Demographic, health, lifestyle, and blood vitamin determinants of serum total homocysteine concentrations in the third National Health and Nutrition Examination Survey, 1988-1994

Plasma Homocysteine Levels and Cardiovascular Events in Patients With End-Stage Renal Disease: A Systematic Review

BACKGROUND

Patients with chronic renal disease or failure are at a heightened risk of mortality due to cardiovascular disease (CVD), which is a predominant cause of death in this population. Hyperhomocysteinemia is prevalent in patients with end-stage renal disease (ESRD), which may increase their susceptibility to CVD.

METHODS

We conducted a comprehensive search of PubMed, Science Direct, and Google Scholar for articles published between 2003 and February 2023, using a combination of keywords such as "plasma homocysteine levels," "hyperhomocysteinemia," "end-stage renal disease," "renal failure," "kidney failure," "cardiovascular events," "cardiovascular disease," "myocardial infarction," "coronary artery disease," and "stroke." Our inclusion criteria were studies that investigated the association between total homocysteine (Hcy) level and CVD or total mortality, as well as the impact of vitamin supplementation on cardiovascular or mortality risk. We restricted our search to English-language studies that included ESRD patients and provided data on plasma Hcy levels and associated CVD events.

RESULTS

This systematic review includes 11 articles published between 2003 and 2023 that enrolled a total of 3,953 subjects, of whom 79.15% were male patients. All studies included in the review were either quantitative randomized trials or non-randomized studies, such as cross-sectional, cohort, or case-control studies. Of the total studies included, 10 reported either cardiovascular mortality or CVD events, including cardiovascular death, myocardial infarction (MI), angina, and stroke. One study reported the CVD risk score of the patients, and most of them had higher total homocysteine (tHcy) levels. Overall, a total of 817 CVD events were reported across the studies.

CONCLUSION

In conclusion, the relationship between Hcy and cardiovascular events in ESRD patients is not straightforward and requires further research. However, our review suggests that Hcy could be a predictor of cardiovascular events in this population, and its nutritional characteristics as well as other associated comorbidities may contribute to its inverse association with outcomes.

Dietary riboflavin intake in relation to psychological disorders in Iranian adults: an observational study

Findings of earlier investigations on association between dietary riboflavin intake and psychological disorders are contradictory. Therefore, the relation between dietary riboflavin intake and depression, anxiety, and psychological distress was assessed in Iranian adults. In this cross-sectional study, dietary intakes of 3362 middle-aged adults were collected using a validated dish-based food frequency questionnaire. Daily intake of riboflavin for each participant was calculated by summing up the amount of riboflavin contents of all foods and dishes. Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ), as validated questionnaires among Iranians, have been applied to assess depression, anxiety, and psychological distress. After considering potential confounders, adults in the top energy-adjusted quartile of riboflavin intake, compared to the bottom quartile, had decreased odds of depression (OR = 0.66; 95%CI 0.49, 0.88), anxiety (OR = 0.64; 95%CI 0.44, 0.94) and high psychological distress (OR = 0.65; 95%CI 0.48, 0.89). Stratified analysis by sex revealed that men in the forth quartile of riboflavin intake, compared with those in the first quartile, had respectively 51 and 55% lower odds of depression (OR = 0.49; 95%CI 0.29, 0.83) and anxiety (OR = 0.45; 95%CI 0.21, 0.95). In women, riboflavin intake was significantly associated with lower odds of psychological distress (OR = 0.67; 95%CI 0.46, 0.98). An inverse relation was observed between dietary riboflavin intake and chance of psychological disorders in Iranian adults. High intake of riboflavin decreased the chance of depression and anxiety in men and high psychological distress in women. More prospective studies are needed to confirm these findings.

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.

Prevalence and risk factors for hyperhomocysteinemia: a population-based cross-sectional study from Hunan, China

OBJECTIVES

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. We aimed to investigate the prevalence and risk factors for hyperhomocysteinemia, especially modifiable lifestyle factors, such as smoking behaviour and dietary factors.

DESIGN

Population-based cross-sectional study.

SETTING

Hunan Province, China PARTICIPANTS: A total of 4012 participants completed the study, between July 2013 and March 2014. The median age is 55 (interquartile range: 45-63) years, with 1644 males (41%) and 2368 females (59%).

MAIN OUTCOME MEASURES

Homocysteine level were measured by the microplate enzyme immunoassay method. Hyperthomocysteinemia was defined as ≥15 µmol/L. Questionnaire was used to investigate potential risk factors of hyperhomocysteinemia. Crude odd ratio (OR) or adjusted OR with 95% CI were determined by using univariable or multivariable logistic regression models.

RESULTS

The prevalence of hyperhomocysteinemia is 35.4% (45.4% vs 28.5% for men, women, respectively). One-year increase in age is significantly associated with 2% higher risk of hyperhomocysteinemia (OR=1.02, 95% CI: 1.01 to 1.03). One unit increase of BMI is associated with 5% higher risk of hyperhomocysteinemia (OR=1.05, 95% CI: 1.03 to 1.07). Compared with the non-smoker, smoking participants have a 24% higher risk of hyperhomocysteinemia (OR=1.24, 95% CI: 1.006 to 1.53), while the risk for those quitting smoking are not significantly different (OR=1.14, 95% CI: 0.85 to 1.54). compared with those consuming fruit and vegetable at least once every day, those consuming less than once every day had a significantly higher risk of hyperhomocysteinemia (OR=1.29, 95% CI:1.11 to 1.50). In addition, we found there were significant sex interaction with education level or alcohol drinking on the risk of hyperhomocysteinemia (p_interaction <0.05).

CONCLUSIONS

Higher BMI and older age are potential risk factors for hyperhomocysteinemia. Current smoking but not quitting smoking is associated with higher risk of hyperhomocysteinemia. Fruit and vegetable consumption may have protective effect against hyperhomocysteinemia. Alcohol consumption or education level might interact to influence the risk of hyperhomocysteinemia.

Methylenetetrahydrofolate reductase (MTHFR) gene C677T (rs1801133) polymorphism and risk of alcohol dependence: a meta-analysis

Alcohol dependence is a complex neuropsychiatric disorder. Numerous studies investigated association between MTHFR gene C677T (rs1801133) polymorphism and alcohol dependence (AD), but the results of this association remain conflicting. Accordingly, authors conducted a meta-analysis to further investigate such an association. PubMed, Elsevier Science Direct and Springer Link databases were searched for studies on the association between the MTHFRC677T polymorphism and AD. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using the fixed- or random-effects model. Statistical analysis was performed with the software program MetaAnayst and MIX.A total of 11 articles were identified through a search of electronic databases, up to February 28, 2020. The results of the present meta-analysis did not show any association between MTHFR C677T polymorphisms and AD risk (for T vs. C: OR = 1.04, 95% CI = 0.88-1.24; CT vs. CC: OR = 1.02, 95% CI = 0.62-1.68; for TT+CT vs. CC: OR = 1.10, 95% CI = 0.94-1.29; for TT vs. CC: OR = 1.01, 95% CI = 0.66-1.51; for TT vs. CT+CC: OR = 0.97, 95% CI = 0.66-1.40). Results of subgroup analysis showed no significant association between MTHFR C677T polymorphism with AD in Asian as well as in Caucasian population. In conclusion, C677T polymorphism is not a risk factor for alcohol dependence.

The Relation between Homocysteine Levels in Patients with Acute Coronary Syndrome and Grace Score

Objectives

This study investigated the correlation between homocysteine levels in patients with Acute Coronary Syndrome and GRACE Score.

Methods

This study included 191 cases -140 Non-ST MI cases and 51 MI with ST-elevation cases in Şişli Etfal Training and Research Hospital Coronary Intensive Care Unit between December 2008 and March 2010. Homocysteine was measured by immulite 2000 device, using kemiluminesans method and competitive immunoassay principle and a kit by DPC was used during the measurement. The reference range given by the producing company was between 5-15 Mmol/L for male and female adults. The patients were classified into three risk groups as low, medium and high on the basis of the criteria identified in GRACE risk score: age, heart rate, systolic blood pressure, serum creatine levels, Killip classification, cardiac arrest on admission, increased cardiac enzymes and ST segment depression. The relation between homocysteine levels in patients with Acute Coronary Syndrome and GRACE risk score was evaluated.

Results

In the Non-ST MI group, a statistically-moderate positive correlation was seen between homocysteine and GRACE risk score during the study (p<0.05). However, in the MI with ST-elevation group, no correlation was found between homocysteine and GRACE risk score (p>0.05). Overall, despite the low figures, a meaningful positive relation was observed between homocysteine and GRACE risk score in all cases.

Conclusion

Homocysteine is independent of other classic risk factors for cardiovascular diseases. Therefore, we believe that routine plasma homocysteine levels should be checked when evaluating risk factors for Atherosclerotic Coronary Artery disease.

