Methods to estimate underlying blood pressure: The Atherosclerosis Risk in Communities (ARIC) Study

Sex differences in blood pressure phenotypes over time - the HELIUS study

BACKGROUND

Hypertension can be classified into different phenotypes according to systolic and diastolic blood pressure (BP). In younger adults, these phenotypical differences have different prognostic value for men and women. However, little is known about sex differences in the natural course of different BP phenotypes over time.

METHODS

We used baseline and follow-up data from the multiethnic, population-based HELIUS study to assess differences in BP phenotypes over time in men and women aged < 45 years stratified according to baseline office BP into normotension (<140/<90 mmHg), isolated systolic hypertension (ISH, ≥140/<90 mmHg), isolated diastolic hypertension (IDH, <140/≥90 mmHg) or systolic diastolic hypertension (SDH, ≥140/≥90 mmHg). Logistic regression adjusted for age, ethnicity, and follow-up time was used to assess the risk of hypertension at follow-up (BP ≥140/90 mmHg or use of antihypertensive medication), stratified by sex.

RESULTS

We included 4103 participants [mean age 33.5 years (SD 7.4), 43.4% men] with a median follow-up time of 6.2 years. Compared to normotensive individuals, the age-adjusted odds ratios (OR) for having hypertension at follow-up were 4.78 (95% CI 2.90; 7.76) for ISH, 6.02 (95% CI 3.70; 9.74) for IDH and 33.73 (95% CI 20.35; 58.38) for SDH in men, while in women, OR were 10.08 (95% CI 4.09; 25.56) for ISH, 27.59 (95% CI 14.68; 53.82) for IDH and 50.58 (95% CI 24.78; 114.84) for SDH.

CONCLUSIONS

The risk of hypertension at follow-up was higher among women for all phenotypes compared to men, particularly in those with IDH. Findings of this study emphasize the importance of close BP monitoring in the young, especially in women.

Association of Cumulative Systolic Blood Pressure With Left Atrial Function in the Setting of Normal Left Atrial Size: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Lower left atrial (LA) function is associated with increased risk for cardiovascular disease events; data on risk factors for impaired LA function are limited. We evaluated the effect of cumulative systolic blood pressure (cSBP) from midlife to older age on LA strain in adults with normal LA size.

METHODS

We included participants in the Atherosclerosis Risk in Communities study with LA strain measured on the visit 5 echocardiogram (2011-13), excluding those with atrial fibrillation and LA volume index >34 mL/m2. The cSBP was calculated from visit 1 (1987-89) through visit 5. Linear regression models were used to evaluate associations between cSBP and LA strain measures.

RESULTS

A total of 3,859 participants with a mean (SD) age of 75.2 (5.0) years were included in the analysis; 725 (18.8%) were Black and 2,342 (60.7%) were women. After adjusting for demographics, cardiovascular disease risk factors, heart failure, and coronary heart disease, each 10 mm Hg increase in cSBP was associated with 0.32% (95% CI, -0.52%, -0.13%) and 0.37% (95% CI, -0.51%, -0.22%) absolute reduction in LA reservoir and conduit strain, respectively. Associations were attenuated after adjustment for left ventricular (LV) systolic and diastolic function and mass (-0.12%: 95% CI, -0.31, 0.06 for reservoir strain; and -0.24%: 95% CI -0.38%, -0.10% for conduit strain). In subgroup analyses, the association of cSBP with conduit strain was statistically significant among those with normal LV systolic and diastolic function.

CONCLUSIONS

Cumulative exposure to elevated blood pressure from midlife to late life was modestly associated with lower LA reservoir and conduit strain in older adults with normal LA size, mostly related to the effect of blood pressure on LV function and mass. However, the association of cSBP and LA conduit strain in subgroups with normal LV function suggests that LA remodeling in response to hypertension occurs before LV dysfunction is detected on echocardiography.

Thyroid-related Hormones and Hypertension Incidence in Middle-Aged and Older Hispanic/Latino Adults: The HCHS/SOL Study

Background

Thyroid-related hormones act to regulate metabolic pathways and blood pressure (BP). However, the relationship of TSH and peripheral thyroid hormones and the role of the hypothalamic-pituitary-thyroid axis on hypertension development is not fully understood. We assessed sex-specific associations of thyroid-related hormones with BP and hypertension in Hispanic/Latino adults followed for 6 years.

