Effect of interaction between adherence to a Mediterranean diet and the methylenetetrahydrofolate reductase 677C-->T mutation on homocysteine concentrations in healthy adults: the ATTICA Study

Egg consumption and risk of coronary artery disease, potential amplification by high genetic susceptibility: a prospective cohort study

BACKGROUND

Remarkable heterogeneity has been observed among population-based studies on egg consumption and risk of coronary artery disease (CAD). Whether genetic susceptibility serves as a potential explanation for this inconsistency remains unknown.

OBJECTIVES

We performed a prospective cohort study to investigate the association of egg consumption with incident CAD at different genetic susceptibilities.

METHODS

We included 34,111 participants without CAD at baseline from the project of Prediction for Atherosclerotic Cardiovascular Disease Risk in China. Egg consumption was assessed with food frequency questionnaires. Genetic susceptibility was quantified by a predefined polygenic risk score (PRS) with 540 genetic variants. The hazard ratio (HR) and 95% confidence interval (95% CI) of incident CAD associated with egg consumption and PRS were estimated using the Cox proportional hazards models.

RESULTS

Over a median 11.7 y of follow-up, 1,128 incident cases of CAD were recorded. Both higher egg consumption and increased PRS were related to higher risk of CAD. When stratified by genetic risk, each increment of 3 eggs/wk was associated with a 5% higher risk of CAD for participants at low to intermediate genetic risk (HR: 1.05; 95% CI: 1.01, 1.09), whereas risk increased to HR 1.10 (95% CI: 1.05, 1.16) for those at high genetic risk; a significant synergistic interaction was also indicated at both multiplicative (Pinteraction = 0.007) and additive (relative excess risk: 0.73; 95% CI: 0.24, 1.22) scales. When the joint effect was examined, in comparison with those at low to intermediate genetic risk and consuming <1 egg/wk, the HR (95% CI) was 2.95 (2.41, 3.62) for participants with high genetic risk and consumption of ≥10 eggs/wk, and the corresponding standardized 10-y CAD rates increased from 1.37% to 4.24%.

CONCLUSIONS

Genetic predisposition may synergistically interact with egg consumption in relation to increased CAD risk. PRS-stratified recommendations on egg consumption may help formulate personalized nutrition policies.

Personalized Nutrition in the Management of Female Infertility: New Insights on Chronic Low-Grade Inflammation

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting a mutual association between nutrition and female fertility. Different “fertile” dietary patterns have been studied; however, in humans, conflicting results or weak correlations are often reported, probably because of the individual variations in genome, proteome, metabolome, and microbiome and the extent of exposure to different environmental conditions. In this scenario, “precision nutrition”, namely personalized dietary patterns based on deep phenotyping and on metabolomics, microbiome, and nutrigenetics of each case, might be more efficient for infertile patients than applying a generic nutritional approach. In this review, we report on new insights into the nutritional management of infertile patients, discussing the main nutrigenetic, nutrigenomic, and microbiomic aspects that should be investigated to achieve effective personalized nutritional interventions. Specifically, we will focus on the management of low-grade chronic inflammation, which is associated with several infertility-related diseases.

The interaction between genetic polymorphisms in FTO, MC4R and MTHFR genes and adherence to the Mediterranean Diet in relation to obesity

AIMS

To investigate the potential interaction between genetic background and adherence to the Mediterranean Diet, macronutrient intake and physical activity with regard to obesity in a sample of healthy adults.

DESIGN

Cross-sectional epidemiological study including 392 adults living in the Mediterranean basin. Data including FFQ, IPAQ and sociodemographic questionnaires were collected via face-to-face interviews. Anthropometric measures were performed and saliva swab for DNA extraction. Two MD scores were calculated to assess the adherence of the population to this pattern. Three single nucleotid polymorphisms (SNPs) related to obesity were studied: FTO, MC4R, MTHFR.

FINDINGS

FTO rs9939609 is significantly associated with WHR, and MC4R with all phenotypic traits linked to obesity (BMI, WC and WHR). However, MTHFR polymorphism didn't show any significant correlation with anthropometric parameters. Adherence to the MD and high level of physical activity do not seem to protect against the occurrence of overweight and obesity in genetically predisposed subjects.

CONCLUSION

Classic lifestyle interventions are insufficient in addressing the challenging obesity pandemic. Identifying more genetic variants and understanding their interaction with lifestyle will improve the clinical outcome of these variants for risk prediction and personalized nutrition and medical therapy. Also, the MD should undergo a redefinition adapted to each country on the Mediterranean basin in order to organize public health measures for its comeback.

