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Results for “Serum Folate Level”

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PubMed2004

Serum vitamin B12 and folic Acid levels in acute cerebral atherothrombotic infarction.

Hyperhomocysteinemia is an independent risk factor for atherothrombotic cerebral stroke. Vitamin B12 and folic acid are important determinants of homocysteine metabolism. We aimed to evaluate the relationship, if present, between vitamin B12 and folic acid levels and acute cerebral stroke in this study. Blood aliquots drawn within 24 hours after the stroke from hospitalized patients (n=66) with the diagnosis of acute ischemic cerebrovascular episode and also blood samples from 38 healthy controls without any vascular risk factor were analyzed. With a competitive, chemoluminescence assay, serum levels of vitamin B12 and folic acid were measured in blood samples taken within 24 hours after the stroke. The differences and correlations were tested using frequency test, student-t test and multivariate analysis. Mean serum vitamin B12 levels were significantly lower in the patients than in the control subjects, 245.40 (S.D.: 72.9) and 343.2 (S.D.: 113.0) pg/ml respectively (p=0.0001). This difference was independent from other risk factors. Likewise, mean serum folic acid levels were lower in the patients than in the control subjects, 4.62 (S.D.: 1.94) and 5.97 (S.D.: 1.19) ng/ml, respectively (p=0.003). Mean serum levels of vitamin B12 and folate at the convalescence phase were 253.05 (S.D.: 68.78) pg/ml and 4.48 (S.D.: 2.08) ng/ml, respectively; the values obtained at the acute phase were not significantly different from the values obtained at the convalescence phase. We conclude that low vitamin B12 and folic acid concentrations are associated with an increased risk of stroke, and the relationship for vitamin B12 is independent from the other known modifiable stroke risk factors. For understanding the effects of B12 and folate in stroke patients, more detailed follow-up studies with long period are needed.

Acute Disease↗

PubMed1989

Dietary folate as a risk factor for neural-tube defects: evidence from a case-control study in Western Australia.

A population-based case-control study was conducted to test the hypothesis that the risk of the occurrence of neural-tube defects in infants with no other birth defects (isolated neural-tube defects) is associated inversely with the maternal dietary intake of free and/or total folate in early pregnancy. Information was collected from the mothers of 77 case subjects with isolated neural-tube defects who were born in Western Australia from 1982 to 1984, from the mothers of 77 control subjects with birth defects other than neural-tube defects (control group 1) and from the mothers of 154 control subjects with no birth defects (control group 2). The case and control subjects were matched individually by the date of the mother's last menstrual period. Odds ratios were adjusted for a number of potentially-confounding variables, such as the country of birth of the parents, paternal social class, previous pregnancy outcome, interval between index and previous pregnancy and pregnancy order. Crude and adjusted odds ratios showed a protective effect of an increasing intake of free folate in the first six weeks of pregnancy. Adjusted odds ratios, with reference to the lowest quartile of intake, (and their 95% confidence intervals) were 0.72 (0.25-2.08), 0.37 (0.11-1.23) and 0.31 (0.10-0.97) for quartiles 2-4 when control group 1 was used, and 0.44 (0.17-1.13), 0.34 (0.13-0.90) and 0.16 (0.06-0.49) when control group 2 was used. Similar, but weaker, trends were seen when total folate intake was the exposure variable. These findings support the hypothesis that the dietary intake of folate in early pregnancy protects against the occurrence of isolated neural-tube defects in infants. Measures of postpartum dietary folate and of postpartum serum and red-cell folate levels showed no association with the occurrence of neural-tube defects in infants.

Diet↗

PubMed2000

Chemopreventive effects of dietary folate on intestinal polyps in Apc+/-Msh2-/- mice.

