC folate status (>906 nmol/L) as recommended by the WHO. These findings call for attention to the insufficiency status of folate and promising strategies to improve the folate status of the pregnancy-preparing population not exposed to folic acid fortification.

Prevalence of hyperhomocysteinemia (HHcy) and its major determinants among hypertensive patients over 35 years of age.

OBJECTIVE: Hyperhomocysteinemia (HHcy) and hypertension are associated with cardiovascular events. However, effects of Hcy-lowing interventions on cardiovascular outcome were conflicting. Serum folate level was proposed to be a possible determinant of efficacy of extra folate supplementation on cardiovascular outcome. The aims of the present study were to describe representative information on the levels of serum homocysteine and folate in hypertensive patients, and to explore the major determinants of HHcy. METHODS: 11,007 participants with hypertension were analyzed in this cross-sectional study. Blood pressure and serum levels of biochemical indicators were measured. Multivariate logistic regression model was used to assess the associated factors of HHcy. RESULTS: Geometric mean of serum total homocysteine was 14.1 (95% CI: 13.9, 14.4) µmol/L and prevalence of HHcy was 36.1 (95% CI: 34.0, 38.1) % in hypertensive patients. HHcy was strongly associated with factors including male sex, older age, elevated serum creatinine (SCr), lower serum folate and vitamin B12, and uncontrolled blood pressure in hypertensive patients. Elevated SCr attributed to HHcy with the etiologic fraction of 0.29. The change of the odds ratio of HHcy associated with folate was significantly higher in patients with elevated SCr compared with that of patients with normal SCr. CONCLUSION: The results suggested the protection of female sex and higher levels of folate and vitamin B12 from HHcy and attribution of older age and elevated SCr to HHcy. Restoring renal function deserved attention for hypertensive patients to benefit from Hcy-lowing measures.

Association of air pollution and homocysteine with global DNA methylation: A population-based study from North India.

BACKGROUND: Anthropogenic air pollution has been implicated in aberrant changes of DNA methylation and homocysteine increase (>15µM/L). Folate (<3 ng/mL) and vitamin B12 (<220 pg/mL) deficiencies also reduce global DNA methylation via homocysteine increase. Although B-vitamin supplements can attenuate epigenetic effects of air pollution but such understanding in population-specific studies are lacking. Hence, the present study aims to understand the role of air pollution, homocysteine, and nutritional deficiencies on methylation. METHODS: We examined cross-sectionally, homocysteine, folate, vitamin B12 (chemiluminescence) and global DNA methylation (colorimetric ELISA Assay) among 274 and 270 individuals from low- and high- polluted areas, respectively, from a single Mendelian population. Global DNA methylation results were obtained on 254 and 258 samples from low- and high- polluted areas, respectively. RESULTS: Significant decline in median global DNA methylation was seen as a result of air pollution [high-0.84 (0.37-1.97) vs. low-0.96 (0.45-2.75), p = 0.01]. High homocysteine in combination with air pollution significantly reduced global DNA methylation [high-0.71 (0.34-1.90) vs. low-0.93 (0.45-3.00), p = 0.003]. Folate deficient individuals in high polluted areas [high-0.70 (0.37-1.29) vs. low-1.21 (0.45-3.65)] showed significantly reduced global methylation levels (p = 0.007). In low polluted areas, despite folate deficiency, if normal vitamin B12 levels were maintained, global DNA methylation levels improved significantly [2.03 (0.60-5.24), p = 0.007]. Conversely, in high polluted areas despite vitamin B12 deficiency, if normal folate status was maintained, global DNA methylation status improved significantly [0.91 (0.36-1.63)] compared to vitamin B12 normal individuals [0.54 (0.26-1.13), p = 0.04]. CONCLUSIONS: High homocysteine may aggravate the effects of air pollution on DNA methylation. Vitamin B12 in low-polluted and folate in high-polluted areas may be strong determinants for changes in DNA methylation levels. The effect of air pollution on methylation levels may be reduced through inclusion of dietary or supplemented B-vitamins. This may serve as public level approach in natural settings to prevent metabolic adversities at community level.

The recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 and systolic blood pressure variability in coronary heart disease patients with hyperhomocysteinemia: A single-center prospective cohort study.