Homocysteine and diabetes: Role in macrovascular and microvascular complications

Diabetes mellitus (DM) can lead to the development of macro- and microvascular complications. Homocysteine (Hcy) may play a role in the development of cardiovascular (CV) diseases (CVDs). The role of Hcy in the development of the vascular complications associated with DM is not clearly defined. Despite a strong initial assumption regarding the importance of Hcy in DM and its complications, over time "enthusiasm has waned" because several studies showed unconvincing and occasionally contradictory results. A universal conclusion is not easy to draw given the diversity of studies (e.g. number of patients, design, folic acid and vitamin B status, ethnic differences, genetic background). For some complications, most results encourages further investigation. Impaired renal function is a major independent determinant of high total Hcy (tHcy) levels. However, the role of hyperhomocysteinaemia (HHcy) in the development of diabetic kidney disease (DKD) has yet to be determined. Hcy-lowering therapies can significantly decrease Hcy levels but their effects on CVD risk reduction are conflicting. Further studies are needed to determine the influence of Hcy-lowering therapy on CVD risk reduction, especially in patients with DM.

Diet, Stress and Mental Health

Introduction: There has long been an interest in the effects of diet on mental health, and the interaction of the two with stress; however, the nature of these relationships is not well understood. Although associations between diet, obesity and the related metabolic syndrome (MetS), stress, and mental disorders exist, causal pathways have not been established. Methods: We reviewed the literature on the relationship between diet, stress, obesity and psychiatric disorders related to stress. Results: Diet and obesity can affect mood through direct effects, or stress-related mental disorders could lead to changes in diet habits that affect weight. Alternatively, common factors such as stress or predisposition could lead to both obesity and stress-related mental disorders, such as depression and posttraumatic stress disorder (PTSD). Specific aspects of diet can lead to acute changes in mood as well as stimulate inflammation, which has led to efforts to assess polyunsaturated fats (PUFA) as a treatment for depression. Bidirectional relationships between these different factors are also likely. Finally, there has been increased attention recently on the relationship between the gut and the brain, with the realization that the gut microbiome has an influence on brain function and probably also mood and behavior, introducing another way diet can influence mental health and disorders. Brain areas and neurotransmitters and neuropeptides that are involved in both mood and appetite likely play a role in mediating this relationship. Conclusions: Understanding the relationship between diet, stress and mood and behavior could have important implications for the treatment of both stress-related mental disorders and obesity.

A nutrigenetics approach to study the impact of genetic and lifestyle factors on cardiometabolic traits in various ethnic groups: findings from the GeNuIne Collaboration

Several studies on gene-diet interactions (nutrigenetics) have been performed in western populations; however, there are only a few studies to date in lower middle-income countries (LMIC). A large-scale collaborative project called gene-nutrient interactions (GeNuIne) Collaboration, the main objective of which is to investigate the effect of GeNuIne on cardiometabolic traits using population-based studies from various ethnic groups, has been initiated at the University of Reading, UK. While South Asians with higher genetic risk score (GRS) showed a higher risk of obesity in response to a high-carbohydrate diet, South East and Western Asian populations with higher GRS showed an increased risk of central obesity in response to a high-protein diet. The paper also provides a summary of other gene-diet interaction analyses that were performed in LMIC as part of this collaborative project and gives an overview of how these nutrigenetic findings can be translated to personalised and public health approaches for the prevention of cardiometabolic diseases such as obesity, type 2 diabetes and CVD.

Benefits of the Mediterranean diet: Epidemiological and molecular aspects

More than 50 years after the Seven Countries Study, a large number of epidemiological studies have explored the relationship between the Mediterranean diet (MD) and health, through observational, case-control, some longitudinal and a few experimental studies. The overall results show strong evidence suggesting a protective effect of the MD mainly on the risk of cardiovascular disease (CVD) and certain types of cancer. The beneficial effects have been attributed to the types of food consumed, total dietary pattern, components in the food, cooking techniques, eating behaviors and lifestyle behaviors, among others. The aim of this article is to review and summarize the knowledge derived from the literature focusing on the benefits of the MD on health, including those that have been extensively investigated (CVD, cancer) along with more recent issues such as mental health, immunity, quality of life, etc. The review begins with a brief description of the MD and its components. Then we present a review of studies evaluating metabolic biomarkers and genotypes in relation to the MD. Other sections are dedicated to observation and intervention studies for various pathologies. Finally, some insights into the relationship between the MD and sustainability are explored. In conclusion, the research undertaken on metabolomics approaches has identified potential markers for certain MD components and patterns, but more investigation is needed to obtain valid measures. Further evaluation of gene-MD interactions are also required to better understand the mechanisms by which the MD diet exerts its beneficial effects on health. Observation and intervention studies, particularly PREDIMED, have provided invaluable data on the benefits of the MD for a wide range of chronic diseases. However further research is needed to explore the effects of other lifestyle components associated with Mediterranean populations, its environmental impact, as well as the MD extrapolation to non-Mediterranean contexts.

Determinants of hyperhomocysteinemia in healthy and hypertensive subjects: A population-based study and systematic review

AIMS

Hyperhomocysteinemia (HHcy) is known to increase the risk of many diseases. Factors influencing HHcy in healthy and hypertensive subjects remain under-researched.

