Maternal plasma homocysteine, placenta status and docosahexaenoic acid concentration in erythrocyte phospholipids of the newborn

A Novel Review of Homocysteine and Pregnancy Complications

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B₆ and B₁₂ deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Preconception folate status and reproductive outcomes among a prospective cohort of folate-replete women

BACKGROUND

Most studies of folate metabolism and reproduction have been conducted after pregnancy and in folate-deficient populations. However, measurement of maternal folate status preconceptionally may be most relevant to certain folate-linked early processes preceding a successful pregnancy, and there has been a major increase in folate concentrations in women of childbearing age in high resource settings.

OBJECTIVE

To examine associations between preconceptional biomarkers of maternal folate status (folate and homocysteine) and reproductive outcomes in folate-replete women.

STUDY DESIGN

Cohort nested within the Effects of Aspirin in Gestation and Reproduction trial, a block-randomized, double-blind, placebo-controlled trial whereby women were randomized to daily low-dose aspirin (81 mg/day) or placebo and all women received folic acid (400 μg/day). In total, 1228 women with 1-2 previous pregnancy losses and no documented infertility were recruited from 4 clinical sites in the United States (2006-2012) and were attempting pregnancy for up to 6 menstrual cycles. Log-binomial regression models were used to estimate relative risks and 95% confidence intervals between preconception serum folate and plasma homocysteine for anovulation, pregnancy, and pregnancy loss.

RESULTS

Greater plasma homocysteine was nonlinearly associated with greater risks of pregnancy loss only among women with 2 previous losses: a relative risk of 1.43 (95% confidence interval, 1.08-1.89) was found for plasma homocysteine concentrations at the study median of 8.0 μmol/L compared with a US population median of 6.0 μmol/L. No meaningful relationships were found between serum folate and any reproductive outcome or between plasma homocysteine and anovulation or becoming pregnant.

CONCLUSION

These data justify further study of the role of folate and homocysteine metabolism in normal and abnormal early pregnancy.

Effect of omega-3 polyunsaturated fatty acid supplementation on semen profile and enzymatic anti-oxidant capacity of seminal plasma in infertile men with idiopathic oligoasthenoteratospermia: a double-blind, placebo-controlled, randomised study

Effective medical treatments of infertile men with idiopathic oligoasthenoteratospermia (OAT) have yet to be determined. This study considered two major aims: (i) to measure the changes in semen parameters, omega-3 fatty acids (FA) compositions and anti-oxidant activity; (ii) to determine if the administration of omega-3 FA affect semen quality in infertile men with OAT. Two hundred thirty-eight infertile men with idiopathic OAT were randomised to eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), 1.84 g per day (EPAX 5500TG; Lysaker, Norway), or placebo for 32 weeks. The semen parameters were assessed according to WHO criteria, and the EPA and DHA concentrations were determined in red blood cells (RBCs), seminal plasma and sperm cells at baseline and 32-week treatment period. Of randomised subjects, 211 (88.7%) completed the full 32-week randomisation period. The anti-oxidant status of seminal plasma was also evaluated by measuring the superoxide dismutase (SOD) and catalase-like activity. In the total group of participants, all EPA and DHA levels in RBC, and seminal plasma, were statistically significantly correlated with those in spermatozoa (both P = 0.001). A significant improvement of sperm cell total count (from 38.7 ± 8.7 ' 10⁶ to 61.7 ± 11.2 ' 10⁶, P = 0.001) and sperm cell concentration (from 15.6 ± 4.1 ' 10⁶ per ml to 28.7 ± 4.4 ' 10⁶ per ml, P = 0.001) was observed in the omega-3 group. A significant positive correlation was found between the EPA and DHA in seminal plasma and the semen parameters. Seminal plasma EPA and DHA concentrations were positively correlated with seminal plasma SOD-like and catalase-like activity (both P = 0.001). In seminal plasma, both SOD-like and catalase-like activity were positively correlated with sperm count, sperm motility, and sperm morphology. Oligoasthenoteratospermic men with low levels of EPA and DHA may benefit from omega-3 FA supplementation. Further studies are warranted to shed more light on this important issue.

Long chain polyunsaturated fatty acids in mothers of preterm babies

AIMS

to examine the levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) in both plasma and erythrocytes of maternal and cord blood as well as in breast milk of mothers of preterm babies.

METHODS

a total of 63 mothers of preterm babies were recruited from the Bharati Medical Hospital, Pune, India.

