A nutrient-wide association study on blood pressure

The impact of folic acid/VB12 deficiency on essential hypertension in children and adolescents: from a nested case-control and a cohort study

To explore the relationship between serum folic acid (FA) or Vitamin B12 (VB12) and elevated BP in children and adolescents. Both a nested case control and a cohort study were designed to explore the relationship between serum folic acid (FA) or Vitamin B12 (VB12) and elevated blood pressure (BP). All the included participants were from primary school. A total of 326 subjects (116:210) in nested case control were from an established cohort. And 270 participants without hypertension at baseline and followed in 2019 in cohort. FA and VB12 levels were lower in the elevated BP group than in the control group, and homocysteine level was higher than that in the control group. In the elevated BP group, overweight/obese children had lower FA than overweight/obese children in the normal BP group. FA was positively correlated with high-density lipoprotein (HDL) and Apo lipoprotein A (APOA), but negatively correlated with triglyceride (TG). FA was significantly correlated with elevated BP in children and adolescents (β = -0.353, P = 0.032), after adjusting VB12, and homocysteine (HCY), and the interaction effect of FA*HCY was significant. Both systolic and diastolic BP levels were statistically lower in the FA high exposure group than in the FA low exposure group in the cohort study. This study found that FA and vitamin B12 deficiency in childhood was correlated with elevated BP levels, which may affect BP by regulating lipid levels, and confirmed the importance of maintaining high levels of FA and vitamin B12 in childhood either by diet or supplementation.

Use of the DASH Diet and Coronary Artery Disease

Initial dietary approach to stop hypertension (DASH) diet feeding trials showed blood pressure (BP)-lowering effects that corresponded to higher degrees of concordance with the diet. These results popularized the idea that adherence to a DASH diet could reduce coronary artery disease (CAD) risk for patients. Recent evidence shows that the impact of DASH on CAD incidence and risk is less clear. While many studies show that the DASH diet impacts CAD risk factors, others suggest that these effects do not remain when important confounders are controlled. Also, the evidence from meta-analyses that the DASH diet impacts incident CAD is still inconclusive. Reassessment of the DASH diet, and the search for an ideal diet to prevent CAD will require a better understanding of the mechanisms through which the DASH diet works. Proposed mechanisms for its benefit include preventing inflammation and atherosclerosis progression as well as providing a heathy balance of dietary sodium and potassium intake.

Vitamin B2 enables regulation of fasting glucose availability

Flavin adenine dinucleotide (FAD) interacts with flavoproteins to mediate oxidation-reduction reactions required for cellular energy demands. Not surprisingly, mutations that alter FAD binding to flavoproteins cause rare inborn errors of metabolism (IEMs) that disrupt liver function and render fasting intolerance, hepatic steatosis, and lipodystrophy. In our study, depleting FAD pools in mice with a vitamin B2-deficient diet (B2D) caused phenotypes associated with organic acidemias and other IEMs, including reduced body weight, hypoglycemia, and fatty liver disease. Integrated discovery approaches revealed B2D tempered fasting activation of target genes for the nuclear receptor PPARα, including those required for gluconeogenesis. We also found PPARα knockdown in the liver recapitulated B2D effects on glucose excursion and fatty liver disease in mice. Finally, treatment with the PPARα agonist fenofibrate activated the integrated stress response and refilled amino acid substrates to rescue fasting glucose availability and overcome B2D phenotypes. These findings identify metabolic responses to FAD availability and nominate strategies for the management of organic acidemias and other rare IEMs.

A medication-wide association study to identify medications associated with incident clinically significant diabetic retinopathy

Background

Diabetic retinopathy, a common microvascular complication of diabetes mellitus, is one of the leading causes of vision loss worldwide. Although some oral drugs have been suggested to affect the risk of diabetic retinopathy, systematic evaluation about the associations between medications and diabetic retinopathy is still absent.

Objective

To comprehensively investigate associations of systemic medications with incident clinically significant diabetic retinopathy (CSDR).

Design

Population-based cohort study.

Methods

From 2006 to 2009, more than 26 000 participants residing in New South Wales were enrolled in the 45 and Up study. Diabetic participants with self-reported physician diagnosis or records of anti-diabetic medication prescriptions were finally included in the current analysis. CSDR was defined as diabetic retinopathy cases requiring retinal photocoagulation recorded in the Medicare Benefits Schedule database from 2006 to 2016. Prescriptions of systemic medication from 5 years to 30 days prior to CSDR were retrieved from the Pharmaceutical Benefits Scheme. The study participants were equally split into training and testing datasets. Logistic regression analyses were performed for the association between each of systemic medication and CSDR in the training dataset. After controlling the false discovery rate (FDR), significant associations were further validated in the testing dataset.

Results

The 10-year incidence of CSDR was 3.9% (n = 404). A total of 26 systemic medications were found to be positively associated with CSDR, among which 15 were validated by the testing dataset. Additional adjustments for pertinent comorbidities suggested that isosorbide mononitrate (ISMN) (OR: 1.87, 95%CI: 1.00-3.48), calcitriol (OR: 4.08, 95% CI: 2.02-8.24), three insulins and analogues (e.g., intermediate-acting human insulin, OR: 4.28, 95% CI: 1.69-10.8), five anti-hypertensive medications (e.g., furosemide, OR: 2.53, 95% CI: 1.77-3.61), fenofibrate (OR: 1.96, 95% CI: 1.36-2.82) and clopidogrel (OR: 1.72, 95% CI: 1.15-2.58) were independently associated with CSDR.

Conclusion

This study investigated the association of a full spectrum of systemic medications with incident CSDR. ISMN, calcitriol, clopidogrel, a few subtypes of insulin, anti-hypertensive and cholesterol-lowering medications were found to be associated with incident CSDR.

Effects of minimally and ultra-processed foods on blood pressure in Brazilian adults: a two-year follow up of the CUME Project

AIM

To assess the association of food consumption according to degree of processing with changes in systolic (SBP) and diastolic (DBP) blood pressure in adult participants of a Brazilian cohort.

METHODS

Longitudinal study with 2496 adult participants of the Cohort of Universities of Minas Gerais (CUME Project). Food consumption was categorized by food groups according to degree of processing following the NOVA grading system: unprocessed/minimally processed foods/culinary ingredients (U/MPF&CI), processed foods (PFs) and ultra-processed foods (UPFs). unprocessed/minimally processed foods/culinary ingredients (U/MPF&CI), processed foods (PFs) and ultra-processed foods (UPFs). Changes in SBP and DBP were categorized (decreased, maintained, increased). Independent associations between exposure and outcomes were verified using multiple generalized ordered logistic models adjusted for potential confounders.

RESULTS

After a two-year follow-up, the consumption of U/MPF&CI (% daily caloric intake) reduced the chance of increasing DBP (P for trend = 0.014), with a more evident effect among participants within the 5th quintile of this food group (odds ratio (OR) = 0.55; 95% confidence interval (CI): 0.34-0.97]. On the other hand, the consumption of UPFs (% daily caloric intake) raised the chance of increasing DBP (P for trend = 0.005) and was more evident among participants within the quintiles of higher consumption (4th quintile - OR = 1.97; 95% CI: 1.25-3.10; 5th quintile - OR = 1.79; 95% CI = 1.12-2.86). No associations were found between food consumption according to degree of processing and changes in SBP.

CONCLUSION

Higher consumption of U/MPF&CI and UPFs were independently associated to lower and greater chances of increased DBP in adult participants from CUME Project.

Diet-wide association study of 92 foods and nutrients and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition study and the Netherlands Cohort Study

It is unclear whether diet, and in particular certain foods or nutrients, are associated with lung cancer risk. We assessed associations of 92 dietary factors with lung cancer risk in 327 790 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC). Cox regression yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) per SD higher intake/day of each food/nutrient. Correction for multiple comparisons was performed using the false discovery rate and identified associations were evaluated in the Netherlands Cohort Study (NLCS). In EPIC, 2420 incident lung cancer cases were identified during a median of 15 years of follow-up. Higher intakes of fibre (HR per 1 SD higher intake/day = 0.91, 95% CI 0.87-0.96), fruit (HR = 0.91, 95% CI 0.86-0.96) and vitamin C (HR = 0.91, 95% CI 0.86-0.96) were associated with a lower risk of lung cancer, whereas offal (HR = 1.08, 95% CI 1.03-1.14), retinol (HR = 1.06, 95% CI 1.03-1.10) and beer/cider (HR = 1.04, 95% CI 1.02-1.07) intakes were positively associated with lung cancer risk. Associations did not differ by sex and there was less evidence for associations among never smokers. None of the six associations with overall lung cancer risk identified in EPIC were replicated in the NLCS (2861 cases), however in analyses of histological subtypes, inverse associations of fruit and vitamin C with squamous cell carcinoma were replicated in the NLCS. Overall, there is little evidence that intakes of specific foods and nutrients play a major role in primary lung cancer risk, but fruit and vitamin C intakes seem to be inversely associated with squamous cell lung cancer.