Epidemiological and animal studies (reviewed in Y. I. Kim, J. Nutr. Biochemistry, 10: 66-88, 1999; J. B. Mason and T. Levesque, Oncology, 10: 1727-1743, 1996) suggest that dietary folate intake is inversely related to the risk of colorectal cancer. However, the optimal timing of folate intervention and mechanisms by which folate modulates colorectal carcinogenesis have not been clearly established. A recently developed murine model of intestinal tumorigenesis, which carries a heterozygous mutation in the Apc gene and a null mutation in the Msh2 gene (Apc+/-Msh2-/-), was used to determine the effect of dietary folate on intestinal tumorigenesis. Apc+/- Msh2-/- mice were randomized to receive either 0 or 8 mg of folate/kg diet starting at either 3 or 6 weeks of age. The 3- and 6-week diet starts represent intervention before and after the establishment of neoplastic foci, respectively. At 11 weeks of age, mice were killed, and the small intestines and colons were analyzed for adenomas and aberrant crypt foci (ACF). Serum folate concentrations were determined by a standard microbiological assay. Genomic DNA methylation was assessed by in vitro [3H]methyl incorporation into hepatic DNA and by a methyl-sensitive restriction digestion method. Microsatellite instability was determined in matched normal and polyp DNA from the small intestine and colon at 5 loci. Serum folate concentrations accurately reflected dietary folate levels (P < 0.005). Folate supplementation, started before the establishment of neoplastic foci, significantly decreased the number of small intestinal adenomas (by 2.7-fold; P = 0.004) and colonic ACF (by 2.8-fold; P = 0.028) and colonic adenomas (by 2.8-fold; P = 0.1) compared with a moderate degree of folate deficiency. In contrast, a moderately folate-deficient diet, started after the establishment of neoplastic foci, significantly reduced the number of small intestinal adenomas (by 4.2-fold; P = 0.001) but had no effect on colonic ACF and adenomas compared with folate supplementation. Genomic DNA methylation and microsatellite instability do not seem to play a major role in folate-modulated intestinal and colonic tumorigenesis in this model. In conclusion, in this murine model, dietary folate supplementation significantly protects against small intestinal and colorectal tumorigenesis if it is provided before the establishment of neoplastic foci However, if it is provided after the establishment of neoplastic foci, dietary folate seems to have an opposite effect. These data suggest that the timing of folate intervention is critical in providing an effective and safe chemopreventive effect on intestinal tumorigenesis. Notwithstanding the limitations associated with this model, our data suggest that the optimal timing of folate intervention must be established before folate supplementation can be used as a safe chemopreventive agent against colorectal cancer.

Adenoma↗

PubMed1976

Thrombocytosis in patients with celiac sprue.

In 57% of the patients (12 of 25) seen with celiac sprue, as shown by clinical course and small bowel biopsy, peripheral blood thrombocytosis was present (range: 350,000 to 815,000 platelets per mm(3); mean: 546,000 +/- 44,060 SE). After clinical and histological remission, the platelet counts in these patients fell significantly (range: 188,000 to 300,0000 platelets per mm(3); mean 252,750 +/- 13,211 SE). There was no correlation between thrombocytosis and serum iron, folate, or vitamin B12 levels. Celiac sprue joins inflammatory bowel disease among gastrointestinal disorders as a consideration in the differential diagnosis of thrombocytosis. In these patients, thrombocytosis reflected active disease and was not present during remission. Evaluation of peripheral blood platelets may be useful in the assessment of patients with celiac sprue.

Adult↗

PubMed1998

The nutritional health of New Zealand vegetarian and non-vegetarian Seventh-day Adventists: selected vitamin, mineral and lipid levels.