Association between adherence to the Mediterranean diet and renal function biomarkers and cardiovascular risk factors among diabetic patients with nephropathy

BACKGROUND AND AIM

Although the relationship between a Mediterranean diet (Med diet) and cardiovascular disease (CVD) risk factors has been widely established, no reports exist regarding this association in patients with Diabetes Nephropathy (DN). The aim of this study was to determine the association between level of adherence to a Med diet and renal and CVD risk factors among patients with DN.

STUDY DESIGN

A cross-sectional study.

METHODS

The current study was conducted in 270 patients with DN. A validated food frequency questionnaire was used to assess dietary intake. The Med diet score was determined based on the eight characteristics of a traditional Med diet. Anthropometrics, fasting blood glucose (FBS), total cholesterol (TC), low-density lipoproteins (LDL-c), triacylglycerol (TG), hemoglobin A1C (HbA1c), creatinine (Cr) and blood urea nitrogen (BUN) were detected using standard methods. Kidney function was estimated using the Modification of Diet in Renal Disease (MDRD) formula for estimated glomerular filtration rate (eGFR).

RESULTS

In fully-adjusted models, high serum TC and diastolic blood pressure (DBP) were reduced in participants that demonstrated a greater adherence to a Med diet, but did not reach statistical significance (OR: 0.20; 95% CI: 0.01, 5.52; P = 0.299; OR: 0.81; 95% CI: 0.28, 2.36; P = 0.667). Waist circumference (WC) was non-significantly lower in male participants (OR: 0.91; 95% CI: 0.27, 3.05; P = 0.889). Greater compliance with a Med diet showed a non-significant reduced risk for increased bodyweight (OR: 0.82; 95% CI: 0.23, 2.85; P = 0.730) and obesity (OR: 0.45; 95% CI: 0.03, 6.06; P = 0.493).

CONCLUSION

Adherence to a Med diet was not significantly associated with cardiovascular risk factors and renal function among patients with Diabetes Nephropathy.

Homocysteine level, body mass index and clinical correlates in Chinese Han patients with schizophrenia

Obesity is common comorbidity in patients with schizophrenia. Previous studies have reported that homocysteine (Hcy) is increased in schizophrenia. However, no study has reported the association between BMI and Hcy levels in schizophrenia. This cross-sectional naturalistic study aimed to evaluate the relationship between BMI, Hcy and clinical symptoms in Chinese Han patients with chronic schizophrenia. Clinical and anthropometric data as well as plasma Hcy level and glycolipid parameters were collected. Psychopathology was measured with the Positive and Negative Syndrome Scale (PANSS). Our results showed that compared with the low BMI group, the high BMI group had a higher PANSS general psychopathology subscore, higher levels of blood glucose, total cholesterol and high-density lipoprotein (HDL) cholesterol (all p < 0.05). Hcy levels were negatively associated with BMI in patients (p < 0.001). Hcy level, the PANSS general psychopathology subscale, total cholesterol and education (all p < 0.05) were the influencing factors of high BMI. Our study suggest that Hcy level may be associated with BMI in patients with schizophrenia. Moreover, patients with high BMI show more severe clinical symptoms and higher glucose and lipid levels.

Dietary intake, clinical-nutritional status, and homocysteine in hemodialysis subjects: the mediating role of inflammation (NUGE-HD study)

The aim of the present study was to test the hypothesis that inflammation mediates the associations among food intake, clinical-nutritional status, and plasma homocysteine (Hcys) in hemodialysis (HD) subjects. This was a cross-sectional analysis of data on 129 subjects undergoing HD (58.9% male, 61.8 ± 15.5 years of age) from the cohort Nutrition and Genetics on HD outcomes (NUGE-HD study). Sociodemographic, anthropometric, and metabolic data were collected, and food intake was assessed using a quantitative food frequency questionnaire. Plasma C-reactive protein (CRP) was used as an inflammatory marker. Data were analyzed by structural equation modeling. Regarding the direct effects, complex B vitamin intake was negatively associated with body mass index, and diabetes mellitus was positively associated with CRP. Plasma CRP also showed a negative association with Hcys, and the ratio of saturated and polyunsaturated fatty acids intake showed a positive association with Hcys. Regarding indirect effects, the results showed that the relationship between the presence of diabetes mellitus and Hcys is mediated by plasma CRP. In conclusion, the ratio of saturated and polyunsaturated fatty acids had a direct effect on plasma Hcys, whereas inflammation had a direct and mediating effect on the relationship between Hcys and diabetes mellitus in HD subjects. Novelty In end-stage renal disease, CRP influences plasma Hcys directly and also indirectly through its mediating effect. The quantity and quality of dietary fatty acids influence plasma Hcys concentrations in HD subjects.

Independent and Interactive Influences of Environmental UVR, Vitamin D Levels, and Folate Variant MTHFD1-rs2236225 on Homocysteine Levels

Elevated homocysteine (Hcy) levels are a risk factor for vascular diseases. Recently, increases in ultraviolet radiation (UVR) have been linked to decreased Hcy levels. This relationship may be mediated by the status of UVR-responsive vitamins, vitamin D and folate, and/or genetic variants influencing their levels; however, this has yet to be examined. Therefore, the independent and interactive influences of environmental UVR, vitamin D and folate levels and related genetic variants on Hcy levels were examined in an elderly Australian cohort (n = 619). Red blood cell folate, 25-hydroxyvitamin D (25(OH)D), and plasma Hcy levels were determined, and genotyping for 21 folate and vitamin D-related variants was performed. Erythemal dose rate accumulated over six-weeks (6W-EDR) and four-months (4M-EDR) prior to clinics were calculated as a measure of environmental UVR. Multivariate analyses found interactions between 6W-EDR and 25(OH)D levels (pinteraction = 0.002), and 4M-EDR and MTHFD1-rs2236225 (pinteraction = 0.006) in predicting Hcy levels. The association between 6W-EDR and Hcy levels was found only in subjects within lower 25(OH)D quartiles (<33.26 ng/mL), with the association between 4M-EDR and Hcy occurring only in subjects carrying the MTHFD1-rs2236225 variant. 4M-EDR, 6W-EDR, and MTHFD1-rs2236225 were also independent predictors of Hcy. Findings highlight nutrient-environment and gene-environment interactions that could influence the risk of Hcy-related outcomes.

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.

Environmental UVR Levels and Skin Pigmentation Gene Variants Associated with Folate and Homocysteine Levels in an Elderly Cohort

Ultraviolet radiation (UVR) is a ubiquitous exposure which may contribute to decreased folate levels. Skin pigmentation mediates the biological effect of UVR exposure, but its relationship to folate levels is unexamined. Interactions may exist between UVR and pigmentation genes in determining folate status, which may, in turn, impact homocysteine levels, a potential risk factor for multiple chronic diseases. Therefore, independent and interactive influences of environmental UVR and genetic variants related to skin pigmentation (MC1R-rs1805007, IRF4-rs12203592 and HERC2-rs12913832) on folate (red blood cell (RBC) and serum) and homocysteine levels were examined in an elderly Australian cohort (n = 599). Genotypes were assessed by RT/RFLP-PCR, and UVR exposures were assessed as the accumulated erythemal dose rate accumulated over 4 months (4M-EDR). Multivariate analysis found significant negative associations between 4M-EDR and RBC folate (p < 0.001, β = −0.19), serum folate (p = 0.045, β = −0.08) and homocysteine levels (p < 0.001, β = −0.28). Significant associations between MC1R-rs1805007 and serum folate levels (p = 0.020), and IRF4-rs12203592 and homocysteine levels (p = 0.026) occurred but did not remain significant following corrections with confounders. No interactions between 4M-EDR and pigmentation variants in predicting folate/homocysteine levels were found. UVR levels and skin pigmentation-related variants are potential determinants of folate and homocysteine status, although, associations are mixed and complex, with further studies warranted.

Prevalence of Hyperhomocysteinaemia and Associated Factors among Ethiopian Adult Population in a 2015 National Survey

Hyperhomocysteinaemia (HHcy) is an independent risk factor for major cardiovascular diseases, but data on the prevalence and predictors of HHcy in low- and middle-income countries like Ethiopia are scant. The aim of this study was to estimate the prevalence of HHcy and associated risk factors in the Ethiopian adult population. A cross-sectional survey on risks of noncommunicable diseases (NCDs) using the STEPwise approach to surveillance (STEPS) survey was conducted between April and June 2015. A total of 4,175 study participants were surveyed. Serum homocysteine (Hcy) and metabolic profile were determined using Cobas Integra 400 Plus and CardioChek PA analyzer, respectively. Factors associated with HHcy were determined using logistic regression. The mean serum tHcy concentration was 14.6 μmol/L, with 16.4 μmol/L in males and 13.4 μmol/L in females. Overall, 38% had HHcy, with figures in males (49%) higher than females (30%). Increased age, being male, and high blood pressure and/or taking blood pressure medication, as well as low consumption of fruit and/or vegetables, were independent risk factors for HHcy. In conclusion, the prevalence of HHcy among the adult Ethiopian population is alarmingly high. Improving diets through the promotion of fruit and vegetable consumption is needed to reduce the risk of NCDs.

