Effect of cigarette smoking on plasma homocysteine concentrations

Bridging the gap: Navigating the impact of dietary supplements on abdominal aortic aneurysm progression- A systematic review

BACKGROUND

Vitamins D, E, A, B, C, and Omega-3 play crucial roles in modulating inflammatory and oxidative stress pathways, both implicated in abdominal aortic aneurysm (AAA) development. Recent research has explored the potential impact of dietary supplements on AAA progression. The systematic review aims to assess interventional studies investigating the effects of various dietary supplements on the development and severity of abdominal aortic aneurysms.

METHOD

A systematic search using relevant keywords related to abdominal aortic aneurysm and dietary supplements was conducted across four databases (PubMed, Embase, Scopus, and Web of Science). Quality assessment for animal studies employed SYRCLE and the Cochrane Collaboration Risk of Bias Tool for randomized control trials. The study protocol is registered in PROSPERO under the registry code CRD42023455958.

RESULTS

Supplementation with Omega-3, Vitamins A, C, D, E, and the Vitamin B family exhibited positive effects in AAA progression. These supplements contributed to a reduction in AAA diameter, elastin degradation, inflammatory responses, and reactive oxygen species. Additional supplements such as Zinc, methionine, and phytoestrogen also played roles in mitigating AAA progression.

CONCLUSION

The findings of this study underscore the potential role of dietary supplements in the progression of AAA. Predominantly based on animal studies, the results indicate that these supplements can limit AAA progression, primarily evidenced by their ability to mitigate inflammatory processes and oxidative stress pathways.

Association between Homocysteine and Vitamin D Levels in Asymptomatic Korean Adults

An increased homocysteine level is a risk factor for cardiovascular disease, venous thromboembolism, cerebrovascular disease, and chronic kidney disease. In addition, vitamin D deficiency is associated with coronary artery disease and metabolic disorders. The present study included data from 1375 adults (895 men and 480 women) with a mean age of 52.62 ± 9.94 years who visited the Health Promotion Center of the University Hospital in Gyeonggi-do, Republic of Korea from January 2018 to December 2022 for routine checkups that included assessments of their homocysteine and vitamin D levels. Homocysteine levels were positively associated with age, a history of hypertension, a history of diabetes, current smoking habits, and levels of low-density lipoprotein cholesterol, creatinine, uric acid, and high-sensitivity C-reactive protein. By contrast, vitamin D levels were negatively associated with serum levels of homocysteine after adjusting for covariates (β = -0.033, p < 0.001). Additional long-term prospective studies are needed to elucidate the presence of a causal relationship between vitamin D status and serum levels of homocysteine in asymptomatic Korean adults. An intervention trial is warranted to determine whether the administration of vitamin D is helpful for the primary prevention of cardiovascular disease by lowering the homocysteine level in this population.

Comprehensive transcriptomics and metabolomics analyses reveal that hyperhomocysteinemia is a high risk factor for coronary artery disease in a chinese obese population aged 40-65: a prospective cross-sectional study

BACKGROUND

Clinical observations suggest a complex relationship between obesity and coronary artery disease (CAD). This study aimed to characterize the intermediate metabolism phenotypes among obese patients with CAD and without CAD.

METHODS

Sixty-two participants who consecutively underwent coronary angiography were enrolled in the discovery cohort. Transcriptional and untargeted metabolomics analyses were carried out to screen for key molecular changes between obese patients with CAD (CAD obese), without CAD (Non-CAD obese), and Non-CAD leans. A targeted GC-MS metabolomics approach was used to further identify differentially expressed metabolites in the validation cohorts. Regression and receiver operator curve analysis were performed to validate the risk model.