AIM: To determine whether adult non-vegetarian Seventh-day Adventists differ in selected nutrition related health aspects from adult vegetarian Seventh-day Adventists. METHODS: One hundred and forty-one Seventh-day Adventist church members responded to a general health questionnaire. Forty-seven sex and age matched subjects (23 non-vegetarians and 24 vegetarians) were selected for further investigation. Blood lipids, serum vitamin B12, folate, haemoglobin and ferritin levels were measured along with stature, weight and blood pressure. A quantitative 7-day diet record was also completed. RESULTS: Body mass index was similar between the non-vegetarian and vegetarian groups but diastolic blood pressure was higher for non-vegetarian than vegetarian males. Even though the dietary vitamin B12 intake was significantly lower (p < 0.01) in the vegetarian group both vegetarians and non-vegetarians recorded similar serum vitamin B12 levels. The vegetarian and non-vegetarian groups had similar haemoglobin concentrations. While dietary iron intake was higher in the female vegetarian group, though predominantly in the non-haem form, the difference was not significant. Low serum ferritin levels were found in both female dietary groups even though the vegetarian group had a significantly (p < 0.05) higher vitamin C intake. Blood lipid levels were similar in the two diet groups even though the vegetarian group had a lower percentage energy contribution from total and saturated fat (p < 0.01) and consumed significantly less cholesterol. CONCLUSION: Both non-vegetarian and vegetarian Seventh-day Adventists appear likely to enjoy a lower risk of nutrition related chronic degenerative disease than the average New Zealander and have a satisfactory iron and vitamin B12 status.

Adult↗

PubMed1999

Whole blood folate, homocysteine in serum, and risk of first acute myocardial infarction.

High level of total homocysteine (tHcy) is a risk factor for coronary artery disease (CAD), but the mechanism is not known. The serum concentration of tHcy, total cholesterol, high density lipoprotein cholesterol (HDL-C), and apolipoprotein A-I (apo A-I) and the concentration of folate in whole blood were measured in 107 patients with first acute myocardial infarction (MI) and 103 controls. The level of whole blood folate was lower and that of tHcy higher in cases than in controls. An increase of 50 nmol/l whole blood folate was associated with an OR for MI of 0.75, and an increase of 5 micromol/l tHcy with an OR for MI of 1.57. Correlations were observed between the levels of whole blood folate and tHcy and between whole blood folate and alcohol intake, and in MI cases, between tHcy, HDL-C, and apo A-I as well as between HDL-C and alcohol intake. The number of cigarette smokers was higher among cases than controls. In smokers, the level of tHcy was higher and that of whole blood folate lower than in non-smokers. After adjustment for smoking, the whole blood folate and tHcy-associated risks of MI became non-significant. We conclude that smoking may affect folate status and tHcy level adversely. The risk of MI in smokers may at least partly be attributed to hyperhomocysteinemia or low folate.

Age Distribution↗

PubMed2004

Serum homocysteine concentrations in children with growth hormone (GH) deficiency before and after 12 months GH replacement.

OBJECTIVE: This open, prospective study was designed to evaluate the effect of growth hormone deficiency (GHD) and GH replacement therapy on serum homocysteine (Hcy) concentration in children with GHD. SUBJECTS: Seventeen prepubertal children with GHD (11 boys and six girls) aged 8.6 +/- 1.9 years were studied before and after 12 months of GH replacement therapy at a dose of GH of 30 microg/kg/day. Seventeen healthy children acted as controls and were matched for age, sex and body mass index (BMI). METHODS: At study entry, height, weight, blood pressure, serum Hcy, serum IGF-I, total-low density lipoprotein (LDL)- and high density lipoprotein (HDL) cholesterol, triglycerides, free T4, free T3, vitamin B12, folate, glucose and creatinine were measured in all subjects. The atherogenic index (AI) was also calculated as the ratio of total cholesterol/HDL cholesterol (T/HDL). In GHD children these parameters were also revaluated after 12 months of GH therapy. RESULTS: At study entry height and serum IGF-I were significantly lower, as expected, in GHD patients than in controls (P < 0.0001 and P < 0.007, respectively). Serum Hcy levels were significantly higher in GHD patients than in healthy children (8.4 +/- 2.9 vs. 6.0 +/- 2.9 micromol/l; P < 0.03), although the absolute values were within the normal values for age and sex. There were no significant differences at baseline with respect to blood pressure, serum vitamin B12, folate, fT3, fT4, lipid profile, creatinine and glucose levels. After 12 months of GH replacement therapy height and serum IGF-I increased significantly compared to pretreatment values (P < 0.0001); serum Hcy levels decreased significantly (6.0 +/- 3.3 micromol/l; P < 0.002) compared to baseline values, becoming similar to control values. Total cholesterol (3.5 +/- 0.6 mmol/l) and the AI (2.5 +/- 0.8) decreased significantly with respect to both pretreatment (4.2 +/- 1.0 mmol/l; P < 0.0002 and 3.4 +/- 0.8; < 0.002, respectively) and control values (4.2 +/- 0.4 mmol/l; P < 0.0005 and 3.3 +/- 1.1; P = 0.02, respectively). CONCLUSIONS: GHD in children is associated with higher serum levels of Hcy compared to controls, without significantly affecting the lipid profile. GH replacement for 12 months significantly decreased the Hcy levels and improved the lipid profile with a decrease of total cholesterol and the total/HDL cholesterol ratio, compared to pretreatment values. Given the small number of patients, further larger studies are needed to clarify whether these results may have significant effects in the prevention of cardiovascular disease in adulthood.