Association of homocysteine with carotid-femoral pulse wave velocity in a southern Chinese population

This study aimed to investigate whether plasma homocysteine levels were associated with carotid-femoral pulse wave velocity (cfPWV), a golden standard of arterial stiffness, in a population from southern China. A cross-sectional study was conducted on 713 patients admitted to the First Affiliated Hospital of Fujian Medical University from February 2016 to August 2017. They were divided into four groups based on gender-specific quartile of homocysteine levels. Age, cfPWV, uric acid levels, and percentage of hypertension increased with ascending quartiles. The duration of hypertension and systolic blood pressure were higher in the highest quartile than in the lowest quartile. Pearson's correlation analysis and multivariate regression showed a correlation of homocysteine levels with cfPWV. A nearly twofold increased risk of cfPWV ≥10 m/s was observed in the highest quartile compared with the lowest quartile (in the highest quartile: odds ratio = 2.917, 95% confidence interval: 1.635-5.202, P < 0.001). After stratification, this correlation was present in both sexes, in patients aged over 65 years, and those with hypertension. The plasma homocysteine levels were independently associated with cfPWV in the population from southern China, especially in the elderly and those with hypertension.

Associations of Metabolic Syndrome with Total Testosterone and Homocysteine Levels in Male Korean Workers

BACKGROUND

Low testosterone is associated with metabolic syndrome (MetS), and homocysteine (Hcy) is elevated in individuals with MetS. We investigated the relationships of total testosterone (TT) and serum Hcy levels with MetS in male Korean workers.

METHODS

We conducted a cross-sectional study including 8,606 male workers, aged 20 to 58 years, who underwent a physical examination in 2015. MetS was diagnosed based on the criteria of the 2009 harmonized definition, while the Korean standard for waist circumference (WC) was used. Participants' biochemical parameters, including TT and serum Hcy, were measured, and participants were divided into quartiles. Multiple logistic regression models were used to estimate the association of MetS and its individual components depending on TT and serum Hcy quartiles.

RESULTS

The prevalence of MetS in the study population was 16%. TT was lower in participants with MetS than in those without MetS (P<0.001). By contrast, Hcy level was similar between groups (P=0.694). In multiple logistic regression analysis, the odds ratio for the lowest TT quartile was 1.29 (95% confidence interval, 1.06 to 1.57) after adjusting for potential confounders. Participants with lower TT were more likely to have high WC, hypertriglyceridemia, and low high density lipoprotein levels. Serum Hcy levels were not significantly associated with MetS. Of the five components of MetS, only WC was significantly associated with serum Hcy.

CONCLUSION

In male Korean workers, TT may be an independent predictor of MetS, and serum Hcy levels could be a marker of abdominal obesity. However, future prospective studies are needed.

Impact of β-thalassemia trait carrier state on inflammatory status in patients with newly diagnosed hypertension

BACKGROUND

B-thalassemia carrier state or thalassemia minor confers cardiovascular protection through favorable lipidemic and blood pressure profile. However, its impact on inflammatory status-a common denominator of the above conditions-has not been addressed.

METHODS

We investigated a wide range of inflammatory markers [white blood cell (WBC) count, homocysteine, C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, plasminogen, fibronectin, plasminogen activator inhibitor-1 (PAI-1), and uric acid] in a large cohort of 15 805 newly diagnosed hypertensive patients (8299 men, 7506 women); 626 of them (4.0%) had thalassemia minor.

RESULTS

The levels of WBC, homocysteine, CRP, SAA, fibrinogen, and PAI-1 were significantly lower in thalassemia minor patients, but not of plasminogen, fibronectin, and uric acid. In multivariate linear regression analyses, the lower values of WBC (<0.001), CRP (<0.001), homocysteine (<0.001), fibrinogen (<0.001), and PAI-1 (0.008), but not of SAA, were independently associated with thalassemia minor. The interaction between thalassemia minor and body mass index had a significant impact only on WBC and CRP (P for the interaction 0.010 and 0.005, respectively), whereas the interaction between thalassemia minor and sex had a significant impact only on fibrinogen (P for the interaction 0.007).

CONCLUSION

Thalassemia minor is followed by a favorable inflammatory profile that may contribute to the overall better cardiovascular health of the carriers.

Single Nucleotide Polymorphisms in Key One-Carbon Metabolism Genes and Their Association with Blood Folate and Homocysteine Levels in a Chinese Population in Yunnan

OBJECTIVE

One-carbon metabolism (OCM) is essential for DNA synthesis and methylation. Single nucleotide polymorphisms (SNPs) within OCM genes may affect folic acid (FA) metabolism, disrupt homocysteine (Hcy) homeostasis, and increase the risk of disease. This study investigated the relationship between SNPs in key OCM genes and their association with blood FA and Hcy levels in a healthy population in Yunnan, China.

METHODS

Six SNPs within five key OCM genes (MTHFR C677T, MTHFR A1298C, MS A2756G, MTRR A66G, CBS T833C, and SHMT C1420T) were genotyped in 300 healthy volunteers (148 males and 152 females) using polymerase chain reaction/restriction fragment length polymorphism. Blood folate [serum FA (SFA) and red blood cell folate (RBC FA)] and Hcy levels were determined by chemiluminescence immunoassays and enzymatic assays.

RESULTS

Subjects with the MTHFR 677TT genotype had significantly higher Hcy levels and RBC FA concentrations compared with those harboring the MTHFR 677CC/CT genotypes (p < 0.01). Both Hcy and blood FA concentrations were also increased in subjects with MS 2756AA, as well as those within CBS 833TT, when compared with those with MS 2756AG/GG (p < 0.05) and CBS 833TC/CC (p < 0.05) genotypes, respectively. Subjects harboring the combined genotype of MTHFR 677TT and MS 2756AA had a higher Hcy concentration than those carrying other MTHFR and MS combinations (p = 0.002). Similarly, subjects harboring the combination of CBS 833TT with MTHFR 677TT had higher Hcy concentrations than those harboring other CBS and MTHFR combinations (p = 0.011).

CONCLUSIONS

The genotypes involving the MTHFR C677T, MS A2756G, and CBS T833C polymorphisms, including combinations of these genotypes, were the most important factors associated with blood FA and Hcy levels of the investigated SNPs in the OCM genes.

Blood homocysteine concentration and mood disorders with mixed features among patients with alcohol use disorder

BACKGROUND

Blood homocysteine concentration (BHC) is higher in patients with alcohol use disorder (AUD). Previous studies have found a relationship between depressive symptoms severity and BHC in AUD patients and recently some authors have found high BHC among patients with bipolar disorder, both during manic and depressive episodes and in euthymic state. However, BHC in patients with mixed mood episode has not yet been investigated. The aim of this study was to evaluate the BHC of patients with AUD and mixed mood episode.

METHODS

A sample of AUD outpatients was assessed by Mini-International Neuropsychiatric Interview (MINI Plus): those with a DSM-IV-TR mood disorder with mixed features were included in the MIXED group (n = 45), whereas those without mood episode were gathered in the NO MOOD group (n = 23). Two subgroups, MIXMANIA and MIXDEPRESSION, were formed according to the prevalence of manic or depressive symptoms, assessed by Young Mania Rating Scale (YMRS), and Hamilton Rating Scale for Depression (HDRS). The Alcohol Use Disorder Identification Test (AUDIT) was used to appraise the AUD. BHC was determined by High-Performance Liquid Chromatography.

RESULTS

The MIXED group showed greater severity of both depressive (26.35 ± 9.96 vs. 4.77 ± 0.92; p < 0.001) and manic (22.35 ± 3.30 vs. 6.14 ± 1.12; p < 0.001) symptoms, and higher BHC (28.80 ± 11.47 vs. 10.83 ± 2.81; p < 0.001), than the NO MOOD group. BHC was strongly correlated to the HDRS, YMRS and AUDIT scores, just as HDRS was to YMRS, and AUDIT was to both HDRS and YMRS, in the MIXED group only (p < 0.001). The MIXDEPRESSION subgroup showed higher BHC than the MIXMANIA subgroup (Mdn = 42.96, IQR = 10.44 vs. Mdn = 19.77, IQR = 5.93; p < 0.001). A linear regression model conducted on the MIXED group found a significant predictive value for BHC of both HDRS (β = 0.560, t = 2.43, p = 0.026) and AUDIT (β = 0.348, t = 2.17, p = 0.044).

CONCLUSIONS

Depressive symptoms seem to be mainly implicated in the BHC elevation among patients with both mixed features mood disorder and AUD.

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.