RESULTS

We found common aberrantly expressed pathways both at the transcriptional and metabolomics levels. These pathways included cysteine and methionine metabolism and arginine and proline metabolism. Untargeted metabolomics revealed that S-adenosylhomocysteine (SAH), 3-hydroxybenzoic acid, 2-hydroxyhippuric acid, nicotinuric acid, and 2-arachidonoyl glycerol were significantly elevated in the CAD obese group compared to the other two groups. In the validation study, targeted cysteine and methionine metabolomics analyses showed that homocysteine (Hcy), SAH, and choline were significantly increased in the CAD obese group compared with the Non-CAD obese group, while betaine, 5-methylpropanedioic acid, S-adenosylmethionine, 4-PA, and vitamin B2 (VB2) showed no significant differences. Multivariate analyses showed that Hcy was an independent predictor of obesity with CAD (hazard ratio 1.7; 95%CI 1.2-2.6). The area under the curve based on the Hcy metabolomic (HCY-Mtb) index was 0.819, and up to 0.877 for the HCY-Mtb.index plus clinical variables.

CONCLUSION

This is the first study to propose that obesity with hyperhomocysteinemia is a useful intermediate metabolism phenotype that could be used to identify obese patients at high risk for developing CAD.

Homocysteine as a potential indicator of endothelial dysfunction and cardiovascular risk in female patients with borderline personality disorder

BACKGROUND

There is increasing evidence suggesting that patients with Borderline Personality Disorder (BPD) are at greater risk of developing cardiovascular diseases (CVD) compared to the general population. Homocysteine (Hcy) has been discussed as a serum marker for endothelial dysfunction as a mechanism involved in CVD and has been shown to be associated with numerous psychiatric conditions. Pathophysiologically, there seems to be a link between Hcy and psychological stress mediated by abnormal activity of the autonomic nervous system. Accordingly, the present study sought to examine Hcy in BPD and to explore possible associations with clinical parameters.

METHODS

Plasma Hcy levels as well as conventional cardiovascular risk factors, such as blood pressure, BMI, smoking habits, HbA_1c, HDL, LDL, and cholesterol, were examined in 49 young female in-patients diagnosed with BPD and 50 psychologically healthy control subjects matched for age and sex. Assessment of borderline symptom severity, childhood trauma, exposure to chronic stress, and quality of sleep was performed using self-reported questionnaires.

RESULTS

BPD patients showed significantly higher mean plasma Hcy concentrations compared to controls, though below ranges considered pathological. Moreover, Hcy correlated significantly with the severity of childhood trauma, chronic stress, and subjective sleep disturbances. In a regression model BPD diagnosis was found to predict Hcy levels best.

CONCLUSION

In conclusion, young female BPD patients with no history of CVD show higher, though non-pathological, Hcy levels compared to healthy controls. Our findings seem to support the assumption that BPD is associated with increased risk of CVD, and that Hcy could serve as potential marker for risk evaluation of midlife CVD in BPD patients.

Plasma Cotinine Is Positively Associated with Homocysteine in Smokers but Not in Users of Smokeless Tobacco

Plasma total homocysteine (tHcy) is a risk marker, and smoking is an established risk factor for cardiovascular disease. It is unclear if the effect of smoked tobacco on homocysteine is mediated by nicotine or other combustion products in smoked tobacco. Snus (moist smokeless tobacco) is high nicotine-containing tobacco, and little is known about the effect of snus on plasma homocysteine. Therefore, we studied, in a cross-section of subjects (n = 1375) from the Northern Sweden Health and Disease Study, with strictly defined current smokers (n = 194) and snus users (n = 47), the impact of tobacco exposure on tHcy, assessed by self-reported tobacco habits and plasma cotinine concentrations. The snus users had higher cotinine concentrations than the smokers. Cotinine, creatinine, methylmalonic acid, and the methylenetetrahydrofolate reductase genotype (MTHFR) T allele were positively associated with tHcy among the smokers, but not among the snus users. No association was observed between tHcy and the number of cigarettes/day. There was a positive association between cotinine and tHcy in the smokers, but not among the snus users. This indicates that substances other than nicotine in tobacco smoke could be responsible for the differential effects on homocysteine status. Self-reported smoking should be complemented by a cotinine assay whenever possible.