Software Application Profile: PXStools—an R package of tools for conducting exposure-wide analysis and deriving polyexposure risk scores

Motivation

Investigating the aggregate burden of environmental factors on human traits and diseases requires consideration of the entire ‘exposome’. However, current studies primarily focus on a single exposure or a handful of exposures at a time, without considering how multiple exposures may be simultaneously associated with each other or with the phenotype. Polyexposure risk scores (PXS) have been shown to predict and stratify risk for disease beyond or complementary to genetic and clinical risk. PXStools provides an analytical package to standardize exposome-wide studies as well as derive and validate polyexposure risk scores.

Implementation

PXStools is a package for the statistical R.

General features

The package allows users to (i) conduct exposure-wide association studies; (ii) derive and validate polyexposure risk scores with and without accounting for exposure interactions, using new approaches in regression modelling (hierarchical lasso);(iii) compare goodness of fit between models with and without multiple exposures; and (iv) visualize results. A data frame with a unique identifier, phenotype and exposures is needed as the only input. Various customizations are allowed including data preprocessing (removing missing or unwanted responses), covariates adjustment, multiple hypothesis correction and model specification (linear, logistic, survival).

Availability

The PXStools source code is freely available on Github at [https://github.com/yixuanh/PXStools ].

Identification of Novel Phenotypes Correlated with CKD: A Phenotype-Wide Association Study

Background: A comprehensive understanding of phenotypes related to CKD will facilitate the identification and management of CKD. We aimed to panoramically test and validate associations between multiple phenotypes and CKD using a phenotype-wide association study (PheWAS). Methods: 15,815 subjects from cross-sectional cohorts of the National Health and Nutrition Examination Survey (1999-2006) were randomly 50:50 split into training and testing sets. CKD was defined as eGFR < 60 mL/min/1.73m2. We performed logistic regression analyses between each of 985 phenotypes with CKD in the training set (false discovery rate < 1%) and validated in the testing set (false discovery rate < 1% ). Random forest (RF) model, Nagelkerke's Pseudo-R2, and the area under the receiver operating characteristic (AUROC) were used to validate the identified phenotypes. Results: We identified 18 phenotypes significantly related to CKD, among which retinol, red cell distribution width (RDW), and C-peptide were less researched. The top 5 identified phenotypes were blood urea nitrogen (BUN), homocysteine (HCY), retinol, parathyroid hormone (PTH), and osmolality in RF importance ranking. Besides, BUN, HCY, PTH, retinol, and uric acid were the most important phenotypes based on Pseudo-R2. AUROC of the RF model was 0.951 (full model) and 0.914 (top 5 phenotypes). Conclusion: Our study demonstrated associations between multiple phenotypes with CKD from a holistic view, including 3 novel phenotypes: retinol, RDW, and C-peptide. Our findings provided valid evidence for the identification of novel biomarkers for CKD.

Questionnaire-based exposome-wide association studies (ExWAS) reveal expected and novel risk factors associated with cardiovascular outcomes in the Personalized Environment and Genes Study

While multiple factors are associated with cardiovascular disease (CVD), many environmental exposures that may contribute to CVD have not been examined. To understand environmental effects on cardiovascular health, we performed an exposome-wide association study (ExWAS), a hypothesis-free approach, using survey data on endogenous and exogenous exposures at home and work and data from health and medical histories from the North Carolina-based Personalized Environment and Genes Study (PEGS) (n = 5015). We performed ExWAS analyses separately on six cardiovascular outcomes (cardiac arrhythmia, congestive heart failure, coronary artery disease, heart attack, stroke, and a combined atherogenic-related outcome comprising angina, angioplasty, atherosclerosis, coronary artery disease, heart attack, and stroke) using logistic regression and a false discovery rate of 5%. For each CVD outcome, we tested 502 single exposures and built multi-exposure models using the deletion-substitution-addition (DSA) algorithm. To evaluate complex nonlinear relationships, we employed the knockoff boosted tree (KOBT) algorithm. We adjusted all analyses for age, sex, race, BMI, and annual household income. ExWAS analyses revealed novel associations that include blood type A (Rh-) with heart attack (OR[95%CI] = 8.2[2.2:29.7]); paint exposures with stroke (paint related chemicals: 6.1[2.2:16.0], acrylic paint: 8.1[2.6:22.9], primer: 6.7[2.2:18.6]); biohazardous materials exposure with arrhythmia (1.8[1.5:2.3]); and higher paternal education level with reduced risk of multiple CVD outcomes (stroke, heart attack, coronary artery disease, and combined atherogenic outcome). In multi-exposure models, trouble sleeping and smoking remained important risk factors. KOBT identified significant nonlinear effects of sleep disorder, regular intake of grapefruit, and a family history of blood clotting problems for multiple CVD outcomes (combined atherogenic outcome, congestive heart failure, and coronary artery disease). In conclusion, using statistics and machine learning, these findings identify novel potential risk factors for CVD, enable hypothesis generation, provide insights into the complex relationships between risk factors and CVD, and highlight the importance of considering multiple exposures when examining CVD outcomes.

Causes of Outcome Learning: a causal inference-inspired machine learning approach to disentangling common combinations of potential causes of a health outcome

Nearly all diseases are caused by different combinations of exposures. Yet, most epidemiological studies focus on estimating the effect of a single exposure on a health outcome. We present the Causes of Outcome Learning approach (CoOL), which seeks to discover combinations of exposures that lead to an increased risk of a specific outcome in parts of the population. The approach allows for exposures acting alone and in synergy with others. The road map of CoOL involves (i) a pre-computational phase used to define a causal model; (ii) a computational phase with three steps, namely (a) fitting a non-negative model on an additive scale, (b) decomposing risk contributions and (c) clustering individuals based on the risk contributions into subgroups; and (iii) a post-computational phase on hypothesis development, validation and triangulation using new data before eventually updating the causal model. The computational phase uses a tailored neural network for the non-negative model on an additive scale and layer-wise relevance propagation for the risk decomposition through this model. We demonstrate the approach on simulated and real-life data using the R package 'CoOL'. The presentation focuses on binary exposures and outcomes but can also be extended to other measurement types. This approach encourages and enables researchers to identify combinations of exposures as potential causes of the health outcome of interest. Expanding our ability to discover complex causes could eventually result in more effective, targeted and informed interventions prioritized for their public health impact.

Exposome-wide ranking of modifiable risk factors for cardiometabolic disease traits

The present study assessed the temporal associations of ~ 300 lifestyle exposures with nine cardiometabolic traits  to identify exposures/exposure groups that might inform lifestyle interventions for the reduction of cardiometabolic disease risk. The analyses were undertaken in a longitudinal sample comprising > 31,000 adults living in northern Sweden. Linear mixed models were used to assess the average associations of lifestyle exposures and linear regression models were used to test associations with 10-year change in the cardiometabolic traits. 'Physical activity' and 'General Health' were the exposure categories containing the highest number of 'tentative signals' in analyses assessing the average association of lifestyle variables, while 'Tobacco use' was the top category for the 10-year change association analyses. Eleven modifiable variables showed a consistent average association among the majority of cardiometabolic traits. These variables belonged to the domains: (i) Smoking, (ii) Beverage (filtered coffee), (iii) physical activity, (iv) alcohol intake, and (v) specific variables related to Nordic lifestyle (hunting/fishing during leisure time and boiled coffee consumption). We used an agnostic, data-driven approach to assess a wide range of established and novel risk factors for cardiometabolic disease. Our findings highlight key variables, along with their respective effect estimates, that might be prioritised for subsequent prediction models and lifestyle interventions.

Investigation of the urinary sodium-to-potassium ratio target level based on the recommended dietary intake goals for the Japanese population: The INTERMAP Japan

Growing epidemiological evidence has shown an association of the urinary sodium (Na) to potassium (K) ratio (Na/K ratio) with blood pressure and cardiovascular diseases. However, no clear cutoff level has been defined. We investigated the cutoff level of the urinary Na/K ratio under different dietary guidelines for Japanese individuals, especially that endorsed by the 2020 revised Japanese Dietary Reference Intakes (DRIs). A population of 1145 Japanese men and women aged 40 to 59 years from the INTERMAP study was examined. Using high-quality standardized data, the averages of two 24 h urinary collections and four 24 h dietary recalls were used to calculate the 24 h urinary and dietary Na/K ratios, respectively. Associations between the urinary and dietary Na/K ratios were tested by sex- and age-adjusted partial correlation. The optimal urinary Na/K ratio cutoff level was determined by receiver operating characteristic (ROC) curves and sex-specific cross tables for recommended dietary K and salt. Overall, the average molar ratio of 24 h urinary Na/K was 4.3. We found moderate correlations (P < 0.001) of the 24 h urinary Na/K ratio with 24 h urinary Na and K excretion (r = 0.52, r = -0.49, respectively) and the dietary Na/K ratio (r = 0.53). ROC curves showed that a 24 h urinary Na/K ratio of approximately 2 predicted Na and K intake that meets the dietary goals of the Japanese DRIs. The range of urinary Na/K ratios meeting the dietary goals of the Japanese DRIs for both Na and K was 1.6‒2.2 for men and 1.7‒1.9 for women. Accomplishing a urinary Na/K ratio of 2 would be desirable to achieve the DRIs dietary goals for both Na and K simultaneously in middle-aged Japanese men and women accustomed to Japanese dietary habits. This observational study is registered at www.clinicaltrials.gov as NCT00005271.

