Folate, vitamin B₁₂ and total homocysteine levels in Arab adolescent subjects: reference ranges and potential determinants

Plasma homocysteine levels and associated factors in community-dwelling adolescents: the EVA-TYROL study

Background

Homocysteine (Hcy) has been associated with an adverse cardiovascular risk profile in adolescents. Assessment of the association between plasma Hcy levels and clinical/laboratory factors might improve our understanding of the pathogenesis of cardiovascular disease.

Methods

Hcy was measured in 1,900 14- to 19-year-old participants of prospective population-based EVA-TYROL Study (44.3% males, mean age 16.4 years) between 2015 and 2018. Factors associated with Hcy were assessed by physical examination, standardized interviews, and fasting blood analysis.

Results

Mean plasma Hcy was 11.3 ± 4.5 µmol/L. Distribution of Hcy was characterized by extreme right skew. Males exhibited higher Hcy and sex differences increased with increasing age. Univariate associations with Hcy emerged for age, sex, body mass index, high-density lipoprotein cholesterol, and for factors pertaining to blood pressure, glucose metabolism, renal function, and diet quality, whereas the most important multivariate predictors of Hcy were sex and creatinine.

Discussion

Clinical and laboratory factors associated with Hcy in adolescents were manifold, with sex and high creatinine identified as strongest independent determinants. These results may aid when interpreting future studies investigating the vascular risk of homocysteine.

Daily Folic Acid and/or Vitamin B12 Supplementation Between 6 and 30 Months of Age and Cardiometabolic Risk Markers After 6-7 Years: A Follow-Up of a Randomized Controlled Trial

BACKGROUND

Deficiencies of vitamin B12 and folate are associated with elevated concentrations of metabolic markers related to CVDs.

OBJECTIVES

We investigated the effect of supplementation of vitamin B12 with or without folic acid for 6 mo in early childhood on cardiometabolic risk markers after 6-7 y.

METHODS

This is a follow-up study of a 2 × 2 factorial, double-blind, randomized controlled trial of vitamin B12 and/or folic acid supplementation in 6-30-mo-old children. The supplement contained 1.8 μg of vitamin B12, 150 μg of folic acid, or both, constituting >1 AI or recommended daily allowances for a period of 6 mo. Enrolled children were contacted again after 6 y (September 2016-November 2017), and plasma concentrations of tHcy, leptin, high molecular weight adiponectin, and total adiponectin were measured (N = 791).

RESULTS

At baseline, 32% of children had a deficiency of either vitamin B12 (<200 pmol/L) or folate (<7.5 nmol/L). Combined supplementation of vitamin B12 and folic acid resulted in 1.19 μmol/L (95% CI: 0.09; 2.30 μmol/L) lower tHcy concentration 6 y later compared to placebo. We also found that vitamin B12 supplementation was associated with a lower leptin-adiponectin ratio in subgroups based on their nutritional status.

CONCLUSIONS

Supplementation with vitamin B12 and folic acid in early childhood was associated with a decrease in plasma tHcy concentrations after 6 y. The results of our study provide some evidence of persistent beneficial metabolic effects of vitamin B12 and folic acid supplementation in impoverished populations. The original trial was registered at www.

CLINICALTRIALS

gov as NCT00717730, and the follow-up study at www.ctri.nic.in as CTRI/2016/11/007494.

The role of the deficiency of vitamin B12 and folic acid on homocysteinemia in children with Turner syndrome

OBJECTIVES

Premature atherosclerosis and ischemic heart disease represent a major cause of comorbidities among children with Turner syndrome. The identification of non-traditional risk aspects is crucial for the early identification and management of such comorbidities through establishing effective preventive measures. The aim of the study is to explore the role of the deficiency of vitamin B12, folic acid and homocysteine in children with Turner syndrome.

METHODS

The study included 78 children with Turner syndrome and 67 healthy age and sex matched children. Karyotype was implemented for all patients. The serum levels of vitamin B12, folic acid and serum homocysteine were assessed. The prevalence of the deficiency of vitamin B12 and folic acid was estimated to study its correlation to hyperhomocysteinemia in Turner syndrome children.