Combined effect of hyperhomocysteinemia and smoking on the severity of coronary artery disease in young adults ≤ 35 years of age: a hospital-based observational study

Background

The prevalence of coronary artery disease (CAD) continues to increase among young Chinese adults. Current smoking has been recognized as a major risk factor for premature CAD, and hyperhomocysteinaemia (HHcy) has also been suggested to be associated with CAD progression. However, the combined effect of current smoking and HHcy on the severity of coronary artery stenosis in young adults is still uncertain.

Methods

We consecutively collected young patients (18–35 years of age), diagnosed with CAD and underwent coronary angiography (CAG) at Anzhen Hospital between January 2013 and May 2020. HHcy was defined as serum homocysteine (Hcy) level > 15 µmol/L. The severity of coronary artery stenosis was evaluated by Gensini Score. The co-effect of current smoking and HHcy on CAD severity as well as the relationship between plasma Hcy, pack-years of smoking and CAD severity were assessed by multivariate linear regression analysis.

Results

A total of 989 participants (mean age, 33 years; 96.2% male) fulfilling the criteria were enrolled in this study. Patients with both HHcy and current smoking accounted for 39.1% of all the subjects. Multivariate liner analysis indicated both serum Hcy levels (β 0.302; 95% CI 0.141–0.462; P < 0.001) and pack-years of smoking (β 0.523; 95% CI 0.265–0.781; P < 0.001) were independently associated with the severity of coronary artery stenosis after adjusting for other traditional confounders. In addition, serum Hcy levels were correlated with pack-years of smoking in young CAD patients (r = 0.116, P = 0.001). Moreover, combination of HHcy and current smoking was suggested to have higher risk for CAD severity (β 17.892; 95% CI 11.314–24.469; P < 0.001), compared with HHcy (β 7.471; 95% CI 0.009–14.934; P = 0.048) or current smoking (β 7.421; 95% CI 0.608–14.233; P = 0.033) alone.

Conclusion

Combination of HHcy and smoking is independently associated with the severity of CAD in young patients ≤ 35 years of age.

Urinary arsenic species and methylation efficiency during pregnancy: Concentrations and associated factors in Spanish pregnant women

BACKGROUND

Arsenic (As) is considered to be toxic for humans, the main routes of exposure being through drinking water and the diet. Once ingested, inorganic arsenic can be methylated sequentially to monomethyl and dimethyl arsenicals. Several factors can affect both As exposure and methylation efficiency.

OBJECTIVES

To describe the urinary concentrations of the different As species and evaluate the methylation efficiency during pregnancy, as well as their associated factors in a birth cohort of pregnant Spanish women.

METHODS

Participants in this cross-sectional study were 1017 pregnant women from two areas of Spain who had taken part in the INMA (Environment and Childhood) project (2003-2008). Total As (organic and inorganic compounds) and its main metabolites (monomethylarsonic acid, [MMA], dimethylarsinic acid, [DMA], inorganic As [iAs]) and arsenobetaine [AB]) were measured in urine samples collected during the first trimester. Sociodemographic and dietary information was collected through questionnaires. Multivariate linear regression models were used to explore the association between As species concentrations and covariates. Arsenic methylation efficiency was determined through the percentages of the metabolites and using As methylation phenotypes, obtained from principal component analysis.

RESULTS

Median urine concentrations were 33.0, 21.6, 6.5, 0.35 and 0.33 μg/g creatinine for total As, AB, DMA, MMA and iAs, respectively. Daily consumption of rice and seafood during the first trimester of pregnancy were positively associated with the concentration of As species (i.e., β [CI95%] = 0.36 [0.09, 0.64] for rice and iAs, and 1.06 [0.68, 1.44] for seafood and AB). TAs, AB and iAs concentrations, and DMA and MMA concentrations were associated with legume and vegetable consumption, respectively. The medians of the percentage of As metabolites were 89.7 for %DMA, 5.1 for %MMA and 4.7 for %iAs. Non-smoker women and those with higher body mass index presented a higher methylation efficiency (denoted by a higher %DMA and lower %MMA).