RESULTS

plasma and erythrocyte DHA and AA levels were higher (P<0.001) in cord blood than in maternal blood. Maternal plasma DHA and AA were positively (P<0.01) associated with their respective maternal erythrocyte levels. There was a positive association (P<0.01) between maternal DHA (both plasma and erythrocyte) and cord DHA. Maternal plasma omega 3 and 6 fatty acids were positively (P<0.01) associated with their respective milk fatty acids.

CONCLUSIONS

higher DHA and AA levels in cord blood compared to the mothers suggests a special mechanism to meet the increased demand of the fetus. Higher levels of milk DHA reflect the increased postnatal requirement of preterm babies suggesting a vital role for maternal milk. Lower maternal erythrocyte DHA concentrations in mothers delivering preterm as compared to term suggest that increased oxidative stress may be responsible for reduced DHA levels. This may alter the uterotonic factors like prostaglandins leading to premature triggering of labor.

Influence of fish oil or folate supplementation on the time course of plasma redox markers during pregnancy

Maternal supplementation with long-chain PUFA, to improve infant neurological development, might cause additional increase of oxidative stress. Pregnant women aged 18-41 years were randomised into one of four supplementation groups. From week 22 on, they received supplements containing either modified fish oil (n 69), 5-methyl-tetrahydro-folate (n 65), both (n 64), or placebo (n 72). Plasma Trolox-equivalent antioxidative capacity (TEAC), concentrations of alpha-tocopherol, retinol, beta-carotene, free thiol groups, uric acid and thiobarbituric acid-reactive substances (TBARS) were determined at weeks 20 and 30 and at delivery. The studied antioxidants showed no significant differences between the four supplementation groups. At week 30 plasma TBARS levels were found to be significantly higher in the fish oil group (0.80 (sem 0.04) micromol/l) than in the folate (0.67 (sem 0.03) micromol/l; P = 0.024) and control (0.69 (sem 0.04) micromol/l; P = 0.01) groups. Concentrations of retinol and free thiol groups decreased during pregnancy, whereas uric acid increased and beta-carotene as well as TEAC showed only minor changes. Fish oil supplementation during the second half of pregnancy appears not to decrease antioxidant status. The increased TBARS levels at week 30 may indicate a period of increased oxidative stress in plasma at this time.

Evidence of inadequate docosahexaenoic acid status in Brazilian pregnant and lactating women

Recently published data concerning dietary intake of fat and food sources of (n-3) long-chain polyunsaturated fatty acids (LCPUFA) in Brazil are reviewed together with data on biochemical indices of PUFA status during pregnancy and lactation and PUFA composition of breast milk in Brazilian adolescents and adults. Potential inadequacies of docosahexaenoic acid (DHA) status among Brazilian pregnant and lactating women have not yet been thoroughly evaluated. The data reviewed show that dietary intake of food sources of n-3 LCPUFA is low and possibly deficient in Brazil, and that biochemical indices of maternal DHA status and breast milk DHA content are low compared to the international literature. These data indicate inadequate DHA status among Brazilian women during pregnancy and lactation, but this evidence needs confirmation through comprehensive and specific population-based studies.

Red blood cell omega-3 fatty acids and the risk of ventricular arrhythmias in patients with heart failure

BACKGROUND

Epidemiological studies support the protective effect of omega-3 fatty acids on sudden cardiac death. However, patients with structural heart disease and an implantable cardioverter defibrillator (ICD) showed no effect or even a proarrhythmic response to fish oil supplementation. Animal studies suggest different electrophysiologic effects of circulating and incorporated omega-3 fatty acids.

METHODS

In 102 ICD patients in New York Health Association functional class II or III, the fatty acid composition of red blood cells was analyzed by gas chromatography. The omega-3 index was calculated from eicosapentaenoic acid and docosahexaenoic acid. Patients were followed for 1 year, and ventricular arrhythmias requiring antitachycardic therapy were analyzed. Twenty-five healthy subjects served as control.

RESULTS

In ICD patients, the fatty acid profile was significantly altered and the baseline omega-3 index was significantly elevated, as compared to control subjects (5.12% +/- 0.87% vs 4.24% +/- 0.96%, P < .001). Kaplan-Meier estimates of probability of ventricular arrhythmias showed significant differences among quartiles of the omega-3 index. Twelve percent of patients in the lowest quartile had ventricular arrhythmias, as compared to 54% of patients in the highest quartile (P = .022). In a multivariate analysis, the omega-3 index was the only independent predictor for ventricular arrhythmias up to 9 months. At 12 months, a reduced ejection fraction was an additional risk predictor.