Methods

We studied 1789 adults, ages 45 to 74, free of diabetes at baseline from a subcohort of the Hispanic Community Health Study/Study of Latinos. We assessed TSH, free T4 (FT4), T3, and various indicators of thyroid axis. Using multivariable linear and Poisson regression adjusted for survey design and confounding variables, we estimated a priori sex-specific associations of thyroid-related hormones with changes in BP and hypertension development.

Results

In men and women, TSH and TSH/FT4 ratios were associated with changes in diastolic BP and T3 with changes in pulse pressure and the development of hypertension from prehypertension. In men, a 1-SD increase in TSH [incident rate ratio (IRR) = 1.42; 95% confidence interval (CI): 1.15, 1.75] and TSH/FT4 ratio (IRR = 1.20; 95% CI: 1.07, 1.35) were positively associated with the development of hypertension from prehypertension while the TSH/FT4 ratio (IRR = 0.85; 95% CI: .72, 1.00) was protective in women. We observed sex-specific differences in associations of the T3/FT4 ratio and indices of pituitary sensitivity to thyroid hormones with changes in pulse pressure and hypertension development.

Conclusion

Thyroid-related hormones are associated with sex-specific changes in BP and hypertension among Hispanic/Latino adults consistent with selected studies conducted in other populations. Mechanisms underlying associations of pituitary sensitivity to thyroid hormones with BP and hypertension development warrant further study.

The Contribution of Declines in Blood Lead Levels to Reductions in Blood Pressure Levels: Longitudinal Evidence in the Strong Heart Family Study

BACKGROUND

Chronic lead exposure is associated with both subclinical and clinical cardiovascular disease. We evaluated whether declines in blood lead were associated with changes in systolic and diastolic blood pressure in adult American Indian participants from the SHFS (Strong Heart Family Study).

METHODS AND RESULTS

Lead in whole blood was measured in 285 SHFS participants in 1997 to 1999 and 2006 to 2009. Blood pressure and measures of cardiac geometry and function were obtained in 2001 to 2003 and 2006 to 2009. We used generalized estimating equations to evaluate the association of declines in blood lead with changes in blood pressure; cardiac function and geometry measures were considered secondary. Mean blood lead was 2.04 μg/dL at baseline. After ≈10 years, mean decline in blood lead was 0.67 μg/dL. In fully adjusted models, the mean difference in systolic blood pressure comparing the highest to lowest tertile of decline (>0.91 versus <0.27 μg/dL) in blood lead was -7.08 mm Hg (95% CI, -13.16 to -1.00). A significant nonlinear association between declines in blood lead and declines in systolic blood pressure was detected, with significant linear associations where blood lead decline was 0.1 μg/dL or higher. Declines in blood lead were nonsignificantly associated with declines in diastolic blood pressure and significantly associated with declines in interventricular septum thickness.

CONCLUSIONS

Declines in blood lead levels in American Indian adults, even when small (0.1-1.0 μg/dL), were associated with reductions in systolic blood pressure. These findings suggest the need to further study the cardiovascular impacts of reducing lead exposures and the importance of lead exposure prevention.

Ethnic differences in blood pressure levels over time: the HELIUS study

AIMS

Hypertension is an important global health burden with major differences in prevalence among ethnic minorities compared with host populations. Longitudinal research on ethnic differences in blood pressure (BP) levels provides the opportunity to assess the efficacy of strategies aimed at mitigating gaps in hypertension control. In this study, we assessed the change in BP levels over time in a multi-ethnic population-based cohort in Amsterdam, the Netherlands.