Associations between maternal periconceptional exposure to secondhand tobacco smoke and major birth defects

BACKGROUND

While associations between secondhand smoke and a few birth defects (namely, oral clefts and neural tube defects) have been noted in the scientific literature, to our knowledge, there is no single or comprehensive source of population-based information on its associations with a range of birth defects among nonsmoking mothers.

OBJECTIVE

We utilized data from the National Birth Defects Prevention Study, a large population-based multisite case-control study, to examine associations between maternal reports of periconceptional exposure to secondhand smoke in the household or workplace/school and major birth defects.

STUDY DESIGN

The multisite National Birth Defects Prevention Study is the largest case-control study of birth defects to date in the United States. We selected cases from birth defect groups having >100 total cases, as well as all nonmalformed controls (10,200), from delivery years 1997 through 2009; 44 birth defects were examined. After excluding cases and controls from multiple births and whose mothers reported active smoking or pregestational diabetes, we analyzed data on periconceptional secondhand smoke exposure-encompassing the period 1 month prior to conception through the first trimester. For the birth defect craniosynostosis, we additionally examined the effect of exposure in the second and third trimesters as well due to the potential sensitivity to teratogens for this defect throughout pregnancy. Covariates included in all final models of birth defects with ≥5 exposed mothers were study site, previous live births, time between estimated date of delivery and interview date, maternal age at estimated date of delivery, race/ethnicity, education, body mass index, nativity, household income divided by number of people supported by this income, periconceptional alcohol consumption, and folic acid supplementation. For each birth defect examined, we used logistic regression analyses to estimate both crude and adjusted odds ratios and 95% confidence intervals for both isolated and total case groups for various sources of exposure (household only; workplace/school only; household and workplace/school; household or workplace/school).

RESULTS

The prevalence of secondhand smoke exposure only across all sources ranged from 12.9-27.8% for cases and 14.5-15.8% for controls. The adjusted odds ratios for any vs no secondhand smoke exposure in the household or workplace/school and isolated birth defects were significantly elevated for neural tube defects (anencephaly: adjusted odds ratio, 1.66; 95% confidence interval, 1.22-2.25; and spina bifida: adjusted odds ratio, 1.49; 95% confidence interval, 1.20-1.86); orofacial clefts (cleft lip without cleft palate: adjusted odds ratio, 1.41; 95% confidence interval, 1.10-1.81; cleft lip with or without cleft palate: adjusted odds ratio, 1.24; 95% confidence interval, 1.05-1.46; cleft palate alone: adjusted odds ratio, 1.31; 95% confidence interval, 1.06-1.63); bilateral renal agenesis (adjusted odds ratio, 1.99; 95% confidence interval, 1.05-3.75); amniotic band syndrome-limb body wall complex (adjusted odds ratio, 1.66; 95% confidence interval, 1.10-2.51); and atrial septal defects, secundum (adjusted odds ratio, 1.37; 95% confidence interval, 1.09-1.72). There were no significant inverse associations observed.

CONCLUSION

Additional studies replicating the findings are needed to better understand the moderate positive associations observed between periconceptional secondhand smoke and several birth defects in this analysis. Increased odds ratios resulting from chance (eg, multiple comparisons) or recall bias cannot be ruled out.

The associations between smoking, physical activity, dietary habits and plasma homocysteine levels in cardiovascular disease-free people: the ‘ATTICA’ study

Homocysteine levels are considered, by some investigators, as an independent factor of cardiovascular disease; however, others suggest that there is not a causal relationship. The aim of this work was to investigate the associations between homocysteine levels and several lifestyle-related factors. The ATTICA study is a population-based cohort that has randomly enrolled 1128 adult men and 1154 women, stratified by age and gender, from the greater area of Athens, during 2001 2002. Among several demographic, lifestyle, clinical and biochemical characteristics, we measured total plasma homocysteine levels. For the present analysis, we excluded people who had a history of cardiovascular disease. The factors that showed the strongest relationship with homocysteine levels, in both genders, even after adjusting for several potential confounders were: cigarette smoking (p=0.03), endurance exercise (inverse, p<0.05), fruit (inverse, p=0.01) and vegetable intake (inverse, p=0.04), and alcohol (p=0.04) and coffee intake (p=0.04). In conclusion, several lifestyle-related factors seem to be associated with homocysteine levels. However, the vast majority of the associations were weak when we adjusted for other co-factors. The latter may indicate the mutual confounding effect of various socio-demographic, anthropometric and other clinical characteristics on the relationship between homocysteine and cardiovascular risk.

Effects of improved fat meat products consumption on emergent cardiovascular disease markers of male volunteers at cardiovascular risk

High meat-product consumption has been related to cardiovascular disease (CVD). However, previous results suggest the benefits of consuming improved fat meat products on lipoprotein-cholesterol and anthropometric measurements. Present study aims to assess the effect of consuming different Pâté and Frankfurter formulations on emergent CVD biomarkers in male volunteers at increased CVD risk. Eighteen male volunteers with at least two CVD risk factors were enrolled in a sequentially controlled study where different pork-products were tested: reduced-fat (RF), omega-3-enriched-RF (n-3RF), and normal-fat (NF). Pork-products were consumed during 4-week periods separated by 4-week washout. The cardiometabolic index (CI), oxidized low density lipoproteins (oxLDL), apolipoproteins (Apo) A1 and B, homocysteine (tHcys), arylesterase (AE), C-reactive Protein (CRP), tumor necrotic factor-alpha (TNFα), and lipoprotein (a) (Lp(a)) were tested and some other related ratios calculated. AE, oxLDL and Lp(a), AE/HDLc, LDLc/Apo B, and AE/oxLDL rate of change were differently affected (P<0.01) by pork-products consumption. RF increased (P < 0.05) AE, AE/HDLc and AE/oxLDL ratios and decreased TNFα, tHcys; n-3RF increased (P < 0.001) AE, AE/HDLc and AE/oxLDL ratios and decreased (P < 0.05) Lp(a); while NF increased (P<0.05) oxLDL and Lp(a) levels. In conclusion, RF and n-3RF products affected positively the level of some emergent CVD markers. The high regular consumption of NF-products should be limited as significantly increased Lp(a) and oxLDL values. The high variability in response observed for some markers suggests the need to perform more studies to identify targets for RF- and n-3RF-products. Graphical Abstract Emergent CVD markers.

Dietary B Vitamins and Serum C-Reactive Protein in Persons With Human Immunodeficiency Virus Infection: The Positive Living With HIV (POLH) Study

BACKGROUND

B vitamins may have beneficial roles in reducing inflammation; however, research on the role of B vitamins in inflammation among HIV-infected persons is lacking.

OBJECTIVE

This study assessed the association between B vitamins and serum C-reactive protein (CRP) concentrations in HIV-infected persons.

METHODS

A cross-sectional survey was conducted among 314 HIV-infected persons (180 men and 134 women) aged 18 to 60 years residing in the Kathmandu, Nepal. High-sensitive and regular serum CRP concentrations were measured by the latex agglutination nephelometry and latex agglutination turbidimetric method, respectively. Dietary intake was assessed using 2 nonconsecutive 24-hour dietary recalls. The relationships between B vitamins and serum CRP concentrations were assessed using multiple regression analysis.

RESULTS

The multivariate-adjusted geometric mean of serum CRP concentrations was significantly decreased with an increasing B vitamins intake across quartiles of niacin (P for trend = .007), pyridoxine (P for trend = .042), and cobalamin (P for trend = .037) in men. In men, the mean serum CRP concentrations in the highest quartiles of niacin, pyridoxine, and cobalamin were 63%, 38%, and 58%, respectively, lower than that in the lowest quartile. In women, the mean serum CRP concentrations in the highest quartiles of riboflavin (P for trend = .084) and pyridoxine (P for trend = .093) were 37% and 47%, respectively, lower than that in the lowest quartile.

CONCLUSION

High intake of niacin, pyridoxine, or cobalamin was independently associated with decreased serum CRP concentrations among HIV-infected men. Further prospective studies are warranted to confirm the role of B vitamins in inflammation among HIV-infected persons.

Hyperhomocysteinaemia as a potential marker of early renal function decline in middle-aged Asian people without chronic kidney disease

PURPOSE

High levels of serum total homocysteine (tHcy), often observed in chronic kidney disease (CKD) patients, are a risk factor for cardiovascular disease. However, little is known about the relationship between tHcy and renal function in healthy individuals. We examined whether tHcy levels are related to renal function in Asian individuals without CKD.

METHODS

This cross-sectional study examined 2032 subjects, aged 40-64 years. Individuals with kidney diseases or other conditions that could affect tHcy were excluded. Renal function was determined by estimated glomerular filtration rate (eGFR) from levels of serum creatinine (sCr) and cystatin C.