ABSTRACT: To Investigate the recent effects of small dose of folic acid on lipoprotein-associated phospholipase A2 (LP-PLA2) and systolic blood pressure variability in coronary heart disease (CHD) patients with hyperhomocysteinemia.In this prospective cohort study, a total of 167 CHD patients with hyperhomocysteinemia were consecutively enrolled, and they were divided into Group A (without folic acid intervention, n = 99), Group B (with 0.4 mg of folic acid intervention, n = 34), Group C (0.8 mg of folic acid intervention, n = 34). General information, fasting blood glucose, and blood lipid, folic acid, homocysteine, Lp-PLA2, and blood pressure variability were compared among 3 groups. The above indicators were reviewed after 3 months of treatment.There were no statistically significant differences of age, gender, blood pressure, incidence of type 2 diabetes mellitus, fasting blood glucose, folic acid, homocysteine, Lp-PLA2, total cholesterol, 3 acyl glycerin, apolipoprotein B, lipoprotein (a), high density lipoprotein cholesterol, and low density lipoprotein cholesterol were found among 3 groups (P > .05); however, after being treated for 3 months, there was statistically significant difference in folic acid among 3 groups (P < .05), there was statistically significant difference in apolipoprotein A between Group A and Group B (t = 0.505, P = .039), and also between Group A and Group C (t = 0.052, P = .017). There were statistically significant differences in Lp-PLA2 (t = 24.320, P = .016) and systolic blood pressure variability (t = 0.154, P = .018) between Group A and Group C.For CHD patients with hyperhomocysteinemia, the higher dose (0.8 mg) of folic acid supplement was beneficial for increasing the apolipoprotein A, reducing the Lp-PLA2, and improving the systolic blood pressure variation, which might help to improve the prognosis in these patients.

Evaluation of hyperhomocysteinemia prevalence and its influence on the selected cognitive functions in patients with schizophrenia.

There is evidence that hyperhomocysteinemia may be associated with the development of schizophrenia and cognitive impairment. Therefore, the aim of this study was to analyze the relationship between cognitive functions and normal homocysteine concentrations vs. hyperhomocysteinemia in schizophrenia patients before and after supplementation with vitamins B6, B12 and folate. An 8-week prospective, non-randomized study enrolled 122 adult patients with schizophrenia (67F/55M, mean age 43.54 ±â€¯11.94 years). Homocysteine concentrations were measured in all individuals and afterwards hyperhomocysteinemia patients (n = 42) were divided into two subgroups: treated with oral vitamins supplementation (B6 - 25 mg/d, B12 - 20 µg/d, folate - 2,5 mg/d) (n = 22) and without supplementation (n = 20). The assessment of schizophrenia symptoms severity in study group was performed using the Positive and Negative Syndrome Scale (PANSS). Cognitive functions were evaluated using the Stroop test and the Trail Making Test (TMT). We observed a higher prevalence of hyperhomocysteinemia in schizophrenia patients (34.4%) in comparison to the general population. Individuals with schizophrenia and coexisting hyperhomocysteinemia had worse performance on the Stroop and the TMT tests as well as higher PANSS scores. In these patients, supplementation with vitamins effectively decreased the homocysteine concentrations to the normal values, however there was no statistically significant improvement in the PANSS and cognitive test scores, except a significant decrease in the number of the Stroop test errors. We conclude that significant results obtained in this study show that there is a relationship between homocysteine blood concentration and schizophrenia severity. Moreover, homocysteine concentration lowering might be beneficial in schizophrenia patients with hyperhomocysteinemia in terms of cognitive functions improvement.

Factors Associated with Alzheimer's Disease: An Overview of Reviews.

Alzheimer's disease (AD) is a frequent pathology, with a poor prognosis, for which no curative treatment is available in 2018. AD prevention is an important issue, and is an important research topic. In this manuscript, we have synthesized the literature reviews and meta-analyses relating to modifiable risk factors associated with AD. Smoking, diabetes, high blood pressure, obesity, hypercholesterolemia, physical inactivity, depression, head trauma, heart failure, bleeding and ischemic strokes, sleep apnea syndrome appeared to be associated with an increased risk of AD. In addition to these well-known associations, we highlight here the existence of associated factors less described: hyperhomocysteinemia, hearing loss, essential tremor, occupational exposure to magnetic fields. On the contrary, some oral antidiabetic drugs, education and intellectual activity, a Mediterranean-type diet or using Healthy Diet Indicator, consumption of unsaturated fatty acids seemed to have a protective effect. Better knowledge of risk factors for AD allows for better identification of patients at risk. This may contribute to the emergence of prevention policies to delay or prevent the onset of AD.