CONCLUSIONS

In heart failure patients, the red blood cell fatty acid profile is altered. Omega-3 fatty acids are elevated and predict the risk of ventricular arrhythmias.

Plasma homocysteine levels in cycling, pregnant, and spayed bitches

The aim of this study was to evaluate the physiological range of homocysteine (Hcy) exhibited by bitches during the follicular (pro-oestrus), luteal (dioestrus) and anoestrus phases of cycling animals, and in pregnant and spayed bitches. The lowest concentrations of Hcy were observed during dioestrus (3.2+/-1.27micromol/L) and in pregnant bitches (3.9+/-1.72micromol/L), and the highest concentrations during anoestrus (7.8+/-0.6micromol/L) and in spayed bitches (12.1+/-5.16micromol/L).

Effects of fish-oil and folate supplementation of pregnant women on maternal and fetal plasma concentrations of docosahexaenoic acid and eicosapentaenoic acid: a European randomized multicenter trial

BACKGROUND

Pregnant women usually meet their increased energy needs but do not always meet their increased micronutrient requirements. The supply of both folic acid and docosahexaenoic acid (DHA) has been related to positive pregnancy and infant outcomes.

OBJECTIVE

We aimed to assess whether fish-oil (FO) supplementation with or without folate from gestation week 22 to birth improves maternal and fetal n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) status.

DESIGN

We conducted a multicenter (Germany, Hungary, and Spain), randomized, double-blind, 2 x 2 factorial, placebo-controlled trial. From gestation week 22 until delivery, 311 pregnant women received daily a preparation with FO [0.5 g DHA and 0.15 g eicosapentaenoic acid (EPA)], 400 microg methyltetrahydrofolic acid (MTHF), FO with MTHF, or placebo. Outcome measures included maternal and cord plasma DHA and EPA contents at gestation weeks 20 and 30 and at delivery, indicators of pregnancy outcome, and fetal development.

RESULTS

FO significantly (P<0.001) increased maternal DHA and EPA (% by wt), as shown by 3-factor repeated-measures ANOVA (ie, MTHF, FO, and time) with adjustment for maternal baseline DHA and EPA. In addition, FO significantly (P<0.001) increased cord blood DHA (% by wt; 2-factor ANOVA). MTHF was significantly (P=0.046) associated with increased maternal DHA (% by wt). There was no FO x MTHF interaction for the time course of DHA or EPA (P=0.927 and 0.893). Pregnancy outcomes and fetal development did not differ significantly among the intervention groups.

CONCLUSIONS

FO supplementation from gestation week 22 until delivery improves fetal n-3 LC-PUFA status and attenuates depletion of maternal stores. MTHF may further enhance maternal n-3 LC-PUFA proportions.

Platelet phospholipid n-3 PUFA negatively associated with plasma homocysteine in middle-aged and geriatric hyperlipaemia patients

Studies showed that increased dietary intake of n-3 polyunsaturated fatty acids (PUFA) has a cardiovascular beneficial effect. Increased plasma phospholipid (PL) docosahexaenoic acid (22:6n-3) is associated with decreased plasma homocysteine (Hcy). The aim of this study was to investigate the relationship between platelet PL fatty acid and plasma Hcy in middle-aged and geriatric hyperlipaemia patients (50 males, 31 females) and 65 healthy subjects (43 males, 22 females) in Hangzhou, China. Plasma Hcy demonstrated significant positive correlation with adrenic acid (22:4n-6) (r = 0.188, P = 0.018) and negative correlation with 22:6n-3 (r = -0.277, P = 0.001) and the ratio of n-3/n-6 (r = -0.231, P = 0.003) in sex-, age- and BMI-controlled partial correlation analysis. The present results suggest that increased ratio of n-3/n-6 PUFA in platelet PL is associated with decreased thrombotic risks such as plasma Hcy in middle-aged and geriatric hyperlipaemia patients in Hangzhou.