RESULTS

Age, tHcy, sCr, and cystatin C of the subjects were 54.1 ± 6.0 years, 9.5 (8.0-11.4) μmol/L, 0.81 ± 0.1 mg/dL, and 0.82 ± 0.1 mg/L, respectively. In a multiple linear regression analysis, tHcy was a significant independent determinant of sCr and cystatin C in men (β = 0.206 and β = 0.282, respectively) and women (β = 0.247 and β = 0.229, respectively). Highest tHcy levels were independently associated with increased cystatin C (>s1.10 mg/L) with an odds ratio (OR) of 5.00 [95% confidence interval (CI) 2.81-8.09] and decreased eGFR (<90 mL/min/1.73 m(2)) with an OR of 1.69 (95% CI 1.36-2.11) compared to tHcy levels in the 1st-3rd quartiles.

CONCLUSIONS

Higher levels of tHcy are independently associated with sCr and cystatin C elevation. Our study suggests that tHcy levels may be influenced by renal function in Asian populations without CKD. Future studies are needed to define the role of tHcy in renal function.

Is there a causal role for homocysteine concentration in blood pressure? A Mendelian randomization study

BACKGROUND

An understanding of whether homocysteine is a cause or a marker of increased blood pressure is relevant because blood homocysteine can be effectively lowered by safe and inexpensive interventions (e.g., vitamin B-6, B-9, and B-12 supplementation).

OBJECTIVE

The aim was to assess the causal influence of homocysteine on systolic and diastolic blood pressure (SBP and DBP, respectively) in adults with the use of Mendelian randomization (MR).

DESIGN

Data from the 1982 Pelotas Birth Cohort (Brazil) were used. A total of 4297 subjects were evaluated in 2004-2005 (mean age: 22.8 y). The association of homocysteine concentration with SBP and DBP was assessed by conventional ordinary least-squares (OLS) linear regression and 2-stage least-squares (2SLS) regression (MR analysis). The single nucleotide polymorphism (SNP) methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) was used as proxy for homocysteine concentration. We also applied MR to data from the International Consortium for Blood Pressure (ICBP) genomewide association studies (>69,000 participants) using rs1801133 and additional homocysteine-associated SNPs as instruments.

RESULTS

In OLS regression, a 1-SD unit increase in log homocysteine concentration was associated with an increase of 0.9 (95% CI: 0.4, 1.4) mm Hg in SBP and of 1.0 (95% CI: 0.6, 1.4) mm Hg in DBP. In 2SLS regression, for the same increase in homocysteine, the coefficients were -1.8 mm Hg for SBP (95% CI: -3.9, 0.4 mm Hg; P = 0.01) and 0.1 mm Hg for DBP (95% CI: -1.5, 1.7 mm Hg; P = 0.24). In the MR analysis of ICBP data, homocysteine concentration was not associated with SBP (β = 0.6 mm Hg for each 1-SD unit increase in log homocysteine; 95% CI: -0.8, 1.9 mm Hg) but was positively associated with DBP (β = 1.1 mm Hg; 95% CI: 0.2, 1.9 mm Hg). The association of genetically increased homocysteine with DBP was not consistent across different SNPs.

CONCLUSION

Overall, the present findings do not corroborate the hypothesis that homocysteine has a causal role in blood pressure, especially in SBP.

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.

Prevalence of hyperhomocysteinaemia and some of its major determinants in Shaanxi Province, China: a cross-sectional study

The aim of the present study was to investigate the prevalence of hyperhomocysteinaemia (HHCY; total plasma homocysteine (tHcy) concentration >15 μmol/l) and its major determinants in healthy Chinese northerners. A descriptive and cross-sectional study was conducted in Shaanxi Province, China. The study sample included 2645 participants (1042 men and 1603 women) aged >20 years. Demographic characteristics and lifestyle factors were assessed via questionnaire interviews and physical examination. Plasma levels of homocysteine and folate and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism were determined according to standard methods. The prevalence of HHCY was 67·7 % (81·4 % in men and 58·8 % in women). The geometric mean of tHcy concentration was 19·1 μmol/l. The OR of HHCY were 0·44 (95 % CI 0·34, 0·57) for women v. men; 1·95 (95 % CI 1·41, 2·70), 1·41 (95 % CI 1·05, 1·88) and 0·76 (95 % CI 0·64, 0·89) for participants with smoking and alcohol drinking cessation and improved physical activity levels, respectively; 0·25 (95 % CI 0·17, 0·38), 0·33 (95 % CI 0·22, 0·49) and 0·56 (95 % CI 0·36, 0·88) for participants with an education level of elementary school, secondary school and university v. illiterate, respectively; 1·41 (95 % CI 1·13, 1·75) and 3·05 (95 % CI 2·35, 3·97) for participants with CT and TT v. CC genotype at MTHFR 677C → T polymorphism, respectively. These results demonstrate that the prevalence of HHCY is considerably high in Chinese northerners, especially in TT subjects, suggesting that implementation of tHcy-lowering strategies, such as lifestyle changes, is necessary.

Derivation and validation of homocysteine score in u.s. Men and women

BACKGROUND

One-carbon metabolism, which is crucial in DNA synthesis and genomic stability, is an interrelated network of biochemical reactions involved in several dietary and lifestyle factors. The development of the homocysteine score using these factors may be useful to reflect the status of one-carbon metabolism in large epidemiologic studies without biologic samples to measure homocysteine directly.

OBJECTIVE

The aim of this study was to develop an homocysteine score that reflects one-carbon metabolism better than individual dietary or lifestyle factors.

METHODS

We divided 2023 participants with measured plasma total homocysteine data in the Nurses' Health Study and the Health Professionals Follow-Up Study into training (n = 1619) and testing (n = 404) subsets. Using multivariable linear regression, we selected lifestyle determinants of plasma homocysteine in the training set and derived the homocysteine score weighted by the β coefficient for each predictor. The validation of the homocysteine score was assessed using the plasma homocysteine in the independent samples of the training set.

RESULTS

In the training set, smoking, multivitamin use, and caffeine, alcohol, and dietary and supplemental folate intake were significant independent determinants of plasma homocysteine in multivariable linear regression (P ≤ 0.01) and were included in the derivation of the homocysteine score. The Pearson correlation of the homocysteine score with plasma homocysteine was 0.30 in the testing subset (P < 0.001). The homocysteine score was positively associated with the plasma homocysteine concentration in the testing subset and in an independent population of women; the mean difference of plasma homocysteine concentration between the extreme quintiles of homocysteine score ranged from 0.83 μmol/L to 1.52 μmol/L. Population misclassification either from the lowest quintile of plasma homocysteine into the highest quintile of the homocysteine score or from the highest quintile of plasma homocysteine into the lowest quintile of the homocysteine score was ≤12%.

CONCLUSION

These data indicate that the homocysteine score may be used with relatively inexpensive and simple questionnaires to rank an individual's one-carbon metabolism status when homocysteine data are not available.

Elevated serum homocysteine is a predictor of accelerated decline in renal function and chronic kidney disease: A historical prospective study

OBJECTIVE

To estimate the effect of elevated serum homocysteine level on renal function decline and on the incidence of chronic kidney disease (CKD) in the general population.

METHODS

A historical prospective study on 3602 subjects attending a screening center in Israel between the years 2000 and 2012. Only subjects with normal estimated glomerular filtration rate (eGFR) and without proteinuria were included. Subjects were divided to two groups according to mean total serum homocysteine level (≤ 15, >15μmol/l). Linear mixed effect model was used to estimate the annual eGRF decline in respect to homocysteine group. Cox proportional hazards models were used to estimate hazard ratios for CKD in the normal compared to the elevated homocysteine group.

RESULTS

Annual eGFR decline was 25% higher in subjects with elevated versus normal mean homocysteine level (0.90 ± 0.16 ml/min/1.37 m(2) vs. 0.72 ± 0.14 ml/min/1.37 m(2), p<0.001). In a median follow up of 7.75 years, 38 subjects developed CKD (1.05%). Elevated mean homocysteine level was highly associated with developing CKD (HR 4.85, 95% CI 2.48-9.49, p<0.001). In a multivariate analysis which adjusted for age, baseline kidney function, HDL cholesterol, BMI, vitamin B12 and folic acid levels, these relationships remained substantially unchanged.

CONCLUSIONS

Elevated mean serum homocysteine level is associated with an accelerated decline in renal function in both men and women, and is an independent risk factor for the development of CKD in the general population. Further prospective randomized clinical trials are needed to clarify whether the reduction in serum homocysteine concentrations will result in an improved renal prognosis.

A quantile regression approach can reveal the effect of fruit and vegetable consumption on plasma homocysteine levels

INTRODUCTION

A reduction in homocysteine concentration due to the use of supplemental folic acid is well recognized, although evidence of the same effect for natural folate sources, such as fruits and vegetables (FV), is lacking. The traditional statistical analysis approaches do not provide further information. As an alternative, quantile regression allows for the exploration of the effects of covariates through percentiles of the conditional distribution of the dependent variable.