Vitamin B 12 deficiency and hyperhomocysteinaemia in outpatients with stroke or transient ischaemic attack: a cohort study at an academic medical centre.

OBJECTIVE: We sought to assess the current magnitude of the opportunity for secondary stroke prevention with B vitamins. DESIGN: A cohort study. SETTING: The Urgent TIA (Transient Ischaemic Attack) Clinic at an academic medical centre. MAIN OUTCOME MEASURES: We assessed the prevalence of biochemical vitamin B12 deficiency (B12Def, serum B12 <156 pmol/L), hyperhomocysteinaemia (HHcy; plasma total homocysteine [tHcy] >14 µmol/L) and metabolic B12 deficiency (MetB12Def, serum B12 <258 pmol/L and HHcy) between 2002 and 2017, by age group and by stroke subtype. RESULTS: Data were available in 4055 patients. B12Def was present in 8.2% of patients overall; it declined from 10.9% of patients referred before 2009 to 5.4% thereafter (p=0.0001). MetB12Def was present in 10.6% of patients, and HHcy was present in 19.1% of patients. Among the patients aged ≥80 years, MetB12Def was present in 18.1% and HHcy in 35%. Among the 3410 patients whose stroke subtype was determined, HHcy was present in 18.4% of patients: 23.3% of large artery atherosclerosis, 18.1% of cardioembolic, 16.3% of small vessel disease, 10.8% of other unusual aetiologies and 13.6% of undetermined subtypes (p=0.0001). CONCLUSIONS: Despite a decline in our referral area since 2009, B12Def, MetB12Def and HHcy remain common in patients with stroke/TIA. Because these conditions are easily treated and have serious consequences, all patients with stroke/TIA should have their serum B12 and tHcy measured.

Guanidinoacetic acid with creatine compared with creatine alone for tissue creatine content, hyperhomocysteinemia, and exercise performance: A randomized, double-blind superiority trial.

PURPOSE: Co-administration of creatine and guanidinoacetic acid (GAA) has been recently put forward as an advanced dietary strategy to optimize tissue bioenergetics. We hypothesized that creatine-GAA mixture would result in a more powerful rise in brain and skeletal muscle creatine, as compared to creatine supplementation alone. METHODS: A randomized, double-blinded, crossover superiority trial has been performed at the University of Novi Sad from December 2016 to November 2017. A total of 14 healthy young men were randomized to receive GAA-creatine mixture (1 grams of GAA and 3 grams of creatine per day) or equimolar creatine (4 grams per day) by oral administration for 4 weeks. RESULTS: Creatine-GAA mixture was superior to creatine alone to increase mean creatine levels in skeletal muscle (16.9 ± 20.2 vs. 2.0 ± 6.0%; P = 0.02) and grey matter (5.8 ± 5.3% vs. 1.5 ± 3.2%; P = 0.02), also for bench press performance (6.0% vs. 5.1%; P < 0.01). Compared with creatine administration alone, combined GAA and creatine resulted in less weight gain (1.6 ± 0.2 kg vs. 0.7 ± 0.2 kg; P < 0.01). No inter-group differences were observed in terms of cardiorespiratory endurance, serum biomarkers, or adverse events. CONCLUSIONS: Creatine-GAA mixture appeared to be superior to creatine alone for up-swinging tissue creatine content and upper body strength, and tended toward a lower risk of weight gain in healthy active men. The formulation might be considered as a novel energy-boosting alternative to creatine alone in weight-sensitive setups. TRIAL REGISTRATION: ClinicalTrials.govNCT03350282.

The Association Between Tea Consumption and Hyperhomocysteine in Chinese Hypertensive Patients.