METHODS

A large population-based study was conducted in 60 communities from Shenzhen, China. Responses to standardized questions on lifestyle factors and blood samples were collected from all participants after a 12-h overnight fast. Multiple linear and multivariate logistic regressions were used to explore risk factors for HHcy. Results were then compared to those from a systematic review of English-language articles listed in Pubmed, EBSCOhost, Web of Science, Embase and Cochrane libraries that investigated HHcy risk factors in healthy and hypertensive subjects.

RESULTS

A total of 1586 healthy (Male/Female = 642/944) and 5935 hypertensive subjects (Male/Female = 2928/3007) participated in our population-based study. In logistic regression analyses, age, BMI and creatinine (Cr) were risk factors, while being female, fruit intake and physical activity were protective factors for HHcy in healthy subjects. In hypertensive subjects, seven [age, smoking, salt intake, systolic blood pressure (SBP), uric acid, triglycerides (TG), and Cr] and four [female, fruit intake, total cholesterol (TC), and glucose] factors were associated with higher and lower HHcy respectively. The review of 71 studies revealed that potential risk factors for Hcy included nutritional, physiologic, lifestyle habits, ethnicity, genetics, interactions between gene-environment, gene-gene, gene-nutritional, environment-environment, nutritional-nutritional.

CONCLUSION

Our study indicates the potential importance of increasing folic acid and vitamin B supplementation, daily fruit and vegetable intake, regular exercise and refraining from tobacco smoking and alcohol consumption as preventive strategies for Hcy.

Nutrigenomics, the Microbiome, and Gene-Environment Interactions: New Directions in Cardiovascular Disease Research, Prevention, and Treatment: A Scientific Statement From the American Heart Association

Cardiometabolic diseases are the leading cause of death worldwide and are strongly linked to both genetic and nutritional factors. The field of nutrigenomics encompasses multiple approaches aimed at understanding the effects of diet on health or disease development, including nutrigenetic studies investigating the relationship between genetic variants and diet in modulating cardiometabolic risk, as well as the effects of dietary components on multiple "omic" measures, including transcriptomics, metabolomics, proteomics, lipidomics, epigenetic modifications, and the microbiome. Here, we describe the current state of the field of nutrigenomics with respect to cardiometabolic disease research and outline a direction for the integration of multiple omics techniques in future nutrigenomic studies aimed at understanding mechanisms and developing new therapeutic options for cardiometabolic disease treatment and prevention.

Adherence to Mediterranean diet and 10-year incidence (2002-2012) of diabetes: correlations with inflammatory and oxidative stress biomarkers in the ATTICA cohort study

BACKGROUND

The purpose of this work was to investigate the links between oxidative stress, inflammation and coagulation and their effect on Mediterranean diet-diabetes relationship.

METHODS

In 2001-2002, a random sample of 1514 men (18-87 years old) and 1528 women (18-89 years old) was selected to participate in the ATTICA study, where Athens is the major metropolis. A validated questionnaire was used to assess lifestyle and dietary factors. Adherence to Mediterranean diet was recorded using MedDietScore. Among others, oxidative stress and inflammatory biomarkers were recorded. During 2011-2012, the 10-year follow-up was performed. Diabetes incidence was defined according to the American Diabetes Association criteria.

RESULTS

A total of 191 incident cases of diabetes were documented, yielding an incidence of 12.9% (13.4% in men and 12.4% in women). Medium and high adherence was found to decrease diabetes risk by 49% (95% CI: 0.30, 0.88) and 62% (95% CI: 0.16, 0.88), respectively, compared with low adherence. A logarithmic trend between Mediterranean diet and diabetes incidence was also revealed (p for trend = 0.042). Individuals with abnormal waist circumference (>94 for men, >80 for women) were benefited the most. Wholegrain cereals, fruits and legumes had the greatest predictive ability. The anti-diabetic effect of Mediterranean diet correlated with measurements of tumour necrosis factor-α, homocysteine and total antioxidant capacity.

CONCLUSIONS

The reported results support the role of Mediterranean diet as a promising dietary tool for the primary prevention of diabetes, by attenuating inflammation and fostering total antioxidant capacity. This dietary pattern may have therapeutic potential for many cardiometabolic disorders associated with inflammation and/or oxidative stress.

Antioxidant activity of phenolic extracts from different cultivars of Italian onion (Allium cepa) and relative human immune cell proliferative induction

CONTEXT

The total antioxidant activity (TAC) may vary considerably between onion cultivars. Immunological effects of onion phenolic compounds are still underestimated.

OBJECTIVE

The objective of this study is to determine the total phenol content (TPC) and the relative TAC of three Allium cepa L. (Liliaceae) onion cultivars cultivated in Cannara (Italy): Rossa di Toscana, Borettana di Rovato, and Dorata di Parma, and to evaluate the phenol extracts ability to induce human immune cell proliferation.