METHODS AND RESULTS

We used baseline and follow-up data from HELIUS to assess differences in BP over time between participants of Dutch, South Asian Surinamese, African Surinamese, Ghanaian, Moroccan, and Turkish descent. Baseline data were collected between 2011 and 2015 and follow-up data between 2019 and 2021. The main outcome was ethnic differences in systolic BP (SBP) over time determined by linear mixed models adjusted for age, sex, and use of antihypertensive medication. We included 22 109 participants at baseline, from which 10 170 participants had complete follow-up data. The mean follow-up time was 6.3 (1.1) years. Compared with the Dutch population, the mean SBP increased significantly more from baseline to follow-up in Ghanaians [1.78 mmHg, 95% confidence interval (CI) 0.77-2.79], Moroccans (2.06 mmHg, 95% CI 1.23-2.90), and the Turkish population (1.30 mmHg, 95% CI 0.38-2.22). Systolic blood pressure differences were in part explained by differences in body mass index (BMI). No differences in SBP trajectory were present between the Dutch and Surinamese population.

CONCLUSION

Our findings indicate a further increase of ethnic differences in SBP among Ghanaian, Moroccan, and Turkish populations compared with the Dutch reference population that are in part attributable to differences in BMI.

Coronary heart disease and ischemic stroke polygenic risk scores and atherosclerotic cardiovascular disease in a diverse, population-based cohort study

The predictive ability of coronary heart disease (CHD) and ischemic stroke (IS) polygenic risk scores (PRS) have been evaluated individually, but whether they predict the combined outcome of atherosclerotic cardiovascular disease (ASCVD) remains insufficiently researched. It is also unclear whether associations of the CHD and IS PRS with ASCVD are independent of subclinical atherosclerosis measures. 7,286 White and 2,016 Black participants from the population-based Atherosclerosis Risk in Communities study who were free of cardiovascular disease and type 2 diabetes at baseline were included. We computed previously validated CHD and IS PRS consisting of 1,745,179 and 3,225,583 genetic variants, respectively. Cox proportional hazards models were used to test the association between each PRS and ASCVD, adjusting for traditional risk factors, ankle-brachial index, carotid intima media thickness, and carotid plaque. The hazard ratios (HR) for the CHD and IS PRS were significant with HR of 1.50 (95% CI: 1.36-1.66) and 1.31 (95% CI: 1.18-1.45) respectively for the risk of incident ASCVD per standard deviation increase in CHD and IS PRS among White participants after adjusting for traditional risk factors. The HR for the CHD PRS was not significant with an HR of 0.95 (95% CI: 0.79-1.13) for the risk of incident ASCVD in Black participants. The HR for the IS PRS was significant with an HR of 1.26 (95%CI: 1.05-1.51) for the risk of incident ASCVD in Black participants. The association of the CHD and IS PRS with ASCVD was not attenuated in White participants after adjustment for ankle-brachial index, carotid intima media thickness, and carotid plaque. The CHD and IS PRS do not cross-predict well, and predict better the outcome for which they were created than the composite ASCVD outcome. Thus, the use of the composite outcome of ASCVD may not be ideal for genetic risk prediction.

Exposure to Volatile Organic Compounds Is Associated with Hypertension in Black Adults: The Jackson Heart Study

BACKGROUND

The prevalence of hypertension is higher among Black adults than among White and Hispanic adults. Nevertheless, reasons underlying the higher rates of hypertension in the Black population remain unclear but may relate to exposure to environmental chemicals such as volatile organic compounds (VOCs).

METHODS

We evaluated the associations of blood pressure (BP) and hypertension with VOC exposure in non-smokers and smokers in a subgroup of the Jackson Heart Study (JHS), consisting of 778 never smokers and 416 age- and sex-matched current smokers. We measured urinary metabolites of 17 VOCs by mass spectrometry.

RESULTS

After adjusting for covariates, we found that amoong non-smokers, metabolites of acrolein and crotonaldehyde were associated with a 1.6 mm Hg (95%CI: 0.4, 2.7; p = 0.007) and a 0.8 mm Hg (95%CI: 0.01, 1.6; p = 0.049) higher systolic BP, and the styrene metabolite was associated with a 0.4 mm Hg (95%CI: 0.09, 0.8, p = 0.02) higher diastolic BP. Current smokers had 2.8 mm Hg (95% CI 0.5, 5.1) higher systolic BP. They were at higher risk of hypertension (relative risk = 1.2; 95% CI, 1.1, 1.4), and had higher urinary levels of several VOC metabolites. Individuals who smoke had higher levels of the urinary metabolites of acrolein, 1,3-butadiene, and crotonaldehyde and were associated with higher systolic BP. The associations were stronger among participants who were <60 years of age and male. Using Bayesian kernel machine regression to assess the effects of multiple VOC exposures, we found that the relationship between VOCs and hypertension among non-smokers was driven primarily by acrolein and styrene in non-smokers, and crotonaldehyde in smokers.