DISCUSSION

Certain dietary, lifestyle, and environmental factors were observed to have an influence on both As species concentrations and methylation efficiency in our population. Further birth cohort studies in low exposure areas are necessary to improve knowledge about arsenic exposure, especially to inorganic forms, and its potential health impact during childhood.

People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Homocysteine and psoriasis

Psoriasis is caused by a complex interplay among the immune system, genetic background, autoantigens, and environmental factors. Recent studies have demonstrated that patients with psoriasis have a significantly higher serum homocysteine (Hcy) level and a higher prevalence of hyperhomocysteinaemia (HHcy). Insufficiency of folic acid and vitamin B₁₂ can be a cause of HHcy in psoriasis. Hcy may promote the immuno-inflammatory process in the pathogenesis of psoriasis by activating Th1 and Th17 cells and neutrophils, while suppressing regulatory T cells. Moreover, Hcy can drive the immuno-inflammatory process by enhancing the production of the pro-inflammatory cytokines in related to psoriasis. Hcy can induce nuclear factor kappa B activation, which is critical in the immunopathogenesis of psoriasis. There may be a link between the oxidative stress state in psoriasis and the effect of HHcy. Hydrogen sulfide (H₂S) may play a protective role in the pathogenesis of psoriasis and the deficiency of H₂S in psoriasis may be caused by HHcy. As the role of Hcy in the pathogenesis of psoriasis is most likely established, Hcy can be a potential therapeutic target for the treatment of psoriasis. Systemic folinate calcium, a folic acid derivative, and topical vitamin B12 have found to be effective in treating psoriasis.

Biochemical and Hematological Correlates of Elevated Homocysteine in National Surveys and a Longitudinal Study of Urban Adults

Elevated blood homocysteine (Hcy) among middle-aged adults can increase age-related disease risk, possibly through other biochemical and hematological markers. We selected markers for hyperhomocysteinemia among middle-aged adults, studied time-dependent Hcy-marker associations and computed highly predictive indices of hyperhomocysteinemia, with cross-sectional and longitudinal validations. We used data from the National Health and Nutrition Examination Survey (NHANES III, phase 2, n_max = 4000), the NHANES 1999–2006 (n_max = 10,151) and pooled NHANES (cross-sectional validation). Longitudinal validation consisted of mixed-effects linear regression models (Hcy predicting markers’ annual rates of change), applied to the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS, n = 227–244 participants, k = 2.4 repeats/participant, Age_base: 30–65 years) data. Machine learning detected nine independent markers for Hcy > 14 µmol/L (NHANES III, phase 2): older age; lower folate and B-12 status; higher serum levels of creatinine, uric acid, alkaline phosphatase, and cotinine; mean cell hemoglobin and red cell distribution widths (RDW); results replicated in the 1999–2006 NHANES [AUC = 0.60–0.80]. Indices combining binary markers increased elevated Hcy odds by 6.9–7.5-fold. In HANDLS, first-visit Hcy predicted annual increase in creatinine, RDW and alkaline phosphatase, with third-visit index (2013–2018) directly predicting Hcy (2004–2009). We provide evidence of the internal and external validity of indices composed of several biomarkers that are strongly associated with elevated Hcy.

Association between smoking status and homocysteine levels and possible effect modification by cholesterol and oestradiol

Introduction: This study aimed to examine the association of smoking status with homocysteine levels and to determine whether the association is modified by oestradiol or cholesterol.Methods: Data (N = 4580) were obtained from National Health and Nutrition Examination Survey 2003-2004 with analysis done in 2018 on adults aged ≥20 years. The outcome was homocysteine; smoking status was the exposure variable and categorized as current, former or never smoker. Generalized linear models were used to examine the associations between smoking status and homocysteine levels, while assessing the impact of oestradiol and cholesterol.Results: After adjusting for age, sex, ethnicity, education and income level, homocysteine levels did differ by smoking status ((current smokers versus never smokers: β: 0.18 CI: 0.00, 0.36), (former smokers: β: 0.10 CI: -0.09, 0.28)). The addition of oestradiol as an interaction term in adjusted models was associated with a 16.6% increase in homocysteine levels when compared to models without the interaction term. Oestradiol but not cholesterol did moderate the association between smoking status and homocysteine levels.Discussion and conclusions: Homocysteine levels did differ across smoking status after adjusting for confounders. Oestradiol did moderate the relationship between homocysteine and smoking status.