MATERIALS AND METHODS

TPC was determined by the Folin-Ciocalteu method, TAC with FRAP, TEAC/ABTS, and DPPH methods. Peripheral blood mononuclear cells from healthy human donors were incubated for 24 h at 37 °C with 1 ng/mL of phenolic extract in PBS, immunostained, and then analyzed by 4-color flow cytometry for the phenotypic characterization of T helper cells (CD4+ cells), cytotoxic T lymphocytes (CD8+ cells), T regulatory cells (CD25high CD4+ cells), and natural killer cells/monocytes (CD16+ cells).

RESULTS

Rossa di Toscana displayed the highest TPC (6.61 ± 0.87 mg GA equivalents/g onion bulb DW) and the highest TAC with the experienced methods: FRAP, 9.19 ± 2.54 μmol Trolox equivalents/g onion bulb DW; TEAC/ABTS, 21.31 ± 0.41 μmol Trolox equivalents/g onion bulb DW; DPPH, 22.90 ± 0.01 μmol Trolox equivalents/g onion bulb DW. Incubation with Rossa di Toscana extract determined an increase in the frequency of the antitumor/anti-infection NK CD16+ immune cells (23.0 ± 0.4%).

DISCUSSION AND CONCLUSIONS

Content of health-promoting phenols and the deriving antioxidant and immunostimulating activity vary considerably among the investigated cultivars. Rossa di Toscana can be considered as a potential functional food.

Aging and cardiovascular diseases: the role of gene-diet interactions

In the study of longevity, increasing importance is being placed on the concept of healthy aging rather than considering the total number of years lived. Although the concept of healthy lifespan needs to be defined better, we know that cardiovascular diseases (CVDs) are the main age-related diseases. Thus, controlling risk factors will contribute to reducing their incidence, leading to healthy lifespan. CVDs are complex diseases influenced by numerous genetic and environmental factors. Numerous gene variants that are associated with a greater or lesser risk of the different types of CVD and of intermediate phenotypes (i.e., hypercholesterolemia, hypertension, diabetes) have been successfully identified. However, despite the close link between aging and CVD, studies analyzing the genes related to human longevity have not obtained consistent results and there has been little coincidence in the genes identified in both fields. The APOE gene stands out as an exception, given that it has been identified as being relevant in CVD and longevity. This review analyzes the genomic and epigenomic factors that may contribute to this, ranging from identifying longevity genes in model organisms to the importance of gene-diet interactions (outstanding among which is the case of the TCF7L2 gene).

Renal insufficiency in non-diabetic subjects: relationship of MTHFR C677t gene polymorphism and left ventricular hypertrophy

BACKGROUND

Association of methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism with hyperhomocysteinemia, renal failure, and cardiovascular events is controversial. We investigated the relationship of MTHFR 677C>T polymorphisms with left ventricular hypertrophy (LVH) and renal insufficiency.

METHODS

Glomerular filtration rate (GFR) and left myocardial ventricular mass/m2 were assessed in 138 non-diabetic subjects (age, 50.93 ± 14.85 years; body mass index, 27.95 ± 5.98 kg/m(2)), 38 no-mutation wild MTHFR C677CC, 52 heterozygous MTHFR C677CT, and 48 homozygous MTHFR C677TT, all with adequate adherence to current international healthy dietary guidelines. Serum homocysteine, insulin resistance, high-sensitivity C-reactive-protein (hsCRP), parathyroid hormone, and renal artery resistive index (RRI) were challenged by odds ratio analysis and multiple linear regression models.

RESULTS

MTHFR 677C>T polymorphism showed higher GFR (73.8 ± 27.99 vs. 58.64 ± 29.95; p= 0.001) and lower renal failure odds (OR, 0.443; 95% confidence interval, 0.141-1.387) in comparison with wild MTHFR genotype. A favorable effect on GFR of MTHFR polymorphism is presented independently by the negative effects of LVH, increased intra-renal arterial resistance, and hyperparathyroidism; GFR is the significant predictive factor to LVH.

CONCLUSIONS

Renal insufficiency in non-diabetic subjects is explained by interactions of MTHFR C677T polymorphism mutation with LVH, hsCRP, intact parathyroid hormone (iPTH), and RRI. Sign of these predictive effects is opposite: subjects with MTHFR 677C>T polymorphism have lower likelihood of renal insufficiency; differently, wild-type MTHFR genotype subjects have lower GFR and greater hsCRP, iPTH, RRI, and LVH.