CONCLUSIONS

Hypertension in Black individuals may be attributed, in part, to VOC exposure from the environment or tobacco smoke.

Corin Missense Variants, Blood Pressure, and Hypertension in 11 322 Black Individuals: Insights From REGARDS and the Jackson Heart Study

Background

Corin enzyme contributes to the processing of inactive natriuretic peptides to bioactive hormones. In Black individuals, Corin gene variants (rs111253292 [Q568P] and rs75770792 [T555I]) have been previously reported to have a modest association with blood pressure (BP) and hypertension.

Methods and Results

We evaluated the association of Corin genotype with BP traits, prevalent hypertension, and incident hypertension among self‐identified 11 322 Black Americans in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study and the JHS (Jackson Heart Study) using multivariable‐adjusted regression modeling. Multivariable‐adjusted genotype‐stratified differences in NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) and BNP (B‐type natriuretic peptide) levels were assessed. Genotype‐stratified NPPA and NPPB expression differences in healthy organ donor left atrial and left ventricular heart tissue (N=15) were also examined. The rs111253292 genotype was not associated with systolic BP (β±SE, 0.42±0.58; −1.24±0.82), diastolic BP (0.51±0.33; −0.41±0.46), mean arterial pressure (0.48±0.38; −0.68±0.51), and prevalent hypertension (odds ratio [OR], 0.93 [95% CI, 0.80–1.09]; OR, 0.79 [95% CI, 0.61–1.01]) in both REGARDS and JHS, respectively. The rs75770792 genotype was not associated with systolic BP (0.48±0.58; −1.26±0.81), diastolic BP (0.52±0.33; −0.33±0.45), mean arterial pressure (0.50±0.38; −0.63±0.50), and prevalent hypertension (OR, 1.02 [95% CI, 0.84–1.23]; OR, 0.87 [95% CI, 0.67–1.13]) in both cohorts, respectively. The Corin genotype was also not associated with incident hypertension (OR, 1.35 [95% CI, 0.94–1.93]; OR, 0.95 [95% CI, 0.64–1.39]) in the study cohorts. The NT‐proBNP levels in REGARDS and BNP levels in JHS were similar between the Corin genotype groups. In heart tissue, the NPPA and NPPB expression was similar between the genotype groups.

Conclusions

Corin gene variants observed more commonly in Black individuals are not associated with differences in NP expression, circulating NP levels, and BP or hypertension as previously reported in candidate gene studies. Understanding the genetic determinants of complex cardiovascular traits in underrepresented populations requires further evaluation.

Association of Transthyretin Val122Ile Variant With Incident Heart Failure Among Black Individuals

IMPORTANCE

A genetic variant in the TTR gene (rs76992529; Val122Ile), present more commonly in individuals with African ancestry (population frequency: 3%-4%), causes misfolding of the tetrameric transthyretin protein complex that accumulates as extracellular amyloid fibrils and results in hereditary transthyretin amyloidosis.

OBJECTIVE

To estimate the association of the amyloidogenic Val122Ile TTR variant with the risk of heart failure and mortality in a large, geographically diverse cohort of Black individuals.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective population-based cohort study of 7514 self-identified Black individuals living in the US participating in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study with genetic data available and without heart failure at baseline. The participants were enrolled at the baseline visit (2003-2007). The end of follow-up for the majority of outcomes was on December 31, 2018. All-cause mortality data were available through December 31, 2020.

EXPOSURES

TTR Val122Ile (rs76992529) genotype.

MAIN OUTCOME AND MEASURES

The primary outcome was incident heart failure (first hospitalization for heart failure or death due to heart failure). The secondary outcomes were heart failure mortality, cardiovascular mortality, and all-cause mortality. The multivariable Cox proportional hazards regression analyses were adjusted for genetic ancestry and demographic, clinical, and social factors.