BACKGROUND: There is no consistent evidence for the relationship between tea-drinking and hyperhomocysteine (hHcy). Because tea-drinking habit and hHcy have prevailed in Chinese hypertensive patients, this study aimed to investigate the association between hHcy and tea consumption in patients with hypertension. METHODS: A total of 335 hypertensive participants were recruited from 7 communities. Demographic characteristics of participants were collected through face-to-face interviews using a standard questionnaire, whereas laboratory data were obtained within 1 week after patient recruitment. Multiple logistic regression analysis was performed to examine the association between tea consumption and hHcy in hypertensive patients. RESULTS: Of the 335 patients, 245 had a tea-drinking habit, and 252 of them were detected with hHcy. A significant association was found between tea consumption and hHcy in hypertensive patients (adjusted odds ratio [OR] = 1.84, 95% confidence interval [CI] = 1.01-3.36, P = 0.048). Subgroup analyses showed that black tea drinking group (adjusted OR = 8.81, 95% CI = 2.74-28.33, P < 0.001) was significantly associated with the risk of hHcy, but not oolong and green tea drinking groups (P > 0.05). Furthermore, consuming a small amount (≤1 cup per day) of green tea was negatively associated with hHcy (adjusted OR = 0.19, 95% CI = 0.07-0.51, P = 0.001), whereas a large intake (>3 cups per day) of green tea was associated with high odds of hHcy (adjusted OR = 5.00, 95% CI = 1.33-18.79, P = 0.02). CONCLUSIONS: These data suggest a hypothesis that selecting green tea or limiting tea consumption might reduce risk of hHcy in hypertensive patients and that warrants further study.

Obesity, hyperhomocysteinaemia and risk of chronic kidney disease: a population-based study.

Background: Obesity is associated with increased risk of cardiovascular disease and chronic kidney disease (CKD). Hyperhomocysteinaemia refers to increased oxidative stress and has been associated with the risk of CKD. Objectives: We investigated the association among body mass index (BMI), homocysteine level and impaired renal function in a Taiwanese adult population. Methods: This was a retrospective cross-sectional study involving 24826 subjects who underwent a health check-up from January 2013 to December 2015. A multivariate linear regression model was developed to analyse the relationship among BMI, serum homocysteine and estimated glomerular filtration rate (eGFR). A multivariate logistic regression model was used to assess the relationship among weight categories, hyperhomocysteinaemia and CKD. Results: The prevalence of CKD in the quartile groups of homocysteine were 2.5%, 2.7%, 3.4% and 5.2% (P < 0.01). For every one-unit increase in BMI (kg/m2), the eGFR decreased by 0.50 ml/min/1.73 m2. Overweight/obese subjects with high homocysteine levels had a higher odds ratio (OR) for CKD, as compared with normal weight subjects (1.84 versus 1.38, respectively; P < 0.01 versus P = 0.02, respectively). Overweight/obese female subjects with hyperhomocysteinaemia had an OR of 3.40 [P < 0.01; 95% confidence interval (CI): 2.06-5.61] for CKD; in males, the OR was 1.66 (P < 0.01; 95% CI: 1.38-1.99). Conclusions: Patients who are overweight/obese with higher homocysteine levels have an increased risk of CKD, especially females. Additional studies exploring whether the effect of weight loss or homocysteine-lowering therapies such as folic acid, vitamin B12 supplements that may prevent or slow the progression of declining renal function, is warranted.

Association between hyperhomocysteinemia and stroke with atherosclerosis and small artery occlusion depends on homocysteine metabolism-related vitamin levels in Chinese patients with normal renal function.