Body Mass Index↗

PubMed1989

Assessment of nutritional status in noninstitutionalized elderly.

Aging may modify both the availability of and needs for certain nutrients. Our study was done to assess the contribution of age alone to micronutrient levels in older volunteers (aged 60 or more). One hundred two healthy elderly white subjects, 63 women and 39 men, carefully screened by history or chart review, were studied in the fasting state. All were noninstitutionalized without serious chronic or acute illness; their diets were nutritionally adequate, containing more than two thirds of the recommended dietary allowance (RDA) for all nutrients, and no subject was taking more than twice the RDA of fat-soluble vitamins. These subjects had higher levels of plasma and red blood cell carnitine, and vitamins A, E, and C. They had lower levels of albumin, transferrin, and zinc than younger laboratory reference subjects. Retinol-binding protein, serum and red blood cell folate, and copper levels were not different. With increasing age, levels of transferrin and vitamins C and E fell; all other measured micronutrient levels were similar. Albumin, vitamin C, and copper values were higher among elderly women, and plasma and red blood cell carnitine values and zinc levels were higher in elderly men. There was great variability in the micronutrient levels despite similar nutrient intakes.

Age Factors↗

PubMed2003

Erythropoietin treatment in the neuropsychiatric porphyrias.

BACKGROUND: In a previous report, 31 patients with neuropsychiatric porphyria were studied and nine of these patients were anaemic in association with inappropriately low serum erythropoietin levels. We were also able to demonstrate that treatment with erythropoietin in non-porphyric patients (mainly diabetic patients with autonomic neuropathy) significantly reduced urinary delta-aminolaevulinic acid levels. METHODS: We treated six porphyric patients, five of whom were anaemic, with recombinant human erythropoietin (1000-2000 IU thrice weekly). They were all in clinical but not biochemical remission. Full blood count, including reticulocytes and platelets, urinary delta-aminolaevulinic acid, porphobilinogen and total porphyrins were measured monthly. Baseline serum ferritin, vitamin B(12), folate and C-reactive protein levels were all within the normal range and serum creatinine did not exceed 126 micromol/l. RESULTS: After 3 months of treatment, the average baseline haemoglobin increased significantly (p=0.01). When treatment was stopped, the haemoglobin decreased and after 3 months pre-treatment, haemoglobin levels were reached. Urinary delta-aminolaevulinic acid, porphobilinogen and porphyrin levels all tended to decrease during treatment with erythropoietin, but the difference between baseline and 3 months of erythropoietin was statistically significant only for porphobilinogen (p=0.03). The severity of porphyria attacks was reduced and the quality of life increased during treatment with erythropoietin. CONCLUSION: We conclude that in some porphyric patients treatment with erythropoietin reduces urinary delta-aminolaevulinic acid, porphobilinogen and porphyrin levels with an increase in well-being and a reduction in the severity of porphyria attacks.

Adult↗

PubMed2001

Decrease of elevated N,N-dimethylglycine and N-methylglycine in human immunodeficiency virus infection during short-term highly active antiretroviral therapy.

