Association between serum folate and cardiovascular deaths among adults with hypertension

Association between Serum Folate and Vaginal High-Risk Human Papillomavirus Infections in United States Women

BACKGROUND

Serum concentration of folate was inversely associated with cervical intraepithelial neoplasia and cervical cancer in some studies. The association between folate and human papillomavirus (HPV) infection, a necessary cause of cervical cancer, has not been well elucidated.

OBJECTIVES

We evaluated whether serum folate concentrations were associated with high-risk HPV (hrHPV) infection.

METHODS

The study population was 11,801 females, aged 18-59 y, enrolled in the National Health and Nutrition Examination Survey (NHANES), from 2003 to 2016, in the United States. In this cross-sectional study, prevalence ratios (PRs) of vaginal hrHPV were calculated using logistic regression models, by quintiles of serum folate.

RESULTS

Females in the lowest quintile had <21.3 nmol/L of folate. Approximately 23% of the females (2733/11,801) were hrHPV positive. In age-adjusted models, folate was significantly associated with hrHPV infection. The PRs and 95% confidence intervals (CIs) were (PR: 1.52; 95% CI: 1.37, 1.70) for the first, (PR: 1.29; 95% CI: 1.15, 1.44) for the second, (PR: 1.19; 95% CI: 1.06, 1.34) for the third, and (PR: 1.09; 95% CI: 0.96, 1.23) for the fourth quintiles, compared with the females in the highest quintile, with a significant P value for trend, <0.0001. The association remained statistically significant after the models were further adjusted for lifestyle and sexual risk factors for hrHPV infection; the females in the lowest quintile were more likely to have hrHPV infection than those in the highest quintile (PR: 1.40; 95% CI: 1.11, 1.53).

CONCLUSIONS

Results from this sample of females in the United States suggest that serum folate concentration is inversely associated with hrHPV infection.

Association Between High Blood Folate Levels and Glaucoma in a Representative Korean Population

Purpose

This study aimed to investigate the association between folate levels and the prevalence of glaucoma.

Methods

This nationwide population-based cross-sectional study included 1790 participants aged ≥40 years. We analyzed data regarding the participants obtained in the 2016-2018 Korean National Health and Nutrition Examination Survey. The diagnosis of glaucoma was defined according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses were used to investigate the relationship between blood folate levels and glaucoma.

Results

There was a significantly lower prevalence of glaucoma in the highest quartile of blood folate levels than in the lowest quartile, after adjusting for confounding factors such as age, sex, systemic hypertension, diabetes, hypercholesterolemia, and smoking (odds ratio [OR] = 0.470; 95% confidence interval [CI], 0.291-0.759; P for trend = 0.017). There was a significantly lower risk of glaucoma in the highest quartile of blood folate levels than in the lowest quartile among women (OR = 0.188; 95% CI, 0.099-0.357; P for trend <0.001) and younger participants (OR =0.443; 95% CI, 0.229-0.856; P for trend = 0.045).

Conclusions

Our findings indicate a strong inverse correlation between blood folate levels and glaucoma.

Interactions of arsenic exposure, arsenic metabolism with red blood cell folate on the risk of hypertension: NHANES 2007-2016

PURPOSE

Arsenic exposure was associated with hypertension, and arsenic metabolism might be influenced by folate concentrations. Thus, this study aimed to explore the interaction between arsenic exposure and metabolism with folate concentrations on hypertension.

METHODS

We studied 6643 adults aged 20 years and older who participated in the National Health and Nutrition Examination Survey from 2007 through 2016. Urinary total arsenic (UTAs), the percentage of urinary dimethylarsinic acid (DMA%), serum and red blood cell (RBC) folate were collected. Logistic regression and restricted cubic spline (RCS) analyses were performed to determine the association and dose-response relationship. Interaction analyses were conducted on both additive and multiplicative scales.

RESULTS

UTAs (median: 7.05 μg/L) was positively associated with hypertension risk, and the adjusted OR was 1.44 (95% CI: 1.06-1.95) when comparing the third with the lowest quartile. And participants with the highest quintile of RBC folate had increased hypertension risk than those with the lowest quintile (adjusted OR = 1.43, 95% CI: 1.06-1.94). Significant additive interaction was observed between excessive RBC folate with high UTAs (AP = 0.323, 95% CI: 0.083-0.564) and low DMA% (AP = 0.381, 95% CI: 0.119-0.643) on hypertension risk.