RESULTS

The karyotype analysis showed 45,X (monosomy X) in the 78 patients. Vitamin B12 and folic acid were significantly decreased in children with Turner syndrome in 65-73% of the patients, respectively, while the serum level of homocysteine significantly increased to 48.7% compared to healthy controls. Homocysteine level negatively correlated with vitamin B12 and folic acid. The deficiency of vitamin B12 and folic acid increased the risk of hyperhomocysteinemia in children with Turner syndrome (OR 2.49 and 2.36, respectively).

CONCLUSIONS

This report highlights that hyperhomocyste-inemia in children with Turner syndrome may be related to the deficiency vitamin B12 and folic acid.

Homocysteine levels and cardiovascular risk factors in children and adolescents: systematic review and meta-analysis

CONTEXT

Studies have indicated that homocysteine levels are nontraditional markers for cardiovascular disease. The onset of atherosclerotic disease begins in childhood and adolescence; thus, prevention of its risk factors should occur early.

OBJECTIVE

This systematic review and meta-analysis was conducted to summarize the association between high homocysteine levels and traditional cardiovascular risk factors in children and adolescents.

DATA SOURCES

This systematic review and meta-analysis were developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the protocol was submitted to PROSPERO. Only observational studies in children and adolescents with homocysteine levels as an exposure variable and cardiovascular risk factors as outcome variables were included and searched in the following electronic bibliographic databases: PubMed/MEDLINE, Web of Science, Embase, Latin American and Caribbean Literature in Health Sciences, Ovid and Scopus.

DATA EXTRACTION

Two authors independently extracted data from eligible studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale.

DATA ANALYSIS

Seven studies were included in the systematic review; they were published from 1999 to 2017, predominantly were of a cross-sectional design, and mainly evaluated adolescents. In the meta-analysis (n = 6), cross-sectional studies (n = 3) identified that high homocysteine levels were positive and weakly correlated with overweight in children and adolescents (odds ratio, 1.08; 95%CI, 1.04-1.11).

CONCLUSION

High homocysteine levels were weakly associated with overweight in children and adolescents in the reviewed cross-sectional studies. However, for the other traditional cardiovascular risk factors, the findings, although important, were inconclusive. Additional robust longitudinal studies are recommended to be conducted to better identify these associations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018086252.

Association of Elevated Plasma Homocysteine Level with Restenosis and Clinical Outcomes After Percutaneous Coronary Interventions: a Systemic Review and Meta-analysis

PURPOSE

We conducted this systemic review and meta-analysis to investigate the association between elevated plasma homocysteine (Hcy) levels and recurrent restenosis and clinical outcomes after percutaneous coronary intervention (PCI).

METHODS

PubMed, EMBASE, and Web of Science were systematically searched prior to May 2018. Studies evaluating the association between plasma Hcy levels and the occurrence of restenosis, major adverse cardiac events (MACE), all-cause mortality, cardiac death, non-fatal myocardial infarction (MI), and target lesion revascularization were identified.

RESULTS

A total of 19 articles with 4340 participants were identified. Higher Hcy levels were not associated with an increased risk of restenosis (relative risk (RR) = 1.10, 95% CI 0.90-1.33). Hcy levels in the restenosis group were not significantly higher than in the non-restenosis group (weighted mean difference = 0.70, 95% CI - 0.23-1.63). Subgroup analysis revealed that higher Hcy levels were not associated with restenosis after stenting but appeared to increase the risk of restenosis after angioplasty. Elevated Hcy levels increased the risk of all-cause mortality by an average of 3.19-fold (RR = 3.19, 95% CI 1.90-5.34, P = 0.000), the risk of MACE by 1.51-fold (RR = 1.51, 95% CI 1.23-1.85, P = 0.000), and the risk of cardiac death by 2.76-fold (RR = 2.76, 95% CI 1.44-5.32, P = 0.000) but appeared not to increase the risk of non-fatal MI (RR = 1.36, 95% CI 0.89-2.09).

CONCLUSIONS

Our meta-analysis suggests that although there is no clear association between higher Hcy levels and restenosis following stent implantation, higher Hcy levels appeared to increase the risk of restenosis after coronary angioplasty and also increased the risk of all-cause mortality, MACE, and cardiac death after PCI.

