The effects of adrenocorticotrophic hormone and cortisol on homocysteine and vitamin B concentrations

Polymorphisms in vitamin B12 and folate metabolising genes and their association with adverse pregnancy outcome: secondary analysis of a population based case control study

Vitamin B12 and folate deficiency leads to accumulation of homocysteine that increases the risk of adverse pregnancy outcomes like preterm birth and low birth weight (LBW) of the neonate. We explored the association of genetic variants of key vitamin B12 and folate metabolising enzymes (MTHFR C677T and A1298C, MTR A2756G, TCN-2 C776G) with preterm birth and LBW in South Indian women. MTHFR A1298C heterozygotes (AC) were at higher risk for preterm delivery, whereas TCN-2 C776G heterozygotes (CG) were at higher risk for both preterm delivery and LBW. MTHFR C677T, A1298C and MTR A2756G haplotype CAG was protective for preterm delivery (p=.036, OR = 0.475; 95% CI: 0.233-0.97), whereas, haplotype CCG increasing the risk of preterm birth by 1.8 folds (p=.018, OR = 1.81; 95% CI: 1.09-2.98). These results underscore the significance of vitamin B12 and folate in the pathophysiology of preterm birth and LBW.Impact StatementWhat is already known on this subject? Polymorphisms of vitamin B12 and folate metabolising genes have been reported to influence preterm birth and LBW, but the reports are not consistent.What do the results of this study add? We observed a relationship of MTHFR A1298C and TCN-2 C776G with preterm birth, and significant association of TCN-2 C776G with LBW in infants.What are the implications of these findings for clinical practice and/or further research? Identification of women carrying these polymorphic risk alleles may benefit from early nutritional modifications.

Cortisol is not associated with telomere shortening or chromosomal instability in human lymphocytes cultured under low and high folate conditions

Chronic psychological stress and nutritional deficiencies are factors that impact negatively on human health and disease risk. Chronic stress has been associated with accelerated leukocyte telomere shortening in numerous cohorts, however, a mechanistic link has proven elusive. This study tested the hypotheses that chronic exposure to the stress hormone, cortisol, causes telomere shortening and chromosome instability (CIN) in vitro, and that these effects would be further exacerbated by folate (vitamin B9) deficiency. Primary human lymphocytes were maintained in vitro for 12 days in medium containing either 25 nM folic acid (FA(low)) or 100 nM FA (FA(high)), together with either 0, 400, 1000 or 3500 nM cortisol. The interactive effects of cortisol and FA were examined by comparing telomere length (TL), biomarkers of DNA damage, and cytostasis. At day 12 TL was 5-17% longer in lymphocytes cultured in FA(low) conditions (mean ± SD;10.2% ± 1.6), compared with those in FA(high) medium (9.1% ± 1, p = 0.02). Refuting the hypothesis, TL was consistently greater in the presence of cortisol. The effect of FA deficiency on the frequency of DNA damage was significant for nucleoplasmic bridges, circular nuclei, micronuclei and nuclear buds, (p < 0.0001-0.001). The effect of cortisol, however, was negligible, only reaching statistical significance for the frequency of fused nuclei (p = 0.04). Cortisol was significantly associated with reduced cell division and growth and had an apparent protective effect on cell viability in the FA(low) conditions. Conclusions: Both chronic cortisol exposure, and folate deficiency, resulted in telomere elongation, however, the effect of cortisol was marginal relative to that of folate. Cortisol was not associated with increased chromosomal instability, but caused a significant reduction in cell division and growth. Together these results indicate that cortisol is not directly genotoxic and that the telomere shortening associated with increased psychological stress in vivo may not be explained by a direct effect of cortisol.

Behavioral and neurochemical effects of dietary methyl donor deficiency combined with unpredictable chronic mild stress in rats

Methyl donor deficiencies and chronic stress cause depression independently, but their interaction has never been thoroughly evaluated. In our study, methyl donor deficient diet and chronic stress condition consisted respectively of a B2, B9, B12, and choline-free diet and a chronic mild stress procedure. Rats were randomly assigned to six groups with three "diet" conditions (free-feeding, pair-fed and methyl donor deficient diet) and two "stress" conditions (no-stress and stress) and were evaluated in the open-field, the elevated plus-maze and the forced swimming test. After the behavioral evaluation, corticosterone and homocysteine plasma levels were measured and dopamine, DOPAC, serotonin, 5HIAA concentrations were evaluated in several brain areas. Rats given a methyl donor deficient diet for 11 weeks causing elevated plasma homocysteine levels were compared to pair-fed and free-feeding rats with or without unpredictable chronic mild stress. Regardless of stress environmental conditions, the methyl donor deficient diet decreased plasma corticosterone levels and caused disinhibition in the elevated plus-maze condition relative to both control groups. However, stress potentiated the effects of the deficient regimen on rearing in the open-field and climbing in the forced swim test. The dietary changes involved in behavior and plasma corticosterone could be caused by homocysteine-induced decreases in dopamine and 5-hydroxytryptamine metabolites in selective brain regions and it can be noted that regardless of stress-conditions, methyl donor deficient diet decreases DOPAC/dopamine and 5HIAA/serotonin ratios in striatum and hypothalamus and selectively 5HIAA/serotonin ratio in the sensorimotor cortex. Our experimental data is particularly relevant in the context of neuropsychiatric disorders frequently associated with folate deficiency and hyperhomocysteinemia.