CONCLUSION

Our results suggested significant interactions between high UTAs and low DMA% with excessive RBC folate on hypertension risk.

The Role of One-Carbon Metabolism in Healthy Brain Aging

Aging results in more health challenges, including neurodegeneration. Healthy aging is possible through nutrition as well as other lifestyle changes. One-carbon (1C) metabolism is a key metabolic network that integrates nutritional signals with several processes in the human body. Dietary supplementation of 1C components, such as folic acid, vitamin B12, and choline are reported to have beneficial effects on normal and diseased brain function. The aim of this review is to summarize the current clinical studies investigating dietary supplementation of 1C, specifically folic acid, choline, and vitamin B12, and its effects on healthy aging. Preclinical studies using model systems have been included to discuss supplementation mechanisms of action. This article will also discuss future steps to consider for supplementation. Dietary supplementation of folic acid, vitamin B12, or choline has positive effects on normal and diseased brain function. Considerations for dietary supplementation to promote healthy aging include using precision medicine for individualized plans, avoiding over-supplementation, and combining therapies.

Comparison of insulin resistance-associated parameters in US adults: a cross-sectional study

BACKGROUND

Triglyceride-glucose (TyG) is correlated with cardiovascular events caused by insulin resistance (IR). The aim of this study was to analyze the relationship between TyG and its related indicators and IR among US adults from 2007 to 2018 in the National Health and Nutrition Examination Survey (NHANES) database so as to identify more accurate and reliable predictors of IR.

METHODS

This is a cross-sectional study including 9884 participants (2255 with IR and 7629 without IR). TyG, TyG-body mass index (TyG-BMI), TyG waist circumference (TyG-WC), and TyG waist-to-height ratio (TyG-WtHR) were measured using standard formulas.

RESULTS

TyG, TyG-BMI, TyG-WC, and TyG-WtHR were significantly correlated with IR in the general population, with TyG-WC being the most strongly correlated, with an odds ratio of 8.00 (95% confidence interval 5.05-12.67) for the fourth quartile of TyG-WC compared with the first quartile in the adjusted model. Receiver operating characteristic (ROC) analysis of the participants showed that the maximum area under the TyG-WC curve was 0.8491, which was significantly higher than that of the other three indicators. Moreover, this trend was stable both among people of both genders and among patients with coronary heart disease (CHD), hypertension, and diabetes.

CONCLUSIONS

The present study confirms that the TyG-WC index is more successful than TyG alone in identifying IR. In addition, our findings demonstrate that TyG-WC is a simple and effective marker for screening the general US adult population and those with CHD, hypertension, and diabetes and can be effectively used in clinical practice.

Non-linear associations of serum and red blood cell folate with risk of cardiovascular and all-cause mortality in hypertensive adults

This study aims to assess the associations of serum and red blood cell (RBC) folate with cardiovascular and all-cause mortality in hypertensive adults. Data on serum and RBC folate from the 1999-2014 National Health and Nutrition Examination Survey were included. Through December 31, 2015, cardiovascular and all-cause mortality were identified from the National Death Index. Multiple Cox regression and restricted cubic spline analyses were used to determine the relationship between folate concentrations and outcomes. A total of 13,986 hypertensive adults were included in the analysis (mean age, 58.5 ± 16.1 years; 6898 [49.3%] men). At a median of 7.0 years of follow-up, 548 cardiovascular deaths and 2726 all-cause deaths were identified. After multivariable adjustment, the fourth quartile of serum folate was associated with cardiovascular (HR = 1.32 [1.02-1.70]) and all-cause (HR = 1.20 [1.07-1.35]) mortality compared to the second quartile, whereas the first quartile was only linked with increased all-cause (HR = 1.29 [1.15-1.46]) mortality. The inflection points for the non-linear associations of serum folate with cardiovascular and all-cause mortality were 12.3 ng/mL and 20.5 ng/mL, respectively. In addition, the highest quartile of RBC folate was associated with cardiovascular (HR = 1.68 [1.30-2.16]) and all-cause (HR = 1.30 [1.16-1.46]) mortality compared to the second quartile, but the lowest quartile was not associated with either outcome. The inflection points for the non-linear associations of RBC folate with cardiovascular and all-cause mortality were 819.7 and 760.1 ng/mL, respectively. The findings suggest non-linear associations between serum and RBC folate levels and the risk of cardiovascular and all-cause mortality in hypertensive adults.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association between hypertension and stroke in US adults in the National Health and Nutrition Examination Surveys (NHANES) 2007 to 2018

BACKGROUND

Hypertension is associated with stroke events. The purpose of this study was to analyze the correlation between hypertension and stroke in American adults from 2007 to 2018 in National health and Nutrition Examination Survey (NHANES) database.