RESULTS

Among 7514 Black participants (median age, 64 years [IQR, 57-70 years]; 61% women), the population frequency of the TTR Val122Ile variant was 3.1% (232 variant carriers and 7282 noncarriers). During a median follow-up of 11.1 years (IQR, 5.9-13.5 years), incident heart failure occurred in 535 individuals (34 variant carriers and 501 noncarriers) and the incidence of heart failure was 15.64 per 1000 person-years among variant carriers vs 7.16 per 1000 person-years among noncarriers (adjusted hazard ratio [HR], 2.43 [95% CI, 1.71-3.46]; P < .001). Deaths due to heart failure occurred in 141 individuals (13 variant carriers and 128 noncarriers) and the incidence of heart failure mortality was 6.11 per 1000 person-years among variant carriers vs 1.85 per 1000 person-years among noncarriers (adjusted HR, 4.19 [95% CI, 2.33-7.54]; P < .001). Deaths due to cardiovascular causes occurred in 793 individuals (34 variant carriers and 759 noncarriers) and the incidence of cardiovascular death was 15.18 per 1000 person-years among variant carriers vs 10.61 per 1000 person-years among noncarriers (adjusted HR, 1.69 [95% CI, 1.19-2.39]; P = .003). Deaths due to any cause occurred in 2715 individuals (100 variant carriers and 2615 noncarriers) and the incidence of all-cause mortality was 41.46 per 1000 person-years among variant carriers vs 33.94 per 1000 person-years among noncarriers (adjusted HR, 1.46 [95% CI, 1.19-1.78]; P < .001). There was no significant interaction between TTR variant carrier status and sex on incident heart failure and the secondary outcomes.

CONCLUSIONS AND RELEVANCE

Among a cohort of Black individuals living in the US, being a carrier of the TTR Val122Ile variant was significantly associated with an increased risk of heart failure.

How measurements affected by medication use are reported and handled in observational research: a literature review

Purpose

In epidemiological research, measurements affected by medication, for example, blood pressure lowered by antihypertensives, are common. Different ways of handling medication are required depending on the research questions and whether the affected measurement is the exposure, the outcome, or a confounder. This study aimed to review handling of medication use in observational research.

Methods

PubMed was searched for etiological studies published between 2015 and 2019 in 15 high‐ranked journals from cardiology, diabetes, and epidemiology. We selected studies that analyzed blood pressure, glucose, or lipid measurements (whether exposure, outcome or confounder) by linear or logistic regression. Two reviewers independently recorded how medication use was handled and assessed whether the methods used were in accordance with the research aim. We reported the methods used per variable category (exposure, outcome, confounder).

Results

A total of 127 articles were included. Most studies did not perform any method to account for medication use (exposure 58%, outcome 53%, and confounder 45%). Restriction (exposure 22%, outcome 23%, and confounders 10%), or adjusting for medication use using a binary indicator were also used frequently (exposure: 18%, outcome: 19%, confounder: 45%). No advanced methods were applied. In 60% of studies, the methods' validity could not be judged due to ambiguous reporting of the research aim. Invalid approaches were used in 28% of the studies, mostly when the affected variable was the outcome (36%).

Conclusion

Many studies ambiguously stated the research aim and used invalid methods to handle medication use. Researchers should consider a valid methodological approach based on their research question.

Statistical Methods for Assessing the Explained Variation of a Health Outcome by a Mixture of Exposures

Exposures to environmental pollutants are often composed of mixtures of chemicals that can be highly correlated because of similar sources and/or chemical structures. The effect of an individual chemical on a health outcome can be weak and difficult to detect because of the relatively low level of exposures to many environmental pollutants. To tackle the challenging problem of assessing the health risk of exposure to a mixture of environmental pollutants, we propose a statistical approach to assessing the proportion of the variation of an outcome explained by a mixture of pollutants. The proposed approach avoids the difficult task of identifying specific pollutants that are responsible for the effects and may also be used to assess interactions among exposures. Extensive simulation results demonstrate that the proposed approach has very good performance. Application of the proposed approach is illustrated by investigating the main and interaction effects of the chemical pollutants on systolic and diastolic blood pressure in participants from the National Health and Nutrition Examination Survey.