This study investigates fasting serum levels of methionine and related metabolites, vitamin B6, and folate during highly active antiretroviral therapy in therapy-naive human immunodeficiency virus (HIV)-1-infected outpatients. The research design consisted of before and during therapy measurements with a median treatment period of 100 days (range, 50 to 188) in frozen samples. The subjects included 17 consecutive HIV-1-infected outpatients (15 men and 2 women; 25 to 65-years-old). Controls were 42 healthy individuals (28 men and 14 women; 24- to 82-years-old) without serologic evidence of HIV and/or hepatitis C infection and normal clinical chemistry. Subjects received treatment with the reverse transcriptase inhibitors, azidothymidine (AZT) or stavudine (D4T) plus lamivudine (3TC) and either the protease inhibitors, indinavir (IND), nelfinavir (NELF), ritonavir (RITV), or saquinavir (SAQ) at the standard dosage. Serum concentrations of methionine, total homocysteine (tHcy), cystathionine (CYSTA), N,N-dimethylglycine (DMG), N-methylglycine (MG), methylmalonic acid (MMA), and total cysteine, as well as vitamin B6, folate, and soluble tumor necrosis factor receptor p75 were taken at baseline and during highly active antiretroviral therapy. Baseline, serum tHcy, MMA, CYSTA, vitamin B6 concentrations were not significantly different from healthy controls. There was, however, a trend towards lower folate serum concentrations at baseline in HIV-infected patients as compared with healthy controls (P =.06). There were no significant correlations between tHcy and vitamin B6, folate, or MMA. Elevated baseline levels of DMG and MG decreased significantly during antiretroviral therapy (P =.0019 and.04, respectively), whereas no significant changes in serum concentrations of CYSTA, MMA, or methionine were detected. tHcy increased in 12 of 17 patients (P =.09). HIV-infected patients displayed significant alterations (elevated DMG and MG serum concentrations) in metabolite levels of the betaine pathway in methionine metabolism, which might be positively influenced by newly initiated antiretroviral combination therapy.

Adult↗

PubMed2004

Increases in homocysteine are related to worsening of stroop scores in healthy elderly persons: a prospective follow-up study.

BACKGROUND: Elevated blood levels of homocysteine have been associated with cerebrovascular disease and cognitive impairment. The authors' objective was to determine the relationship between cognitive changes and variations in tHcy levels over time in healthy elderly volunteers. METHODS: This prospective cohort study was conducted in healthy community-dwelling older adults without cerebrovascular disease at baseline and followed them for 2.3 years. Cobalamin, red blood cell folate, total serum homocysteine (tHcy), and creatinine levels were measured and recorded. Cognitive measures included the Mini Mental State Examination, California Verbal Learning Test, Mattis Dementia Rating Scale, and Stroop Neuropsychological Inventory. RESULTS: At baseline, participants with elevated tHcy levels had lower Stroop scores (72.7 vs 85.35, p <.05) than did participants with normal tHcy levels. The tHcy levels correlated significantly with Stroop scores at baseline and follow-up. At follow-up, tHcy levels had increased in 104 participants (group I) and decreased in 76 participants (group II). Compared to mean baseline values, the mean tHcy in both groups had changed significantly at follow-up (p <.05 and p <.001, respectively). Participants in group I had significantly lower Stroop scores in multivariate analyses at follow-up than at baseline. The scores of participants in group II at follow-up were not significantly different than their scores at baseline. The rate of change of tHcy levels and the rate of change of the Stroop scores were significantly correlated (r = -0.264, p <.001) after multivariate analysis. Stroop scores decreased by 22% at follow-up in participants whose tHcy levels increased by 40% from baseline to follow-up. CONCLUSION: Elevated tHcy levels and increases in tHcy during a short period of time are associated with decreased Stroop scores in otherwise cognitively normal elderly volunteers.

Aged↗

PubMed2002

Enhanced risk of thrombotic disease in patients with acquired vitamin B12 and/or folate deficiency: role of hyperhomocysteinemia.