METHODS

28528 individuals in the NHANES from 2007 to 2018 were included in the cross-sectional analysis. The independent variable was blood pressure (BP) and the outcome variable was stroke. Multivariate linear regression model was used to study the correlation between BP and stroke.

RESULTS

In each multivariate linear regression model, BP level was positively correlated with stroke, and this positive correlation was stable in both men and women (man OR: 1.36, 95% CI: 0.95 to 1.69; woman OR: 1.45, 95% CI: 1.12 to 1.78).

CONCLUSION

Our results show that there is a significant positive correlation between BP and stroke. When the systolic blood pressure (SBP) is about 140 mmHg, the risk of stroke is the lowest; Male patients with diastolic blood pressure (DBP) of about 80 mmHg have a lower risk of stroke.

Effect of baseline resting heart rate on the risk of all-cause death in Chinese patients with hypertension

The aim of this study was to investigate the association between baseline resting heart rate (RHR) and all-cause death in the China Stroke Primary Prevention Trial (CSPPT). A post hoc analysis was conducted using data from 20,648 hypertensive adults without cardiovascular disease in the CSPPT and with baseline RHR data available. Over a median follow-up duration of 4.5 years, the baseline RHR and risk for all-cause death had a nonlinear relationship. The risk of all-cause death was higher in participants with an RHR ≥85 bpm (hazard ratio 1.42; 95% confidence interval 1.03-1.96, p = .031) than in those with a baseline RHR of 75-80 bpm. The effect of RHR on all-cause death during the treatment period was modified by the folate level (p = .020) and systolic blood pressure (SBP) during treatment(p = .056). The effect of RHR on the risk of all-cause death was stronger when the folate level was low than when it was high; the risk was higher when the RHR was < 75 bpm or ≥80 bpm than when it was 75-80 bpm. RHR had a greater effect on the risk of all-cause death when SBP during treatment was well controlled than when it was not; again, the risk was higher when the RHR was < 75 bpm or ≥80 bpm than when it was 75-80 bpm. A higher baseline RHR resulted in an increased risk of all-cause mortality in Chinese adults with hypertension but no history of stroke or myocardial infarction.

Associations of Serum and Red Blood Cell Folate With All-Cause and Cardiovascular Mortality Among Hypertensive Patients With Elevated Homocysteine

Objectives

This study aims to explore the associations between serum and red blood cell (RBC) folate as indicators of short- and long-term folate status, respectively, and all-cause as well as CVD mortality among hypertensive patients with elevated homocysteine.

Methods

A prospective cohort study of the National Health and Nutrition Examination Survey (1999–2006) and 2015 Linked Mortality File was performed. All-cause and CVD mortality risk estimated using Cox proportional hazards models with adjusting for multiple potential covariates.

Results

A total of 1,753 hypertensive patients with elevated homocysteine [mean (SD) age, 68.5 (13.1)] were included in the analysis. During a median follow-up of 10.0 years, a total of 899 all-cause and 257 CVD deaths occurred. Compared the highest with the lowest quartile of RBC folate, the multivariable adjusted hazard ratios and 95% confidence intervals for all-cause and CVD death were 1.13 (0.92–1.39) and 1.47 (1.01–2.16) respectively. There was a significant and positive trend between RBC folate and the risk of CVD death (p for trend = 0.0196). No significant association was found between serum folate and mortality risk among the study sample.

Conclusions

High level of RBC folate is associated with an increased risk of cardiovascular mortality among hypertensive patients with elevated homocysteine while serum folate has no such effects.

Associations of Serum Folate and Vitamin B12 Levels With Cardiovascular Disease Mortality Among Patients With Type 2 Diabetes

Importance

The associations of serum folate and vitamin B12 levels with cardiovascular outcomes among patients with type 2 diabetes (T2D) remain unclear.

Objective

To investigate the associations of serum folate and vitamin B12 levels with risk of cardiovascular disease (CVD) mortality among individuals with T2D.

