Association between Homocysteine Levels and All-cause Mortality: A Dose-Response Meta-Analysis of Prospective Studies

Serum Homocysteine Levels and All-Cause and Cause-Specific Mortality in Korean Adult Men: A Cohort Study

BACKGROUND

Hyperhomocysteinemia can increase the risk of cardiovascular disease (CVD), cancer, and neurological disorders; however, hypohomocysteinemia is generally not considered harmful. This study aimed to evaluate the relationship between all levels of homocysteine, both low and high homocysteine levels, and the risk of all-cause and cause-specific mortality in adult Korean men.

METHODS

Adult Korean men (n = 221,356) were categorized into quintiles based on their homocysteine levels. The primary endpoints were all-cause, CVD, cancer, and dementia mortality. Hazard ratios were calculated using Cox proportional hazards models, and the dose-response relationship between homocysteine levels and mortality risk was further explored using restricted cubic spline models.

RESULTS

Compared with the reference category (Q2, 8.8-9.9 µmol/L), there was a significant increase in all-cause mortality associated with both low and high levels after multivariable adjustment (Pinteraction = 0.002). Additionally, in spline regression, a U-shaped association between homocysteine levels and all-cause and CVD mortality was observed (inflection point = 9.1 µmol/L). This association was not observed in the vitamin supplementation subgroup.

CONCLUSION

Among Korean adult men, both low and high homocysteine levels increased the risk of all-cause and CVD mortality, indicating a U-shaped relationship. However, this relationship was not statistically significant with vitamin supplementation, suggesting a potential protective role for vitamins.

Homocysteine, blood pressure and gene-diet interactions in relation to vascular function measures of black South Africans

BACKGROUND AND AIMS

We investigated circulating homocysteine (Hcy), a cardiovascular disease (CVD) risk factor, examining its dietary associations to provide personalized nutrition advice. This study addressed the inadequacy of current dietary interventions to ultimately address the disproportionately high incidence of CVD in Black populations.

METHODS AND RESULTS

Cross-sectional analyses of 1,867 Black individuals of the PURE-SA study allowed the identification of dietary intake and cardiovascular measure interactions on three sub-categories: (1) normal blood pressure (BP), hypertension or Hcy-related hypertension (H-type), (2) low, normal or high Hcy concentrations, and (3) Hcy-related genetic combinations. Favorable body composition, but adverse dietary intake and cardiovascular determinants, were observed in higher Hcy categories. H-types, compared to regular hypertensives, had higher alcohol and lower macronutrient and micronutrient consumption. Inverse associations with carotid-radial pulse wave velocity were evident between monounsaturated fatty acid (FA) consumption and H-type hypertension as well as polyunsaturated FA and CBS883/ins68 TT carriers. Energy intake was positively associated with vascular cell adhesion molecule-1 (VCAM-1) in variant CBST883C/ins68 and CBS9276 GG carriers. VCAM-1 was also positively associated with plant protein intake in CBS9276 GG and MTR2756 AA carriers and negatively with total protein intake and CBS9276 GG carriers. Alcohol intake was positively associated with intercellular adhesion molecule-1 in MTR2756 minor allele carriers.

CONCLUSION

Because Hcy gene-diet interactions are evident, personalized nutrition, by adjusting diets based on genetic profiles (e.g., CBS and MTR variations) and dietary interactions (e.g., FAs and proteins), can enhance cardiovascular outcomes by managing Hcy and related hypertension in genetically susceptible individuals.

Homocysteine Metabolism, Subclinical Myocardial Injury, and Cardiovascular Mortality in the General Population

Background

Homocysteine (Hcy) is a recognized cardiovascular disease (CVD) risk factor linked with atherosclerosis. However, the association between Hcy and myocardial injury is little known.

Objectives

This study aimed to examine the associations between Hcy metabolism, subclinical myocardial injury, and cardiovascular mortality.

Methods

We included 10,871 participants without diagnosed CVD. Generalized linear regression was used to investigate the relationship between Hcy-related indicators (plasma total Hcy [tHcy], vitamin B12, and folate) and myocardial injury biomarkers (high-sensitivity troponin T [hs-cTnT], high-sensitivity troponin I [hs-cTnI] measured using 3 assays [Abbott, Siemens, and Ortho], and N-terminal pro-B-type natriuretic peptide [NT-proBNP]).

Results

Among 10,871 participants, the weighted mean levels for tHcy, folate, and vitamin B12 were 8.58 μmol/L, 32.43 nmol/L, and 447.08 pmol/L, respectively. Plasma tHcy levels were positively associated with elevated hs-cTnT, hs-cTnI, and NT-proBNP, whereas folate and vitamin B12 were not inversely related to myocardial injury biomarkers. Multivariable-adjusted odds ratios for elevated hs-cTnT (19 ng/L) and NT-proBNP (125 pg/mL) per doubling of tHcy were 2.80 (95% CI: 1.17-6.73; P < 0.001) and 1.58 (95% CI: 1.20-2.08; P < 0.001), respectively. The associations of tHcy levels with elevated hs-cTnI (Abbott: 28 ng/L; Siemens: 46.5 ng/L; Ortho: 11 ng/L) were consistent. Indirect effects of tHcy on cardiovascular mortality risk via hs-cTnT and NT-proBNP explained up to 26.6% and 12.3% of the total effect, respectively.

Conclusions

Plasma tHcy, not folate or vitamin B12, is significantly associated with elevated hs-cTnT, hs-cTnI, and NT-proBNP in adults without CVD. Subclinical myocardial injury may substantially mediate Hcy-related cardiovascular mortality risk.

Homocysteine, hyperhomocysteinemia, and H-type hypertension

Homocysteine (Hcy) is a sulphur-containing nonessential amino acid derived from the intermediate metabolites of methionine. Methionine is obtained from dietary proteins, such as poultry, meat, eggs, seafood, and dairy products. Abnormalities in Hcy metabolic pathways, deficiencies in dietary methionine, folate, and vitamins B12, B6, and B2 and genetic defects, polymorphisms, or mutations in Hcy metabolism-related enzymes may lead to an increase in plasma Hcy levels. Generally, a plasma Hcy level higher than 10 or 15 μmol/L has been defined as hyperhomocysteinemia (HHcy). An individual with essential hypertension complicated with HHcy is considered to have H-type hypertension (HTH). Currently, HHcy is considered a novel independent risk factor for various cardiovascular diseases. To provide a useful reference for clinicians, the research progress on Hcy, HHcy, and HTH in recent years was systematically reviewed here, with a focus on the source and metabolic pathways of Hcy, plasma Hcy levels and influencing factors, detection methods for plasma Hcy levels, relationship between Hcy concentration and hypertension, pathogenesis of HTH, cardiovascular complications of HTH, and treatment of HTH.

The Association of Plasma Homocysteine Concentrations with a 10-Year Risk of All-Cause and Cardiovascular Mortality in a Community-Based Chinese Population

This study is aimed to examine the association of plasma homocysteine (Hcy) concentrations with a 10-year risk of all-cause and cardiovascular (CV) mortality and to explore the modification effect of methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphism. This study included 5200 participants from a community-based Chinese population. Cox proportional hazard regression models were used to analyze the associations of Hcy and MTHFR C677T genotype with all-cause and CV mortality. The possible modification effect of the MTHFR C677T genotype on the Hcy-mortality relationship was assessed. The individuals with Hcy concentrations ≥ 10 μmol/L had a significantly higher risk of all-cause mortality compared to those with Hcy < 10 μmol/L (hazard ratio [HR]: 1.72, 95% confidence interval [CI]: 1.11-2.68, p = 0.015). The risk of CV mortality increased by 2% per 1 μmol/L Hcy increment (HR: 1.02, 95% CI: 1.00-1.03, p = 0.036). Despite the MTHFR genotype alone not being correlated with the mortality, the relationship between Hcy and all-cause mortality was significant in the CC genotype compared with CT/TT genotype (p for interaction = 0.036). Elevated plasma Hcy concentrations were associated with an increased 10-year risk of all-cause and CV mortality among the Chinese population. MTHFR C677T genetic polymorphism could modify the association between Hcy and all-cause mortality.