Validation of Self-Monitoring Devices Supporting Sodium Intake Reduction: An Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

INTRODUCTION

Although several approaches for approximating daily Na intake and the Na/K ratio using casual urine are available, the most useful method remains unclear during daily practice and at home.

METHODS

Twenty-seven participants measured their casual urinary Na/K ratio repeatedly using a Na/K ratio monitor and also measured overnight urine once daily using a monitoring device which delivers on-site feedback to estimate their salt intake under unrestricted, low-salt (LS) (6 g/day), and high-salt (HS) (12 g/day) diets.

RESULTS

The monitoring method utilizing overnight urine to estimate daily Na remained insensitive, resulting in significant overestimation during the LS diet and underestimation during the HS diet periods; estimated salt intake during the LS and HS diet periods plateaued at 7-8 g/day and 9-10 g/day within 3 day; mean estimated salt intake was 11.3 g/day, 7.9 g/day, and 9.8 g/day on the last day of the unrestricted, LS, and HS diets; the coefficient of variation (CV) of the estimated Na intake was 0.23 and 0.17 in the latter half of the low- and high-salt diet periods, respectively. The mean urinary Na/K molar ratio was 5.6, 2.5, and 5.3 on the last day of the unrestricted, LS, and HS diets; the CV of the daily mean Na/K ratio was 0.41 and 0.36 in the latter half of the LS and HS diet periods, respectively. The urinary Na/K ratio during the LS and HS diet periods plateaued within 2 days. The monitoring method based on the daily mean of the casual urinary Na/K ratio reflected the actual change in Na intake, and the estimated value tracked the actual changes in salt intake with smaller difference than the overnight urine estimates when using the estimation coefficient set at 2; estimated salt intake during the LS and HS diet periods plateaued at 5-6 g/day and 10-12 g/day within 2-3 day; mean estimated salt intake was 11.0 g/day, 5.7 g/day, and 10.7 g/day on the last day of the unrestricted, LS, and HS diets, respectively.

DISCUSSION/CONCLUSION

Estimates of daily Na intake derived from overnight urine may remain insensitive during dietary interventions. The urinary Na/K ratio reflects the actual change in Na intake during dietary modification and may serve as a practical marker, particularly during short-term interventions. Conversion from the urinary Na/K ratio to estimated salt intake may be useful, if the coefficient was set appropriate by further investigations.

Food processing and risk of hypertension: Cohort of Universities of Minas Gerais, Brazil (CUME Project)

OBJECTIVE

To analyse the association between food consumption according to the degree of processing and incidence of hypertension in CUME project participants.

DESIGN

Longitudinal study in which food consumption was evaluated according to the percentage contribution of daily energetic intake (%/d) of each NOVA classification group (unprocessed/minimally processed foods and culinary preparations (U/MPF&CP); processed foods and ultra-processed foods (UPF)). Hypertension was defined according to American College of Cardiology/American Heart Association (ACC/AHA) criteria. Adjusted relative risks (RR) and their 95% confidence intervals (95 % CI) were estimated by Poisson regression models with robust variances.

SETTING

Brazil.

PARTICIPANTS

1221 graduates classified as non-hypertensive at baseline and monitored for 2 years.

RESULTS

Daily energetic percentage from each group according to degree of processing was 64·3 (sd 12) % for U/MPF&CP; 9·9 (sd 5·8) % for processed foods and 25·8 (sd 11) % for UPF. Incidence of hypertension was high (152/1000 person-years; n 113, 193/1000 person-years in males and n 257, 138/1000 person-years in females). After adjusting for potential confounders, participants in the upper quintile of daily energetic intake of U/MPF&CP presented a reduced risk of hypertension (RR: 0·72; 95 % CI 0·52, 0·98), while those in the upper quintile of daily energetic intake of UPF presented an increased risk of the outcome (RR: 1·35; 95 % CI 1·01, 1·81).

CONCLUSIONS

In this prospective cohort of Brazilian middle-aged adult university graduates, the highest consumptions of U/MPF&CP and UPF were associated with, respectively, reduced and increased risk of hypertension. Additional longitudinal studies are needed to confirm our results.

Data-driven assessment, contextualisation and implementation of 134 variables in the risk for type 2 diabetes: an analysis of Lifelines, a prospective cohort study in the Netherlands

AIMS/HYPOTHESIS

We aimed to assess and contextualise 134 potential risk variables for the development of type 2 diabetes and to determine their applicability in risk prediction.

METHODS

A total of 96,534 people without baseline diabetes (372,007 person-years) from the Dutch Lifelines cohort were included. We used a risk variable-wide association study (RV-WAS) design to independently screen and replicate risk variables for 5-year incidence of type 2 diabetes. For identified variables, we contextualised HRs, calculated correlations and assessed their robustness and unique contribution in different clinical contexts using bootstrapped and cross-validated lasso regression models. We evaluated the change in risk, or 'HR trajectory', when sequentially assigning variables to a model.

RESULTS

We identified 63 risk variables, with novel associations for quality-of-life indicators and non-cardiovascular medications (i.e., proton-pump inhibitors, anti-asthmatics). For continuous variables, the increase of 1 SD of HbA_1c, i.e., 3.39 mmol/mol (0.31%), was equivalent in risk to an increase of 0.53 mmol/l of glucose, 19.8 cm of waist circumference, 8.34 kg/m² of BMI, 0.67 mmol/l of HDL-cholesterol, and 0.14 mmol/l of uric acid. Other variables required an increase of >3 SD, which is not physiologically realistic or a rare occurrence in the population. Though moderately correlated, the inclusion of four variables satiated prediction models. Invasive variables, except for glucose and HbA_1c, contributed little compared with non-invasive variables. Glucose, HbA_1c and family history of diabetes explained a unique part of disease risk. Adding risk variables to a satiated model can impact the HRs of variables already in the model.

CONCLUSIONS

Many variables show weak or inconsistent associations with the development of type 2 diabetes, and only a handful can reliably explain disease risk. Newly discovered risk variables will yield little over established factors, and existing prediction models can be simplified. A systematic, data-driven approach to identify risk variables for the prediction of type 2 diabetes is necessary for the practice of precision medicine.

Genetic Variations in Thiamin Transferase SLC35F3 and the Risk of Hypertension in Koreans

Hypertension is a major health issues globally. Multiple genetic and environmental factors are involved in hypertension etiology. Solute carrier family 35 member F3 (SLC35F3) is a type of transporter uptakes thiamin across the cellular and mitochondrial membrane. Recent studies suggested that variations in SLC35F3 are associated with the risk of hypertension; however, studies are limited in Koreans. This study examined the association of the genetic variations in SLC35F3 and the risk of hypertension in Koreans using the Korean Genome Epidemiology Study (Ansan/Ansung study). A total of 8,298 Koreans (males 3,983, females 4,315) were analyzed for their general characteristics, dietary intake, and blood pressure. Twenty-four tagging variations in SLC35F3 were selected and investigated for their association with the risk of hypertension using a sex-stratified approach. Findings suggested that, in males, rs12135117 A allele carriers were at the lower risk for hypertension (adjusted odds ratio, 0.859; 95% confidence interval [CI], 0.740–0.998). In females, rs10910387 TC genotype tended to increase the risk 1.172-fold for hypertension (95% CI, 1.002–1.370). Multiple linear regression models exhibited that rs12135117 A allele was negatively associated with blood pressure in males, and rs10910387 TC genotype had a positive association with blood pressure in females. However, statistical significance for these genetically modified effects was in lacked (Bonferroni's corrected p > 0.002). In conclusion, genetic variation in SLC35F3 is not a decisive prediction marker for hypertension risk in Koreans. Given the rarity of data, more studies are required to evaluate the role of SLC35F3 and thiamin in the hypertension etiology.