OBJECTIVE

To investigate how the associations of FV intake with plasma total homocysteine (tHcy) differ through percentiles in the distribution using quantile regression.

MATERIALS AND METHODS

A cross-sectional population-based survey was conducted among 499 residents of Sao Paulo City, Brazil. The participants provided food intake and fasting blood samples. Fruit and vegetable intake was predicted by adjusting for day-to-day variation using a proper measurement error model. We performed a quantile regression to verify the association between tHcy and the predicted FV intake. The predicted values of tHcy for each percentile model were calculated considering an increase of 200 g in the FV intake for each percentile.

RESULTS

The results showed that tHcy was inversely associated with FV intake when assessed by linear regression whereas, the association was different when using quantile regression. The relationship with FV consumption was inverse and significant for almost all percentiles of tHcy. The coefficients increased as the percentile of tHcy increased. A simulated increase of 200 g in the FV intake could decrease the tHcy levels in the overall percentiles, but the higher percentiles of tHcy benefited more.

CONCLUSIONS

This study confirms that the effect of FV intake on lowering the tHcy levels is dependent on the level of tHcy using an innovative statistical approach. From a public health point of view, encouraging people to increase FV intake would benefit people with high levels of tHcy.

Dietary carotenoids are associated with cardiovascular disease risk biomarkers mediated by serum carotenoid concentrations

Hyperlipidemia and elevated circulating C-reactive protein (CRP) and total homocysteine (tHcy) concentrations are cardiovascular disease (CVD) risk factors. Previous studies indicated that higher serum carotenoid concentrations were inversely associated with some of these biomarkers. However, whether dietary carotenoid intake is inversely associated with these CVD risk biomarkers is not well known. We assessed the associations between individual dietary carotenoid intake and CVD risk biomarkers and tested whether the serum carotenoid concentrations explain (mediate) or influence the strength of (moderate) the associations, if any association exists. Dietary data collected from 2 24-h dietary recalls and serum measurements in adult men (n = 1312) and women (n = 1544) from the NHANES 2003-2006 were used. Regression models designed for survey analysis were used to examine the associations between individual dietary carotenoids and log-transformed blood cholesterol, CRP, and tHcy. The corresponding individual serum carotenoid concentration was considered as mediator (and moderator if applicable). After adjustment for covariates, significant inverse associations with LDL cholesterol were observed for dietary β-carotene (P < 0.05) and lutein + zeaxanthin (P < 0.001), and with tHcy for dietary β-carotene (P < 0.05), lycopene (P < 0.05), and total carotenoids (P < 0.05). Dietary lutein + zeaxanthin intake was also positively associated with HDL cholesterol concentrations (P < 0.01). Most of these associations were null after additional adjustment for corresponding serum carotenoid concentrations, indicating the complete mediation effects of serum carotenoids. Serum β-carotene significantly moderated the associations between dietary β-carotene and CRP (P-interaction < 0.05), and quartile 4 of dietary β-carotene was associated with lower CRP concentrations only among participants with serum β-carotene > 0.43 μmol/L. In this population-based cross-sectional study, serum carotenoids were mediators of dietary carotenoids and CVD risk biomarker associations. Serum β-carotene was also a moderator of the dietary β-carotene and CRP association. These findings may help in the design of future intervention studies on dietary carotenoids in the prevention of CVD.

Maternal smoking during pregnancy and neural tube defects in offspring: a meta-analysis

PURPOSE

This study aims to examine the association between maternal smoking during pregnancy and neural tube defects (NTDs) in offspring.

METHODS

We retrieved published studies on the association between maternal smoking during pregnancy and NTDs risk in offspring. Meta-analysis was applied to calculate the overall odds ratios (ORs) and their 95 % confidence intervals (CIs). The publication bias was assessed by the Egger's regression asymmetry test and Begg's rank correlation test.

RESULTS

The overall effect of maternal smoking during pregnancy on NTDs was 1.03 (OR = 1.03, 95 % CI = 0.80-1.33). When subgroup analysis was conducted by geographic regions, the overall effects were 1.39 (OR = 1.39, 95 % CI = 1.18-1.64), 0.88 (OR = 0.88, 95 % CI = 0.66-1.17) in Europe and USA; when subgroup analysis was conducted by NTDs types, the overall effect was 1.55 (OR = 1.55, 95 % CI = 1.06-2.26) for spina bifida.

CONCLUSIONS

Women who smoked during pregnancy had mildly elevated risk of having infants with NTDs.

Effect of weight reduction on concentration of plasma total homocysteine in obese Japanese men

SUMMARY

OBJECTIVE

To test whether weight reduction would lower tHcys concentration, and whether adding exercise training to dietary weight reduction would further reduce tHcys concentration over diet alone.

DESIGN

A randomized, controlled, prospective, 14-week weight-loss intervention.

SETTING AND PARTICIPANTS

Forty-eight obese Japanese men aged 27-66 years were assigned to 2 subgroups depending on the type of treatment: diet alone (DA) and diet plus exercise training (DE). Concentration of tHcy was measured in frozen plasma samples by an HPLC method.

RESULTS

Body weight decreased significantly for both groups: DA -7.8 ± 3.2 kg and DE -9.1 ± 3.6 kg. A significant decrease was found in tHcys concentration of the DE group (-2.3 ± 5.0 μmol/L) but not of the DA (-0.3 ± 2.7 μmol/L). For subjects with hyperhomocysteinemia (≥15 μmol/L, n = 17), tHcys concentration decreased from 20.1 ± 7.0 to 13.9 ± 3.0 μmol/L (p < 0.01) for the DE group (n = 8) but did not change for the DA group (16.6 ± 1.9 μmol/L → 15.4 ± 2.3 μmol/L, n = 9). Furthermore, to consider a statistical phenomenon "regression to the mean", we excluded two subjects with the highest two tHcys values of the DE group. The DE group (n = 7) still displayed a significant reduction after the exclusion.

CONCLUSIONS

A weight reduction with diet alone did not improve tHcy levels. Adding aerobic exercise training to a dietary weight-reduction program may be effective for a reduction in tHcy.

Dietary protein and plasma total homocysteine, cysteine concentrations in coronary angiographic subjects

Background

Dietary patterns are associated with plasma total homocysteine (tHcy) concentrations in healthy populations, but the associations between dietary protein and tHcy, total cysteine (tCys) in high risk populations are unclear. We therefore examined the association between dietary protein and tHcy and tCys concentrations in coronary angiographic subjects.

Methods

We conducted a cross-sectional study of 1015 Chinese patients who underwent coronary angiography (40–85 y old). With the use of food-frequency questionnaires, we divided the total protein intakes into high animal-protein and high plant-protein diets. Circulating concentrations of tHcy and tCys were simultaneously measured by high-performance liquid chromatography with fluorescence detection.

Results

We found that high animal-protein diet was positively associated with hyperhomocysteinemia after adjustment for potential confounders, with the subjects in the highest quartile of intake having the greatest increase in risk (OR: 4.14, 95% CI: 2.67-6.43), whereas high plant-protein diet was inversely related to hyperhomocysteinemia, with a higher intake being protective. Compared with the first quartile of intake, the adjusted OR was 0.59 (95% CI: 0.38-0.91) for the fourth quartile. The total protein intake was positively associated with the risk of hypercysteinemia and the participants in highest quartile had significant OR of 1.69 (95% CI: 1.02-2.87) compared with those in lowest quartile. In multivariate linear regression analyses, high animal-protein and total-protein intakes were positively associated with plasma tHcy and tCys concentrations. The plant-protein intake was a negative determinant of plasma tHcy concentrations.

Conclusions

High animal-protein diet was positively associated with high tHcy concentrations, whereas high plant-protein diet was inversely associated with tHcy concentrations. Furthermore the total protein intake was strongly related to tCys concentrations.

Effect of alcohol consumption on risk of hyperhomocysteinemia based on alcohol-related facial flushing response

BACKGROUND

This study examined the relationship between alcohol consumption and hyperhomocysteinemia based on facial flushing caused by drinking.

METHODS

Among male patients aged ≥ 18 years who visited Health Promotion Center of Chungnam National University Hospital in Daejeon from January 2008 to December 2010, 948 males (182 nondrinkers, 348 subjects with drinking-related facial flushing, and 418 subjects without drinking-related facial flushing) were selected. After adjusting for confounding factors such as age, body mass index, hypertension, diabetes, smoking, triglycerides, high density lipoprotein cholesterol, and gamma-glutamyl transpeptidase, a multiple logistic regression analysis was performed to assess the risk of hyperhomocysteinemia in the nonfacial flushing and facial flushing groups compared with the nondrinkers.