Associations of total homocysteine and kidney function with all-cause and cause-specific mortality in hypertensive patients: a mediation and joint analysis

Plasma total homocysteine (tHcy) and kidney function are both associated with mortality risk, but the degree to which kidney function modifies the impact of tHcy on mortality remains unknown. This prospective cohort study included a total of 14,225 hypertensive adults. Cox proportional hazard regression was used to analyze the separate and combined association of tHcy and estimated glomerular filtration rate (eGFR) with all-cause and cause-specific mortality. Mediation analysis was conducted to explore the mediating effect of eGFR. During a median follow-up of 4.0 years, 805 deaths were identified, including 397 deaths from cardiovascular disease (CVD). There were significant, positive relationships of tHcy with all-cause mortality (per 5 μmol/L; HR: 1.09; 95% CI: 1.07, 1.11), CVD mortality (HR: 1.11; 95% CI: 1.08, 1.13), and non-CVD mortality (HR: 1.07; 95% CI: 1.04, 1.10). The proportions of eGFR mediating these relationships were 39.1%, 35.7%, and 49.7%, respectively. There were additive interactions between tHcy and eGFR. Compared with those with low tHcy (<15 μmol/L) and high eGFR (≥90 mL·min-1·1.73 m-2), participants with high tHcy (≥20 μmol/L) and low eGFR (<60 mL·min-1·1.73 m-2) had the highest risk of all-cause mortality (HR: 4.89; 95% CI: 3.81, 6.28), CVD mortality (HR: 5.80; 95% CI: 4.01, 8.40), and non-CVD mortality (HR: 4.25; 95% CI: 3.02, 5.97). In conclusion, among Chinese hypertensive adults, high tHcy and impaired kidney function were independently and jointly associated with higher risks of all-cause and cause-specific mortality. Importantly, kidney function explained most (nearly 40%) of the increased risk of mortality conferred by high tHcy.

Association of vitamin B12, folate, and homocysteine with COVID-19 severity and mortality: A systematic review and meta-analysis

Objective

We aimed to review the available evidence on the association between vitamin B12, folate, and homocysteine levels with worse outcomes among COVID-19 patients.

Methods

The search was carried out in ten databases simultaneously run on 10 May 2023, without language restrictions. We included cross-sectional, case-control, and cohort studies. The random-effects meta-analysis was performed using the Sidik-Jonkman method and corrected 95% confidence intervals using the truncated Knapp-Hartung standard errors. Standardized mean difference and 95% CI was used as the measure effect size.

Results

Thirteen articles were included in this review (n = 2134). Patients with COVID-19 who did not survive had the highest serum vitamin B12 values (SMD: 1.05; 95% CI: 0.31-1.78; p = 0.01, I2 = 91.22%). In contrast, low serum folate values were associated with patients with severe COVID-19 (SMD: -0.77; 95% CI: -1.35 to -0.19; p = 0.02, I2 = 59.09%). The remaining tested differences did not yield significant results.

Conclusion

Elevated serum levels of vitamin B12 were associated with higher mortality in patients with COVID-19. Severe cases of COVID-19 were associated with low serum folate levels. Future studies should incorporate a larger sample size.

A Proactive Intervention Study in Metabolic Syndrome High-Risk Populations Using Phenome-Based Actionable P4 Medicine Strategy

The integration of predictive, preventive, personalized, and participatory (P4) healthcare advocates proactive intervention, including dietary supplements and lifestyle interventions for chronic disease. Personal profiles include deep phenotypic data and genetic information, which are associated with chronic diseases, can guide proactive intervention. However, little is known about how to design an appropriate intervention mode to precisely intervene with personalized phenome-based data. Here, we report the results of a 3-month study on 350 individuals with metabolic syndrome high-risk that we named the Pioneer 350 Wellness project (P350). We examined: (1) longitudinal (two times) phenotypes covering blood lipids, blood glucose, homocysteine (HCY), and vitamin D3 (VD3), and (2) polymorphism of genes related to folic acid metabolism. Based on personalized data and questionnaires including demographics, diet and exercise habits information, coaches identified 'actionable possibilities', which combined exercise, diet, and dietary supplements. After a 3-month proactive intervention, two-thirds of the phenotypic markers were significantly improved in the P350 cohort. Specifically, we found that dietary supplements and lifestyle interventions have different effects on phenotypic improvement. For example, dietary supplements can result in a rapid recovery of abnormal HCY and VD3 levels, while lifestyle interventions are more suitable for those with high body mass index (BMI), but almost do not help the recovery of HCY. Furthermore, although people who implemented only one of the exercise or diet interventions also benefited, the effect was not as good as the combined exercise and diet interventions. In a subgroup of 226 people, we examined the association between the polymorphism of genes related to folic acid metabolism and the benefits of folate supplementation to restore a normal HCY level. We found people with folic acid metabolism deficiency genes are more likely to benefit from folate supplementation to restore a normal HCY level. Overall, these results suggest: (1) phenome-based data can guide the formulation of more precise and comprehensive interventions, and (2) genetic polymorphism impacts clinical responses to interventions. Notably, we provide a proactive intervention example that is operable in daily life, allowing people with different phenome-based data to design the appropriate intervention protocol including dietary supplements and lifestyle interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00115-z.

Homocysteine serum levels in patients with ruptured and unruptured intracranial aneurysms: a case-control study

BACKGROUND

There is very few data regarding homocysteine's influence on the formation and rupture of intracranial aneurysms.

OBJECTIVE

To compare homocysteine levels between patients with ruptured and unruptured intracranial aneurysms, and to evaluate possible influences of this molecule on vasospasm and functional outcomes.

METHODS

This is a retrospective, case-control study. We evaluated homocysteinemia differences between patients with ruptured and unruptured aneurysms; and the association of homocysteine levels with vasospasm and functional outcomes. Logistic regressions were performed.

RESULTS

A total of 348 participants were included: 114 (32.8%) with previous aneurysm rupture and 234 (67.2%) with unruptured aneurysms. Median homocysteine was 10.75µmol/L (IQR = 4.59) in patients with ruptured aneurysms and 11.5µmol/L (IQR = 5.84) in patients with unruptured aneurysms. No significant association was detected between homocysteine levels and rupture status (OR = 0.99, 95% CI = 0.96-1.04). Neither mild (>15µmol/L; OR = 1.25, 95% CI 0.32-4.12) nor moderate (>30µmol/L; OR = 1.0, 95% CI = 0.54-1.81) hyperhomocysteinemia demonstrated significant correlations with ruptured aneurysms. Neither univariate (OR = 0.86; 95% CI 0.71-1.0) nor multivariable age-adjusted (OR = 0.91; 95% CI = 0.75-1.05) models evidenced an association between homocysteine levels and vasospasm. Homocysteinemia did not influence excellent functional outcomes at 6 months (mRS≤1) (OR = 1.04; 95% CI = 0.94-1.16).

CONCLUSION

There were no differences regarding homocysteinemia between patients with ruptured and unruptured intracranial aneurysms. In patients with ruptured aneurysms, homocysteinemia was not associated with vasospasm or functional outcomes.

Associations between homocysteine, vitamin B12, and folate and the risk of all-cause mortality in American adults with stroke

Objective

Associations between plasma homocysteine (Hcy), vitamin B12, and folate and the risk of all-cause mortality are unclear. This study aimed to examine whether plasma Hcy, vitamin B12, and folate levels independently predict the risk of all-cause mortality in American adults with stroke.

Methods

Data from the United States National Health and Examination Survey (NHANES; 1999-2006) were used and linked with the latest (2019) National Death Index (NDI). Cox proportional hazards models and restricted cubic splines were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) of all-cause mortality for Hcy, folate, and B12 levels in adults with stroke. Sample weights were calculated to ensure the generalizability of the results.

Results

A total of 431 participants were included (average age: 64.8 years). During a median follow-up of 10.4 years, 316 deaths occurred. Hcy was positively associated with all-cause mortality in adults with stroke (HR, 1.053; 95% CI: 1.026-1.080). Stroke patients with plasma Hcy levels in the fourth quartile had a 1.631-fold higher risk of all-cause mortality (HR, 1.631; 95% CI: 1.160-2.291) than those in the first quartile. The association between plasma Hcy and all-cause mortality was strong significant in older patients (p for interaction = 0.020). Plasma folate and vitamin B12 concentrations were inversely correlated with Hcy concentrations [B-value (95% CI): -0.032 (-0.056- -0.008), -0.004 (-0.007- -0.002), respectively]. No significant associations were observed between folate, vitamin B12 levels, and all-cause mortality in adults with stroke.

Conclusion

Plasma Hcy levels were positively associated with all-cause mortality in older adults with stroke. Folate and vitamin B12 levels were inversely correlated with Hcy. Plasma Hcy may serve as a useful predictor in mortality risk assessment and targeted intervention in adults with stroke.