Gaussian graphical modeling of the serum exposome and metabolome reveals interactions between environmental chemicals and endogenous metabolites

Given the complex exposures from both exogenous and endogenous sources that an individual experiences during life, exposome-wide association studies that interrogate levels of small molecules in biospecimens have been proposed for discovering causes of chronic diseases. We conducted a study to explore associations between environmental chemicals and endogenous molecules using Gaussian graphical models (GGMs) of non-targeted metabolomics data measured in a cohort of California women firefighters and office workers. GGMs revealed many exposure-metabolite associations, including that exposures to mono-hydroxyisononyl phthalate, ethyl paraben and 4-ethylbenzoic acid were associated with metabolites involved in steroid hormone biosynthesis, and perfluoroalkyl substances were linked to bile acids-hormones that regulate cholesterol and glucose metabolism-and inflammatory signaling molecules. Some hypotheses generated from these findings were confirmed by analysis of data from the National Health and Nutrition Examination Survey. Taken together, our findings demonstrate a novel approach to discovering associations between chemical exposures and biological processes of potential relevance for disease causation.

Trend in potassium intake and Na/K ratio in the Italian adult population between the 2008 and 2018 CUORE project surveys

BACKGROUND AND AIMS

Low potassium intake, in addition to high sodium, has been associated with higher risk of hypertension and CVD. The Study assessed habitual potassium intake and sodium/potassium ratio of the Italian adult population from 2008 to 2012 to 2018-2019 based on 24-h urine collection, in the framework of the CUORE Project/MINISAL-GIRCSI/MENO SALE PIU' SALUTE national surveys.

METHODS AND RESULTS

Data were from cross-sectional surveys of randomly selected age-and-sex stratified samples of resident persons aged 35-74 years in 10 (out of 20) Italian regions. Urinary electrolyte and creatinine measurements were performed in a central laboratory. Analyses considered 942 men and 916 women, examined in 2008-2012, and 967 men and 1010 women, examined in 2018-2019. In 2008-2012, the age-standardized mean of potassium intake (urinary potassium accounts for 70% of potassium intake) was 3147 mg (95% CI 3086-3208) in men and 2784 mg (2727-2841) in women, whereas in 2018-2019, it was 3043 mg (2968-3118) and 2561 mg (2508-2614) respectively. In 2008-2012, age-adjusted prevalence of persons with an adequate potassium intake (i.e. ≥ 3510 mg/day) was 31% (95% CI 28-34%) for men and 18% (16-21%) for women; in 2018-2019, it was 26% (23-29%) and 12% (10-14%) respectively. The sodium/potassium ratio significantly decreased both in men and women.

CONCLUSIONS

The average daily potassium intake of the Italian general adult population remains lower than the WHO and EFSA recommended level. These results suggest the need of a revision to strengthen initiatives for the promotion of an adequate potassium intake at the population level.

Evaluating and Strengthening the Evidence for Nutritional Bone Research: Ready to Break New Ground?

A healthy diet is essential to attain genetically determined peak bone mass and maintain optimal skeletal health across the adult lifespan. Despite the importance of nutrition for bone health, many of the nutritional requirements of the skeleton across the lifespan remain underexplored, poorly understood, or controversial. With increasingly aging populations, combined with rapidly changing diets and lifestyles globally, one anticipates large increases in the prevalence of osteoporosis and incidence of osteoporotic fractures. Robust, transparent, and reproducible nutrition research is a cornerstone for developing reliable public health recommendations to prevent osteoporosis and osteoporotic fractures. However, nutrition research is often criticized or ignored by healthcare professionals due to the overemphasis of weak science, conflicting, confusing or implausible findings, industry interests, common misconceptions, and strong opinions. Conversely, spurious research findings are often overemphasized or misconstrued by the media or prominent figures especially via social media, potentially leading to confusion and a lack of trust by the general public. Recently, reforms of the broader discipline of nutrition science have been suggested and promoted, leading to new tools and recommendations to attempt to address these issues. In this perspective, we provide a brief overview of what has been achieved in the field on nutrition and bone health, focusing on osteoporosis and osteoporotic fractures. We discuss what we view as some of the challenges, including inherent difficulties in assessing diet and its change, disentangling complex interactions between dietary components and between diet and other factors, selection of bone-related outcomes for nutrition studies, obtaining evidence with more unbiased designs, and perhaps most importantly, ensuring the trust of the public and healthcare professionals. This perspective also provides specific recommendations and highlights new developments and future opportunities for scientists studying nutrition and bone health. © 2021 American Society for Bone and Mineral Research (ASBMR).

Urinary sodium-to-potassium ratio: a simple and useful indicator of diet quality in population-based studies

Background

Current evidence regarding the prognostic relevance of urinary sodium-to-potassium ratio (Na-to-K ratio), as an indicator of diet quality is limited. This study was conducted to investigate whether urinary Na-to-K ratio could be related to habitual dietary patterns, in a general population.

Methods

This study was conducted in the framework of the Tehran Lipid and Glucose Study (2014–2017) on 1864 adult men and women. Urinary Na and K concentrations were measured in the morning spot urine samples. Dietary intakes of the participants were assessed using a validated 147-item Food Frequency Questionnaire (FFQ) and major dietary patterns were obtained using principal component analysis. Mediterranean dietary pattern and Dietary Approaches to Stop Hypertension (DASH) score, were also calculated. Multivariable-adjusted linear regression was used to indicate association of dietary patterns and urinary Na-to-K ratio.

Results

Mean (± SD) age of participants was 43.7 ± 13.9 years and 47% were men. Mean (± SD) urinary Na, K and the ratio was 139 ± 41.0 and 57.9 ± 18.6 mmol/L, 2.40 ± 0.07, respectively. Higher urinary Na-to-K ratio (> 2.37 vs. < 1.49) was related to lower intakes of vegetables (282 vs. 321 g/day), low-fat dairy (228 vs. 260 g/day) and fruits (440 vs. 370 g/day). Western dietary pattern was related to higher urinary Na-to-K ratio (β = 0.06; 95% CI 0.01, 0.16). Traditional dietary pattern, Mediterranean and DASH diet scores were inversely associated with urinary Na-to-K ratio (β = − 0.14; 95% CI − 0.24, − 0.11, β = − 0.07; 95% CI − 0.09, − 0.01, β = − 0.12; 95% CI − 0.05, − 0.02, respectively).

Conclusions

Spot urinary Na-to-K ratio may be used as a simple and inexpensive method to monitor diet quality in population-based epidemiological studies.

Inverse Association Between Riboflavin Intake and New-Onset Hypertension

The prospective relation of dietary riboflavin intake with hypertension remains uncertain. We aimed to investigate the relationship of dietary riboflavin intake with new-onset hypertension and examine possible effect modifiers in general population. A total of 12 245 participants who were free of hypertension at baseline from China Health and Nutrition Survey were included. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. The study outcome was new-onset hypertension, defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or diagnosed by physician or under antihypertensive treatment during the follow-up. A total of 4303 (35.1%) subjects developed hypertension during 95 573 person-years of follow-up. Overall, there was a nonlinear, inverse association between total, plant-based, or animal-based riboflavin intake and new-onset hypertension (allPfor nonlinearity, <0.001). The risk of new-onset hypertension was increased only in participants with relatively lower riboflavin intake. Accordingly, a significantly lower risk of new-onset hypertension was found in participants in quartiles 2 to 4 of total riboflavin intake (hazard ratio, 0.74 [95% CI, 0.68–0.80]), plant-derived riboflavin intake (hazard ratio, 0.77 [95% CI, 0.71–0.84]), or animal-derived riboflavin intake (hazard ratio, 0.70 [95% CI, 0.65–0.77]), compared with those in quartile 1. In addition, the association between total riboflavin intake and new-onset hypertension was particularly evident in those with lower dietary sodium/potassium intake ratio (Pinteraction, <0.001). In summary, there was an inverse association between riboflavin intake and new-onset hypertension in general Chinese adults. Our results emphasized the importance of maintaining relatively higher riboflavin intake levels for the prevention of hypertension.

A systematic comprehensive longitudinal evaluation of dietary factors associated with acute myocardial infarction and fatal coronary heart disease

Environmental factors, and in particular diet, are known to play a key role in the development of Coronary Heart Disease. Many of these factors were unveiled by detailed nutritional epidemiology studies, focusing on the role of a single nutrient or food at a time. Here, we apply an Environment-Wide Association Study approach to Nurses' Health Study data to explore comprehensively and agnostically the association of 257 nutrients and 117 foods with coronary heart disease risk (acute myocardial infarction and fatal coronary heart disease). After accounting for multiple testing, we identify 16 food items and 37 nutrients that show statistically significant association - while adjusting for potential confounding and control variables such as physical activity, smoking, calorie intake, and medication use - among which 38 associations were validated in Nurses' Health Study II. Our implementation of Environment-Wide Association Study successfully reproduces prior knowledge of diet-coronary heart disease associations in the epidemiological literature, and helps us detect new associations that were only marginally studied, opening potential avenues for further extensive experimental validation. We also show that Environment-Wide Association Study allows us to identify a bipartite food-nutrient network, highlighting which foods drive the associations of specific nutrients with coronary heart disease risk.