Effects of maternal hyperhomocysteinemia induced by high methionine diet on the learning and memory performance in offspring

In this study, we suggest that chronic maternal hyperhomocysteinemia results in learning deficits in the offspring due to delayed brain maturation and altered expression pattern of neural cell adhesion molecule. Although the deleterious effects of hyperhomocysteinemia were extensively investigated in the adults, there is no clear evidence suggesting its action on the developing fetal rat brain and cognitive functions of the offspring. Therefore, in the present work we aimed to investigate effects of maternal hyperhomocysteinemia on the fetal brain development and on the behavior of the offspring. A group of pregnant rats received daily methionine (1 g/kg body weight) dissolved in drinking water to induce maternal hyperhomocysteinemia, starting in the beginning of gestational day 0. The levels of glial fibrillary acidic protein, S100B protein, and neural cell adhesion molecule were determined in the tissue samples from the pups. Learning and memory performances of the young-adult offsprings were tested using Morris water maze test. There were significant reductions in the expressions of glial fibrillary acidic protein and S100B protein in the brains of maternally hyperhomocysteinemic pups on postnatal day 1, suggesting that hyperhomocysteinemia delays brain maturation. In conclusion, maternal hyperhomocysteinemia changes the expression pattern of neural cell adhesion molecule and therefore leads to an impairment in the learning performance of the offspring.

A significant inverse relationship between concentrations of plasma homocysteine and phospholipid docosahexaenoic acid in healthy male subjects

The aim of this study was to investigate the possibility of a relationship between plasma homocysteine (Hcy) and phospholipid FA (PUFA) in healthy Australian males. One hundred thirty six healthy male subjects aged 20-55 yr were recruited from the Melbourne metropolitan area. Each volunteer completed a semiquantitative food frequency questionnaire and gave a blood sample. Plasma Hcy concentrations were determined by an established HPLC method; the plasma phospholipid FA were determined by standard methods. Plasma Hcy concentration was significantly negatively correlated with plasma phospholipid concentration of the PUFA 20:5n-3 (r = -0.226, P = 0.009), 22:5n-3 (r= -0.182, P= 0.036), 22:6n-3 (r= -0.286, P= 0.001), total n-3 (r = -0.270, P = 0.002) and the ratio n-3/n-6 PUFA (r = -0.265, P = 0.002), and significantly positively correlated with 20:4n-6 (r= 0.180, P= 0.037). In the partial correlation analysis, after controlling for serum vitamin B12 and folate concentration, plasma Hcy was significantly negatively correlated with the plasma phospholipid concentration of 22:6n-3 (r = -0.205, P = 0.019), total n-3 (r = -0.182, P= 0.038) and the ratio n-3/n-6 PUFA (r= -0.174, P= 0.048). Evidence indicates that an increased concentration of n-3 PUFA in tissues has a beneficial effect on cardiovascular health. Our findings provide further evidence that increased consumption of dietary n-3 PUFA increases the concentration of n-3 PUFA in plasma phospholipid, which is associated with a protective effect on cardiovascular diseases and lower plasma Hcy levels. The mechanism that might explain the association between plasma 22:6n-3 and Hcy levels is not clear.

n-6 and n-3 Long-chain polyunsaturated fatty acids in the erythrocyte membrane of Brazilian preterm and term neonates and their mothers at delivery

Placental transfer of the long-chain polyunsaturated fatty acids (LCPUFA) arachidonic (AA) and docosahexaenoic (DHA) acids is selectively high to maintain accretion to fetal tissues, especially the brain. The objectives of the present study were to investigate the essential fatty acid (EFA) and LCPUFA status at birth of preterm and term Brazilian infants and their mothers, from a population of characteristically low intake of n-3 LCPUFA, and to evaluate the association between fetal and maternal status, by the determination of the fatty acid composition of the erythrocyte membrane. Blood samples from umbilical cord of preterm (26-36 weeks of gestation; n = 30) and term (37-42 weeks of gestation; n = 30) infants and the corresponding maternal venous blood were collected at delivery. The LCPUFA composition of the erythrocyte membrane and DHA status were similar for mothers of preterm and term infants. Neonatal AA was higher (P < 0.01) whereas its precursor 18:2n-6 was lower (P < 0.01) than maternal levels, as expected. There was no difference in LCPUFA erythrocyte composition between preterm and term infants, except for DHA. Term infants presented a worse DHA status than preterm infants (P < 0.01) and than their mothers (P < 0.01) at delivery. There was a negative correlation of neonatal DHA with maternal AA and a positive correlation between neonatal AA and maternal AA and 18:2n-6 only at term. These results suggest that the persistent low DHA maternal status, together with the comparatively better AA and 18:2n-6 status, might have affected maternal-fetal transfer of DHA when gestation was completed up to term, and possibly contributed to the worse DHA status of term neonates compared with the preterm neonates.