Potential inflammatory targets in the integrative health care of patients with sickle cell disease

Inflammation plays an integral role in the complications of sickle cell disease (SCD), which can lead to vaso-occlusive crisis and extreme pain. SCD is accompanied by numerous complications, including cardiovascular disease, cognitive decline and endothelial dysfunction, contributing to mortality. As disease severity increases with age, the present study aimed to assess if age is also correlated with a definite pattern of progression of the two inflammatory markers, high-sensitivity C-reactive protein (hsCRP) and total homocysteine (tHCY). The findings of the present study could lead to an improved understanding of the threshold levels of these inflammatory markers and timely interventions to delay complications. In an observational study, levels of hsCRP and tHCY were analyzed in 70 patients (35 male and 35 female patients) with SCD aged between 5 and 16 years. hsCRP levels were in the high-risk range in 64.29% (n=45) of all male and female patients. A sex-wise distribution showed that, of the 35 male patients, 74.28% (n=26) were in the high-risk range, and of the 35 female patients, 54.28% (n=19) were in the high-risk range. An age-wise distribution showed that of the 41 patients in the 5-10-years age group, 70.73% (n=29), were in the high-risk range. In comparison, of the 29 patients in the 11-16-years age group, 55.17% (n=16) were in the high-risk range. tHCY levels were observed to be in the normal range in 98.57% (n=69) of all children, as compared with 1.43% (n=1) in the high-risk range. Furthermore, a sex-wise distribution showed that female patients in the high-risk group of hsCRP had higher concentrations of tHCY as compared with the male patients in that risk group. An age-wise distribution of hsCRP concentration also showed that the risk of CVD in patients in the 11-16-years age group was higher with increased concentrations of tHCY. A weak negative correlation was observed between age and hsCRP concentrations (r-value=-0.280; P=0.026) and a weak positive correlation was detected between tHCY and age (r-value=0.259; P=0.036). In conclusion, the results of the present study indicated that higher levels of hsCRP could be a useful marker in children with SCD, and levels of tHCY may be an adjunct marker as the disease progresses with age.

Association Between Plasma Homocysteine Level and Mortality: A Mendelian Randomization Study

BACKGROUND AND OBJECTIVES

In previous studies, high homocysteine levels were associated with high cardiovascular mortality. However, these results were inconsistent with those of randomized controlled trials. We aimed to evaluate the causal role of homocysteine on all-cause and cardiovascular mortality using Mendelian randomization (MR) analysis.

METHODS

This study included the 10,005 participants in the Namwon Study. In conventional observational analysis, age, sex, survey years, lifestyles, body mass index, comorbidities, and serum folate level were adjusted using multivariate Cox proportional regression. MR using 2-stage least squares regression was used to evaluate the association between genetically predicted plasma homocysteine levels and mortality. Age, sex, and survey years were adjusted for each stage. The methylenetetrahydrofolate reductase (MTHFR) polymorphism was used as an instrumental variable for predicting plasma homocysteine levels.

RESULTS

Observed homocysteine levels were positively associated with all-cause (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.26-1.54) and cardiovascular (HR, 1.62; 95% CI, 1.28-2.06) mortality when plasma homocysteine levels doubled. However, these associations were not significant in MR analysis. The HRs of doubling genetically predicted plasma homocysteine levels for all-cause and cardiovascular mortality were 0.99 (95% CI, 0.62-1.57) and 1.76 (95% CI, 0.54-5.77), respectively.

CONCLUSIONS

This MR analysis did not support a causal role for elevated plasma homocysteine concentrations in premature deaths.

Homocysteine May Decrease Glucose Uptake and Alter the Akt/GSK3β/GLUT1 Signaling Pathway in Hippocampal Slices: Neuroprotective Effects of Rivastigmine and Ibuprofen

Homocysteine (Hcy) is a risk factor for neurodegenerative diseases, such as Alzheimer's Disease, and is related to cellular and tissue damage. In the present study, we verified the effect of Hcy on neurochemical parameters (redox homeostasis, neuronal excitability, glucose, and lactate levels) and the Serine/Threonine kinase B (Akt), Glucose synthase kinase-3β (GSK3β) and Glucose transporter 1 (GLUT1) signaling pathway in hippocampal slices, as well as the neuroprotective effects of ibuprofen and rivastigmine alone or in combination in such effects. Male Wistar rats (90 days old) were euthanized and the brains were dissected. The hippocampus slices were pre-treated for 30 min [saline medium or Hcy (30 µM)], then the other treatments were added to the medium for another 30 min [ibuprofen, rivastigmine, or ibuprofen + rivastigmine]. The dichlorofluorescein formed, nitrite and Na+, K+-ATPase activity was increased by Hcy at 30 µM. Ibuprofen reduced dichlorofluorescein formation and attenuated the effect of Hcy. The reduced glutathione content was reduced by Hcy. Treatments with ibuprofen and Hcy + ibuprofen increased reduced glutathione. Hcy at 30 µM caused a decrease in hippocampal glucose uptake and GLUT1 expression, and an increase in Glial Fibrillary Acidic Protein-protein expression. Phosphorylated GSK3β and Akt levels were reduced by Hcy (30 µM) and co-treatment with Hcy + rivastigmine + ibuprofen reversed these effects. Hcy toxicity on glucose metabolism can promote neurological damage. The combination of treatment with rivastigmine + ibuprofen attenuated such effects, probably by regulating the Akt/GSK3β/GLUT1 signaling pathway. Reversal of Hcy cellular damage by these compounds may be a potential neuroprotective strategy for brain damage.

Homocysteine levels, H-Hypertension, and the MTHFR C677T genotypes: A complex interaction

Background and objectives

High homocysteine levels are associated with increased risk of hypertension and stroke. Homocysteine is metabolized by the methylenetetrahydrofolate reductase (MTHFR). We aimed to investigate the levels of homocysteine and their association with hypertension, stroke, and antihypertensive medication usage in patients with different MTHFR C677T genotypes.

Methods and results

Genotype frequency of MTHFR polymorphism was performed, and plasma homocysteine levels were measured in 2,640 adult Lebanese patients. Hypertension, history of stroke, and list of medications were documented, among other clinical and demographic parameters. The TT mutant genotype and the T mutant allele of MTHFR were more prevalent in hyperhomocysteinemia (HHcy) and H-hypertensive (H-HTN, defined as hypertension with hyperhomocysteinemia) patients when compared to non-HHcy subjects and non H-HTN patients respectively. Homocysteine levels were significantly higher in hypertensive patients specifically among those on diuretics. A higher level of homocysteine was found in hypertensive patients with the MTHFR T allele compared to patients carrying the C allele. Among the T allele carriers, the average plasma homocysteine level was 13.3 ± 0.193 μmol/L for hypertensive subjects compared to 11.9 ± 0.173 μmol/L (non-hypertensives). Furthermore, homocysteine levels significantly correlated with stroke risk in patients with the T alleles.

Conclusions

We found an association of homocysteine with hypertension, hypertensive medication, and stroke risk among patients with the MTHFR T allele and the TT genotype. The association of diuretics therapy with higher homocysteine levels calls for routine measurements and therapeutic control of homocysteine in patients on diuretic, to improve health-related outcomes.

Selective Hepatic Cbs Knockout Aggravates Liver Damage, Endothelial Dysfunction and ROS Stress in Mice Fed a Western Diet

Cystathionine-β-synthase (CBS) is highly expressed in the liver, and deficiencies in Cbs lead to hyperhomocysteinemia (HHCy) and disturbed production of antioxidants such as hydrogen sulfide. We therefore hypothesized that liver-specific Cbs deficient (LiCKO) mice would be particularly susceptible to the development of non-alcoholic fatty liver disease (NAFLD). NAFLD was induced by a high-fat high-cholesterol (HFC) diet; LiCKO and controls were split into eight groups based on genotype (con, LiCKO), diet (normal diet, HFC), and diet duration (12 weeks, 20 weeks). LiCKO mice displayed intermediate to severe HHCy. Plasma H₂O₂ was increased by HFC, and further aggravated in LiCKO. LiCKO mice fed an HFC diet had heavier livers, increased lipid peroxidation, elevated ALAT, aggravated hepatic steatosis, and inflammation. LiCKO mice showed decreased L-carnitine in the liver, but this did not result in impaired fatty acid oxidation. Moreover, HFC-fed LiCKO mice demonstrated vascular and renal endothelial dysfunction. Liver and endothelial damage correlated significantly with systemic ROS status. In conclusion, this study demonstrates an important role for CBS in the liver in the development of NAFLD, which is most probably mediated through impaired defense against oxidative stress.

Associations of Serum Folate and Homocysteine Concentrations with All-Cause, Cardiovascular Disease, and Cancer Mortality in Men and Women in Korea: the Cardiovascular Disease Association Study

BACKGROUND

Evidence on the association of serum folate and homocysteine concentrations with risk of mortality in the general population is unclear.

OBJECTIVES

This study aimed to examine the associations of serum folate and homocysteine concentrations with all-cause, CVD, and cancer mortality risk in Korean men and women aged ≥40 y.

METHODS

In this population-based prospective cohort study, serum folate and homocysteine concentrations were measured in a subset of participants enrolled between 2005 and 2012. A total of 21,260 participants were linked to mortality data from the survey date to 31 December 2019. Cox proportional hazards models and restricted cubic splines were used to identify the associations of serum folate and homocysteine concentrations with mortality.