A number of studies have identified elevated levels of homocysteine (Hcy) as a risk factor for thrombosis. Given the relationship between Hcy and thrombosis, a high prevalence of thrombosis would be expected in patients with megaloblastic anemia. The aim of our study was to determine whether an acquired vitamin B12/folate deficiency is a risk factor for thrombosis. A retrospective case and control study was performed that included 193 cases with reduced levels of vitamin B12/folate. The cases were divided initially into two groups (105 with serum vitamin B12 < or =150 pmol/l and/or low red cell folate < or = 450 nmol/l and 88 with serum vitamin B12 between 150 and 200 pmol/l and/or red cell folate between 450 and 590 nmol/l). The control group consisted of 87 additional patients who had normal levels of serum vitamin B12, red cell folate, and normal renal function. Serum Hcy, thrombotic events, and risk factors were evaluated in all participants. Eight patients (9%) in the control group had had previous vascular events although only three of these events (37.5%) were observed between the vitamin study and 2 years prior to the study. In the case group, 20% of the patients had a history of thrombosis. In contrast with controls, 85% of cases suffered thrombosis between the time they were diagnosed and 2 years prior to the time they were diagnosed as showing a vitamin deficiency. Multivariate analysis demonstrated that vitamin deficiency was a significant risk factor for arterial thrombosis [adjusted odds ratio (OR) 3.3, confidence interval (CI) 1.1-10.2]. However, when hyperhomocysteinemia was included in the analysis, vitamin deficiency was no longer a risk factor, suggesting that hyperhomocysteinemia was responsible for arterial thrombotic risk in these patients (adjusted OR 2.5, CI 1.1-5.8). As a consequence of hyperhomocysteinemia, patients with acquired vitamin deficiency of vitamin B12/folate had a high risk of thrombosis. However, a more extensive study that controls risk variables and genetic factors is needed to sort out the various contributing factors.

Adolescent↗

PubMed2000

Lack of association between carotid intima-media thickness and methylenetetrahydrofolate reductase gene polymorphism or serum homocysteine in non-insulin-dependent diabetes mellitus.

We assessed the contribution of the serum homocysteine (Hcy) level, an independent risk factor for vascular disease, and methylene tetrahydrofolate reductase (MTHFR) gene polymorphism to the variability of intimal-medial thickness (IMT) of the common carotid artery in middle-aged non-insulin-dependent diabetes mellitus (NIDDM) subjects. One hundred thirty NIDDM patients (60 males and 70 females) with a mean age of 53 +/- 10 years and a mean diabetes duration of 11.3 +/- 7.9 years were enrolled for the study. Exclusion criteria included liver, heart, kidney, or other major-organ disease. Fasting total serum Hcy, folate, and vitamin B12 and clinical chemistry analyte levels were measured. MTHFR polymorphism was determined by polymerase chain reaction (PCR). IMT and plaques or stenosis in the common carotid were measured by ultrasonography. Serum Hcy was inversely correlated with vitamin levels and was slightly higher in subjects with the Val/Val genotype versus Ala/Val and Ala/Ala (P = .02); no differences in genotype were found in subjects with folate or vitamin B12 at or above the median level. In univariate analysis, common carotid IMT was significantly associated with age (P = .00001), the body mass index ([BMI] P = .0003), uric acid (P = .004), systolic blood pressure (P = .03), glycemia (P = .03), and total cholesterol (P = .04). No significant association was found between serum Hcy or MTHFR polymorphism and IMT. In multiple regression analysis, age (P = .0001), uric acid (P = .03), glycemia, and the BMI (P = .05) were independently associated with IMT and explained about 42% of IMT variability. In 130 NIDDM patients without nephropathy, basal levels of serum Hcy, as well as MTHFR polymorphism, did not predict significant changes in common carotid IMT.

Arteriosclerosis↗

PubMed1987

Effect of intracellular folate concentration on the modulation of 5-fluorouracil cytotoxicity by the elevation of phosphoribosylpyrophosphate in cultured human KB cells.