The effects of multivitamin supplementation on diurnal cortisol secretion and perceived stress

Recent evidence suggests that dietary intake of vitamins, in particular the B-vitamins including B6, B9 and B12 may have a number of positive effects on mood and stress. Given the effects of stress on a range of biological mechanisms including the endocrine system, it could be reasonably expected that multivitamin supplementation may also affect markers of these mechanisms such as diurnal cortisol secretion. In the current double-blind placebo-controlled study 138 adults (aged 20 to 50 years) were administered a multivitamin containing B-vitamins versus placebo over a 16-week period. Salivary cortisol measurements were taken at waking, 15-min, 30-min and at bedtime, at baseline, 8-weeks and 16-weeks. Perceived Stress (PSS) was measured at baseline, 8-weeks and 16-weeks, while blood serum measures of B6, B12 and homocysteine (HCy) as well as red cell folate (B9) were also collected at these time points. A significant interaction was found between treatment group and study visit for the Cortisol Awakening Response (CAR). Compared to placebo, at 16-weeks multivitamin supplementation was found to be associated with a near-significant trend towards an increased CAR. No significant differences in PSS were found between groups, with PSS increasing in both groups across the course of the study. Red cell folate was found to be significantly correlated with the CAR response at 16-weeks while HCy levels were not found to be associated with the CAR response, although HCy significantly correlated with waking cortisol levels at 8-weeks. A possible interpretation of the elevation in CAR associated with multivitamin supplementation is that this represents an adaptive response to everyday demands in healthy participants.

Homocysteine and alpha-1 antitrypsin concentration in patients with subclinical hypercortisolemia

PURPOSE

Glucocorticoids have particularly strong impact on the thromboembolic complications. A factor which increases the risk of thrombosis is hyperhomocysteinemia, observed in patients with hypercortisolemia. Proinflammatory factors also affect the haemostatic balance. There has been an extensive research which estimates hemostatic system in patients with Cushing's syndrome. Undoubtedly, much fewer publications are available on thromboembolic complications in patients with Subclinical Cushing's Syndrome (SCS). The purpose of this study was to estimate of homocysteine (HCY) and alpha-1 antitrypsin (α1ATp) concentrations in patients with SCS.

MATERIALS AND METHODS

We studied 35 patients (56.0 ± 15.0 years) with SCS and 33 healthy volunteers (53.3 ± 17.7 years). In all subjects the analysis of HCY and α1ATp concentration in serum was determined with an immunonephelometric method. P-values below 0.05 were considered statistically significant.

RESULTS

A comparison of HCY and α1ATp mean concentrations in patients with SCS and healthy representatives indicated statistically higher values of both analysed parameters in the sera of patients than in the healthy controls (p values were 0.018 and 0.008, respectively). In the patients with SCS a negative correlation between α1ATp and cortisol concentration in overnight dexamethasone test was found (p=0.017, R=-0.40). We did not reveal any statistically significant correlation between the concentrations of HCY and α1ATp, and coagulation parameters such as INR, APTT, fibrinogen concentration in patients with SCS.

CONCLUSIONS

On the basis of the obtained results, a slight increase in the concentration of homocysteine and α1ATp is observed in patients with SCS, which may influence vascular complications.

Acute benzodiazepine administration induces changes in homocysteine metabolism in young healthy volunteers

PURPOSE

High cortisol plasma concentrations have been shown to be associated with increases in homocysteine levels. Here we studied whether decreases in cortisol concentration, induced by an acute oral dose of a benzodiazepine, could decrease homocysteine, and if changes were similar in both genders.

METHODS

This was a double-blind, cross-over design study of acute oral flunitrazepam (1.2 mg) and placebo in young, healthy, male and female (n=21) volunteers. Blood samples were collected 3 h after ingestion (after peak-plasma concentration of flunitrazepam was reached). Various biochemical parameters were analysed, such as plasma homocysteine, cysteine, folate, vitamins B6, B12, and sexual hormones.

RESULTS

Flunitrazepam reduced cortisol (p=0.0011), cysteine (p=0.014) and homocysteine (p=0.028) concentrations, irrespective of gender. No correlations were found between cortisol and other biochemical markers (all r's<0.03). Concentration of cysteine and homocysteine were negatively correlated with plasma flunitrazepam concentration, suggesting that changes in these amino acids might be related to the metabolism of this benzodiazepine.

CONCLUSION

Acute administration of flunitrazepam decreases plasma homocysteine and cysteine by mechanisms that seem unrelated to changes in cortisol. Given the importance of homocysteine as a marker of life-threatening disorders, the mechanisms involved in the decrease of these amino acids are potential targets for clinical application.