RESULTS

During a median follow-up of 12.3 y, 2501, 549, and 842 deaths were attributed to all-cause, CVD, and cancer, respectively. The prevalence of folate deficiency and hyperhomocysteinemia were higher in men than in women. In men, a nonlinear inverse association was observed between serum folate concentrations and all-cause mortality. Men in the third quartile of serum folate concentrations exhibited a lower risk of all-cause mortality (HR: 0.85; 95% CI: 0.73, 0.99) than those in the lowest quartile. Serum homocysteine concentration was positively associated with all-cause and CVD mortality. Men and women in the highest compared with those in the lowest serum homocysteine quartile showed a higher risk of CVD mortality (HR: 1.60; 95% CI: 1.07, 2.39; and HR: 1.79; 95% CI: 1.11, 2.89, respectively). Hyperhomocysteinemia combined with folate deficiency was associated with increased all-cause, CVD, and cancer-related mortality rates.

CONCLUSIONS

Higher serum homocysteine and lower serum folate concentrations were associated with an increased risk of all-cause, CVD, and cancer-related mortality in Korean adults. The finding of a nonlinear inverse relationship between serum folate concentration and mortality in men warrants further investigation.

Is It Feasible to Predict Cardiovascular Risk among Healthy Vegans, Lacto-/Ovo-Vegetarians, Pescatarians, and Omnivores under Forty?

Guidelines for cardiovascular (CV) risk assessment among young adults are uncertain. Researchers are still looking for new tools for earlier diagnosis of cardiovascular diseases (CVD), the leading cause of mortality in the modern world. This study aimed to assess whether CV risk estimation is possible in groups of healthy individuals under the age of 40 on different dietary patterns (vegans-VEGAN (n = 48), lacto-/ovo-vegetarians-VEGE (n = 49), pescatarians-PESCA (n = 23), and omnivores-OMN (n = 35)) during the pandemic period. Four metrics containing selected risk classifiers were created, and participants were assessed using them. Groups including meat consumption showed increased CV risk predictions in the metrics assessment. The next analyzes showed statistically significant relationships between the results from the created metrics and selected non-basic biomarkers for ApoA1 (OMN group, p = 0.028), IL-6 (PESCA group, p = 0.048), HCY (VEGAN group, p = 0.05), and hsCRP (OMN + PESCA groups, p = 0.025). We found that predicting CV risk among healthy people under 40 adhering to different dietary patterns, taking into account basic and non-basic laboratory assessments and created metrics, is challenging but feasible. Furthermore, the OMN group appeared to be at the highest risk of increased CV risk in the future, while risk tended to be the lowest in the VEGAN group.

Genetic susceptibility, homocysteine levels, and risk of all-cause and cause-specific mortality: A prospective cohort study

BACKGROUND

The associations of homocysteine (Hcy) and gene-Hcy interactions with the risk of all-cause and cause-specific mortality remain unclear.

METHODS

A total of 19,826 middle-aged and elderly Chinese adults were included from the Dongfeng-Tongji cohort in 2013-2014 and were followed-up to 31 December 2018. Cox regression was used to examine the association between Hcy and mortality. We selected 18 well-established Hcy-associated genetic variants to constructed the weighted genetic risk score (GRS) among 15,434 participants with genetic data, and interactions between genetic susceptibility and Hcy on mortality were assessed.

RESULTS

After multivariate adjustment, elevated serum Hcy levels were associated with higher risk of mortality from all-cause, CVD, coronary heart disease (CHD), stroke, and cancer. We also observed a significant interaction between GRS and Hcy on CHD mortality. Moreover, the rs7130284 and rs957140 on NOX4 modified the association between Hcy and mortality from CVD and CHD, and rs154657 on DPEP1 modified the association between Hcy and CHD mortality.

CONCLUSIONS

Elevated Hcy levels were associated with increased risk of all-cause and cause-specific mortality among middle-aged and elderly Chinese. Hcy-related genetic variants on NOX4 and DPEP1 might modify the associations of Hcy with CVD mortality or CHD mortality.

Homocysteine concentrations in overweight children and adolescents

OBJECTIVE

The aim of this study was to describe homocysteine concentrations in overweight and obese children and adolescents and relate them to blood pressure levels, renal function, and insulin resistance.

METHODS

This is a cross-sectional and observational study with 64 overweight children and adolescents (mean age: 11.6±3.5 years) in outpatient follow-up. The following parameters were evaluated: body mass index z-score, waist-to-height circumference ratio, pubertal stage, blood pressure, serum homocysteine, glycemia, insulin, lipid profile, renal function, high-sensitivity C-reactive protein, microalbuminuria, and creatinuria. Statistical analysis: analysis of variance and logistic regression (dependent variable: homocysteine) (p<0.05).

RESULTS

The mean body mass index z-score was 2.9±1.1. The mean homocysteine concentrations were 8.6±2.2 μmol/L (10th and 90th percentiles: 6.6 and 11.2 μmol/L, respectively), with no difference when compared with children with severe obesity and obesity/overweight (p=0.431). High values of waist-to-height ratio (93.8%), systolic blood pressure (18.8%), diastolic blood pressure (12.5%), glycemia (4.7%), low-density lipoprotein cholesterol (31.1%), triglycerides (35.9%), non-high-density lipoprotein cholesterol (34.4%), and microalbuminuria (21.9%) were obtained. The mean glomerular filtration rate was 122.9±24.6 mL/min/1.73 m². Homocysteine concentrations were not associated with any of the studied variables (R²=0.095).

CONCLUSION

Homocysteine concentrations in overweight children and adolescents (mean 8.6±2.2 μmol/L) were not associated with body mass index z-score, blood pressure, renal function, and insulin resistance.

Distribution and Determinants of Plasma Homocysteine Levels in a Preconception Population: A Retrospective Single-Center Study

BACKGROUND Raised plasma homocysteine (Hcy) levels have been associated with various diseases and pregnancy complications. Preconception is the primary prevention period to prevent birth defects. This retrospective study aimed to investigate the distribution of plasma Hcy levels among men and women at preconception and further evaluate the factors influencing plasma Hcy levels in a Southern China population. MATERIAL AND METHODS Sex, age, serum folate levels, plasma Hcy levels, and the time of Hcy and folate detection were obtained by medical records. Univariate analysis and multi-factor mixed virtual linear regression were used to explore the distribution and determinants of plasma Hcy levels. RESULTS A total of 3031 participants (1091 men [35.99%] and 1940 women [64.01%]) were included. The average levels of Hcy and the rates of hyperhomocysteinemia (HHcy) in men were higher than those in women (P<0.05). Hcy levels were observed to be lowest during autumn and highest during winter (P<0.05). In the normal Hcy (NHcy) group, serum folate levels were higher than in the HHcy group (P<0.05). Regression analysis suggested that sex, season, and serum folate levels had an effect on Hcy levels, but age was not an influencing factor of Hcy level in the preconception population. CONCLUSIONS This retrospective study showed that Hcy levels are higher in men and in the winter season. Sex, season, and serum folate levels were the influencing factors of Hcy in the preconception population.

Association of Serum Homocysteine with Cardiovascular and All-Cause Mortality in Adults with Diabetes: A Prospective Cohort Study

Background

Homocysteine (Hcy) was implicated in oxidative stress and diabetes biologically. However, the clinical evidence on the link between Hcy level and diabetes is limited and controversial. This study is aimed at investigating the association of serum Hcy with all-cause and cardiovascular mortality in diabetic patients.

Methods

Serum Hcy was measured among 2,286 adults with type 2 diabetes in NHANES 1999-2006. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% CIs for the association of Hcy with all-cause and cause-specific mortality.

Results

Over a median follow-up of 11.0 (interquartile range, 8.9-13.4) years, 952 of the 2286 patients with diabetes died, covering 269 (28.3%) cardiovascular deaths and 144 (15.2%) cancer deaths. Restricted cubic spline showed the linear relationship between Hcy and all-cause mortality risk. After multivariate adjustment, higher serum Hcy levels were independently associated with increased risk of all-cause and cardiovascular mortality. Compared with participants in the bottom tertile of Hcy, the multivariate-adjusted HRs and 95% CI for participants in the top quartile were 2.33 (1.64-3.30) for all-cause mortality (p_trend < 0.001), 2.24 (1.22-4.10) for CVD mortality (p_trend = 0.017), and 2.05 (0.90-4.69) for cancer mortality (p_trend = 0.096). The association with total mortality was especially stronger among patients with albuminuria. Serum Hcy significantly improved reclassification for 10-year mortality in diabetic patients (net reclassification index = 0.253 and integrated discrimination improvement = 0.011).

Conclusions

Serum Hcy was associated with risks of all-cause and cardiovascular mortality in diabetic adults. Our results suggested that Hcy was a promising biomarker in risk stratification among diabetic patients.