Design, Setting, and Participants

This prospective cohort study included 8067 patients with T2D who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2014 and NHANES III (1988-1994). American Diabetes Association criteria were used to define T2D. Data were analyzed between October 1, 2020, and April 1, 2021.

Exposures

Serum folate and vitamin B12 levels.

Main Outcomes and Measures

Multivariable Cox proportional hazards regression models were used to compute hazard ratios and 95% CIs for the associations of serum folate and vitamin B12 levels with risks of CVD and all-cause mortality. Two multivariable models were constructed. Restricted cubic spline analyses were used to examine the nonlinear association of serum folate levels and vitamin B12 levels with CVD mortality, and nonlinearity was assessed using the likelihood ratio test.

Results

This cohort study included data from 7700 participants in the folate analysis (mean [SE] age, 57.8 [0.3] years; 3882 men [weighted, 50.5%]; median serum folate level, 12.1 ng/mL [IQR, 7.1-19.5 ng/mL]) and 4860 participants for the vitamin B12 analysis (mean [SE] age, 57.8 [0.3] years; 2390 men [weighted, 50.7%]; median serum vitamin B12 level, 506.1 pg/mL [IQR, 369.1-703.5 pg/mL]). During 72 031 person-years of follow-up, 799 CVD deaths were documented for the folate analysis, and during 43 855 person-years of follow-up, 467 CVD deaths were reported for the vitamin B12 analysis. Nonlinear associations were observed for serum levels of folate (P = .04 for nonlinearity) and vitamin B12 (P = .04 for nonlinearity) with risk of CVD mortality among patients with T2D. Compared with participants in the second quartile of serum folate levels (7.1-12.1 ng/mL), the hazard ratios for CVD mortality were 1.43 (95% CI, 1.04-1.98) for participants in the lowest serum folate level quartile (<7.1 ng/mL) and 1.03 (95% CI, 0.74-1.44) for participants in the highest quartile (≥19.5 ng/mL). In addition, compared with participants in the second quartile of serum vitamin B12 levels (369.1-506.0 pg/mL), the hazard ratios for CVD mortality were 1.74 (95% CI, 1.20-2.52) for participants in the lowest quartile (<369.1 pg/mL) and 2.32 (95% CI, 1.60-3.35) for participants in the highest quartile (≥703.5 pg/mL). Similar patterns of association were observed for all-cause mortality (nonlinearity: P = .01 for folate and P = .02 for vitamin B12).

Conclusions and Relevance

This cohort study found that both low and high serum levels of vitamin B12 as well as low serum levels of folate were significantly associated with higher risk of CVD mortality among individuals with T2D.

Development and validation using NHANES data of a predictive model for depression risk in myocardial infarction survivors

Background

Depression after myocardial infarction (MI) is associated with poor prognosis. This study aimed to develop and validate a nomogram to predict the risk of depression in patients with MI.

Methods

This retrospective study included 1615 survivors of MI aged >20 years who were selected from the 2005–2018 National Health and Nutrition Examination Survey database. The 899 subjects from the 2005–2012 survey comprised the development group, and the remaining 716 subjects comprised the validation group. Univariate and multivariate analyses identified variables significantly associated with depression. The least absolute shrinkage and selection operator (LASSO) binomial regression model was used to select the best predictive variables.

Results

A full predictive model and a simplified model were developed using multivariate analysis and LASSO binomial regression results, respectively, and validated using data from the validation group. The receiver operator characteristic curve and Hosmer–Lemeshow goodness of fit test were used to assess the nomogram's performance. The full nomogram model included 8 items: age, BMI, smoking, drinking, diabetes, exercise, insomnia, and PIR. The area under the curve for the development group was 0.799 and for the validation group was 0.731, indicating that our model has good stability and predictive accuracy. The goodness of fit test showed a good model calibration for both groups. The simplified model includes age, smoking, PIR, and insomnia. The AUC of the simplified model was 0.772 and 0.711 in the development and validation groups, respectively, indicating that the simplified model still possessed good predictive accuracy.

Conclusion

Our nomogram helped assess the individual probability of depression after MI and can be used as a complement to existing depression screening scales to help physicians make better treatment decisions.

Red blood cell folate and severe abdominal aortic calcification: Results from the NHANES 2013-2014

BACKGROUND AND AIMS

Abdominal aortic calcification (AAC) has been introduced as a good predictor of cardiovascular disease (CVD) events, but no previous study has investigated the relationship between folate levels and AAC. The present study aims to explore the relationship between red blood cell (RBC) folate, a better indicator reflecting long-term folate intake, and severe AAC in the United States (US) middle-aged and elderly population.