Changes in the body mass index and blood pressure association across time: Evidence from multiple cross-sectional and cohort studies

Although body mass index (BMI) is considered a key determinant of high blood pressure, its importance may differ over time and by age group. We utilised separate data sources to investigate temporal changes in this association: 23 independent (newly sampled), repeated cross-sectional studies (Health Survey for England (HSE)) at ≥25 years (1994-2018; N = 126,742); and three British birth cohorts at 43-46 years (born 1946, 1958, and 1970; N = 18,657). In HSE, associations were weaker in more recent years, with this trend most pronounced amongst older adults. After adjustment for sex, anti-hypertensive treatment and education, the mean difference in systolic blood pressure (SBP) per 1 kg/m² increase in BMI amongst adults ≥55 years was 0.75 mmHg (95%CI: 0.60-0.90) in 1994, 0.66 mmHg (0.46-0.85) in 2003, and 0.53 mmHg (0.35-0.71) in 2018. In the 1958 and 1970 cohorts, BMI and SBP associations were of similar magnitude yet weaker in the 1946 cohort, potentially due to differences in blood pressure measurement device. Quantile regression analyses suggested that associations between BMI and SBP were present both below and above the hypertension threshold. A weaker association between BMI and blood pressure may partly offset the public health impacts of increasing obesity prevalence. However, despite sizable increases in use of antihypertensive medication, BMI remains positively associated with SBP in all ages. Our findings highlight the need to tackle non-medical factors such as population diet which influence both BMI and blood pressure, and the utility of using multiple datasets to obtain robust inferences on trends in risk factor-outcome associations across time.

Association between egg intake and blood pressure in the USA: the INTERnational study on MAcro/micronutrients and blood Pressure (INTERMAP)

OBJECTIVES

To investigate associations of egg intake with blood pressure (BP) and the role of dietary variables and other macro- and micro-nutrients in the association.

DESIGN

We used cross-sectional data for the USA as part of the INTERnational study on MAcro/micronutrients and blood Pressure (INTERMAP). INTERMAP was surveyed between 1996 and 1999, including four 24-h dietary recalls, two 24-h urine collections and eight measurements of systolic BP and diastolic BP (SBP, DBP). Average egg intake (g/d) was calculated. Multivariable linear regression models were used to estimate the association between egg intake (per each 50 g/d or per quintile) and BP. The roles of dietary variables and other macro- and micro-nutrients in this association were also investigated.

SETTING

In the USA.

PARTICIPANTS

In total, 2195 US INTERMAP men and women aged 40-59 years.

RESULTS

Participants were 50 % female, 54 % non-Hispanic White and 16 % non-Hispanic Black. Mean egg intake (sd) in men and women was 30·4(29·8) and 21·6(20·5) g/d, respectively. Adjusting for demographics, socio-economics, lifestyle and urinary Na:K excretion ratios, we found non-linear associations with BP in non-obese women (P-quadratic terms: 0·004 for SBP and 0·035 for DBP).The associations remained after adjusting for dietary variables, macro/micro nutrients or minerals. Dietary cholesterol was highly correlated with egg intake and may factor in the association. No association was found in obese women and in obese or non-obese men.

CONCLUSION

Egg intake was non-linearly associated with SBP and DBP in non-obese women, but not in obese women or men. Underlying mechanisms require additional study regarding the role of obesity and sex.

Exposure to endocrine disrupting chemicals (EDCs) and cardiometabolic indices during pregnancy: The HOME Study

BACKGROUND

Toxicology studies have identified pregnancy as a window of susceptibility for endocrine disrupting chemicals (EDCs) and cardiometabolic indices in women. No study in humans, however, has examined EDC mixtures and cardiometabolic indices during pregnancy.