Individual and joint effects of borderline ankle-brachial index and high plasma total homocysteine on all-cause death in hypertensive adults

BACKGROUND

The cardiovascular hazards of total homocysteine (tHcy) are long known. In addition, despite the acknowledgment on the importance of low ankle-brachial index (ABI) (< 0.9), borderline ABI (0.91-0.99) was once commonly overlooked. This study aims to explore the independent and joint effect of tHcy level and borderline ABI on all-cause death in hypertensive population.

METHODS

This study included 10,538 participants from China H-type Hypertension Registry Study. ABI was described into two groups: normal ABI (1.00-1.40) and borderline ABI. tHcy level was also divided into two groups: < 15.02 and ≥ 15.02 μmo/L. Four groups were analyzed, using COX proportional hazard regression model, separately and pairwise to observe the independent and joint effect on all-cause death.

RESULTS

A total of 126 (1.2%) deaths were observed in the 1.7 years follow-up time. Borderline ABI has a higher predicted risk of death than normal ABI (HR = 1.87, 95%CI: 1.17-3.00) after adjusting for potential covariates. Compare with tHcy level < 15.02 μmo/L (low tHcy), those with tHcy ≥ 15.02 μmo/L (high tHcy) had higher risk to event outcome (HR = 1.99, 95% CI: 1.30-3.05). According to the cumulative hazard curve, group with borderline ABI and high tHcy level has significantly higher altitude and larger increasing rate over follow-up period compare to other groups. Among those with borderline ABI, participants with high tHcy had higher death risk than those with low tHcy, nevertheless, no significant different between borderline and normal ABI among those with low tHcy levels.

CONCLUSIONS

Borderline ABI and tHcy level both have independent predictive value on all-cause death. The combined group of borderline ABI and high tHcy has highest risk factor of outcomes, which suggested the mutual additive value of borderline ABI and tHcy. More attention should be given to the importance of borderline ABI in hypertensive population, especially with elevated tHcy level.

Plasma homocysteine and macular thickness in older adults-the Rugao Longevity and Aging Study

OBJECTIVES

To determine the association of plasma homocysteine levels with retinal layer thickness in a large community cohort of older adults.

METHODS

The Rugao Longevity and Ageing Study is an observational, prospective and community-based cohort study. A total of 989 older adults who underwent spectral-domain optical coherence tomography (SD-OCT) were included and analyzed. Foveal, macular retinal nerve fibre layer (mRNFL) and ganglion cell layer plus inner plexiform layer (GC-IPL) thicknesses were measured by SD-OCT. Plasma homocysteine levels were measured using chemiluminescence immunoassay. Linear regression analyses were performed to evaluate the relationship between plasma homocysteine and retinal layer thickness while controlling for confounding factors.

RESULTS

Of the 989 participants, 500 (50.56%) were men. The mean age was 78.26 (4.58) years, and the mean plasma homocysteine level was 16.38 (8.05) μmol/L. In multivariable analyses, each unit increase in plasma homocysteine was associated with an 8.84 × 10^-2 (95% CI: -16.54 × 10^-2 to -1.15 × 10^-2, p = 0.032) μm decrease in the average inner thickness of the GC-IPL after controlling for confounding factors. The association remained significant even in participants without major cardiovascular disease or diabetes (β = -10.33 × 10^-2, 95% CI: -18.49 × 10^-2 to -2.18 × 10^-2, p = 0.013). No significant associations of plasma homocysteine levels with macular thickness or mRNFL were found in primary and sensitivity analyses (p > 0.05).

CONCLUSIONS

Increased plasma homocysteine levels are associated with a thinner GC-IPL. Plasma homocysteine may be a risk factor for thinner retinas in older adults.

The Controversial Role of HCY and Vitamin B Deficiency in Cardiovascular Diseases

Plasma homocysteine (HCY) is an established risk factor for cardiovascular disease CVD and stroke. However, more than two decades of intensive research activities has failed to demonstrate that Hcy lowering through B-vitamin supplementation results in a reduction in CVD risk. Therefore, doubts about a causal involvement of hyperhomocysteinemia (HHcy) and B-vitamin deficiencies in atherosclerosis persist. Existing evidence indicates that HHcy increases oxidative stress, causes endoplasmatic reticulum (ER) stress, alters DNA methylation and, thus, modulates the expression of numerous pathogenic and protective genes. Moreover, Hcy can bind directly to proteins, which can change protein function and impact the intracellular redox state. As most mechanistic evidence is derived from experimental studies with rather artificial settings, the relevance of these results in humans remains a matter of debate. Recently, it has also been proposed that HHcy and B-vitamin deficiencies may promote CVD through accelerated telomere shortening and telomere dysfunction. This review provides a critical overview of the existing literature regarding the role of HHcy and B-vitamin deficiencies in CVD. At present, the CVD risk associated with HHcy and B vitamins is not effectively actionable. Therefore, routine screening for HHcy in CVD patients is of limited value. However, B-vitamin depletion is rather common among the elderly, and in such cases existing deficiencies should be corrected. While Hcy-lowering with high doses of B vitamins has no beneficial effects in secondary CVD prevention, the role of Hcy in primary disease prevention is insufficiently studied. Therefore, more intervention and experimental studies are needed to address existing gaps in knowledge.

Association of Homocysteine and Risks of Long-Term Cardiovascular Events and All-Cause Death among Older Patients with Obstructive Sleep Apnea: A Prospective Study

OBJECTIVES

This study aimed to assess whether raised baseline plasma tHcy concentrations increased the risks of major adverse cardiovascular events (MACE) and all-cause death outcomes in older patients with obstructive sleep apnea (OSA).

DESIGN

A multicenter, prospective, observational study.

SETTING

Beijing, Shandong Province, Gansu Province of China.

PARTICIPANTS

A total of 1, 290 OSA patients aged 60 to 96 years from sleep centers of six hospitals in China consecutively recruited between January 2015 and October 2017.

MEASUREMENTS

Cox proportional models assessed the association between tHcy and the risk of new-onset all events among Chinese older OSA patients.

RESULTS

The final analysis (60.1% male; median age, 66 years) used data from 1, 100 subjects during a median follow-up of 42 months, a total of 105 (9.5%) patients developed MACE and 42 (3.8%) patients died. Multivariable Cox regression analysis showed higher adjusted hazard ratios (aHRs) of MACE, myocardial infarction (MI), hospitalization for unstable angina, and composite of all events with tHcy levels in the 4th quartile (HR=5.93, 95% CI: 2.79-12.59; HR=4.72, 95% CI:1.36-4.61; HR=4.26, 95% CI:1.62-5.71; HR=4.17, 95% CI:2.23-7.81) and the 3rd quartile (HR=3.79, 95% CI:1.76-8.20; HR=3.65, 95% CI:1.04-2.98; HR=2.75, 95% CI:1.08-3.76; HR=2.51, 95% CI:1.31-4.83) compared to reference tHcy levels in quartile 1, respectively, while the aHRs (95% CIs) of all-cause death showed significantly higher only in the highest tHcy level quartile than in the lowest quartile (HR=3.20, 95% CI=1.16-8.84, P=0.025) with no significant differences in risks of cardiovascular death and hospitalisation for heart failure among groups (P>0.05).

CONCLUSIONS

tHcy, a marker of prognosis for older OSA patients, was significantly associated with the increased risk of MACE and all-cause death in this population independent of BMI, smoking status, and other potential risk factors, but not all clinical components events of MACE. New therapeutic approaches for older patients with OSA should mitigate tHcy-associated risks of MACE, and even all-cause death.

Homocysteine metabolism as the target for predictive medical approach, disease prevention, prognosis, and treatments tailored to the person

Homocysteine (Hcy) metabolism is crucial for regulating methionine availability, protein homeostasis, and DNA-methylation presenting, therefore, key pathways in post-genomic and epigenetic regulation mechanisms. Consequently, impaired Hcy metabolism leading to elevated concentrations of Hcy in the blood plasma (hyperhomocysteinemia) is linked to the overproduction of free radicals, induced oxidative stress, mitochondrial impairments, systemic inflammation and increased risks of eye disorders, coronary artery diseases, atherosclerosis, myocardial infarction, ischemic stroke, thrombotic events, cancer development and progression, osteoporosis, neurodegenerative disorders, pregnancy complications, delayed healing processes, and poor COVID-19 outcomes, among others. This review focuses on the homocysteine metabolism impairments relevant for various pathological conditions. Innovative strategies in the framework of 3P medicine consider Hcy metabolic pathways as the specific target for in vitro diagnostics, predictive medical approaches, cost-effective preventive measures, and optimized treatments tailored to the individualized patient profiles in primary, secondary, and tertiary care.