A nutrient-wide association study for risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition and the Netherlands Cohort Study

PURPOSE

The evidence from the literature regarding the association of dietary factors and risk of prostate cancer is inconclusive.

METHODS

A nutrient-wide association study was conducted to systematically and comprehensively evaluate the associations between 92 foods or nutrients and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). Cox proportional hazard regression models adjusted for total energy intake, smoking status, body mass index, physical activity, diabetes and education were used to estimate hazard ratios and 95% confidence intervals for standardized dietary intakes. As in genome-wide association studies, correction for multiple comparisons was applied using the false discovery rate (FDR < 5%) method and suggested results were replicated in an independent cohort, the Netherlands Cohort Study (NLCS).

RESULTS

A total of 5916 and 3842 incident cases of prostate cancer were diagnosed during a mean follow-up of 14 and 20 years in EPIC and NLCS, respectively. None of the dietary factors was associated with the risk of total prostate cancer in EPIC (minimum FDR-corrected P, 0.37). Null associations were also observed by disease stage, grade and fatality, except for positive associations observed for intake of dry cakes/biscuits with low-grade and butter with aggressive prostate cancer, respectively, out of which the intake of dry cakes/biscuits was replicated in the NLCS.

CONCLUSIONS

Our findings provide little support for an association for the majority of the 92 examined dietary factors and risk of prostate cancer. The association of dry cakes/biscuits with low-grade prostate cancer warrants further replication given the scarcity in the literature.

Association of urinary sodium and potassium excretion with systolic blood pressure in the Dietary Approaches to Stop Hypertension Sodium Trial

The 2019 National Academy of Science, Engineering and Medicine Dietary Reference Intakes (DRI) for Sodium (Na⁺) and Potassium (K⁺) Report concluded there remains insufficient evidence to establish a K⁺ DRI. This study tested the hypothesis that reduced Na⁺ and increased K⁺ excretion will positively associate with lower blood pressure in salt sensitive (SS) and salt resistant (SR) participants in the Dietary Approaches to Stop Hypertension Sodium Trial (DASH–Sodium). Via the NHLBI BioLINCC we accessed the DASH-Sodium dataset for data on systolic blood pressure (SBP), 24-h urinary Na⁺ and K⁺ excretion at screening (regular patient diet; N = 186, SS N = 222 SR) and post DASH diet (N = 71 SS, N = 119 SR). The relationships between SBP, urinary Na⁺ and K⁺ excretion, and Na⁺/K⁺ ratio were assessed via linear regression. At screening elevated urinary Na⁺ excretion positively associated with SBP in SS (1 g increase in urinary Na⁺ excretion = +1 0 ± 0.4 mmHg) but not SR participants, and urinary K⁺ excretion of <1 g K⁺/day was associated with higher SBP in SS and SR participants. Urinary K⁺ excretion ≥1 g/day, or a decreases in urinary Na⁺/K⁺ ratio, was not associated with lower SBP. Post the DASH–sodium diet intervention, SBP was reduced in SS and SR participants. However, no correlation was observed between reduced SBP and urinary K⁺ excretion or the urinary Na⁺/K⁺ ratio irrespective of the salt sensitivity of blood pressure. Our data support the DRI recommendation not to establish a K⁺ DRI and suggest further evidence is required to support a reduced Na⁺/K⁺ ratio to lower SBP.

Design and methodology challenges of environment-wide association studies: A systematic review

Environment-wide association studies (EWAS) are an untargeted, agnostic, and hypothesis-generating approach to exploring environmental factors associated with health outcomes, akin to genome-wide association studies (GWAS). While design, methodology, and replicability standards for GWAS are established, EWAS pose many challenges. We systematically reviewed published literature on EWAS to categorize scope, impact, types of analytical approaches, and open challenges in designs and methodologies. The Web of Science and PubMed databases were searched through multiple queries to identify EWAS articles between January 2010 and December 2018, and a systematic review was conducted following the Preferred Reporting Item for Systematic Reviews and Meta-Analyses (PRISMA) reporting standard. Twenty-three articles met our inclusion criteria and were included. For each study, we categorized the data sources, the definitions of study outcomes, the sets of environmental variables, and the data engineering/analytical approaches, e.g. neighborhood definition, variable standardization, handling of multiple hypothesis testing, model selection, and validation. We identified limited exploitation of data sources, high heterogeneity in analytical approaches, and lack of replication. Despite of the promising utility of EWAS, further development of EWAS will require improved data sources, standardization of study designs, and rigorous testing of methodologies.

Sodium and Potassium Intakes and Their Ratio in Adults (18-90 y): Findings from the Irish National Adult Nutrition Survey

An individual's sodium to potassium intake ratio (Na:K) has been shown to be an important predictor of hypertension. The aim of this study was to estimate the mean 24 h urinary Na, K and Na:K of Irish adults and to identify the foods that determine Na:K in a nationally representative sample of Irish adults. This study was based on data from the Irish National Adult Nutrition Survey (2008-2010) (NANS), which collected spot urine samples and dietary data in a nationally representative sample of Irish adults aged 18+ years. The mean urinary molar Na:K of Irish men and women was 1.90 and 2.15, respectively, which exceed target molar ratios of ≤1.0 and ≤2.0. The mean estimated 24-h urinary excretion of Na was 4631 mg for men and 3525 mg for women, which exceed target maximum population intakes for all gender and age groups. The mean estimated 24-h urinary excretion of K was 3894 mg for men and 2686 mg for women, with intakes in women of all ages and older men (65+ years) below current recommendations. The key foods positively associated with a lower Na:K were fruits, vegetables, potatoes, breakfast cereals, milk, yogurt and fresh meat, while the foods negatively associated with a lower Na:K were breads, cured and processed meats and butters and fat spreads. Strategies to reduce sodium and increase potassium intakes are necessary to lower population Na:K, which may help to reduce the burden of hypertension-related diseases in the Irish population.

Nutrient-wide association study of 92 foods and nutrients and breast cancer risk

BACKGROUND

Several dietary factors have been reported to be associated with risk of breast cancer, but to date, unequivocal evidence only exists for alcohol consumption. We sought to systematically assess the association between intake of 92 foods and nutrients and breast cancer risk using a nutrient-wide association study.

METHODS

Using data from 272,098 women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, we assessed dietary intake of 92 foods and nutrients estimated by dietary questionnaires. Cox regression was used to quantify the association between each food/nutrient and risk of breast cancer. A false discovery rate (FDR) of 0.05 was used to select the set of foods and nutrients to be replicated in the independent Netherlands Cohort Study (NLCS).

RESULTS

Six foods and nutrients were identified as associated with risk of breast cancer in the EPIC study (10,979 cases). Higher intake of alcohol overall was associated with a higher risk of breast cancer (hazard ratio (HR) for a 1 SD increment in intake = 1.05, 95% CI 1.03-1.07), as was beer/cider intake and wine intake (HRs per 1 SD increment = 1.05, 95% CI 1.03-1.06 and 1.04, 95% CI 1.02-1.06, respectively), whereas higher intakes of fibre, apple/pear, and carbohydrates were associated with a lower risk of breast cancer (HRs per 1 SD increment = 0.96, 95% CI 0.94-0.98; 0.96, 95% CI 0.94-0.99; and 0.96, 95% CI 0.95-0.98, respectively). When evaluated in the NLCS (2368 cases), estimates for each of these foods and nutrients were similar in magnitude and direction, with the exception of beer/cider intake, which was not associated with risk in the NLCS.

CONCLUSIONS

Our findings confirm a positive association of alcohol consumption and suggest an inverse association of dietary fibre and possibly fruit intake with breast cancer risk.

Mapping the Human Exposome to Uncover the Causes of Breast Cancer

Breast cancer is an important cause of morbidity and mortality for women, yet a significant proportion of variation in individual risk is unexplained. It is reasonable to infer that unexplained breast cancer risks are caused by a myriad of exposures and their interactions with genetic factors. Most epidemiological studies investigating environmental contribution to breast cancer risk have focused on a limited set of exposures and outcomes based on a priori knowledge. We hypothesize that by measuring a rich set of molecular information with omics (e.g., metabolomics and adductomics) and comparing these profiles using a case-control design we can pinpoint novel environmental risk factors. Specifically, exposome-wide association study approaches can be used to compare molecular profiles between controls and either breast cancer cases or participants with phenotypic measures associated with breast cancer (e.g., high breast density, chronic inflammation). Current challenges in annotating compound peaks from biological samples can be addressed by creating libraries of environmental chemicals that are breast cancer relevant using publicly available high throughput exposure and toxicity data, and by mass spectra fragmentation. This line of discovery and innovation will extend understanding of how environmental exposures interact with genetics to affect health, and provide evidence to support new breast cancer prevention strategies.