This study was conducted to investigate the role of different homocysteine metabolism-related vitamin (HMRV) levels in the correlation between hyperhomocysteinemia (HHCY) and ischemic stroke (IS) subtypes. Three hundred and forty-eight IS patients manifesting different vascular subtypes were subclassified on the basis of HMRV deficiencies. Correlation between HHCY and IS subtypes was investigated in all the subgroups. In this study, HHCY was significantly correlated with the IS subtypes in large artery atherosclerosis (OR 1.126, 95%CI: 1.051 ~ 1.206, P = 0.001) and small artery occlusion (OR 1.105, 95%CI: 1.023 ~ 1.193, P = 0.012). Subgroup analysis revealed a correlation between HHCY and IS subgroup (OR 1.201, 1.178, 95%CI: 1.081 ~ 1.334, 1.058 ~ 1.313, P = 0.001, P = 0.003, respectively) in HMRV deficiency, but not significantly with the IS subgroup in normal HMRV levels. Serum vitamin B12 concentrations are inversely correlated with both IS subtypes in HMRV deficiency subgroups (OR 0.992, 0.995, 95%CI: 0.987 ~ 0.996, 0.991 ~ 0.999, P < 0.001, P = 0.007, respectively), which may contribute to HHCY incidence in these populations. The correlation between HHCY and IS subtypes is affected by HMRV levels in this case-control study. Our findings are helpful to understand the inconsistency in prior homocysteine studies. Serum vitamin B12 levels may play a critical role in HHCY incidence in this Chinese population.Cerebrovascular disease has emerged as the leading cause of disability and mortality in both urban and rural areas of China (Neurology branch of Chinese Medical Association 2015). Ischemic stroke (IS) constitutes 60% to 80% of all cerebrovascular disease (Neurology branch of Chinese Medical Association 2014). Among a variety of risk factors, hyperhomocysteinemia (HHCY) has been closely correlated with IS due to intracranial small-vessel disease and extracranial large-artery disease (Selhub et al. 1995; Eikelboom et al. 2000; Alvarez et al. 2012; Jeon et al. 2014). However, the failure to lower homocysteine (HCY) via homocysteine metabolism-related vitamin (HMRV, including folic acid and vitamin B12 but not vitamin B6 in this study) supplementation to reduce stroke morbidity questions the role of HCY as a risk factor for stroke (Lonn et al. 2006; Hankey et al. 2010). Theoretically, HMRV supplementation merely lowers the incidence of stroke induced by HHCY resulting from HMRV deficiency, whereas HHCY-induced stroke concomitant with normal HMRV levels may be refractory to treatment. The correlation between HCY varying with HMRV levels and IS subtypes is still unclear. In this study, we investigated the impact of variation in HMRV levels on the correlation between HHCY and IS subtypes in 348 acute IS patients with large and small vessel diseases. We sought to determine the factors underlying the conflicting results associated with lowering HCY by HMRV supplementation to reduce stroke incidence.

Determinants of hyperhomocysteinemia in healthy and hypertensive subjects: A population-based study and systematic review.

AIMS: Hyperhomocysteinemia (HHcy) is known to increase the risk of many diseases. Factors influencing HHcy in healthy and hypertensive subjects remain under-researched. METHODS: A large population-based study was conducted in 60 communities from Shenzhen, China. Responses to standardized questions on lifestyle factors and blood samples were collected from all participants after a 12-h overnight fast. Multiple linear and multivariate logistic regressions were used to explore risk factors for HHcy. Results were then compared to those from a systematic review of English-language articles listed in Pubmed, EBSCOhost, Web of Science, Embase and Cochrane libraries that investigated HHcy risk factors in healthy and hypertensive subjects. RESULTS: A total of 1586 healthy (Male/Female = 642/944) and 5935 hypertensive subjects (Male/Female = 2928/3007) participated in our population-based study. In logistic regression analyses, age, BMI and creatinine (Cr) were risk factors, while being female, fruit intake and physical activity were protective factors for HHcy in healthy subjects. In hypertensive subjects, seven [age, smoking, salt intake, systolic blood pressure (SBP), uric acid, triglycerides (TG), and Cr] and four [female, fruit intake, total cholesterol (TC), and glucose] factors were associated with higher and lower HHcy respectively. The review of 71 studies revealed that potential risk factors for Hcy included nutritional, physiologic, lifestyle habits, ethnicity, genetics, interactions between gene-environment, gene-gene, gene-nutritional, environment-environment, nutritional-nutritional. CONCLUSION: Our study indicates the potential importance of increasing folic acid and vitamin B supplementation, daily fruit and vegetable intake, regular exercise and refraining from tobacco smoking and alcohol consumption as preventive strategies for Hcy.

Serum folate predicts muscle strength: a pilot cross-sectional study of the association between serum vitamin levels and muscle strength and gait measures in patients >65 years old with diabetes mellitus in a primary care setting.