The significance of homocysteine in patients with hypertension

Cardiovascular disease is the most common cause of death in developed countries. Important factors leading to ischemic heart disease and strokes are hypertension and high levels of homocysteine in blood serum. The coexistence of these two factors significantly increases the risk of these diseases and premature deaths. Many studies indicate that patients with hypertension are significantly more likely to demonstrate increased blood serum homocysteine levels than those with normal blood pressure. This may be caused by a higher incidence of overweight, high intake of salt and increased uric acid levels. It has been shown that both these factors increase the prevalence of hypertension and lead to higher homocysteine levels. However, the results of some studies indicate that arterial hypertension and homocysteinemia are causally related. It was shown, among other things, that high homocysteine levels damage the endothelium and reduce nitric oxide synthesis, which may directly lead to hypertension. Serum homocysteine levels are slightly higher in patients with white coat hypertension than they are in healthy individuals and may therefore also increase the risk of cardiovascular diseases. Several authors have also shown that the levels of homocysteine in blood serum are higher in so-called non-dippers, i.e., patients with no night-time pressure drop. The lack of a 10%–20% decrease in blood pressure at night is associated with increased cardiovascular complications. Strokes occur especially frequently in older people with arterial hypertension and hyperhomocysteinemia. The administration of B vitamins and folic acid significantly reduces serum homocysteine levels. The administration of this acid also slightly, but statistically significantly, increases the effectiveness of hypotensive drugs. Large meta-analyses meta-analysis indicate that the increased supply of folic acid in patients with hypertension significantly reduces the risk of stroke. Such management is particularly effective in patients with hypertension and hyperhomocysteinemia.

Homocysteine - from disease biomarker to disease prevention

We have reviewed the literature and have identified more than 100 diseases or conditions that are associated with raised concentrations of plasma total homocysteine. The commonest associations are with cardiovascular diseases and diseases of the central nervous system, but a large number of developmental and age-related conditions are also associated. Few other disease biomarkers have so many associations. The clinical importance of these associations becomes especially relevant if lowering plasma total homocysteine by B vitamin treatment can prevent disease and so improve health. Five diseases can at least in part be prevented by lowering total homocysteine: neural tube defects, impaired childhood cognition, macular degeneration, primary stroke, and cognitive impairment in the elderly. We conclude from our review that total homocysteine values in adults of 10 μmol/L or below are probably safe, but that values of 11 μmol/L or above may justify intervention. Homocysteine is more than a disease biomarker: it is a guide for the prevention of disease.

The association of physical activity on homocysteine in pregnant women

INTRODUCTION

Women with high levels of physical activity have improved pregnancy, labor, and delivery outcomes related to cardiovascular health. Hyperhomocysteinemia, which predicts cardiovascular disease risk, is associated with maternal vascular complications during pregnancy, such as placental abruption and preeclampsia. However, studies are lacking on whether physical activity impacts homocysteine in pregnant women, pointing to a potential mechanism behind the improved cardiovascular health in women who exercise during pregnancy. The purpose of this study was to examine if women with high levels of physical activity have lower levels of homocysteine compared to women with low levels of physical activity.

METHODS

This study was a secondary analysis using data from the 2003 to 2006 National Health and Nutrition Examination Survey. A total of 257 pregnant women were included. Physical activity was assessed objectively over seven days with accelerometers. High and low groups based on moderate-to-vigorous physical activity (MVPA) and steps/day were defined. Homocysteine and related laboratory biomarkers (vitamin B12, folate, pyridoxal 5'-phosphate) were assessed through blood draws. Data assembly was performed using SAS and analysis via SPSS Complex Samples.

RESULTS

Only an estimated 17.7 ± 4.7% of women met guidelines to achieve at least 150 min per week of MVPA. Plasma homocysteine was not different between pregnant women with high and low levels of moderate-to-vigorous physical activity (4.39 ± 0.21 and 4.44 ± 0.17 µmol/L; p > .05) or between those with high and low levels of steps (3.95 ± 0.26 and 4.62 ± 0.27 µmol/L; p > .05) when the data was split into two quantiles by the median. These results were similar when using log-transformed values for homocysteine to normalize the distribution of data. Pregnant women in the group of the high steps tended to have higher vitamin B12, folate, and pyridoxal 5'-phosphate than those in the group of the low steps. Sensitivity analyses revealed that homocysteine was not different between the upper 25% (4.04 ± 0.22 µmol/L) and lower 25% (4.17 ± 0.26 µmol/L) MVPA (p = .716) but that it was statistically higher in the low (<5000 steps/day) (4.99 ± 0.20 µmol/L) steps/day group compared to high (>7500 steps/day) steps/day (3.99 ± 0.23 µmol/L) (p = .003) after excluding individuals with hypertension and thyroid/kidney issues.

CONCLUSION

Maternal steps/day, but not MVPA, appear to be associated with homocysteine (albeit weakly) in the present study after excluding potential factors which impact homocysteine. The volume of physical activity appears to be an important indicator as this difference was not revealed until the physical activity was more distinctly separated.

Gender differences in risk factors for high plasma homocysteine levels based on a retrospective checkup cohort using a generalized estimating equation analysis

Background

Hyperhomocysteinemia (HHcy) is associated with various health problems, but less is known about the gender differences in risk factors for high plasma homocysteine (Hcy) levels.

Methods

In this study, a retrospective study was carried out on 14,911 participants (7838 males and 7073 females) aged 16–102 years who underwent routine checkups between January 2012 and December 2017 in the Health Management Department of Xuanwu Hospital, China. Anthropometric measurements, including body mass index (BMI) and waist-to-hip ratio, were collected. Fasting blood samples were collected to measure the biochemical indexes. The outcome variable was Hcy level, and a generalized estimating equation (GEE) analysis was used to identify the associations of interest based on gender.

Results

Males exhibited increased Hcy levels (16.37 ± 9.66 vs 11.22 ± 4.76 μmol/L) and prevalence of HHcy (37.0% vs 11.3%) compared with females. Hcy levels and HHcy prevalence increased with age in both genders, except for the 16- to 29-year-old group. GEE analysis indicated that irrespective of gender, aspartate aminotransferase, creatinine, uric acid, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels were positively correlated with Hcy levels, and alanine aminotransferase, total cholesterol and glucose were negatively correlated with Hcy levels. However, age, BMI and triglycerides (TGs) were positively correlated with Hcy levels exclusively in females.

Conclusions

Gender differences in risk factors for high plasma Hcy levels were noted. Although common correlational factors existed in both genders, age, BMI and TGs were independent risk factors for Hcy levels specifically in females.

Classical homocystinuria, is it safe to exercise?

Background Cystationine β-synthase (CBS) deficiency is a genetic disorder characterized by severe hyperhomocysteinemia and thrombotic complications. In healthy individuals, physical exercise may result in a transient increase in plasma total homocysteine (tHcy) raising the possibility that exercise might be detrimental in CBS deficiency. Our main objective was to determine plasma tHcy kinetics in response to physical exercise in homocystinuria patients. Methods Six adult patients (2 males, 4 females) with homocystinuria and 6 age- and gender-matched controls completed a 30-min aerobic exercise of moderate-intensity with fixed power output (50 W for women and 100 W for men). Blood samples were drawn before, immediately, 180 min and 24 h after exercise. tHcy levels were determined by standard procedures; substrate oxidation and energy expenditure were measured using indirect calorimetry. Results Acute exercise was well tolerated and safe in patients and controls. During the exercise bout, heart rate and energy expenditure increased equally in both groups. tHcy levels were higher in patients compared to controls at all time points (p < 0.05). There was no significant effect of exercise on tHcy levels at any time point (p = 0.36). Although two patients with partial pyridoxine responsiveness presented higher homocysteine responses, their highest value remained below 55 μmol/l. Conclusions Overall metabolic responses to acute exercise were similar between homocystinuria patients and controls; specifically, exercise did not significantly change tHcy concentrations. Moderate physical exercise was well tolerated without any adverse event in our cohort of patients. Further studies are needed to identify the effects of different intensities and modes of exercise in larger cohorts of CBS patients with different levels of pyridoxine responsiveness.

High Serum Folate Concentrations Are Associated with Decreased Risk of Mortality among Japanese Adults

BACKGROUND

Folate and vitamin B-12 are essential nutrients for normal cell growth and replication, but the association of serum folate and vitamin B-12 concentrations with mortality risk remains uncertain.

OBJECTIVE

This study was performed to investigate the associations of serum folate and vitamin B-12 concentrations with mortality risk and test whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism modifies these associations.

METHODS

A total of 3050 Japanese community residents aged ≥40 y were prospectively followed-up for mortality between 2002 and 2012. Cox proportional hazards models and restricted cubic splines were used to estimate HRs and 95% CIs of mortality.