The effects of extracellular folate concentration on intracellular folate and phosphoribosylpyrophosphate (PRPP) levels and the cytotoxicity of methotrexate and 5-fluorouracil were studied in human KB cells grown in fetal bovine serum-supplemented Eagle's minimum essential medium, which contained standard high folic acid levels (2.3 microM) (standard or S medium), or folic acid-free serum-supplemented medium containing approximately 4 nM 5-methyltetrahydrofolate (physiological or P medium), a folate level and form more comparable to that in normal human serum. Macrocytosis and prolongation of the doubling time by 150% were observed after 5-10 serial passes in P medium, but after 10-15 serial passes, KB cells became "adapted" to P medium with return of size and doubling time to values indistinguishable from cells maintained in S medium. Cellular folate levels fell, and marked elevations in PRPP levels from 68 +/- 43 to 642 +/- 287 pmol/mg cell protein (mean +/- SD) were observed as KB cells were serially passed through P medium. Human leukemia HL-60 and K562 cells and MJY-alpha mouse mammary tumor cells serially passed in P medium also exhibited 10- to 20-fold elevations in PRPP levels. Glucose consumption, glucose decarboxylation, thymidine and adenosine specific uptake, thymidine incorporation into DNA, and 5-fluorouracil uptake were studied in KB cells with elevated and control PRPP levels. As determined by clonal assay, despite elevated PRPP levels, KB cells cultured in P medium were less sensitive to 5-fluorouracil than cells cultured in S medium unless exogenous folate was added. These data support the concept that endogenous folate levels may be inadequate for optimal 5-FU pharmacological action in KB cells with a modulated increase in PRPP levels.

Adenosine↗

PubMed2006

Effect of folate supplementation on N-terminal pro-brain natriuretic peptide.

BACKGROUND: Increased plasma homocysteine (HCY) has been suggested as a novel risk factor for chronic heart failure (CHF). This study investigated the effect of a HCY lowering therapy by folic acid (FA) supplementation on N-terminal pro-brain natriuretic peptide (NT-proBNP) in healthy subjects. METHODS: We treated 61 healthy individuals (median age [25th-75th percentile]: 57 [53-69] years with placebo, 0.4, 1.0 or 5.0 mg FA daily for 2 months. Fasting blood samples were taken after 0, 4 and 8 weeks. Serum HCY, folate, vitamin B12 and NT-proBNP were studied. RESULTS: Baseline HCY, folate and NT-proBNP levels were 13.6 (10.0-16.4) micromol/L, 5.0 (3.8-6.4) microg/L and 40.4 (21.8-67.3) ng/L, respectively. Serum folate increased during supplementation (4 weeks of placebo, 0.4, 1.0, 5.0 mg of FA: -9%, +131%, +150%, +314%; 8 weeks: -72%, +152%, +185%, +62%) and HCY decreased (4 weeks: +2%, -12%, -20%, -15%; 8 weeks: -2%, -9%, -17%, -15%) in the treatment groups. NT-proBNP did not change within groups. Pooling FA treated subjects, individuals with a baseline NT-proBNP above the median of 40 ng/L exhibited a 20% decrease of NT-proBNP (significant on a 10% level) while HCY decreased by 15%. CONCLUSION: FA supplementation with doses between 0.4 and 5 mg does not affect NT-proBNP in healthy subjects with an NT-proBNP concentration <40 ng/L, but possibly lowers NT-proBNP in individuals with NT-proBNP levels >40 ng/L.

Aged↗

PubMed1999

Hyperhomocysteinaemia.

Homocysteine is a sulphur-containing amino acid that is derived primarily from protein of animal origin. Classical homocystinuria is an inherited metabolic disorder that arises from defects in either the re-methylation or trans-sulphuration pathways of homocysteine metabolism and leads to skeletal abnormalities, mental retardation and a high risk of vascular disease. In contrast, moderate hyperhomocysteinaemia is associated with an increased risk of both arterial and venous thrombotic disease but no other abnormalities. This increased risk appears to be independent of other conventional risk factors. Many cases of hyperhomocysteineaemia have been attributed to defects in the enzyme cystathionine-beta-synthase (CBS) but this accounts for less than 1.5% of cases. A thermolabile variant of the enzyme methylenetetrahydrofolate reductase (MTHFR) arises from a C --> T transition at nucleotide 677 in the MTHFR gene resulting in an alanine-to-valine substitution. While the mutation does not appear to be associated with an increased risk of vascular disease, it results in excessively high homocysteine levels in response to a low or low-normal serum folate. Supplementation of the diet with folate, B6 and B12 can reduce homocysteine levels and this is the mainstay of treatment. Supplementation of grain with folate is undertaken in the USA to reduce the risk of neural tube defects in pregnant women. However, by reducing plasma homocysteine levels, it is estimated that this will save up to 50,000 lives per annum.