BACKGROUND: Old age and diabetes mellitus are risk factors for vitamin deficiencies, weakness and falls. Deficiencies of vitamin D, and possibly vitamin B12 and folate (which are associated with hyperhomocysteinaemia), contribute to sarcopenia. Determination of the physical effects of vitamin deficiencies in specific groups of people can help to guide public health policy with regard to vitamin supplementation. METHODS: A pilot cross-sectional study was conducted to determine the association of levels of vitamin D, vitamin B12, folate and homocysteine with muscle strength, gait and fall history in 56 patients >65 years old with diabetes mellitus in primary care in Singapore. Hand-grip and leg-quadriceps strength measures were obtained and divided by body mass index (BMI). The timed up-and-go and Tinetti tests were used to measure gait. A history of "at least one fall in the preceding year" was obtained. RESULTS: Vitamin B12 deficiency (<150 pmol/l) was present in 43 % of patients, folate deficiency (<13.5 mmol/l) in 20 %, hyperhomocysteinaemia (≥15.0 µmol/l) in 52 % and vitamin D deficiency (<49.9 nmol/l) in 25 %. Levels of vitamin D, vitamin B12 and homocysteine did not significantly predict muscle strength in regression analyses. Folate (B = 0.010, P < 0.01) and gender (B = 0.356, P < 0.001) predicted average grip strength corrected for BMI (F(2,53) = 17.74, P < 0.001, R 2 = 0.40) Folate (B = 0.011, P < 0.05) and gender (B = 0.367, P < 0.001) also predicted average leg quadriceps strength corrected for BMI (F(2,53) = 9.79, P < 0.001, R 2 = 0.27). Average leg strength and average leg strength corrected for BMI were both negatively associated with the risk of having fallen in the preceding year (odds ratio (OR) = 0.89, 95 % CI 0.80-0.98, P < 0.05 and OR = 0.12, 95 % CI 0.02-0.92, P < 0.05, respectively). CONCLUSIONS: The prevalence of vitamin deficiency was very high in our sample of patients >65 years old with diabetes mellitus. Folate levels were significantly correlated with grip and leg strength (with correction for BMI). Leg strength was positively correlated with gait measures and negatively correlated with a history of falls. The role of folate in muscle weakness and falls warrants further study.

Homocysteine, B Vitamins, and Cognitive Impairment.

Moderately elevated plasma total homocysteine (tHcy) is a strong modifiable risk factor for vascular dementia and Alzheimer's disease. Prospectively, elevated tHcy is associated with cognitive decline, white matter damage, brain atrophy, neurofibrillary tangles, and dementia. Most homocysteine-lowering trials with folate and vitamins B6 and/or B12 tested as protective agents against cognitive decline were poorly designed by including subjects unlikely to benefit during the trial period. In contrast, trials in high-risk subjects, which have taken into account the baseline B vitamin status, show a slowing of cognitive decline and of atrophy in critical brain regions, results that are consistent with modification of the Alzheimer's disease process. Homocysteine may interact with both risk factors and protective factors, thereby identifying people at risk but also providing potential strategies for early intervention. Public health steps to slow cognitive decline should be promoted in individuals who are at risk of dementia, and more trials are needed to see if simple interventions with nutrients can prevent progression to dementia.

Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-µmol/L increase above 10 µmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 µmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements.

Nutritional status of the elderly in rural North China: a cross-sectional study.

OBJECTIVES: This study aimed to describe the nutritional status of elderly people living in a rural area of North China. DESIGN: Community-based, cross-sectional prevalence survey. SETTING: 3 rural towns of Lvliang City, Shanxi Province, China. PARTICIPANTS: A sample of 1845 community residents (29.1% of those eligible) 55 years or older (birth before 1958-01-01). MEASUREMENTS: The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels. RESULTS: 991 (53.7%) were female and 139 (7.5%) did not complete the anthropometric measurement. Prevalence of underweight and obesity was 3.5% and 24.9% in men and 6.7% and 31.0% in women (P = 0.003, P = 0.005, respectively). Prevalence of hypercholesterolemia and hypocholesterolemia was 13.5% and 52.6% in men and 25.0% and 34.3% in women (P < 0.001, P < 0.001, respectively). Prevalence of high LDL-c concentrations was 8.8% in men and 16.8% in women (P < 0.001). The mean serum tHcy in men (28.8 ± 20.1 µmmol/l) was significantly higher than in women (21.0 ± 15.1 µmmol/L, P < 0.001). Prevalence of hyperhomocysteinemia (defined as > 15µmmol/L) was 79.7% in men and 65.5% in women (P < 0.001). Prevalence of low folate (defined as < 11 nmol/L) and vitamin B12 levels (defiend as < 185 pmol/L) was 70.8 % and 76.8% in men and 56.5% and 72.6% in women (P < 0.001, P = 0.036, respectively). Correlation coefficients between tHcy, folate, and vitamin B12 indicated an inverse linear correlation (r = -0.21, P < 0.001, r = -0.35, P < 0.001, respectively). CONCLUSIONS: As China's economic climate has developed, the nutritional status of elderly people in the rural parts of the country has improved in some aspects. However, the trend toward obesity will lead to a shift in the burden of obesity-related chronic diseases. In addition, rurally-located elderly people are at high risk of death that may be associated with abnormal serum cholesterol. The data also suggest that severe deficiencies in folate and vitamin B12 levels exist, as well as there being a high prevalence of hyperhomocysteinemia. Folate and vitamin B12 supplementation are necessary to prevent related diseases.