Association between shift work and hyperhomocysteinemia in male workers

Background

Shift work is associated with a higher risk of cardiovascular diseases. Here, we sought to assess the relationship between shift work and plasma homocysteine levels. Determining the correlations between shift work and homocysteine levels may provide a better understanding of the mechanisms underlying cardiovascular diseases.

Methods

This study was performed using data from routine health examinations of steel workers in 2017. In total, 431 male workers (70 daytime workers and 361 shift workers) employed on a rolling departure schedule were recruited. Plasma homocysteine levels > 15 μmol/L were considered elevated. The χ², analysis of variance, and multiple logistic regression analyses were used to examine the association between shift work and plasma homocysteine levels.

Results

In comparison to daytime workers, the odds ratio (OR) of hyperhomocysteinemia in individuals with < 10 years of shift work was 1.14 (95% confidence interval [CI]: 0.64–2.03), compared to 2.01 (95% CI: 1.14–3.54) for workers with ≥ 10 years of experience. After adjusting for confounding variables, the adjusted OR for shift workers with < 10 years of experience was 0.95 (95% CI: 0.50–1.80), compared to 2.00 (95% CI: 1.07–3.74) for workers with ≥ 10 years of experience.

Conclusions

The risk of hyperhomocysteinemia was significantly higher in shift workers compared to those working normal daytime hours, particularly among long-term shift workers.

Vitamin B12 Levels in Methamphetamine Addicts

Objective: It has been established that reduced vitamin B12 serum levels are associated with cognitive decline and mental illness. The chronic use of methamphetamine (MA), which is a highly addictive drug, can induce cognitive impairment and psychopathological symptoms. There are few studies addressing the association of MA with vitamin B12 serum levels. This study examined whether the serum levels of B12 are associated with MA addiction.

Methods: Serum vitamin B12, homocysteine (Hcy), glucose and triglyceride concentrations were measured in 123 MA addicts and 108 controls. In addition, data were collected on their age, marital status, level of education and Body Mass Index (BMI) for all participants. In the patient group, the data for each subject were collected using the Fagerstrom Test for Nicotine Dependence (FTND), the Alcohol Use Disorders Identification Test (AUDIT), and a drug use history, which included the age of onset, total duration of MA use, the number of relapses and addiction severity.

Results: Our results showed that MA addicts had lower vitamin B12 levels (p < 0.05) than those of healthy controls, but Hcy levels were not significantly different between the two groups (p > 0.05). Serum B12 levels were negatively correlated with the number of relapses in the MA group. Furthermore, binary logistics regression analysis indicated that the B12 was an influencing factor contributing to addiction severity.

Conclusion: The findings of this study suggest that some MA addicts might have vitamin B12 deficiency, and serum B12 levels may be involved in the prognosis of MA addiction.

Novel Cardiovascular Risk Markers in Nigerian Cigarette Smokers

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity worldwide. While the effect of cigarette smoking on conventional markers that account for <50% of CVD s has been well studied, there are only a few studies on the effect of cigarette smoking on novel cardiovascular (CV) risk markers.

OBJECTIVE

To evaluate the effect of cigarette smoking on the novel CV markers such as homocysteine (HCY), lipoprotein (a) (Lp(a)), and C-reactive protein (CRP).

MATERIALS AND METHODS

One hundred and forty smokers, 12 ex-smokers, and 84 controls were recruited for the study. A structured questionnaire was used to obtain information on their clinical history, daily cigarette consumption, and duration of smoking. The smokers were further grouped according to the amount of cigarette consumption: light (<5 sticks/day), moderate (6-10 sticks/day), and heavy (>10 sticks/day) and duration of smoking: short (5-10 years), medium (11-20 years), and long (>20 years). HCY was determined by enzyme-linked immunosorbent assay method, and Lp(a) and CRP were determined spectrophotometrically.