Towards Mass Spectrometry-Based Chemical Exposome: Current Approaches, Challenges, and Future Directions

The proposal of the “exposome” concept represents a shift of the research paradigm in studying exposure-disease relationships from an isolated and partial way to a systematic and agnostic approach. Nevertheless, exposome implementation is facing a variety of challenges including measurement techniques and data analysis. Here we focus on the chemical exposome, which refers to the mixtures of chemical pollutants people are exposed to from embryo onwards. We review the current chemical exposome measurement approaches with a focus on those based on the mass spectrometry. We further explore the strategies in implementing the concept of chemical exposome and discuss the available chemical exposome studies. Early progresses in the chemical exposome research are outlined, and major challenges are highlighted. In conclusion, efforts towards chemical exposome have only uncovered the tip of the iceberg, and further advancement in measurement techniques, computational tools, high-throughput data analysis, and standardization may allow more exciting discoveries concerning the role of exposome in human health and disease.

Signals Among Signals: Prioritizing Nongenetic Associations in Massive Data Sets

Massive data sets are often regarded as a panacea to the underpowered studies of the past. At the same time, it is becoming clear that in many of these data sets in which thousands of variables are measured across hundreds of thousands or millions of individuals, almost any desired relationship can be inferred with a suitable combination of covariates or analytic choices. Inspired by the genome-wide association study analysis paradigm that has transformed human genetics, X-wide association studies or "XWAS" have emerged as a popular approach to systematically analyzing nongenetic data sets and guarding against false positives. However, these studies often yield hundreds or thousands of associations characterized by modest effect sizes and miniscule P values. Many of these associations will be spurious and emerge due to confounding and other biases. One way of characterizing confounding in the genomics paradigm is the genomic inflation factor. An analogous "X-wide inflation factor," denoted λX, can be defined and applied to published XWAS. Effects that arise in XWAS may be prioritized using replication, triangulation, quantification of measurement error, contextualization of each effect in the distribution of all effect sizes within a field, and pre-registration. Criteria like those of Bradford Hill need to be reconsidered in light of exposure-wide epidemiology to prioritize signals among signals.

Urinary sodium-to-potassium ratio and intake of sodium and potassium among men and women from multiethnic general populations: the INTERSALT Study

The Na/K ratio may be more strongly related to blood pressure and cardiovascular disease than sodium or potassium. The casual urine Na/K ratio can provide prompt on-site feedback, and with repeated measurements, may provide useful individual estimates of the 24-h ratio. The World Health Organization has published guidelines for sodium and potassium intake, but no generally accepted guideline prevails for the Na/K ratio. We used standardized data on 24 h and casual urinary electrolyte excretion obtained from the INTERSALT Study for 10,065 individuals aged 20-59 years from 32 countries (52 populations). Associations between the casual urinary Na/K ratio and the 24-h sodium and potassium excretion of individuals were assessed by correlation and stratification analyses. The mean 24-h sodium and potassium excretions were 156.0 mmol/24 h and 55.2 mmol/24 h, respectively; the mean 24-h urinary Na/K molar ratio was 3.24. Pearson's correlation coefficients (r) for the casual urinary Na/K ratio with 24-h sodium and potassium excretions were 0.42 and -0.34, respectively, and these were 0.57 and -0.48 for the 24-h ratio. The urinary Na/K ratio predicted a 24-h urine Na excretion of <85 mmol/day (the WHO recommended guidelines) with a sensitivity of 99.7% and 94.0%, specificity of 39.5% and 48.0%, and positive predictive value of 96.3% and 61.1% at the cutoff point of 1 in 24 h and casual urine Na/K ratios, respectively. A urinary Na/K molar ratio <1 may be a useful indicator for adherence to the WHO recommended levels of sodium and, to a lesser extent, the potassium intake across different populations; however, cutoff points for Na/K ratio may be tuned for localization.

Influence of the Urban Exposome on Birth Weight

BACKGROUND

The exposome is defined as the totality of environmental exposures from conception onwards. It calls for providing a holistic view of environmental exposures and their effects on human health by evaluating multiple environmental exposures simultaneously during critical periods of life.

OBJECTIVE

We evaluated the association of the urban exposome with birth weight.

METHODS

We estimated exposure to the urban exposome, including the built environment, air pollution, road traffic noise, meteorology, natural space, and road traffic (corresponding to 24 environmental indicators and 60 exposures) for nearly 32,000 pregnant women from six European birth cohorts. To evaluate associations with either continuous birth weight or term low birth weight (TLBW) risk, we primarily relied on the Deletion-Substitution-Addition (DSA) algorithm, which is an extension of the stepwise variable selection method. Second, we used an exposure-by-exposure exposome-wide association studies (ExWAS) method accounting for multiple hypotheses testing to report associations not adjusted for coexposures.

RESULTS

The most consistent statistically significant associations were observed between increasing green space exposure estimated as Normalized Difference Vegetation Index (NDVI) and increased birth weight and decreased TLBW risk. Furthermore, we observed statistically significant associations among presence of public bus line, land use Shannon's Evenness Index, and traffic density and birth weight in our DSA analysis.

CONCLUSION

This investigation is the first large urban exposome study of birth weight that tests many environmental urban exposures. It confirmed previously reported associations for NDVI and generated new hypotheses for a number of built-environment exposures. https://doi.org/10.1289/EHP3971.

Dietary Phosphorus and Ambulatory Blood Pressure in African Americans: The Jackson Heart Study

BACKGROUND

Higher dietary phosphorus is associated with left ventricular hypertrophy and mortality, which are blood pressure (BP)-related outcomes. For this reason, we hypothesized that dietary phosphorus may be associated with adverse clinic and ambulatory BP patterns.

METHODS

Our study included 973 African American adults enrolled in the Jackson Heart Study (2000-2004) with 24-hour ambulatory BP monitoring (ABPM) data at baseline. We quantified dietary phosphorus from a validated Food Frequency Questionnaire as follows: (i) absolute daily intake, (ii) ratio of phosphorus-to-protein intake, (iii) phosphorus density, and (iv) energy-adjusted phosphorus intake. Using multivariable linear regression, we determined associations between dietary phosphorus intake and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure in clinic and over daytime, nighttime, and 24-hour periods from ABPM. Extent of nocturnal BP dipping was also assessed. Using logistic regression, we modeled relationships between dietary phosphorus intake and clinically relevant qualitative BP phenotypes, such as masked, sustained, or white-coat hypertension and normotension.

RESULTS

There were no statistically significant associations between phosphorus intake and SBP or pulse pressure in adjusted models. Most metrics of higher phosphorus intake were associated with lower daytime, nighttime, and clinic DBP. Higher phosphorus intake was not associated with clinic or ABPM-defined hypertension overall, but most metrics of higher phosphorus intake were associated with lower odds of sustained hypertension compared to sustained normotension, white-coat hypertension, and masked hypertension. There were no associations between dietary phosphorus and nocturnal BP dipping.

CONCLUSIONS

These data do not support a role for higher phosphorus intake and higher BP in African Americans.

Daily urinary sodium and potassium excretion in Chinese first-generation migrants in Italy

BACKGROUND

China has one of the highest salt intake levels in the world, and Chinese people form one of the largest foreign-born communities now living in Europe. The present study was performed to assess 24-hour urinary sodium and potassium excretion in Chinese migrants in Italy and to explore possible associations with hypertension, hypertension awareness, and length of residence in Italy.

METHODS

A cross-sectional evaluation was conducted on 319 first-generation Chinese migrants (154 women and 165 men) aged 18-70 years. Subjects were asked to do a 24-hour urine collection and the relationships of urinary sodium and potassium and arterial blood pressure, hypertension (BP ≥ 140/90 mmHg or anti-hypertensive drug use), hypertension awareness, and years of residence in Italy were investigated with linear or logistic regression analysis.

RESULTS

Sodium excretion was 145.2 mmol/day (95%CI 138.0-152.3) in men, and 134.7 (95%CI 127.6-141.8) in women corresponding to a dietary salt intake of 9.4 g/day (95%CI 9.0-9.9) and 8.8 (95%CI 8.3-9.2) respectively. Potassium excretion was 35.1 mmol/day (95%CI 33.6-36.5), with no significant difference by gender. At multivariable adjusted linear regression analysis body mass index, low education level, and hypertension were positive predictors of sodium urinary excretion; gender (women), and body mass index were positive predictors of potassium excretion. Sodium and potassium excretion were unaffected by hypertension awareness or years of residence in Italy.

CONCLUSIONS

Sodium excretion in Chinese workers is higher than recommended and in line with high salt intake in Italy. Potassium consumption remains low.