Arachidonic acid predominates in the membrane phosphoglycerides of the early and term human placenta

The aim of this study was to determine whether the high concentration of arachidonic acid (AA) in term placentae accumulates during pregnancy or is an inherent characteristic of placental lipids. We investigated the lipid content and fatty acid composition of the human placental phospholipids at 2 gestational periods, early in pregnancy (8-14 wk, n = 48) and at term (38-41 wk of gestation, n = 19). The subjects were healthy, normotensive, and free of medical and obstetric complications. The lipid concentration of placentae increased from 0.8% in early gestation to 1.4% at term (P < 0.0001). The mean proportions of AA were lower in the choline (P < 0.05), inositol (P < 0.0001), and ethanolamine (P < 0.0001) phosphoglycerides of the term compared with the early placenta. In contrast, the proportions of the immediate precursor of AA, dihomo-gamma-linolenic acid (DGLA), were higher in the term placenta, particularly in the inositol and serine phosphoglycerides (P < 0.0001). In sphingomyelin, the percentage of lignoceric acid was increased and that of nervonic acid was reduced at term (P < 0.01). The dominance of AA, particularly in the early placenta, suggests that it has an important role for placental development, i.e., organogenesis and vascularization. There was no evidence of an accumulation of AA in the placenta toward term, which might be a trigger for parturition. In contrast, the increased proportion of DGLA (precursor of the vasorelaxant and anticoagulant prostaglandin E(1)) at term is more consistent with a profile favoring optimal blood flow to nourish the fetal growth spurt.

Higher homocysteine concentrations in women undergoing caesarean section under general anesthesia

To determine whether homocysteine, a risk factor for possible endothelial cell dysfunction, procoagulant effects and premature vascular disease but with a potential nutritional role for fetal and neonatal metabolism and development, is elevated in women at time of elective caesarean section with nitrous oxide general anesthesia. Plasma homocysteine levels were measured in 50 consecutive women, 25 of whom undergoing vaginal delivery and 25 elective caesarean section under nitrous oxide general anesthesia, and in the cord plasma of the respective offspring. Mean (+/-standard deviation) plasma homocysteine levels in the women of the caesarean section group were significantly higher than in the women of the vaginal delivery group (9.77+/-2.3 vs. 6.60+/-2.6 micromol/l, respectively; p<0.02). Cord plasma homocysteine levels in the neonates of the caesarean section group were also significantly higher than in the group of neonates vaginally delivered (9.47+/-3.94 and 7.36+/-2.35 micromol/l; p<0.01). Maternal homocysteine levels significantly correlated with cord levels of caesarean and vaginally delivered neonates (r=0.57; p<0.01 and r=0.66; p<0.001, respectively). Homocysteine levels were elevated at time of delivery in women undergoing elective caesarean section in nitrous oxide general anesthesia, and cord levels of corresponding neonates were affected by mode of delivery. Future studies are necessary to identify factors involved in the hyperhomocysteinemia observed in pregnant women at time of delivery by elective caesarean section in general anesthesia.

Fatty acids and homocysteine levels in patients with recurrent depression: an explorative pilot study

Major depressive disorders (MDD) and cardiovascular disease are mutually associated. They share signs and symptoms of the "metabolic syndrome". Two observations that may be causally related with the metabolic syndrome and therefore with both MDD and cardiovascular disease are a decrease in omega-3 polyunsaturated fatty acids (PUFAs) and a rise in plasma homocysteine (tHcy) levels. Both the rise in tHcy and the decrease in omega-3 PUFAs may be associated with enhanced lipid peroxidation. We exploratively studied 44 randomly chosen patients out of a cohort of 134 patients with the recurrent form of MDD (MDD-R). We measured tHcy levels together with saturated FAs, monounsaturated fatty acids (MUFAs) and PUFAs of the omega-3, omega-6 and omega-9 series in plasma and erythrocytes. Levels were compared with laboratory reference values. The main findings were a decrease in the erythrocytes of C22:5omega-3, C22:6omega-3, C24:1omega-9 and C20:3omega-9 and in the plasma a decrease in C24:1omega-9 and C20:3omega-9. The only significant association we found was between the total of omega-6 fatty acids and plasma tHcy. The FA alterations were found in patients although most of them were clinically recovered, suggesting that the alterations may represent a biological" trait" marker for recurrent depression.