RESULTS

During a median follow-up period of 10.2 y, 336 participants died. Higher serum folate concentrations were associated with lower risks of all-cause mortality [multivariable-adjusted HR: 0.73; 95% CI: 0.56, 0.96 for the second tertile (8.8-12.2 nmol/L; median 10.4 nmol/L) and HR: 0.61; 95% CI: 0.46, 0.80 for the third tertile (≥12.5 nmol/L; median 15.6 nmol/L) serum folate concentrations compared with the first tertile (≤8.6 nmol/L; median 7.0 nmol/L)]. This association remained significant in all sensitivity analyses. Spline analyses showed a steady decline in all-cause mortality risk with increasing serum folate concentrations up to 20-25 nmol/L. This association persisted regardless of the MTHFR C677T genotypes. For serum vitamin B-12, the multivariable-adjusted HR of 1.32 (95% CI: 0.97, 1.79) of all-cause mortality was marginally significantly greater in the first tertile compared with the second tertile. This association was attenuated and nonsignificant after the exclusion of participants with a history of cardiovascular disease or cancer, or participants aged ≥85 y at baseline, or deaths in the first 3 y of follow-up.

CONCLUSIONS

Serum folate concentrations were inversely associated with the risk of all-cause mortality in Japanese adults. Serum vitamin B-12 concentrations were not consistently associated with all-cause mortality risk after accounting for reverse-causation bias.

The effect of physical activity on total homocysteine concentrations and cardiovascular risk in older Brazilian adults with type 2 diabetes

A low level of physical activity has a potential association with high levels of homocysteine, which implies an increased chance of older adults with type 2 diabetes mellitus developing cardiovascular disease (CVD). However, the effects of physical activity on homocysteine levels have been poorly explored in the literature. Therefore, this study compared homocysteine levels and cardiovascular risk among physically active and inactive older women with type 2 diabetes mellitus. Fifty-nine women with type 2 diabetes mellitus, between 60 and 91 years old, were evaluated. The level of physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) long version to identify active and inactive older women. Blood samples were collected and anthropometric, body composition, and blood pressure measurements were performed to determine homocysteine levels and cardiovascular risk. The results demonstrated that active older women with type 2 diabetes mellitus have lower homocysteine values (F = 17.79, p < 0.001, ηp² = 0.238), cardiovascular risk scores (F = 15.84, p = p < 0.001, ηp² = 0.217), and waist circumferences (F = 2.95, p = 0.013, ηp² = 0.049) when compared with inactive older women. It was concluded that there was a difference in the levels of homocysteine, cardiovascular risk, and waist circumference between active and inactive older women with type 2 diabetes. Active older women are less likely to have cardiovascular risk than inactive older women.

Impact of combined elevations of homocysteine and asymmetric dimethylarginine on all-cause death - The Tanushimaru Study

BACKGROUND

Both homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) induce endothelial dysfunction. However, the impact of both elevations on all-cause death is not known. We investigated the association between elevations of Hcy or ADMA and all-cause death in a general population.

METHODS

A total of 517 subjects (224 men, 293 women; mean age, 62.8 years) were recruited from a population-based survey in 1999 in Tanushimaru, and we measured fasting plasma Hcy and ADMA levels. We followed them up for over 20 years and examined the effect on mortality using Cox proportional hazard regression model.

RESULTS

The mean follow-up years were 17.7 (1.8-20.8). In this period, 182 subjects have died (35.2%). The correlation between Hcy and ADMA was high (r=0.194; p<0.001). With Cox regression analysis after adjustments for age and sex, elevated log transformed Hcy levels were significantly associated with all-cause death (p=0.028). When Hcy and ADMA levels were divided into quintiles, the hierarchical model showed the synergistic effect of Hcy and ADMA on all-cause death.

CONCLUSIONS

This is the first report that we have measured Hcy and ADMA levels simultaneously in this community-dwelling Japanese, and we demonstrated that combined elevations of Hcy and ADMA had big impact on all-cause death in this epidemiological study.

The Link between Exercise and Homocysteine in the Alzheimer's Disease: A Bioinformatic Network Model

Elevated peripheral expression of homocysteine (Hcy) is associated with an increased risk of coronary heart disease and stroke, diabetes, and cancer. It is also associated with cognitive impairment as it has been reported that high levels of Hcy cause cognitive dysfunction and memory deficit. Among several etiological factors that contribute to the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD), Hcy seems to directly contribute to the generation of neurotoxicity factors. This study aims to hypothesize the molecular mechanism by which exercise can reduce the risk of neurological complications promoted by hyperhomocysteinemia (HHcy), and discuss how exercise could reduce the risk of developing AD by using bioinformatics network models. According to the genes network, there are connections between proteins and amino acids associated with Hcy, exercise, and AD. Studies have evidenced that exercise may be one of several processes by which acid nitric availability can be maximized in the human body, which is particularly important in reducing cell loss and tau pathology and, thereby, leading to a reduced risk of complications associated with HHcy and AD.

The Importance of Telomere Shortening for Atherosclerosis and Mortality

Telomeres are the protective end caps of chromosomes and shorten with every cell division. Short telomeres are associated with older age and adverse lifestyle factors. Leucocyte telomere length (LTL) has been proposed as a biomarker of biological age. The shortening of LTL with age is the result of the end-replication problem, environmental, and lifestyle-related factors. Epidemiologic studies have shown that LTL predicts cardiovascular disease, all-cause mortality, and death from vascular causes. Age appears to be an important co-variate that explains a substantial fraction of this effect. Although it has been proposed that short telomeres promote atherosclerosis and impair the repair of vascular lesions, existing results are inconsistent. Oxidative stress and chronic inflammation can both accelerate telomere shortening. Multiple factors, including homocysteine (HCY), vitamin B6, and vitamin B12 modulate oxidative stress and inflammation through direct and indirect mechanisms. This review provides a compact overview of telomere physiology and the utility of LTL measurements in atherosclerosis and cardiovascular disease. In addition, it summarizes existing knowledge regarding the impact of oxidative stress, inflammation, HCY, and B-vitamins on telomere function.

Influence of Dietary Supplementation for Hyperhomocysteinemia Treatments

Hyperhomocysteinemia is recognized as risk factor for cardiovascular and age-associated diseases. Folic acid supplementation efficiently lowers plasma homocysteine (Hcy) levels, but high intake may negatively affect health because of unnatural levels of unmetabolized folic acid in the systemic circulation. Oxoproline (Oxo) provides by glutamic acid production an increase of intracellular folic acid trapping. Aim of this study was to compare the efficacy of three supplementation protocols: (1) traditional therapy (5-methyl-tetrahydrofolate: 15 mg/day); (2) 5 mL/day of Oxo with 300 μg folic acid (oxifolic); (3) 5 mL/day of Oxo alone (magnesio+) in a 90 days randomized trial on thirty-two moderate hyperhomocysteinemic (18.6 ± 2.4 μmol.L-1) patients (age 48 ± 14 yrs). Thiols: cysteine (Cys), cysteinylglycine (Cys-Gly) and glutathione levels were assessed too. Every supplementation induced significant (p range <0.05-0.0001) reductions of Hcy level and Cys concentration after the three protocols adopted. Otherwise glutathione concentration significantly increased after oxifolic (p < 0.01) and traditional (p < 0.05) supplementation. The integration of Oxo resulted an interesting alternative to traditional therapy because absence or minimal number of folates in the integrator eliminates any chance of excess that can constitute a long-term risk.

Relative Validity of Dietary Total Antioxidant Capacity for Predicting All-Cause Mortality in Comparison to Diet Quality Indexes in US Adults

While traditionally diet quality index scores (DQIS) as noted later in this abstract have been used to predict health outcomes, dietary total antioxidant capacity (TAC), a useful tool for assessing total antioxidant power in the diet, may also be a novel predictor. This study evaluated the associations between dietary TAC and DQIS and all-cause mortality. Based on the National Health and Nutrition Examination Survey (NHANES) 1988-1994 and 1999-2006, 23,797 US adults were followed-up until 2015. Dietary TAC and DQIS including the Healthy Eating Index-2015 (HEI-2015), Alternative Healthy Eating Index-2010 (AHEI-2010), alternate Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH) were calculated using a 1-day 24 h dietary recall. US adults in the highest quintiles of DQIS had lower rates of all-cause mortality compared to those in the lowest quintiles (HEI-2015 hazard ratio (HR): 0.87, 95% confidence interval (CI): 0.77-0.98; AHEI-2010 HR: 0.84, 95% CI: 0.74-0.94; aMED HR: 0.79, 95% CI: 0.69-0.90; DASH HR: 0.80, 95% CI: 0.70-0.92). Similarly, those in the highest quintile of dietary TAC also had a lower all-cause mortality than those in the lowest quintile (HR: 0.88, 95% CI: 0.79-0.98). These findings suggest that dietary TAC might be a relatively valid predictor of all-cause mortality in the US population compared to the DQIS.

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 ).