Open data informatics and data repurposing for IBD

Biomedical ‘big data’ has opened opportunities for data repurposing to reveal new insights into complex diseases. Public data on IBD have been repurposed for novel diagnostics and therapeutics, and these datasets continue to grow. Here, we discuss the practicalities and implications of open data informatics for IBD.

The relationship between repeated measurement of casual and 24-h urinary sodium-to-potassium ratio in patients with chronic kidney disease

This study aimed to clarify the relationship between repeated measurements of casual (spot) and 24-h urinary sodium-to-potassium (Na/K) ratios in patients with chronic kidney disease (CKD). A total of 61 inpatients with CKD, 31 in stage 1-3 (eGFR [estimated glomerular filtration rate] ≥ 30 ml/min/1.73 m²) and 30 in stage 4-5 (eGFR < 30 ml/min/1.73 m²), aged 20-85 consuming a low-sodium diet (NaCl [sodium chloride] 6 g/day) were recruited. Urinary Na, K, and Na/K ratios were measured in both casual urine samples and 2-day, 24 h urine samples, and then analyzed by correlation and Bland-Altman analyses. Mean 24-h urine Na/K ratio was higher in participants in stage 4-5 (5.1) than in participants in stage 1-3 (4.1) CKD. Casual urine Na/K ratio was strongly correlated with 2-day, 24-h urine Na/K ratio by sampling 4 casual urine specimens every morning and evening in participants in stage 1-3 (r = 0.69-0.78), but not in stage 4-5 (r = 0.12-0.19). The bias for mean Na/K ratio between 2-day, 24-h urine, and the 4 casual urine sampling ranged from -0.86 to 0.16 in participants in stage 1-3, and the quality of agreement for the mean of this casual urine sampling was similar to that of sampling 8 casual urine samples for estimating 2-day, 24-h values. Methods using repeated casual urine Na/K ratios may provide a reasonable estimation of 24-h urine Na/K ratio in normotensive and hypertensive as well as individuals with stage 1-3, but not stage 4-5 CKD.

Update on Chronic Kidney Disease Mineral and Bone Disorder in Cardiovascular Disease

Chronic kidney disease mineral and bone disorder (MBD) encompasses changes in mineral ion and vitamin D metabolism that are widespread in the setting of chronic kidney disease and end-stage renal disease. MBD components associate with cardiovascular disease in many epidemiologic studies. Through impacts on hypertension, activation of the renin-angiotensin-aldosterone system, vascular calcification, endothelial function, and cardiac remodeling and conduction, MBD may be a direct and targetable cause of cardiovascular disease. However, assessment and treatment of MBD is rife with challenges owing to biological tensions between its many components, such as calcium and phosphorus with their regulatory hormones fibroblast growth factor 23 and parathyroid hormone; fibroblast growth factor 23 with its co-receptor klotho; and vitamin D with control of calcium and phosphorus. These complex interactions between MBD components hinder the simple translation to clinical trials, which ultimately are needed to prove the benefits of treating MBD. Deeper investigation using precision medicine tools and principles, including genomics and individualized risk assessment and therapy, may help move the field closer toward clinical applications. This review provides a high-level overview of conventional and precision epidemiology in MBD, potential mechanisms of cardiovascular disease pathogenesis, and guiding therapeutic principles for established and emerging treatments.

Toward a panoramic perspective of the association between environmental factors and cardiovascular disease: An environment-wide association study from National Health and Nutrition Examination Survey 1999-2014

OBJECTIVES

An environment-wide association study (EWAS) may be useful to comprehensively test and validate associations between environmental factors and cardiovascular disease (CVD) in an unbiased manner.

APPROACH AND RESULTS

Data from National Health and Nutrition Examination Survey (1999-2014) were randomly 50:50 spilt into training set and testing set. CVD was ascertained by a self-reported diagnosis of myocardial infarction, coronary heart disease or stroke. We performed multiple linear regression analyses associating 203 environmental factors and 132 clinical phenotypes with CVD in training set (false discovery rate < 5%) and significant factors were validated in the testing set (P < 0.05). Random forest (RF) model was used for multicollinearity elimination and variable importance ranking. Discriminative power of factors for CVD was calculated by area under the receiver operating characteristic (AUROC). Overall, 43,568 participants with 4084 (9.4%) CVD were included. After adjusting for age, sex, race, body mass index, blood pressure and socio-economic level, we identified 5 environmental variables and 19 clinical phenotypes associated with CVD in training and testing dataset. Top five factors in RF importance ranking were: waist, glucose, uric acid, and red cell distribution width and glycated hemoglobin. AUROC of the RF model was 0.816 (top 5 factors) and 0.819 (full model). Sensitivity analyses reveal no specific moderators of the associations.

CONCLUSION

Our systematic evaluation provides new knowledge on the complex array of environmental correlates of CVD. These identified correlates may serve as a complementary approach to CVD risk assessment. Our findings need to be probed in further observational and interventional studies.

Postulating the major environmental condition resulting in the expression of essential hypertension and its associated cardiovascular diseases: Dietary imprudence in daily selection of foods in respect of their potassium and sodium content resulting in oxidative stress-induced dysfunction of the vascular endothelium, vascular smooth muscle, and perivascular tissues

We hypothesize that the major environmental determinant of the expression of essential hypertension in America and other Westernized countries is dietary imprudence in respect of the consumption of daily combinations of foods containing suboptimal amounts of potassium and blood pressure-lowering phytochemicals, and supraphysiological amounts of sodium. We offer as premise that Americans on average consume suboptimal amounts of potassium and blood pressure-lowering phytochemicals, and physiologically excessive amounts of sodium, and that such dietary imprudence leads to essential hypertension through oxidative stress-induced vascular endothelial and smooth muscle dysfunction. Such dysfunctions restrict nitric oxide bioavailability, impairing endothelial cell-mediated relaxation of the underlying vascular smooth muscle, initiating and maintaining inappropriately increased peripheral and renal vascular resistance. The biochemical steps from oxidative stress to vascular endothelial dysfunction and its pernicious cardiovascular consequences are well established and generally accepted. The unique aspect of our hypothesis resides in the contention that Americans' habitual consumption of foods resulting in suboptimal dietary intake of potassium and supraphysiological intake of sodium result in oxidative stress, the degree of which, we suggest, will correlate with the degree of deviation of potassium and sodium intake from optimal. Because suboptimal intakes of potassium reflect suboptimal intakes of fruits and vegetables, associated contributors to oxidative stress include suboptimal intakes of magnesium, nitrate, polyphenols, carotenoids, and other phytochemical antioxidants for which fruits and vegetables contain abundant amounts. Currently Americans consume potassium-to-sodium in molar ratios of less than or close to 1.0 and the Institute of Medicine (IOM) recommends a molar ratio of 1.2. Ancestral diets to which we are physiologically adapted range from molar ratios of 5.0 to 10.0 or higher. Accordingly, we suggest that the average American is usually afflicted with oxidative stress-induced vascular endothelial dysfunction, and therefore the standards for normal blood pressure and pre-hypertension often reflect a degree of clinically significant hypertension. In this article, we provide support for those contentions, and indicate the findings that the hypothesis predicts.

Diet-Related Risk Factors for Incident Hypertension During an 11-Year Follow-Up: The Korean Genome Epidemiology Study

Using long-term follow-up cohort data from the Korean Genome Epidemiology Study, we assessed the dietary risk factors for incident hypertension (HTN). In total, 6792 subjects (3300 males and 3492 females) aged 40⁻69 years were included in the study. Physician-diagnosed HTN self-reported by the participants was used as the outcome. Daily intake of 20 food groups was assessed while using a dish-based semi-quantitative food-frequency questionnaire. After controlling for known risk factors, the food groups that were most closely associated with HTN were identified by forward stepwise selection while using the Cox proportional hazards model. The median follow-up period was 11.5 years (interquartile range, 6.0⁻11.7 years) and the incidence of HTN was 20 per 1000 person-years. Older age, obesity, lower education level, high alcohol intake, and having at least one parent with HTN were associated with the risk for HTN. In addition, a high intake of salted seafood and a low intake of eggs and meat were independently associated with the incidence of HTN after controlling for the known risk factors. Those in the top quartile of salted seafood intake had a 28% greater risk for incident HTN than those in the bottom quartile. The population-attributable fraction of three dietary factors accounted for 29.0% of the incidence of HTN. A high intake of salted seafood and a low intake of eggs and meat were associated with a greater risk for HTN.