RESULTS

After adjusting for confounding factors, risk of hyperhomocysteinemia was significantly lower in the group with a weekly alcohol consumption of < 8 standard drinks (1 drink = 14 g alcohol) in the nonfacial flushing group (<4 drinks: odds ratio [OR], 0.27; 95% confidence interval [CI], 0.10 to 0.74; 4≤, <8 drinks: OR, 0.21; 95% CI, 0.06 to 0.73). Risk of hyperhomocysteinemia was significantly lower in the group with a weekly alcohol consumption < 4 drinks in the facial flushing group (OR, 0.30; 95% CI, 0.13 to 0.68).

CONCLUSION

Our results suggest that the risk of hyperhomocysteinemia is likely lowered by alcohol consumption based on drinking quantity, as lowering the risk of hyperhomocysteinemia differs depending on vulnerability associated with facial flushing.

Dietary supplement use and smoking are important correlates of biomarkers of water-soluble vitamin status after adjusting for sociodemographic and lifestyle variables in a representative sample of U.S. adults

Biochemical indicators of water-soluble vitamin (WSV) status were measured in a nationally representative sample of the U.S. population in NHANES 2003-2006. To examine whether demographic differentials in nutritional status were related to and confounded by certain variables, we assessed the association of sociodemographic (age, sex, race-ethnicity, education, income) and lifestyle (dietary supplement use, smoking, alcohol consumption, BMI, physical activity) variables with biomarkers of WSV status in adults (aged ≥ 20 y): serum and RBC folate, serum pyridoxal-5'-phosphate (PLP), serum 4-pyridoxic acid, serum total cobalamin (vitamin B-12), plasma total homocysteine (tHcy), plasma methylmalonic acid (MMA), and serum ascorbic acid. Age (except for PLP) and smoking (except for MMA) were generally the strongest significant correlates of these biomarkers (|r| ≤ 0.43) and together with supplement use explained more of the variability compared with the other covariates in bivariate analysis. In multiple regression models, sociodemographic and lifestyle variables together explained from 7 (vitamin B-12) to 29% (tHcy) of the biomarker variability. We observed significant associations for most biomarkers (≥ 6 of 8) with age, sex, race-ethnicity, supplement use, smoking, and BMI and for some biomarkers with PIR (5 of 8), education (1 of 8), alcohol consumption (4 of 8), and physical activity (5 of 8). We noted large estimated percentage changes in biomarker concentrations between race-ethnic groups (from -24 to 20%), between supplement users and nonusers (from -12 to 104%), and between smokers and nonsmokers (from -28 to 8%). In summary, age, sex, and race-ethnic differentials in biomarker concentrations remained significant after adjusting for sociodemographic and lifestyle variables. Supplement use and smoking were important correlates of biomarkers of WSV status.

Associations between elevated homocysteine, cognitive impairment, and reduced white matter volume in healthy old adults

OBJECTIVES

Elevated homocysteine has emerged as a risk factor for cognitive impairment even in healthy elderly persons. Reduced brain volume and white matter hyperintensities also occur in healthy elderly as well, but the interrelationships between these have not been well studied. We report these interrelationships in non demented, relatively healthy, community-dwelling older adults from a single East Asian population.

METHODS

Two hundred twenty-eight right-handed participants age 55 years and above were evaluated. Persons with medical conditions or neurological diseases other than well-controlled diabetes mellitus and hypertension were excluded. Participants underwent quantitative magnetic resonance imaging of the brain using a standardized protocol and neuropsychological evaluation. Plasma homocysteine, folate, vitamin B(12), and markers for cardiovascular risk: blood pressure, body mass index, fasting blood glucose, and lipid profile were measured.

RESULTS

Elevated homocysteine was associated with reduced global cerebral volume, larger ventricles, reduced cerebral white matter volume, and lower cognitive performance in several domains. Elevated homocysteine was associated with reduced white matter volume (β = -20.80, t = -2.9, df = 223, p = 0.004) and lower speed of processing (β = -0.38, t = -2.1, df = 223, p = 0.03), even after controlling for age, gender, and education. However, the association between homocysteine and lower speed of processing disappeared after controlling for white matter volume. Elevated homocysteine was not associated with white matter hyperintensity volume or with hippocampal volume. Although homocysteine and folate levels were correlated, their effects on white matter volume were dissociated.

CONCLUSION

In non demented, relatively healthy adults, elevated homocysteine is associated with lower cognitive scores and reduced cerebral white matter volume. These effects can be dissociated from those related to white matter hyperintensities or reduced folate level.

Cardiovascular disease in chronic kidney disease: untying the Gordian knot

Chronic kidney disease (CKD) affects around 10-13% of the general population, with only a small proportion in end stage renal disease (ESRD), either on dialysis or awaiting renal transplantation. It is well documented that CKD patients have an extremely high risk of developing cardiovascular disease (CVD) compared with the general population, so much so that in the early stages of CKD patients are more likely to develop CVD than they are to progress to ESRD. Various pathophysiological pathways and explanations have been advanced and suggested to account for this, including endothelial dysfunction, dyslipidaemia, inflammation, left ventricular hypertrophy and cardiac autonomic dysfunction. In this review, we try to understand and further explore the link between CKD and CVD, as well as offering interventional advice where available, while exposing the current lack of RCT-based research and trial evidence in this area. We also suggest pragmatic Interim measures we could take while we wait for definitive RCTs.

The association of fasting plasma sulfur-containing compounds with BMI, serum lipids and apolipoproteins

BACKGROUND AND AIM

Sulfur amino acids are recognized as potent modulators of lipid metabolism. Plasma total cysteine (tCys) is associated with fat mass, obesity and serum LDL-cholesterol and apolipoprotein (Apo)-B in large population studies. It is not known how fasting plasma concentrations of cysteine precursors and products relate to these associations in humans, given that sulfur-containing compounds (SCC) influence rodent weight gain and serum lipids.

METHODS AND RESULTS

We investigated the cross-sectional associations of fasting plasma SCC (methionine, total homocysteine, cystathionine, tCys, taurine and total glutathione) with BMI and fasting serum lipids and apolipoproteins in 854 men and women with and without cardiovascular disease (CVD). In multiple linear regression analysis adjusted for age, gender, CVD and other SCC, neither methionine, taurine, nor total glutathione was associated with BMI. Plasma taurine was, however, inversely related to HDL-cholesterol (partial r = -0.12, p = 0.004) and its associated apoA1 (partial r = -0.18, p < 0.001). Plasma cystathionine correlated positively with triglycerides and BMI, while tCys positively correlated with total cholesterol, LDL-cholesterol (partial r = 0.20, p < 0.001) and its associated apoB. The associations of SCC with serum lipids were independent of BMI. tCys was also independently associated with BMI (partial r = 0.20, p < 0.001) after adjustment for other SCC, glucose, lipids and apolipoproteins.

CONCLUSIONS

Fasting tCys is associated with BMI independently of metabolically related SCC. Elevation of plasma SCC is generally associated with an unfavorable lipid profile. The negative relations of plasma taurine with HDL-C and apoA1 deserve further investigation.

Association of homocysteine levels with blood lead levels and micronutrients in the US general population

Objectives

Even though several epidemiological studies have observed positive associations between blood lead levels and homocysteine, no study has examined whether this association differs by the levels of micronutrients, such as folate, vitamin B6, and vitamin B12, which are involved in the metabolism of homocysteine. In this study, we examined the interactions between micronutrients and blood lead on homocysteine levels.

Methods

This study was performed with 4089 adults aged ≥20 years old in the US general population using the National Health and Nutrition Examination Survey 2003-2004.

Results

There were significant or marginally significant interactions between micronutrients and blood lead levels on mean homocysteine levels. Positive associations between blood lead and homocysteine were clearly observed among subjects with low levels of folate or low vitamin B6 (p-trend <0.01, respectively). However, in the case of vitamin B12, there was a stronger positive association between blood lead and homocysteine among subjects with high levels of vitamin B12, compared to those with low levels of vitamin B12. In fact, the levels of homocysteine were already high among subjects low in vitamin B12, irrespective of blood lead levels. When we used hyperhomocysteinemia (homocysteine>15 µmol/L) as the outcome, there were similar patterns of interaction, though p-values for each interaction failed to reach statistical significance.

Conclusions

In the current study, the association between blood lead and homocysteine differed based on the levels of folate, vitamin B6, or vitamin B12 present in the blood. It may be important to keep sufficient levels of these micronutrients to prevent the possible harmful effects of lead exposure on homocysteine levels.