RESULTS

HCY, Lp(a), and CRP were significantly elevated in smokers when compared with control (P < 0.05) and they correlated with daily cigarette consumption and duration of smoking. Ex-smokers also exhibited a significant increase in HCY, Lp(a), and CRP level (P < 0.05) when compared with the control, but were significantly lower than the current smokers.

CONCLUSION

There is a linear relationship between the intensity and duration of cigarette smoking and serum levels of all three novel risk CV markers. These findings suggest that these markers may be an important mechanism by which smoking promotes atherosclerosis.

Prevalence of hyperhomocysteinemia during routine physical examination in Guangxi Province, China and related risk factors

BACKGROUND

Studies on homocysteine (Hcy) have mainly focused on the correlation between the homocysteine concentration and disease development. Few epidemiological investigations have been performed. This study was conducted to investigate the prevalence of hyperhomocysteinemia (HHcy) during routine physical examination in Guangxi Province, China and the correlation of serum Hcy with gender, age, serum uric acid (UA), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and blood glucose (GLU) to provide evidence for preventing and treating HHcy.

METHODS

Data of 8043 patients who underwent physical examinations at the First Affiliated Hospital of Guangxi Medical University, China from 2015 to 2016 were collected. These data included gender, age, and the serum Hcy, UA, GLU, TC, TG, HDL-C, and LDL-C concentrations.

RESULTS

The overall prevalence of HHcy was 50.8% (52.3% in males, 48.1% in females). Age, UA, TC, TG, and LDL-C were significantly higher and HDL-C was significantly lower in patients with than without HHcy, regardless of gender (all P<.05). The Hcy level was positively correlated with UA, TC, TG, and LDL-C but negatively correlated with HDL-C. Gender, age, UA, TC, and TG were independent risk factors for HHcy.

CONCLUSION

The prevalence of HHcy was very high during routine physical examination in Guangxi Province, China. HHcy was related to gender, age, high concentrations of UA, TC, TG, and LDL-C; and low concentrations of HDL-C. Strengthening early intervention of HHcy can reduce the risk of cardiovascular disease.

Acute Myocardial Infarction in a Young Man with Hyperhomocysteinemia and Pulmonary Tuberculosis

Acute myocardial infarction, hyperhomocysteinemia and pulmonary tuberculosis (PTB) are rare in individuals under the age of 30 years. We herein report the case of a 27-year-old man who presented with intermittent chest pain, elevated homosysteine level, and PTB. The patient was treated successfully with a combination of medications and percutaneous coronary intervention. This uncommon case highlights that homocysteine, folate and B vitamins levels should be regularly evaluated, and that chest X-rays or thoracic computed tomography should be ordered routinely to exclude PTB in patients under the age of 30 years who present acute myocardial infarction and lack the traditional risk factors.

Hyperhomocysteinemia Is Associated with Vitamin B-12 Deficiency: A Cross-sectional Study in a Rural, Elderly Population of Shanxi China

OBJECTIVES

To report the association of lifestyle factors and plasma vitamin B-12 with hyperhomocysteinemia in a large sample of men and women living in a region of China where there is an increased risk of NTDs.

DESIGN

Community-based, cross-sectional study of Lvliang City, Shanxi Province, China.

SETTING

Hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD) and a sensitive marker of vitamin B-12 and folate deficiency.

PARTICIPANTS

A total of 2355 (1044 men and 1311 women) participants born before 1 January 1958 (≥55 years of age) and living in Lvliang City for at least 2 months a year were included.

MEASUREMENTS

The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels.