REGISTRATION DETAILS

The protocol of this meta-analysis was registered on PROSPERO (CRD42018096466). ( http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018096466 ).

Joint Effects of Plasma Homocysteine Concentration and Traditional Cardiovascular Risk Factors on the Risk of New-Onset Peripheral Arterial Disease

PURPOSE

Hyperhomocysteinemia is an independent risk factor for cardio- and cerebrovascular diseases. However, the relationship between plasma homocysteine (Hcy) concentration and peripheral arterial disease (PAD) has not been completely characterized. The aim of the present study was to determine the relationship between plasma Hcy concentration and new-onset PAD and to assess the effects of combinations of Hcy and traditional cardiovascular risk factors.

PATIENTS AND METHODS

We conducted a prospective community-based cohort study of 3119 Chinese participants who did not have PAD at baseline, with a median follow-up period of 2.30 years. We used multivariate logistic regression models to evaluate the relationship between high Hcy (≥10µmol/L) and new-onset PAD. The effects of combinations of high Hcy and traditional cardiovascular risk factors were assessed using logistic regression analysis.

RESULTS

After adjustment for 14 covariates, high Hcy concentration was significantly associated with new-onset PAD (odds ratio [OR]=2.08, 95% confidence interval [CI]: 1.08-4.03, P=0.030). Smokers with high Hcy concentration were substantially more likely to have new-onset PAD than non-smokers with normal Hcy concentration (OR=4.44, 95% CI: 1.77-11.12, P=0.001). The effect of diabetes on PAD became significant when present in combination with high Hcy concentration (OR=3.67, 95% CI: 1.25-10.80, P=0.018). Participants with both elevated Hcy levels and older age had the highest risk of new-onset PAD (OR=4.28, 95% CI: 1.83-10.01, P<0.001). With regard to the joint effect of Hcy and hypertension, dyslipidemia or sex, there was also a trend towards increased risk across four different groups (P for trend=0.026, 0.035, 0.016, respectively).

CONCLUSION

High plasma Hcy concentration independently predicts the incidence of PAD. Furthermore, there is a joint effect of high Hcy concentration and traditional cardiovascular risk factors such as smoking, diabetes and aging on the incidence of PAD.

Homocysteine is a bystander for ST-segment elevation myocardial infarction: a case-control study

Background

Homocysteine has been long considered a risk factor for atherosclerosis. However, cardiovascular events cannot be reduced through homocysteine lowering by B vitamin supplements. Although several association studies have reported an elevation of serum homocysteine levels in cardiovascular diseases, the relationship of homocysteine with ST-segment elevation myocardial infarction (STEMI) is not well established.

Methods

We prospectively enrolled STEMI patients who were consecutively admitted to an intensive care unit following coronary intervention in a single medical center in Taiwan. Control subjects were individuals who presented to the outpatient or emergency department with acute chest pain but subsequently revealed patent coronary arteries by coronary arteriography. The association between serum homocysteine levels and STEMI was investigated. A culture system using human coronary artery endothelial cells was also established to examine the toxic effects of homocysteine at the cellular level.

Results

Patients with chest pain were divided into two groups. The STEMI group included 56 patients who underwent a primary percutaneous coronary intervention. The control group included 17 subjects with patent coronary arteries. There was no difference in serum homocysteine levels (8.4 ± 2.2 vs. 7.6 ± 1.9 μmol/L, p = 0.142). When stratifying STEMI patients by the Killip classification into higher (Killip III-IV) and lower (Killip I-II) grades, CRP (3.3 ± 4.1 vs. 1.4 ± 2.3 mg/L, p = 0.032), peak creatine kinase (3796 ± 2163 vs. 2305 ± 1822 IU/L, p = 0.023), and SYNTAX scores (20.4 ± 11.1 vs. 14.8 ± 7.6, p = 0.033) were significantly higher in the higher grades, while serum homocysteine levels were similar. Homocysteine was not correlated with WBCs, CRP, or the SYNTAX score in STEMI patients. In a culture system, homocysteine at even a supraphysiological level of 100 μmol/L did not reduce the cell viability of human coronary artery endothelial cells.