Animals↗

PubMed2005

Treatment of depression: time to consider folic acid and vitamin B12.

We review the findings in major depression of a low plasma and particularly red cell folate, but also of low vitamin B12 status. Both low folate and low vitamin B12 status have been found in studies of depressive patients, and an association between depression and low levels of the two vitamins is found in studies of the general population. Low plasma or serum folate has also been found in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similarly been found in patients with alcoholism. It is interesting to note that Hong Kong and Taiwan populations with traditional Chinese diets (rich in folate), including patients with major depression, have high serum folate concentrations. However, these countries have very low life time rates of major depression. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants. A recent study also suggests that high vitamin B12 status may be associated with better treatment outcome. Folate and vitamin B12 are major determinants of one-carbon metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates methyl groups that are crucial for neurological function. Increased plasma homocysteine is a functional marker of both folate and vitamin B12 deficiency. Increased homocysteine levels are found in depressive patients. In a large population study from Norway increased plasma homocysteine was associated with increased risk of depression but not anxiety. There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the MTHFR C677T polymorphism that impairs the homocysteine metabolism is shown to be overrepresented among depressive patients, which strengthens the association. On the basis of current data, we suggest that oral doses of both folic acid (800 microg daily) and vitamin B12 (1 mg daily) should be tried to improve treatment outcome in depression.

Brain↗

PubMed1986

Anemia in alcoholics.

In order to develop a diagnostic approach to the common problem of anemia associated with alcoholism, 121 chronic alcoholics admitted to a general medical service with a low hematocrit were evaluated. Multiple contributing causes of anemia were present in most patients. Megaloblastic marrow change was found in 33.9% of patients, sideroblastic change in 23.1%, absent iron stores in 13.2%, aggregated macrophage iron in 81.0%, and acute blood loss in 24.8%. The MCV was of little value in predicting the presence of megaloblastic change unless markedly elevated (greater than 110 fl). In 15 of 41 patients with megaloblastic marrow morphology (36.6%) the MCV was normal or low. Among 40 patients with MCV values between 100 and 110 fl, megaloblastic change was not present in the bone marrow smears of 24 (60.0%). Neutrophil hypersegmentation was 95% specific but only 78% sensitive for megaloblastic change; in contrast, the presence of macroovalocytosis was 90% sensitive but only 68% specific. Serum lactic dehydrogenase, plasma folate, and erythrocyte folate levels had such low sensitivities and specificities for megaloblastic change as to be of little predictive value. Hematologic responses to folic acid were often inadequate in patients with megaloblastic morphologic changes, apparently because of associated acute and chronic illness. Our findings are consistent with the hypothesis that 2 mechanisms account for the development of megaloblastic hematopoiesis in alcoholics: induction of folate deficiency and a direct toxic effect of alcohol on erythroid precursors independent of folate depletion, as reflected by the presence of normal plasma and erythrocyte folate levels in several patients with megaloblastic change. In no patient was sideroblastic change the sole apparent cause of anemia. Megaloblastic hematopoiesis and aggregated macrophage iron frequently accompanied sideroblastic change. Examination of the blood smear revealed siderocytes in one-third of patients with sideroblastic marrows and dimorphic erythrocyte morphology in the majority. Dimorphic blood smears, however, were neither sensitive nor specific for sideroblastic change. Serum iron concentrations were usually not elevated in the group with sideroblastic abnormalities. In predicting marrow iron stores, serum iron and iron-binding capacity concentrations were often non-diagnostic or misleading. Serum ferritin levels less than 100 ng/ml, however, showed 100% sensitivity and 95% specificity for absent marrow iron stores despite the frequent presence of abnormal liver function. On the basis of our findings, practical guidelines have been formulated for the evaluation and therapy of anemia in alcohol

Adult↗