Food Patterns are Associated with Likelihood of CKD in US Adults

We investigated the association between dietary patterns and prevalent chronic kidney diseases (CKD), in participants of the 2005–2012 US National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2012, who had measured data on dietary intake and kidney function. Analyse of covariance (ANCOVA) and logistic regression models were employed to account for the survey design and sample weights. A total of 21,649 eligible participants (634 with and 20,015 without prevalent CKD) were included in the final analysis. Three food patterns together explained 50.8% of the variance of the dietary nutrients consumption. The first food pattern was representative of a diet containing high levels of saturated and mono-unsaturated fatty acids; the second food pattern comprised vitamins and trace elements; and the third food pattern was mainly representative of polyunsaturated fatty acids. The odd of prevalent CKD decreased across increasing quarters of vitamins and trace elements, so that the top quarter was associated with a 53% (95%CI: 42–62%) lower odds of CKD in age, sex and race adjusted logistic regression models. These results suggest that vitamins and trace elements intake are associated with lower risk of prevalent CKD.

Correlation between Na/K ratio and electron densities in blood samples of breast cancer patients

The main purpose of this study was to investigate the relationship between the electron densities and Na/K ratio which has important role in breast cancer disease. Determinations of sodium and potassium concentrations in blood samples performed with inductive coupled plasma-atomic emission spectrometry. Electron density values of blood samples were determined via ZXCOM. Statistical analyses were performed for electron densities and Na/K ratio including Kolmogorov-Smirnov normality tests, Spearman's rank correlation test and Mann-Whitney U test. It was found that the electron densities significantly differ between control and breast cancer groups. In addition, statistically significant positive correlation was found between the electron density and Na/K ratios in breast cancer group.

Nutritional Epidemiology Methods and Related Statistical Challenges and Opportunities

The public health importance of nutritional epidemiology research is discussed, along with methodologic challenges to obtaining reliable information on dietary approaches to chronic disease prevention. Measurement issues in assessing dietary intake need to be addressed to obtain reliable disease association information. Selfreported dietary data typically incorporate major random and systematic biases. In-take biomarkers offer potential for more reliable analyses, but biomarkers have been established only for a few dietary variables, and these may be too expensive to apply to all participants in large epidemiologic cohorts. A possible way forward involves additional nutritional biomarker development using high-dimensional metabolomic profiling, using blood and urine specimens, in conjunction with further development of statistical approaches for accommodating measurement error with failure time response data. Statisticians have the opportunity to contribute greatly to worldwide public health through the development of statistical methods to address these nutritional epidemiology research challenges, as is elaborated in this contribution.

Systematic identification of correlates of HIV infection: an X-wide association study

OBJECTIVE

Better identification of at-risk groups could benefit HIV-1 care programmes. We systematically identified HIV-1 risk factors in two nationally representative cohorts of women in the Demographic and Health Surveys.

METHODS

We identified and replicated the association of 1415 social, economic, environmental, and behavioral factors with HIV-1 status. We used the 2007 and 2013-2014 surveys conducted among 5715 and 15 433 Zambian women, respectively (688 shared factors). We used false discovery rate criteria to identify factors that are strongly associated with HIV-1 in univariate and multivariate models of the entire population, as well as in subgroups stratified by wealth, residence, age, and past HIV-1 testing.

RESULTS

In the univariate analysis, we identified 102 and 182 variables that are associated with HIV-1 in the two surveys, respectively (79 factors were associated in both). Factors that were associated with HIV-1 status in full-sample analyses and in subgroups include being formerly married (adjusted OR 2007, 2.8, P < 10(-16); 2013-2014 2.8, P < 10(-29)), widowhood (aOR 3.7, P < 10(-12); and 4.2, P < 10(-30)), genital ulcers within 12 months (aOR 2.4, P < 10(-5); and 2.2, P < 10(-6)), and having a woman head of the household (aOR 1.7, P < 10(-7); and 2.1, P < 10(-26), while owning a bicycle (aOR 0.6, P < 10(-6); and 0.6, P < 10(-8)) and currently breastfeeding (aOR 0.5, P < 10(-9); and 0.4, P < 10(-26)) were associated with decreased risk. Area under the curve for HIV-1 positivity was 0.76-0.82.

CONCLUSION

Our X-wide association study identifies under-recognized factors related to HIV-1 infection, including widowhood, breastfeeding, and gender of head of the household. These features could be used to improve HIV-1 identification programs.

Systematic correlation of environmental exposure and physiological and self-reported behaviour factors with leukocyte telomere length

Background

It is hypothesized that environmental exposures and behaviour influence telomere length, an indicator of cellular ageing. We systematically associated 461 indicators of environmental exposures, physiology and self-reported behaviour with telomere length in data from the US National Health and Nutrition Examination Survey (NHANES) in 1999-2002. Further, we tested whether factors identified in the NHANES participants are also correlated with gene expression of telomere length modifying genes.

Methods

We correlated 461 environmental exposures, behaviours and clinical variables with telomere length, using survey-weighted linear regression, adjusting for sex, age, age squared, race/ethnicity, poverty level, education and born outside the USA, and estimated the false discovery rate to adjust for multiple hypotheses. We conducted a secondary analysis to investigate the correlation between identified environmental variables and gene expression levels of telomere-associated genes in publicly available gene expression samples.

Results

After correlating 461 variables with telomere length, we found 22 variables significantly associated with telomere length after adjustment for multiple hypotheses. Of these varaibales, 14 were associated with longer telomeres, including biomarkers of polychlorinated biphenyls([PCBs; 0.1 to 0.2 standard deviation (SD) increase for 1 SD increase in PCB level, P  < 0.002] and a form of vitamin A, retinyl stearate. Eight variables associated with shorter telomeres, including biomarkers of cadmium, C-reactive protein and lack of physical activity. We could not conclude that PCBs are correlated with gene expression of telomere-associated genes.

Conclusions

Both environmental exposures and chronic disease-related risk factors may play a role in telomere length. Our secondary analysis found no evidence of association between PCBs/smoking and gene expression of telomere-associated genes. All correlations between exposures, behaviours and clinical factors and changes in telomere length will require further investigation regarding biological influence of exposure.

Machine learning approaches to the social determinants of health in the health and retirement study

BACKGROUND

Social and economic factors are important predictors of health and of recognized importance for health systems. However, machine learning, used elsewhere in the biomedical literature, has not been extensively applied to study relationships between society and health. We investigate how machine learning may add to our understanding of social determinants of health using data from the Health and Retirement Study.

METHODS

A linear regression of age and gender, and a parsimonious theory-based regression additionally incorporating income, wealth, and education, were used to predict systolic blood pressure, body mass index, waist circumference, and telomere length. Prediction, fit, and interpretability were compared across four machine learning methods: linear regression, penalized regressions, random forests, and neural networks.

RESULTS

All models had poor out-of-sample prediction. Most machine learning models performed similarly to the simpler models. However, neural networks greatly outperformed the three other methods. Neural networks also had good fit to the data (R2 between 0.4-0.6, versus <0.3 for all others). Across machine learning models, nine variables were frequently selected or highly weighted as predictors: dental visits, current smoking, self-rated health, serial-seven subtractions, probability of receiving an inheritance, probability of leaving an inheritance of at least $10,000, number of children ever born, African-American race, and gender.

DISCUSSION

Some of the machine learning methods do not improve prediction or fit beyond simpler models, however, neural networks performed well. The predictors identified across models suggest underlying social factors that are important predictors of biological indicators of chronic disease, and that the non-linear and interactive relationships between variables fundamental to the neural network approach may be important to consider.

Nutrient profiling and adherence to components of the UK national dietary guidelines association with metabolic risk factors for CVD and diabetes: Airwave Health Monitoring Study

CVD is the leading cause of death worldwide. Diet is a key modifiable component in the development of CVD. No official UK diet quality index exists for use in UK nutritional epidemiological studies. The aims of this study are to: (i) develop a diet quality index based on components of UK dietary reference values (DRV) and (ii) determine the association between the index, the existing UK nutrient profile (NP) model and a comprehensive range of cardiometabolic risk markers among a British adult population. A cross-sectional analysis was conducted using data from the Airwave Health Monitoring Study (n 5848). Dietary intake was measured by 7-d food diary and metabolic risk using waist circumference, BMI, blood lipid profile, glycated Hb (HbA1c) and blood pressure measurements. Diet quality was assessed using the novel DRV index and NP model. Associations between diet and cardiometabolic risk were analysed via multivariate linear models and logistic regression. A two-point increase in NP score was associated with total cholesterol (β -0·33 mmol/l, P<0·0001) and HbA1c (β -0·01 %, P<0·0001). A two-point increase in DRV score was associated with waist circumference (β -0·56 cm, P<0·0001), BMI (β -0·15 kg/m2, P<0·0001), total cholesterol (β -0·06 mmol/l, P<0·0001) and HbA1c (β -0·02 %, P=0·002). A one-point increase in DRV score was associated with type 2 diabetes (T2D) (OR 0·94, P=0·01) and obesity (OR 0·95, P<0·0001). The DRV index is associated with overall diet quality and risk factors for CVD and T2D, supporting its application in nutritional epidemiological studies investigating CVD risk in a UK population.