Folate and homocysteine phenotypes: Comparative findings using research and clinical laboratory data

OBJECTIVES

A low folate/high homocysteine phenotype is associated with several pathologies, including spina bifida and cardiovascular disease. Folate and total homocysteine (tHcy) measurements are used clinically to assess risk and the need for folic acid supplementation and in research to investigate the metabolic basis of disease. Red blood cell (RBC) folate, the best indicator of long-term folate status, is usually measured as "total" folate. However, different folate derivatives support distinct biochemical functions, suggesting a need to develop more precise methods. This study was designed to evaluate a method based on stable isotope dilution liquid chromatography-multiple reaction monitoring/mass spectrometry (LC-MRM/MS).

DESIGN AND METHODS

We used LC-MRM/MS to quantify the RBC folate derivatives 5-methyltetrahydrofolate (5-CH(3)-THF), tetrahydrofolate (THF), and 5,10-methenyltetrahydrofolate (5,10-methenylTHF) in pre-menopausal women. The concentration of each folate derivative was assessed for utility in predicting tHcy levels, and compared to folate and tHcy measurements derived by routine clinical laboratory methods.

RESULTS

LC-MRM/MS was qualitatively and quantitatively superior to routine clinical laboratory methods for determining folate and tHcy concentrations. RBC 5-CH(3)-THF had a reciprocal relationship with tHcy (p=0.0003), whereas RBC THF and RBC 5,10-methenylTHF had direct relationships (p=0.01, 0.04 respectively). In combination, these three variables accounted for 42% of the variation in tHcy.

CONCLUSIONS

Robust methods for measuring RBC 5-CH(3)-THF would improve the utility of folate/homocysteine phenotyping in patient management. The use of LC-MRM/MS would allow studies of hyperhomocysteinemia and diseases associated with a low folate/high homocysteine phenotype to be performed with less measurement error and greater statistical power to generate data with the potential to elucidate the etiologic mechanisms of complex diseases and traits.

Mathematical modeling of folate metabolism: predicted effects of genetic polymorphisms on mechanisms and biomarkers relevant to carcinogenesis

Low-folate status and genetic polymorphisms in folate metabolism have been linked to several cancers. Possible biological mechanisms for this association include effects on purine and thymidine synthesis, DNA methylation, or homocysteine concentrations. The influence of genetic variation in folate metabolism on these putative mechanisms or biomarkers of cancer risk has been largely unexplored. We used a mathematical model that simulates folate metabolism biochemistry to predict (a) the effects of polymorphisms with defined effects on enzyme function (MTHFR and TS) and (b) the effects of potential, as-of-yet-unidentified polymorphisms in a comprehensive set of folate-metabolizing enzymes on biomarkers and mechanisms related to cancer risk. The model suggests that there is substantial robustness in the pathway. Our predictions were consistent with measured effects of known polymorphisms in MTHFR and TS on biomarkers. Polymorphisms that alter enzyme function of FTD, FTS, and MTCH are expected to affect purine synthesis, FTS more so under a low-folate status. In addition, MTCH polymorphisms are predicted to influence thymidine synthesis. Polymorphisms in methyltransferases should affect both methylation rates and thymidylate synthesis. Combinations of polymorphisms in MTHFR, TS, and SHMT are expected to affect nucleotide synthesis in a nonlinear fashion. These investigations provide information on effects of genetic polymorphisms on biomarkers, including those that cannot be measured well, and highlight robustness and sensitivity in this complex biological system with regard to genetic variability. Although the proportional changes in biomarkers of risk with individual polymorphisms are frequently small, they may be quite relevant if present over an individual's lifetime.

Mediterranean diet and plasma concentration of inflammatory markers in old and very old subjects in the ZINCAGE population study

BACKGROUND

Aging is associated with low-grade elevation of circulating inflammatory markers, leading to increased risk of morbidity and mortality. The Mediterranean diet has been suggested as a determinant of longevity. In the current study, we investigated the impact of the Mediterranean diet on inflammatory status in old subjects.

METHODS

Within the ZINCAGE study, 957 healthy old subjects (>or=60 years old) from five European countries were recruited. Plasma interleukin (IL)-6, IL-8, monocyte chemoattractant protein, tumor necrosis factor-alpha, high-density lipoprotein cholesterol (HDL-C) and erythrocyte sedimentation rate (ESR) were measured. Dietary data were collected applying a food frequency questionnaire and were used to estimate adherence to the Mediterranean diet.

RESULTS

The Italians presented the greatest adherence to the Mediterranean diet, while the Polish the poorest. In females, higher diet score was significantly associated with lower body mass index and ESR and higher HDL-C levels (beta=-0.127, p=0.003; beta=-0.144, p=0.001; beta=0.144, p=0.029, respectively). In males, diet score was negatively associated with IL-8 levels (beta=-0.101, p=0.044). The Mediterranean diet was associated with reduced IL-8 concentrations in Greeks (beta=-0.213, p=0.007).

CONCLUSIONS

There were significant effects of the components of the Mediterranean diet on inflammation markers. The Mediterranean diet score is useful in assessing nutritional influence on immune status.