[Hyperhomocysteinemia in patients with cardiovascular disease]. / Hiperhomocysteinemia u chorych na schorzenia ukladu krazenia

Homocysteine (Hcy) is an endogenous, non-structural protein, a sulfur-containing amino acid emerging on the pathway of methionine and cysteine, actively involved in numerous biochemical reactions. Total concentration of homocysteine in plasma of healthy humans is low and its level is between 5.0 and 15.0 mmol/l, assessed with the use of HPLC, or 5.0-12.0 mmol/l, using immunoassay methods. Higher concentration of this amino acid in blood is called hyperhomocysteinemia. Hyperhomocysteinemia is significantly correlated with cardiovascular disease and its complications: heart attacks and strokes. It is believed that hyperhomocysteinemia damages endothelial cells, reduces the flexibility of vessels, and adversely affects the process of hemostasis. In addition, hyperhomocysteinemia enhances the adverse effects of risk factors such as hypertension, smoking, and impaired glucose, lipid and lipoprotein metabolism, as well as promoting the development of inflammation. The concentration of homocysteine can be effectively lowered by supplementation with folic acid and vitamins B12 and B6. However, intervention studies conducted in the past decade did not confirm the clinical benefit of vitamin therapy lowering the level of homocysteine in blood of patients with cardiovascular disease. Moreover, there is not clear evidence from genetic studies that the presence of the gene for MTFHR polymorphism 677C>T, which is one of the most common causes of hyperhomocysteinemia, is also associated with the development of cardiovascular disease. These results led the researchers to discuss the role of homocysteine in the development and treatment of cardiovascular disease as well as the need for further research on this issue.

Relationship between metformin use, vitamin B12 deficiency, hyperhomocysteinemia and vascular complications in patients with type 2 diabetes.

Aim of the study was to clarify the relationship between metformin-induced vitamin B12 (B12) deficiency, hyperhomocysteinemia and vascular complications in patients with type 2 diabetes. Serum B12 concentrations, homocysteine plasma levels, the presence of retinopathy and history of macroangiopathy (stroke or coronary heart disease) were analyzed in patients without renal dysfunction (serum creatinine<115 µmol/L). Firstly, B12 status was analyzed in 62 consecutive metformin-treated patients. Secondly, the relationship between B12, homocysteine and vascular complications was analyzed in 46 metformin-treated and 38 age- and sex-matched non-metformin-treated patients. Among the 62 consecutive metformin-treated patients, B12 was deficient (<150 pmol/L) in 8 (13%) and borderline-deficient (150-220 pmol/L) in 18 (29%): the larger the metformin dosage, the lower the B12 (P=0.02, Spearman's ρ=-0.30). There were independent correlations between metformin use and B12 lowering (P=0.02, r = -0.25), and B12 lowering and elevation of homocysteine (P<0.01, r=-0.34). Elevation of homocysteine was a risk for retinopathy (P=0.02, OR 1.26, 95%CI 1.04-1.52). There was no significant relation between homocysteine and macroangiopathy. Correlation between B12 and homocysteine was stronger in metformin-treated (P<0.01, r=-0.48) than non-metformin-treated (P=0.04, r=-0.38) patients. In ten B12 deficient patients, B12 supplementation (1,500 µg/day) for 2.2±1.0 months with continued use of metformin raised B12 levels: 152±42 and 299±97 pmol/L before and after treatment, respectively (P<0.01). Metformin-induced B12 lowering in diabetes was associated with elevation of homocysteine, and hyperhomocysteinemia was independently related to retinopathy. Metformin-induced B12 deficiency was correctable with B12 supplementation.