RESULTS

The median (25th-75th percentile) tHcy concentration was 21.5 (15.8-33.6) µmol/L in men and 18.0 (13.4-24.8) µmol/L in women. The overall prevalence of hyperhomocysteinemia (tHcy ≥15 µmol/L) was 72.6% (84.3% in men and 63.2% in women), inversely correlated with folate (r=-0.230, P=0.006) and vitamin B-12 (r=-0.540, P<0.001), and positively correlated with uric acid (r=0.054, P<0.001). Vitamin B-12 and folate deficiency, older age, and male gender were associated with elevated tHcy; with vitamin B-12 deficiency being the strongest.

CONCLUSIONS

Plasma tHcy concentration and hyperhomocysteinemia were significantly higher in this population than in previously studied populations. Vitamin B-12 and folate supplementation, concomitant lifestyle changes such as smoking cessation, and lipid-lowering treatments may help to decrease plasma tHcy concentrations and reduce the CVD risk in this population.

Study of cardiovascular disease biomarkers among tobacco consumers. Part 3: evaluation and comparison with the US National Health and Nutrition Examination Survey

Cardiovascular disease (CVD) biomarkers of biological effect (BoBE), including hematologic biomarkers, serum lipid-related biomarkers, other serum BoBE, and one physiological biomarker, were evaluated in adult cigarette smokers (SMK), smokeless tobacco consumers (STC), and non-consumers of tobacco (NTC). Data from adult males and females in the US National Health and Nutrition Examination Survey and a single site, cross-sectional study of healthy US males were analyzed and compared. Within normal clinical reference ranges, statistically significant differences were observed consistently for fibrinogen, C-reactive protein (CRP), hematocrit, mean cell volume, mean cell hemoglobin, hemoglobin, white blood cells, monocytes, lymphocytes, and neutrophils in comparisons between SMK and NTC; for CRP, white blood cells, monocytes, and lymphocytes in comparisons between SMK and STC; and for folate in comparisons with STC and NTC. Results provide evidence for differences in CVD BoBE associated with the use of different tobacco products, and provide evidence of a risk continuum among tobacco products and support for the concept of tobacco harm reduction.

Hyperhomocysteinemia and neurologic disorders: a review

Homocysteine (Hcy) is a sulfur-containing amino acid that is generated during methionine metabolism. It has a physiologic role in DNA metabolism via methylation, a process governed by the presentation of folate, and vitamins B6 and B12. Physiologic Hcy levels are determined primarily by dietary intake and vitamin status. Elevated plasma levels of Hcy (eHcy) can be caused by deficiency of either vitamin B12 or folate, or a combination thereof. Certain genetic factors also cause eHcy, such as C667T substitution of the gene encoding methylenetetrahydrofolate reductase. eHcy has been observed in several medical conditions, such as cardiovascular disorders, atherosclerosis, myocardial infarction, stroke, minimal cognitive impairment, dementia, Parkinson's disease, multiple sclerosis, epilepsy, and eclampsia. There is evidence from laboratory and clinical studies that Hcy, and especially eHcy, exerts direct toxic effects on both the vascular and nervous systems. This article provides a review of the current literature on the possible roles of eHcy relevant to various neurologic disorders.

Smokeless tobacco use: a risk factor for hyperhomocysteinemia in a Pakistani population

Background

Smokeless tobacco (ST) use is highly prevalent in the South Asian populations. While there have been a number of reports on association of ST consumption with cancer, very few studies have been conducted to investigate its relationship with cardiovascular disease. Hyperhomocysteinemia is a well-recognized risk factor for cardiovascular disease; however, its association with ST use has never been investigated. The objective of this study was to evaluate the relationship of ST use with hyperhomocysteinemia in an urban Pakistani population.