Hyperhomocysteinemia and elevated ox-LDL in Tunisian type 2 diabetic patients: Role of genetic and dietary factors

INTRODUCTION

Total plasma homocysteine (tHcy) is an emerging risk factor for the development of atherosclerosis. However, its relationship with diabetes is still unclear.

OBJECTIVES

We evaluated the association between tHcy levels and methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype in a type 2 diabetes mellitus (DM) population and their relationship with oxidized LDL (ox-LDL) according to dietary habits and vascular complications.

DESIGN AND METHODS

Eighty-six DM patients were compared to 120 healthy volunteers.

RESULTS

Associated higher tHcy levels and significantly higher ox-LDL levels (p<0.001) were found in DM patients compared to healthy subjects. Homozygosity for the T allele of MTHFR was more frequent in diabetics than in healthy subjects (12.8% vs. 7.2%) and it was associated with higher tHcy levels. Moreover, this elevated level was associated with significantly higher ox-LDL levels in DM patients with hypertension (p<0.05). Improving folate and vitamin C intakes could have beneficial effects on lowering the tHcy and ox-LDL levels.

CONCLUSIONS

The interplay of genetic and dietary factors modulates the effect of homocysteine on cardiovascular risk factors.

MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension in Indians

The goals of our present study were to measure plasma homocysteine levels and determine their association with methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) in essential hypertensive subjects. Plasma total homocysteine and folic acid levels were measured in essential hypertensive patients (n = 153) before and after oral supplementation with either 5 mg folic acid tablet/day or 5 mg placebo/day for 4 weeks and compared with age and sex matched normotensive controls (n = 133). MTHFR gene polymorphisms (C677T and A1298C) were studied by restriction fragment length polymorphism and correlated with plasma homocysteine levels. Homocysteine levels were significantly higher in hypertensive patients as compared to controls and showed a negative correlation with plasma folate levels. Folic acid supplementation (5 mg/day) for 4 weeks resulted in a significant decrease in plasma homocysteine concentrations in these patients. Patients carrying MTHFR 677T allele (OR = 1.90; 95%CI: 1.14-3.19) or MTHFR 1298C (OR = 2.6, 95%CI: 1.55-4.40) allele were at increased risk of hypertension. The frequency of co-occurrence of MTHFR 677 CT/1298 CC genotypes was significantly higher in the patients compared to controls (P < 0.05) and was associated with increased risk of hypertension (OR = 3.54, 95%CI: 0.37-4.30). Subjects with MTHFR 1298 CC genotype had significantly higher homocysteine levels compared to those with MTHFR 1298 AA genotype (P < 0.05). Our results indicate that MTHFR 677T and 1298C alleles and co-occurrence of MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension and MTHFR 1298 CC genotype is associated with higher homocysteine levels in our subjects.

Importance of functional foods in the Mediterranean diet

Objective

Analyse the importance of components of Mediterranean diet in functional feeding.

Design

We have based the study in a bibliographic review.

Results

Many of the characteristic components of the traditional Mediterranean diet (MD) are known to have positive effects on health, capacity and well-being, and can be used to design functional foods. Vegetables, fruits and nuts are all rich in phenols, flavonoids, isoflavonoids, phytosterols and phytic acid—essential bioactive compounds providing health benefits. The polyunsaturated fatty acids found in fish effectively regulate haemostatic factors, protect against cardiac arrhythmias, cancer and hypertension, and play a vital role in the maintenance of neural functions and the prevention of certain psychiatric disorders. Accumulating evidence suggests that olive oil, an integral component of the MD, may have health benefits, including the reduction of the risk of coronary heart disease, the prevention of several types of cancer and the modification of the immune and inflammatory responses. Olive oil is known for its high levels of monounsaturated fatty acids and is a good source of phytochemicals, such as polyphenolic compounds, squalene and α-tocopherol.

In the context of the MD, the benefits associated with the consumption of several functional components may be intensified by certain forms of food preparation. In addition, the practice of more physical activity (once common among Mediterranean populations) and the following of other healthy lifestyle habits may have additive effects.

Conclusions

The identification of the active constituents of the MD is crucial in the formulation of appropriate dietary guidelines. Research into the pharmacological properties of the minor components of this diet (vitamins, sterols, polyphenols, etc.) is very active and could lead to the formulation of functional foods and nutraceuticals.