Using synthetic datasets to bridge the gap between the promise and reality of basing health-related decisions on common single nucleotide polymorphisms

Background: While the academic genetic literature has clearly shown that common genetic single nucleotide polymorphisms (SNPs), and even large polygenic SNP risk scores, cannot reliably be used to determine risk of disease or to personalize interventions, a significant industry of companies providing SNP-based recommendations still exists. Healthcare practitioners must therefore be able to navigate between the promise and reality of these tools, including being able to interpret the literature that is associated with a given risk or suggested intervention. One significant hurdle to this process is the fact that most population studies of common SNPs only provide average (+/- error) phenotypic or risk descriptions for a given genotype, which hides the true heterogeneity of the population and reduces the ability of an individual to determine how they themselves or their patients might truly be affected. Methods: We generated synthetic datasets generated from descriptive phenotypic data published on common SNPs associated with obesity, elevated fasting blood glucose, and methylation status. Using simple statistical theory and full graphical representation of the generated data, we developed a method by which anybody can better understand phenotypic heterogeneity in a population, as well as the degree to which common SNPs truly drive disease risk. Results: Individual risk SNPs had a <10% likelihood of effecting the associated phenotype (bodyweight, fasting glucose, or homocysteine levels). Example polygenic risk scores including the SNPs most associated with obesity and type 2 diabetes only explained 2% and 5% of the final phenotype, respectively. Conclusions: The data suggest that most disease risk is dominated by the effect of the modern environment, providing further evidence to support the pursuit of lifestyle-based interventions that are likely to be beneficial regardless of genetics.

Telomere length, vitamin B12 and mortality in persons undergoing coronary angiography: the Ludwigshafen risk and cardiovascular health study

Background: Vitamin B12 (B12) deficiency and excess are associated with increased risk of age-related-diseases and mortality. It has been suggested that high- and low-B12 concentrations link to increased mortality through accelerated genomic aging and inflammation. Evidence to support this is limited.

Results: B12 was associated with all-cause-mortality, RTL and hsCRP in a non-linear fashion. The association between B12 and mortality was not independent, as it lost significance after adjustment for potential confounders. In the lowest-(LB12) and highest-(HB12) quartiles of B12 mortality was higher than in the mid-range (HR:LB12:1.23;CI95%:1.06-1.43; HR:HB12:1.24;CI95%:1.06-1.44). We divided subjects with LB12 in quartiles of their RTL. Those with the longest-telomeres had a lower mortality-rate (HR:0.57;95%CI:0.39-0.83) and lower homocysteine than those with the shortest-telomeres. Amongst subjects with HB12, those with long-telomeres also had a lower mortality than those with short-telomeres (HR:0.40;95%CI:0.27-0.59). IL-6 and hsCRP concentrations were low in HB12LT but were high in HB12ST.

Methods: B12, homocysteine, telomere length (RTL), interleukin-6 (IL-6) and high-sensitive-C-reactive-protein (hsCRP) were measured in 2970 participants of the LURIC study.

Conclusions: Mortality, stratified according to B12 and RTL, seems to be driven by different mechanisms. In LB12 and HB12 subjects, mortality and accelerated telomere shortening might be driven by homocysteine and inflammation, respectively.

Subclinical inflammation, telomere shortening, homocysteine, vitamin B6, and mortality: the Ludwigshafen Risk and Cardiovascular Health Study

Purpose

Short telomeres and B vitamin deficiencies have been proposed as risk factors for age-related diseases and mortality that interact through oxidative stress and inflammation. However, available data to support this concept are insufficient. We aimed to investigate the predictive role of B vitamins and homocysteine (HCY) for mortality in cardiovascular patients. We explored potential relationships between HCY, B vitamins, relative telomere length (RTL), and indices of inflammation.

Methods

Vitamin B6, HCY, interleukin-6 (IL-6), high-sensitive-C-reactive protein (hs-CRP), and RTL were measured in participants of the Ludwigshafen Risk and Cardiovascular Health Study. Death events were recorded over a median follow-up of 9.9 years.

Results

All-cause mortality increased with higher concentrations of HCY and lower vitamin B6. Patients in the 4th quartile of HCY and vitamin B6 had hazard ratios (HR) for all-cause mortality of 2.77 (95% CI 2.28–3.37) and 0.41(95% CI 0.33–0.49), respectively, and for cardiovascular mortality of 2.78 (95% CI 2.29–3.39) and 0.40 (95% CI 0.33–0.49), respectively, compared to those in the 1st quartile. Multiple adjustments for confounders did not change these results. HCY and vitamin B6 correlated with age-corrected RTL (r = − 0.086, p < 0.001; r = 0.04, p = 0.031, respectively), IL-6 (r = 0.148, p < 0.001; r = − 0.249, p < 0.001, respectively), and hs-CRP (r = 0.101, p < 0.001; r = − 0.320, p < 0.001, respectively). Subjects with the longest telomeres had a significantly higher concentration of vitamin B6, but lower concentrations of HCY, IL-6, and hs-CRP. Multiple regression analyses identified HCY as an independent negative predictor of age-corrected RTL.

Conclusions

In conclusion, hyperhomocysteinemia and vitamin B6 deficiency are risk factors for death from any cause. Hyperhomocysteinemia and vitamin B6 deficiency correlate with increased mortality. This correlation might, at least partially, be explained by accelerated telomere shortening induced by oxidative stress and systemic inflammation in these circumstances.

Electronic supplementary material

The online version of this article (10.1007/s00394-019-01993-8) contains supplementary material, which is available to authorized users.

Homocysteine and age-associated disorders

There are numerous theories of aging, a process which still seems inevitable. Aging leads to cancer and multi-systemic disorders as well as chronic diseases. Decline in age- associated cellular functions leads to neurodegeneration and cognitive decline that affect the quality of life. Accumulation of damage, mutations, metabolic changes, failure in cellular energy production and clearance of altered proteins over the lifetime, and hyperhomocysteinemia, ultimately result in tissue degeneration. The decline in renal functions, nutritional deficiencies, deregulation of methionine cycle and deficiencies of homocysteine remethylation and transsulfuration cofactors cause elevation of homocysteine with advancing age. Abnormal accumulation of homocysteine is a risk factor of cardiovascular, neurodegenerative and chronic kidney disease. Moreover, approximately 50% of people, aged 65 years and older develop hypertension and are at a high risk of developing cardiovascular insufficiency and incurable neurodegenerative disorders. Increasing evidence suggests inverse relation between cognitive impairment, cerebrovascular and cardiovascular events and renal function. Oxidative stress, inactivation of nitric oxide synthase pathway and mitochondria dysfunction associated with impaired homocysteine metabolism lead to aging tissue degeneration. In this review, we examine impact of high homocysteine levels on changes observed with aging that contribute to development and progression of age associated diseases.

Impaired Homocysteine Metabolism Associated with High Plasma Interleukin-17A Levels, a Pro-Atherogenic Marker, in an Endogamous Population of North India

Background

Impaired homocysteine metabolism (IHM; hyperhomocysteinemia) has been linked with many complex disorders like cardiovascular diseases and immunological disturbances. However, studies understanding IHM in light of pro- and anti- atherogeneic markers like Interleukin-17A & -10 (IL-17A & IL-10) and Forkhead box p3 (Foxp3, a master transcription factor) are scarce.

Aim

In our present study, we aimed to understand the relation of IHM with plasma IL-17A and IL-10 levels and Foxp3 mRNA expression in peripheral blood mononuclear cells (PBMCs) from an endogamous population (Jats of Haryana, North India) with high prevalence of IHM without the concurrence of significant adverse cardiovascular outcomes.

Methods

Forty (40) clinically healthy individuals, unrelated up to first cousins, were recruited and were subjected to demographic, physiological and anthropometric profiling, followed by intravenous blood sample collection (fasting) and lipid profiling. Plasma homocysteine levels were estimated and individuals with homocysteine levels ≥ 15umol/L and <15umol/L were categorized as the impaired homocysteine metabolism group (IHM, n=30) and normal homocysteine metabolism group (NHM, n=10) respectively. Plasma folate and vitamin B12 and MTHFR C677T (methylenetetrahydrofolate reductase) polymorphism were detected. Relative mRNA expression of Foxp3 in PBMCs (normalized to 18S) was quantitated using SyBR green technology. Plasma IL-10 & 17 levels were estimated by ELISA assays.

Results and Conclusions

None of the physiological, anthropometric and lipid variables were different between the two groups. Foxp3 mRNA expression levels were relatively lower, and plasma IL-10 levels were found to be comparable among IHM and NHM group. However, significantly higher IL-17A levels and relatively high LDL cholesterol levels were present in the IHM group as compared with NHM. Our findings suggest that the Jats of Haryana, North India, exhibiting high levels of homocysteine, might also carry the high IL-17A -pro-atherogenic marker, suggesting an increasing burden of pre-morbid condition. This apparently does not reach to significant mortality/morbidity attributed to the counter action or balancing act of IL-10 (an anti-atherogenic marker). This further suggests environment-influenced epigenetic control mechanisms of the targeted genes in the present population.