The balance of dietary sulfur amino acids and the route of feeding affect plasma homocysteine concentrations in neonatal piglets

Plasma total homocysteine (tHcy) concentrations are associated with atherogenesis in adults and increased risk of stroke in infants and children. After a series of experiments to compare the methionine (Met) requirement and cysteine (Cys)-sparing capacity in piglets that were parenterally or enterally fed, we examined the effects of route of feeding and dietary Cys on plasma tHcy concentrations. Piglets (n = 60; 6-8 d old) were fed elemental diets, intragastrically (n = 28) or intravenously (n = 32), with 0.55 g. kg(-1). d(-1) dietary Cys (n = 28) or without dietary Cys (n = 32). Dietary Met ranged from deficient to excess. Increasing Met intake increased (P < 0.01) plasma tHcy in all treatment groups. Plasma tHcy concentrations were higher (P < 0.05) in the enterally fed piglets that did not receive dietary Cys than in all other groups, which did not differ from each other. Therefore, both route of feeding and dietary supply of Met and Cys significantly affected the concentrations of plasma tHcy. These dramatic and rapid alterations in plasma tHcy warrant further studies of sulfur amino acid metabolism in neonatal animals.

Homocysteine and methylmalonic acid in diagnosis and risk assessment from infancy to adolescence

The concentration of total homocysteine (tHcy) in serum and plasma is elevated in both folate and cobalamin deficiencies, whereas methylmalonic acid (MMA) in serum, plasma, or urine is a specific marker of cobalamin function. The combined measurement of both metabolites is useful for the diagnosis and follow-up of these deficiency states. In addition, tHcy is elevated under various pathologic states (eg, renal failure), and hyperhomocysteinemia is associated with an increased risk of cardiovascular disease, cognitive dysfunction, and adverse pregnancy outcomes. The diagnostic utility of tHcy and MMA concentrations as markers of folate and cobalamin deficiencies in healthy and diseased children has been documented. This article briefly summarizes the biochemical background of tHcy and MMA and the associations of tHcy and MMA with various disease states and focuses on novel data obtained in infants, children, and adolescents, with emphasis on cobalamin status in infants. The utility of tHcy and MMA as indicators of cobalamin and folate deficiencies in adults can be extended to infants and older children. Furthermore, as in adults, tHcy is related to unhealthy lifestyle factors and is a risk factor for vascular disease. High MMA concentrations in newborns, occasionally denoted as benign methylmalonic aciduria, may reflect impaired cobalamin function.

Hyperhomocysteinemia as risk factor for ischemic and hemorrhagic stroke in newborn infants

We studied the association between plasma total homocysteine concentrations and the occurrence of stroke in newborn infants (n = 24). Newborn infants with stroke had significantly higher mean total homocysteine concentrations compared with 94 healthy newborn infants (9.3 vs 7.4 micromol/L). The odds ratio for neonatal stroke was 3.95 (95" CI 1.53-10.16) at the 80" cutoff level.

Folic acid: nutritional biochemistry, molecular biology, and role in disease processes

This paper reviews the chemistry, metabolism, and molecular biology of folic acid, with a particular emphasis on how it is, or may be, involved in many disease processes. Folic acid prevents neural tube defects like spina bifida, while its ability to lower homocysteine suggests it might have a positive influence on cardiovascular disease. A role for this B vitamin in maintaining good health may, in fact, extend beyond these clinical conditions to encompass other birth defects, several types of cancer, dementia, affective disorders, Down's syndrome, and serious conditions affecting pregnancy outcome. The effect of folate in these conditions can be explained largely within the context of folate-dependent pathways leading to methionine and nucleotide biosynthesis, and genetic variability resulting from a number of common polymorphisms of folate-dependent enzymes involved in the homocysteine remethylation cycle. Allelic variants of folate genes that have a high frequency in the population, and that may play a role in disease formation include 677C --> T-MTHFR, 1298A --> C-MTHFR, 2756A --> G-MetSyn, and 66A --> G-MSR. Future work will probably uncover further polymorphisms of folate metabolism, and lead to a wider understanding of the interaction between this essential nutrient and the many genes which underpin its enzymatic utilization in a plethora of critical biosynthetic reactions, and which, under adverse nutritional conditions, may promote disease.