A mathematical model gives insights into nutritional and genetic aspects of folate-mediated one-carbon metabolism

Impaired folate-mediated 1-carbon metabolism has been linked to multiple disease outcomes. A better understanding of the nutritional and genetic influences on this complex biochemical pathway is needed to comprehend their impact on human health. To this end, we created a mathematical model of folate-mediated 1-carbon metabolism. The model uses published data on folate enzyme kinetics and regulatory mechanisms to simulate the impact of genetic and nutritional variation on critical aspects of the pathway. We found that the model predictions match experimental data, while providing novel insights into pathway kinetics. Our primary observations were as follows: 1) the inverse association between folate and homocysteine is strongest at very low folate concentrations, but there is no association at high folate concentrations; 2) the DNA methylation reaction rate is relatively insensitive to changes in folate pool size; and 3) as folate concentrations become very high, enzyme velocities decrease. With regard to polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR), the modeling predicts that decrease MTHFR activity reduces concentrations of S-adenosylmethionine and 5-methyltetrahydrofolate, as well as DNA methylation, while modestly increasing S-adenosylhomocysteine and homocysteine concentrations and thymidine or purine synthesis. Decreased folate together with a simulated vitamin B-12 deficiency results in decreases in DNA methylation and purine and thymidine synthesis. Decreased MTHFR activity superimposed on the B-12 deficiency appears to reverse the declines in purine and thymidine synthesis. These mathematical simulations of folate-mediated 1-carbon metabolism provide a cost-efficient approach to in silico experimentation that can complement and help guide laboratory studies.

Role of lifestyle factors on plasma homocysteine levels in Parkison's disease patients treated with levodopa

Many papers documented that Parkinson's disease (PD) patients treated with levodopa (L-dopa) shows elevated plasma homocysteine (Hcy) levels. Several lifestyle factors are able to influence plasma Hcy levels. We review the evidence that L-dopa therapy is related with an increase in plasma Hcy levels and that several behaviours could be able to cause changes in plasma Hcy concentrations. Therefore, there are reasons to suggest that a healthy lifestyle lowering Hcy may prevent this potential iatrogenic complication during L-dopa therapy. Moreover, at present, no controlled prospective studies have evaluated this phenomenon.

Serum homocysteine levels and paraoxonase 1 activity in preschool aged children in Greece

BACKGROUND

Over the past decade, it has been well established that elevated total serum homocysteine (tHcy) in adults is associated with increased risk of cardiovascular and thromboembolic diseases. Since risk factors for such diseases are established at a young age, the aim of the present study was to measure serum tHcy levels in 134 (71 boys, 63 girls) randomly selected healthy preschool children aged 4-6 years (mean 5.1), and to investigate possible correlation with paraoxonase 1 (PON1) activity, an antioxidant enzyme that contributes to the antiatherogenic properties of high-density lipoprotein (HDL).

METHODS

tHcy was determined using an IMX tHcy assay (FPIA). PON1 was measured by a spectrophotometric method at 412 nm.

RESULTS

Mean serum tHcy was 7.71+/-2.35 mumol/L. A relatively significant percentage (15.6%) of boys and girls had elevated serum tHcy levels (>10 mumol/L). tHcy levels were slightly higher in girls compared to boys (8.20+/-2.80 vs. 7.29+/-1.79 mumol/L, respectively; p<0.11). There was no significant interaction between age and tHcy levels. Mean PON1 activity was 124.86+/-66.62 U/L. No statistical difference in enzyme activity was observed between boys and girls (126.81+/-69.99 vs. 121.74+/-64.78 U/L) was observed. On the contrary, a weak negative relationship between tHcy concentration and PON1 activity was detected, with Pearson's correlation coefficient of r=-0.27.

CONCLUSIONS

The significant percentage of elevated tHcy levels observed in healthy preschool cases and the negative tHcy correlation with PON1 activity are reported for the first time. Since children with a family history of cardiovascular disease have higher levels of serum Hcy, tHcy screening in children, even of this age, in relation to other parameters, such the protective PON1, might prove a useful prevention procedure for the genetic risk of premature atherosclerosis.

Natriuretic peptide Val7Met substitution and risk of coronary artery disease in Greek patients with familial hypercholesterolemia

Atrial natriuretic peptide (ANP or NPPA) is the precursor protein of the form of amyloidosis called isolated atrial amyloid (IAA), which is related to the increased incidence of cardiac pathological conditions with age. Familial hypercholesterolemia (FH) patients are characterized by high concentrations of low-density lipoprotein cholesterol (LDL-C), which frequently gives rise to premature coronary artery disease (CAD). However, not all FH patients have the same clinical phenotype. The aim of the present study was to assess the relationship between ANP polymorphisms and apolipoprotein (Apo) A1 levels and CAD risk in FH patients. Transition T2238C, which leads to ANP with two additional arginines, and G664A (Val7Met) were investigated with lipid values and clinical phenotype in 83 FH patients. ApoA1 and HDL cholesterol levels were lower in GA patients compared to GG homozygotes for the G664A polymorphism. No association was found between the G664A polymorphism and CAD in our population. Moreover, ApoA1 and high-density lipoprotein cholesterol (HDL-C) levels did not differ among the different genotypes of the T2238C polymorphism, even after adjusting for age and sex. The 664A allele of the ANP polymorphism is associated with lower levels of ApoA1 and HDL-C in FH patients, but not with CAD risk. Concerning the T2238C polymorphism, no effect was found on lipid parameters or CAD incidence.