Methodology/Principal Findings

In a cross-sectional study for assessment of risks of hyperhomocysteinemia, 872 healthy adults (355 males and 517 females of age range 18–60 years) were recruited from a low-income population in Karachi, Pakistan. A detailed questionnaire was administered which included information about smoking, non-smoking, use of ST alone (chewing as well as sniffing) and use of ST with betel nuts. Fasting serum/plasma levels of homocysteine, folate, vitamin B12 and pyridoxal phosphate (PLP; a coenzymic form of vitamin B6) were analyzed. In this population, 43.4% males and 15.5% females were found to be regular users of ST products. Laborers and vendors were the major ST consumers. Smoking was not found to be associated with plasma/serum concentrations of homocysteine, folate, vitamin B12 and PLP. However, homocysteine concentrations in the group which consumed ST alone and the group which consumed ST along with betel nut were significantly higher compared to the non-user group (17.7±7.5 µmol/L, 25.48 µmol/L vs. 11.95 µmol/L, respectively; p<0.01). Odds ratio for the association of hyperhomocysteinemia (>15 µmol/L) was 11-fold higher in the ST-consumer group compared to the non-user group, [OR (95%CI)  = 11.34 (7.58–16.96); p<0.001], when the model was adjusted for age, gender, folate and vitamin B12 status.

Conclusion

This study shows a positive association between ST consumption and hyperhomocysteinemia in a low-income urban Pakistani population.

Dietary folate intake and blood biomarkers reveal high-risk groups in a Mediterranean population of healthy women of childbearing potential

BACKGROUND/AIMS

An important public health issue is monitoring folate inadequacy in women of childbearing potential. The aim of the present study was to investigate associations between folate intake, red blood cell (RBC) folate, total homocysteine (tHcy) and the MTHFR 677T allele.

METHODS

A total of 204 women were enrolled in a cross-sectional study. Folate intake was assessed by a food frequency questionnaire, and RBC folate, tHcy and MTHFR C677T genotype were determined.

RESULTS

About half of the women had a decreased RBC folate level (<305 nmol/l) and all were <906 nmol/l, even though 51% of the subjects reported use of supplements. Overall 91.5% had a high Hcy concentration. Notably, younger women, and those with a low level of education, were shown to be at higher risk of inadequate RBC folate levels. Additionally, younger women were also at higher risk of carrying the TT genotype, particularly unfavorable in the setting of a low folate status.

CONCLUSIONS

Our study revealed significant folate deficiency in our Mediterranean population and higher than ideal Hcy concentrations, thus emphasizing that in these groups an improvement in the folate status is needed via a food-based approach or supplement. Consequently, public health policy strategies aiming at improved supplementation are required.

Nɛ-homocysteinyl-lysine isopeptide is associated with progression of peripheral artery disease in patients treated with folic acid

OBJECTIVE

Folic acid (FA) administration can reduce plasma total homocysteine (tHcy); however, it fails to decrease cardiovascular events and progression of peripheral artery disease (PAD). Nɛ-homocysteinyl-lysine isopeptide (Nɛ-Hcy-Lys) is formed during catabolism of homocysteinylated proteins. We sought to investigate factors that determine the presence of Nɛ-Hcy-Lys in PAD patients with hyperhomocysteinemia receiving FA.

PATIENTS AND METHODS

We studied 131 consecutive PAD patients with tHcy > 15 μmol l(-1) taking FA 0.4 mg d(-1) for 12 months. Serum Nɛ-Hcy-Lys was determined by high-performance liquid chromatography (HPLC). We also measured interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA) and 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)).

RESULTS

FA administration resulted in a 70.5% decrease in tHcy (p < 0.0001). However, serum Nɛ-Hcy-Lys was detectable in 28 (21.4%) patients on FA who were more frequently current smokers and survivors of ischaemic stroke (p < 0.001). They had higher tHcy by 46.0%, PAI-1 by 51.7%, 8-iso-PGF(2α) by 59.1% and ADMA by 26.4% (all, p < 0.0001). The presence of Nɛ-Hcy-Lys was associated with lower ankle-brachial index (ABI) values (p < 0.001) and higher prevalence of cardiovascular events (p < 0.001) following therapy.

CONCLUSION

The presence of Nɛ-Hcy-Lys in one-fifth of hyperhomocysteinemic individuals with PAD despite FA treatment is associated with progression of PAD and with increased ADMA formation, oxidative stress and hypofibrinolysis.