METHODS

We used the Health Outcomes and Measures of the Environment (HOME) Study to examine whether bisphenol A (BPA), polybrominated diphenyl ethers (PBDEs), per- and polyfluoroalkyl substances (PFAS), and phthalates are associated with blood pressure, glucose, and lipids in 388 pregnant women. We measured PBDEs and PFAS in serum at 16 weeks gestation, while BPA and phthalate metabolites were quantified in urine at 16 and 26 weeks gestation. We used linear regression and Bayesian Kernel Machine Regression (BKMR) to estimate covariate-adjusted associations of individual EDCs and their mixtures with cardiometabolic indices during pregnancy.

RESULTS

A 10-fold increase in BDE-28 was associated with a 13.1 mg/dL increase in glucose (95% Confidence Interval [CI] 2.9, 23.2) in linear regression. The BKMR model also identified BDE-28 as having a positive association with glucose. BDE-28, BDE-47, and BDE-99 were positively associated with total cholesterol in both single- and multi-pollutant models, whereas a suggestive negative association was noted with BDE-153. Mono-n-butyl phthalate (MBP) (β = -7.9 mg/dL, 95% CI -12.9, -3.0) and monobenzyl phthalate (MBzP) (β = -6.3 mg/dL, 95% CI -10.6, -2.0) were both associated with significant decreases in cholesterol in linear regression, but only MBzP was identified as an important contributor in the BKMR model.

CONCLUSION

Overall, we observed positive associations between PBDEs with glucose and cholesterol levels during pregnancy, while negative associations were found between some phthalate biomarkers and cholesterol. No relationship was noted for BPA or PFAS with cardiometabolic indices during pregnancy across both models.

Effects of Within-Person Variability in Spot Urinary Sodium Measurements on Associations With Blood Pressure and Cardiovascular Disease

Randomized trials of salt restriction have consistently demonstrated that decreasing salt consumption lowers blood pressure, but results of observational studies of salt intake and cardiovascular disease have been conflicting. After excluding individuals with prevalent cardiovascular or kidney disease in the prospective UK Biobank study, we examined the within-person variability in spot urinary sodium excretion and its impact on associations with systolic blood pressure and risk of incident cardiovascular disease. Spearman correlation coefficients were used to assess within-person variability in spot urinary sodium, and associations between sodium and blood pressure were assessed using linear regression in participants with measurements at baseline (N=355 134) and after 9 years (N=33 915). Cox regression was used to assess associations with the risk of cardiovascular disease over the same follow-up period (N=5566 events). The within-person variability in urinary sodium was extreme, with a self-correlation coefficient of 0.35 over 4 years. Each 100 mmol/L higher usual urinary sodium was associated with 3.09 mm Hg higher systolic blood pressure (95% CI, 2.7–3.48) at baseline, but had no association at 9 years (0.97 [−0.44 to 2.37]). Likewise, there was no association between urinary sodium and risk of cardiovascular disease over the same follow-up period (hazard ratio, 1.05, [0.87–1.26]). While spot urinary sodium measurements were associated with immediate effects on blood pressure at baseline, the extreme within-person variability in urinary sodium precluded detection of associations with future blood pressure at resurvey or risk of cardiovascular disease. The limitations of observational studies, irrespective of study size, should be recognized when assessing public policy on salt restriction.

Longitudinal Measures of Blood Pressure and Subclinical Atrial Arrhythmias: The MESA and the ARIC Study

Background High blood pressure (BP) is a well-known risk factor for atrial fibrillation (AF), but a single BP measurement may provide limited information about AF risk in older adults. Methods and Results This study included 1256 MESA (Multi-Ethnic Study of Atherosclerosis) and 1948 ARIC (Atherosclerosis Risk in Communities) study participants who underwent extended ambulatory electrocardiographic monitoring and who were free of clinically detected cardiovascular disease, including AF. Using BP measurements from 6 examinations (2000-2018 in MESA and 1987-2017 in ARIC study), we calculated individual long-term mean, trend, and detrended visit-to-visit variability in systolic BP and pulse pressure for each participant. Outcomes, assessed at examination 6, included subclinical AF and supraventricular ectopy. Results from each study were combined with inverse variance-weighted meta-analysis. At examination 6, the mean age was 73 years in MESA and 79 years in ARIC study, and 4% had subclinical AF. Higher visit-to-visit detrended variability in systolic BP was associated with a greater prevalence of subclinical AF (odds ratio [OR], 1.20; 95% CI, 1.02-1.38) and with more premature atrial contractions/hour (geometric mean ratio, 1.08; 95% CI, 1.01-1.15). For pulse pressure as well, higher visit-to-visit detrended variability was associated with a greater prevalence of AF (OR, 1.18; 95% CI, 1.00-1.37). In addition, higher long-term mean pulse pressure was associated with a greater prevalence of subclinical AF (OR, 1.36; 95% CI, 1.08-1.70). Conclusions Antecedent visit-to-visit variability in systolic BP and pulse pressure, but not current BP, is associated with a higher prevalence of subclinical atrial arrhythmias. Prior longitudinal BP assessment, rather than current BP, may be more helpful in identifying older adults who are at higher risk of atrial arrhythmias.