Changes in lifestyle and total homocysteine in relation to MTHFR(C677T) genotype: the Inter99 study

BACKGROUND

Reduction in total homocysteine (tHcy) may be clinically relevant in the prevention of cardiovascular disease (CVD) in the general population.

OBJECTIVE

To examine the effects of changes in various lifestyle habits and lifestyle related biological CVD risk markers on changes in tHcy in relation to MTHFR(C677T) genotype.

DESIGN

A 1 year follow-up study.

SETTING

Copenhagen County, Denmark.

SUBJECTS

Statistical analyses were based on a population-based sample of 915 men and women aged 30-60 years assessed to be at increased CVD risk at baseline and therefore offered lifestyle intervention and re-examination after one year.

RESULTS

None of the studied lifestyle changes-- smoking, physical activity, dietary habits, and coffee, tea, and alcohol consumption-- was significantly associated with changes in tHcy, either overall, or in any of the MTHFR genotype subgroups. In addition, changes in tHcy did not differ between participants randomized to low- and high-intensity lifestyle intervention. However, the MTHFR TT genotype was associated with a significant decrease in tHcy compared with the CC/CT genotype in which an increase was observed. In addition, changes in tHcy were associated with changes in several of the biological CVD risk markers: weight, total cholesterol, HDL cholesterol, LDL cholesterol and systolic blood pressure.

CONCLUSIONS

Our results indicate that tHcy may not be reduced by lifestyle changes; additionally, they suggest that tHcy may be related to biological CVD risk markers through a lifestyle independent pathway.

Geographical influences on the association between adherence to the Mediterranean diet and the prevalence of acute coronary syndromes, in Greece: the CARDIO2000 study

OBJECTIVE

We evaluated the interaction between adherence to the Mediterranean diet and region of Greece on the likelihood of having acute coronary syndromes (ACS).

METHODS

During 2000-2001, a random sample of 848 patients (61+/-10 years) with their first coronary heart disease event, and 1078 frequency matched (by age-sex) controls with no cardiovascular disease in their medical history, from all the country, entered into the study. Among several factors, adherence to the Mediterranean diet was assessed by a diet-score that incorporated the inherent characteristics of this diet.

RESULTS

The multi-adjusted analysis showed that a 10-unit increase in the diet score was associated with a 27% (95% CI 0.66 to 0.89) decrease of the odds of having ACS. Moreover, a highly significant interaction was observed between region and diet score (p<0.001). The odds ratios varied from roughly 0.5 in Southern to 1.2 or more in Northern Greek regions (p for heterogeneity<0.05). Differences in food patterns consumed did not explain the previous findings. In addition, when we stratified our analysis by rural and urban areas we found significant differences in the estimated odds ratios (p for interaction between diet score and area=0.01), since a 10-unit increase in the diet score was associated with 22% (95% CI 0.63 to 0.96) lower odds n urban areas and 31% (95% CI 0.48 to 0.98) lower odds in rural areas.

CONCLUSION

Our findings underline the significance of the Mediterranean diet on the primary prevention of ACS. Moreover, we revealed a geographical variation in the importance of this dietary pattern on coronary risk, independent from the composition of food patterns followed and the prevalence of the common cardiovascular risk factors.

Plasma homocysteine concentrations in Greek children are influenced by an interaction between the methylenetetrahydrofolate reductase C677T genotype and folate status

Risk factors established at young ages may set the stage for later cardiovascular disease (CVD). Elevated total homocysteine (tHcy) in blood is an emerging risk factor for CVD, yet few studies have been conducted in children, especially in the Mediterranean. We described plasma tHcy concentrations in a group of healthy Greek children and examined its relation with physiologic, metabolic, and genetic variables. Fasting blood samples were collected from 186 students, 11.6 +/- 0.4 years old, and tHcy, folate, vitamin B-12, and routine biochemistry variables in plasma were measured. The methylenetetrahydrolate reductase (MTHFR) C677T genotype was determined and anthropometric and dietary data were obtained. The distribution of tHcy was positively skewed with a median of 7.9 micromol/L (mean: 8.2 +/- 2.3 micromol/L; range: 4.4-22.2 micromol/L). tHcy was inversely related to plasma folate (r = -0.34, P < 0.0001), vitamin B-12 (r = -0.20, P = 0.008), and glucose (r = -0.15, P = 0.045). An interaction between the MTHFR genotype and plasma folate on tHcy was detected (P = 0.047). Specifically, the homozygous mutant TT genotype was associated with higher tHcy only in children with lower plasma folate (< 19.9 nmol/L), (P = 0.012). In our sample of healthy Greek children, plasma tHcy concentrations were higher than values reported in children of Northern European descent and were associated with folate, vitamin B-12, and glucose in plasma. The results also show that, similar to adults, plasma folate concentration is important in determining the contribution of the MTHFR C677T mutation to tHcy concentrations in children.