METHODS AND RESULTS

Cross-sectional data were derived from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 of 2818 men and women aged 40 years or older. Multivariable logistic regression models were used to determine odds ratios (ORs) and 95% confidence intervals (CIs) for severe AAC of each RBC folate quintile category. The restricted cubic spline model was used for the dose-response analysis. A U-shaped dose-response relation between RBC folate and the odds of severe AAC was found after adjustment for multiple potential confounding factors, p for nonlinear = 0.0032. With the third quintile category of RBC folate as the reference, multivariable-adjusted ORs and 95% CIs of the lowest, second, fourth, and the highest quintile categories were 2.34 (1.37-4.00), 1.24 (0.70-2.19), 1.58 (0.92-2.70), and 2.26 (1.35-3.76), respectively.

CONCLUSIONS

Individuals with either low or high levels of RBC folate were at increased risks of severe AAC in a representative sample of US adults. While folate deficiency is widely recognized as harmful, these results highlight the need to investigate the potential adverse health outcomes of high folate level.

Serum Folate and All-Cause Mortality is of Non-Linear Relationship Among Population with Chronic Kidney Disease: A Retrospective Cohort Study

AIM

A transition toward high serum folate concentrations has been noticed following the mandatory folate fortification. To explore this further, we studied the relationship between folate and health outcomes in population with chronic kidney disease (CKD).

METHODS

We retrospectively explored the relationships between serum folate and risk of all-cause death in this population. We analyzed data of 2142 subjects with CKD who participated in the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Vital status was followed through December 31, 2006.

RESULTS

Cox regression was used to estimate hazard ratios (HRs) of mortality for individuals with serum folate in rest quintiles compared with individuals with the fourth quintile. After an average follow-up of 57.4 months with 157 deaths recorded, a reversed J-shaped association was revealed after conducting multivariable adjustment. The mortality rate in population with lower and higher folate levels were 8.29% and 12.67%, respectively, and the corresponding adjusted HRs were 2.41 (95% confidence interval, CI=1.32-4.40) and 2.10 (1.20-3.70). Kaplan-Meier curve showed survival benefits for the fourth quintile of serum folate as compared to the first and fifth quintile.

CONCLUSION

Serum folate concentrations may influence all-cause mortality in a non-linear pattern in the CKD population. It is reasonable to recommend periodic surveillance in the CKD population to maintain the serum folate concentration in an appropriate level.

Identification of Featured Metabolism-Related Genes in Patients with Acute Myocardial Infarction

Objective

A growing body of emerging evidence indicates that metabolic processes play a pivotal role in the biological processes underlying acute myocardial infarction (AMI). The aim of the current study was to identify featured metabolism-related genes in patients with AMI using a support vector machine (SVM) and to further explore the value of these genes in the diagnosis of AMI.

Methods

Gene microarray expression data related to AMI were downloaded from the GSE66360 dataset in the Gene Expression Omnibus (GEO) database. This data set consisted of 50 AMI samples and 49 normal controls that were randomly classified into a discovery cohort (21 AMI samples and 22 normal controls) and a validation cohort (28 AMI and 28 normal controls). We applied a machine learning method that combined SVM with recursive feature elimination (RFE) to discriminate AMI patients from normal controls. Based on this, an SVM classifier was constructed. Receiver operating characteristic (ROC) analysis was used to investigate the predictive value for the early diagnosis of AMI in the two cohorts and was then further verified in an independent external cohort.

Results

Three metabolism-related genes were identified based on SVM-RFE (AKR1C3, GLUL, and PDE4B). The SVM classifier based on the three genes allowed for excellent discrimination between AMI and healthy samples in both the discovery cohort (AUC = 0.989) and the validation cohort (AUC = 0.964), and this was further confirmed in the GSE68060 dataset (AUC = 0.839). Additionally, the SVM classifier allowed for perfect discrimination between recurrent AMI events and nonrecurrent events in the GSE68060 cohort (AUC = 0.992). GO and KEGG pathway enrichment analysis of the identified featured genes revealed significant enrichment of specific metabolic pathways.

Conclusion

The identified metabolism-related genes may play important roles in the development of AMI and may represent diagnostic and therapeutic biomarkers of AMI.