Prevalence of hyperhomocysteinaemia and its major determinants in rural Chinese hypertensive patients aged 45–75 years

We aimed to investigate the prevalence of hyperhomocysteinaemia (total plasma homocysteine (tHcy) ≥ 10 μmol/l) and its major determinants in rural Chinese hypertensive patients. A cross-sectional investigation was carried out in Lianyungang of Jiangsu province, China. This analysis included 13 946 hypertensive adults. The prevalence of hyperhomocysteinaemia was 51·6 % (42·7 % in women and 65·6 % in men). The OR of hyperhomocysteinaemia were 1·52 (95 % CI 1·39, 1·67) and 2·32 (95 % CI 2·07, 2·61) for participants aged 55–65 and 65–75 v. 45–55 years; 1·27 (95 % CI 1·18, 1·37) for participants with a BMI ≥ 25 v. < 25 kg/m2; 1·14 (95 % CI 1·06, 1·23) for participants with v. without antihypertensive treatment; 1·09 (95 % CI 1·00, 1·18) for residents inland v. coastal; 0·89 (95 % CI 0·82, 0·97) and 0·83 (95 % CI 0·74, 0·92) for participants with moderate and high v. low physical activity levels; 1·54 (95 % CI 1·41, 1·68) and 2·47 (95 % CI 2·17, 2·81) for participants with a glomerular filtration rate 60–90 and < 60 v. ≥ 90 ml/min per 1·73 m2; and 1·20 (95 % CI 1·07, 1·35) and 3·81 (95 % CI 3·33, 4·36) for participants with CT and TT v. CC genotype at methylenetetrahydrofolate reductase 677C>T polymorphism, respectively. Furthermore, higher tHcy concentrations were observed in smokers of both sexes (men: geometric mean 12·1 (interquartile range (IQR) 9·2–14·5) v. 11·9 (IQR 9·3–14·0) μmol/l, P= 0·005; women: geometric mean 10·3 (IQR 8·3–13·0) v. 9·6 (IQR 7·8–11·6) μmol/l, P= 0·010), and only in males with hypertension grade 3 (v. grade 1 or controlled blood pressure) (geometric mean 12·1 (IQR 9·2–14·4) v. 11·7 (IQR 9·2–14·0), P= 0·016) and in male non-drinkers (yes v. no) (geometric mean 12·3 (IQR 9·4–14·8) v. 11·7 (IQR 9·1–13·9), P= 0·014). In conclusion, there was a high prevalence of hyperhomocysteinaemia in Chinese hypertensive adults, particularly in the inlanders, who may benefit greatly from tHcy-lowering strategies, such as folic acid supplementation and lifestyle change.

Cysteine and obesity: consistency of the evidence across epidemiologic, animal and cellular studies

PURPOSE OF REVIEW

The concentrations of several plasma amino acids increase in obesity. Notably, plasma total concentrations of the sulphur amino acid cysteine (tCys) are linearly associated with fat mass in large population studies. Animal and cellular experiments support the concept that cysteine may be obesogenic. Here we review experimental and epidemiologic findings linking cysteine and related compounds with fat regulation and obesity.

RECENT FINDINGS

tCys, and to a lesser extent cystathionine, are the only plasma sulphur amino acids consistently associated with human obesity, whereas glutathione is inversely associated with BMI. Supplementing cyste(i)ne in rodents decreases energy expenditure and promotes adiposity, whereas defects of cysteine-synthesizing enzymes decrease body weight. In adipocytes, cysteine inhibits lipolysis and promotes lipogenesis via H2O2 production. Unlike most plasma amino acids, tCys levels do not decrease with gastric bypass-induced weight loss, further supporting the concept that elevated cysteine may be a cause, not a consequence of obesity. Although cysteine products (glutathione, taurine and H2S) are altered in obesity, they do not appear to explain cysteine's effects on body weight.

SUMMARY

Cellular, animal and epidemiologic data are consistent with the view that cysteine is obesogenic. Targeted research linking in-vitro and in-vivo findings is needed to elucidate mechanisms involved.

Associations among objectively measured physical activity, fasting plasma homocysteine concentration, and MTHFR C677T genotype

Elevated fasting plasma homocysteine (Hcy) level is a vascular disease risk factor. Plasma Hcy is affected by 5,10-methylenetetrahydofolate reductase (MTHFR) genotype and dietary folate intake. This cross-sectional study in 434 Japanese adults examined the associations among objectively measured physical activity (PA), plasma Hcy adjusting for dietary folate intake, and MTHFR C677T genotype. Daily PA was measured by triaxial accelerometry and all subjects completed a questionnaire about their dietary habits. Plasma Hcy and MTHFR C677T genotype were determined. Plasma Hcy in subjects with the TT genotype was significantly higher than in those with CC or CT genotype (p < 0.001). Plasma Hcy was significantly different between ≥ 200 (7.6 ± 0.2 nmol/mL) and <200 µg/day (8.3 ± 0.3 nmol/mL) folate intake groups (p = 0.003). There were no differences in plasma Hcy adjusting for age, sex, and folate intake between groups according to PA category in all subjects. However, there were significant interactions between time spent in light PA (p = 0.003), vigorous PA (p = 0.001), or inactivity (p = 0.004), and MTHFR genotype. In only the TT genotype, shorter time spent in light PA was associated with higher plasma Hcy than a longer time spent in light PA (11.5 ± 3.3 nmol/mL vs. 8.5 ± 3.3 nmol/mL, p < 0.001), and longer time spent in vigorous PA and inactivity were associated with higher plasma Hcy (11.8 ± 3.3 nmol/mL vs. 8.4 ± 3.2 nmol/mL, 11.6 ± 3.3 nmol/mL vs. 8.4 ± 3.3 nmol/mL, respectively, p < 0.001). In conclusion, light and vigorous PA were associated with plasma Hcy only in the TT genotype, but there were no such associations in all genotypes.

Alcohol and the older adult: a comprehensive review

Alcohol consumption in the older adult is of major concern with the advent of baby boomers coming into the over 65-age bracket. Alcohol consumption has been touted as beneficial for health, and while that may be accurate for moderate consumption in younger persons, there is considerable risk associated with increased alcohol intake in older adults. This increase is partially due to age-related physiological changes, existing diagnoses, number of comorbid conditions, and increased use of prescribed and/or over-the-counter medications, coupled with other concerns. This review addresses the current research regarding ethanol consumption in older adults and all-cause mortality as well as several conditions more frequently seen in the geriatric population. These conditions include vascular diseases, hypertension, type 2 diabetes, gastrointestinal disorders, hepatic disorders, dental and oro-facial problems, bone density decline, and falls and fractures. In addition, drug interactions and recent research into select vitamin and mineral considerations with increased alcohol intake in older persons are addressed. While recommendations for alcohol intake have not been specifically established for age ranges within the 65-year-and-older bracket, and practitioners do not routinely assess alcohol intake or ethanol related adverse events in this population, common sense approaches to monitoring will become increasingly important as the generation of "boomers" who believe that alcohol intake improves health comes of age.

Maternal smoking, passive tobacco smoke, and neural tube defects

BACKGROUND

Although cigarette smoke is a well-established toxin and harmful to the developing embryo, the evidence for an independent effect on the occurrence of neural tube defects (NTDs) is mixed. In this study, we examined the relation between NTDs and maternal exposures to cigarette smoke, including passive smoke exposure.

METHODS

We used cases and controls from the large, multistate, population-based National Birth Defects Prevention Study. A total of 1041 NTD cases and 5862 live birth controls, delivered during 1997 to 2004, were available for analyses. Mothers were interviewed by telephone between 6 weeks and 24 months after delivery. Participation rates were 71% for NTD case mothers and 69% for control mothers.

RESULTS

Compared with nonsmokers (and also not exposed to passive cigarette smoke), mothers exposed only to passive smoke had an increased NTD odds ratio (OR, 1.7; 95% confidence interval [CI], 1.4-2.0), adjusted for race-ethnicity, and study center. There was no increased OR for mothers who actively smoked 24 or fewer cigarettes per day. Mothers who smoked 25 or more cigarettes per day had an elevated OR (OR, 1.6; 95% CI, 0.9-3.0), but the OR adjusted for race-ethnicity, and center was compatible with the null.

CONCLUSION

Results suggest that maternal exposure to passive smoke is associated with NTDs. Women who plan on becoming pregnant should minimize their exposure to passive smoke and refrain from smoking.

Physical Activity and Adherence to Mediterranean Diet Increase Total Antioxidant Capacity: The ATTICA Study

We studied the association of physical activity and adherence to the Mediterranean diet, in total antioxidant capacity (TAC). A random sample of 1514 men and 1528 women was selected from Attica region. Physical activity was assessed with a translated version of the validated "International Physical Activity Questionnaire" (iPAQ), and dietary intake through a validated Food Frequency Questionnaire (FFQ). Adherence to the Mediterranean diet was assessed by the MedDietScore that incorporated the inherent characteristics of this diet. TAC was positively correlated with the degree of physical activity (P < .05). TAC was also positively correlated with MedDietScore (r = 0.24, P < .001). Stratified analysis by diet status revealed that the most beneficial results were observed to highly active people as compared to inactive, who also followed the Mediterranean diet (288 ± 70 μmol/L, 230 ± 50 μmol/L, resp.), after adjusting for various confounders. Increased physical activity and greater adherence to the Mediterranean diet were associated with increased total antioxidant capacity.