Conclusions

Homocysteine was not elevated in STEMI patients regardless of Killip severity, suggesting that homocysteine is a bystander instead of a causative factor of STEMI. Our study therefore supports the current notion that homocysteine-lowering strategies are not essential in preventing cardiovascular disease.

Dietary Intakes of Folic Acid and Methionine in Early Childhood Are Associated with Body Composition at School Age

BACKGROUND

Deficiency of vitamin B-6, vitamin B-12, folate, folic acid, or methionine may lead to dysregulation of DNA methylation, which might lead to disturbed energy and lipid metabolism.

OBJECTIVE

We aimed to explore whether intakes of vitamin B-6, vitamin B-12, folate, folic acid, and methionine at 1 y are associated with measures of growth and body composition at the age of 6 y.

METHODS

This study was performed in 2922 children participating in The Generation R Study, a population-based prospective cohort study. Dietary intakes of vitamins B-6 and B-12, folate, folic acid, and methionine were assessed at a median age of 12.9 mo by using a validated food-frequency questionnaire. At the age of 6 y, height and weight were measured, and body mass index (BMI; in kg/m(2)) was calculated. Body fat was measured with dual-energy X-ray absorptiometry, and body fat percentage and the ratio of android fat mass to gynoid fat mass (android:gynoid) were calculated.

RESULTS

In models adjusted for maternal and child characteristics, children with folic acid intakes in the highest tertile had a 0.16 SD score (SDS) lower weight (95% CI: -0.31, -0.02 SDS) and a 0.14 SDS lower BMI (95% CI: -0.26, -0.01 SDS) than children in the lowest tertile. Children with vitamin B-12 intakes in the highest tertile had a 0.13 SDS higher android:gynoid (95% CI: 0.00, 0.25 SDS) than children in the lowest tertile. In addition, children with intakes in the highest tertile of methionine had a 0.09 SDS higher BMI (95% CI: 0.01, 0.17) and a 0.12 SDS higher android:gynoid (95% CI: 0.02, 0.22) than children in the lowest tertile. Vitamin B-6 and folate intakes were not associated with any of the body composition outcomes measured.

CONCLUSIONS

In this population of children, early high folic acid intakes were associated with a lower body weight and BMI at the age of 6 y. In contrast, early higher methionine intakes were associated with unfavorable body composition at the age of 6 y. Future studies should investigate long-term consequences of these outcomes on health.

Folate Status and Intake of Tribal Indian Adolescents Aged 10 to 17 Years

Background

Adequate folate intake and levels are advisable throughout life but are of particular importance during adolescence, a period of rapid growth. However, folate insufficiency in economically deprived Indian adolescents is understudied.

Objective

This cross-sectional study examined the prevalence of folate deficiency and adequacy of folate intake of 224 tribal Indian adolescents (10 to 17 years of age). The secondary aim was to study the association between anemia status and folate status.

Methods

Radioimmunoassay, multiple-pass 24-hour dietary recall, and HemoCue were used to measure red blood cell (RBC) folate, folate intake, and anemia status, respectively.

Results

The geometric mean (95% CI) RBC folate concentration (nmol/L) was 360.2 (329.7 to 393.6), and the mean ± SD folate intake (μg/day) and hemoglobin level (g/L) were 159.9 ± 44.7 and 125.4 ± 13.0, respectively. Almost half of boys and girls aged 10 to 12 and 13 to 15 years and 66.7% of girls aged 16 to 17 years were deficient in RBC folate (< 340 nmol/L). The mean ± SD folate intake (μg/day) of girls (139.4 ± 34.5) was lower than that of boys (173.8 ± 45.5) ( p < .001). With respect to adequacy of folate intake, a greater proportion of girls in the age group of 13–15 years (78.5% vs 38.6%, p < 0.001) and 16–17 years (100.0% vs 76.9%, p = 0.04) had intakes below their Recommended Dietary Allowance (RDA). No association was observed between folate intake and RBC folate deficiency or between anemia status and RBC folate deficiency.

Conclusions

Folate insufficiency was widespread in tribal Indian adolescents. There is an urgent need to develop culturally sensitive strategies for improvement.