Impact of prior preterm or term small for gestational age birth on maternal blood pressure during the menopause transition in the Study of Women's Health Across the Nation

OBJECTIVE

To examine whether blood pressure (BP) accelerates more rapidly during the menopause transition for women with a history of preterm or term small for gestational age (SGA) delivery compared to women with all term and appropriate for gestational age (AGA) births.

METHODS

A longitudinal analysis was conducted with 1,008 parous women who had BP data at ≥2 study visits. We used generalized linear modeling to examine BP before the final menstrual period, at the final mentrual period, and up to 10 years after the final menstrual period, according to pregnancy group. We assessed maternal changes in BP over time in relation to years near the final menstrual period using a piece-wise linear model, consistent with menopause-induced changes. Models were adjusted for socio-demographics, body mass index, smoking, physical activity, medications, parity, age at first birth, gestational diabetes, and gestational hypertension/preeclampsia.

RESULTS

At baseline, women were on average 46 years old, 101 (10%) reported a prior preterm birth, and 102 (10.1%) reported a term SGA birth. Compared to women with all term AGA births, women with a term SGA birth had higher BP before the final menstrual period, at the final menstrual period, and up to 10 years after the final menstrual period; women with a preterm birth had higher BP in the postmenopausal years. Annual rate of change in BP during the menopause transition did not differ between pregnancy groups.

CONCLUSIONS

Women with a history preterm and term SGA delivery have higher BP than women with all term AGA births during the menopause transition, but rate of change in BP does not differ in these groups relative to final menstrual period.

Socioeconomic inequalities in blood pressure: co-ordinated analysis of 147,775 participants from repeated birth cohort and cross-sectional datasets, 1989 to 2016

BACKGROUND

High blood pressure (BP) is a key modifiable determinant of cardiovascular disease and a likely determinant of other adverse health outcomes. While socioeconomic inequalities in BP are well documented, it remains unclear (1) how these inequalities have changed across time, given improvements over time in the detection and treatment of high BP (hypertension); (2) whether BP inequalities are present below and above hypertension treatment thresholds; and (3) whether socioeconomic position (SEP) across life has cumulative effects on BP. We sought to address these gaps using evidence from two complementary sources: birth cohort and repeated cross-sectional datasets.

METHODS

We used three British birth cohort studies-born in 1946, 1958, and 1970-with BP measured at 43-46 years (in 1989, 2003, and 2016), and 21 repeated cross-sectional datasets-the Health Survey for England (HSE), with BP measured among adults aged ≥ 25 years (1994-2016). Adult education attainment was used as an indicator of SEP in both datasets; childhood father's social class was used as an alternative indicator of (early life) SEP in cohorts. Adjusting for the expected average effects of antihypertensive medication use, we used linear regression to quantify SEP differences in mean systolic BP (SBP), and quantile regression to investigate whether inequalities differed across SBP distributions-below and above hypertension treatment thresholds.

RESULTS

In both datasets, lower educational attainment was associated with higher SBP, with similar absolute magnitudes of inequality across the studied period. Differences in SBP by education (Slope Index of Inequality) based on HSE data were 3.0 mmHg (95% CI 1.8, 4.2) in 1994 and 4.3 mmHg (2.3, 6.3) in 2016. Findings were similar for diastolic BP (DBP) and survey-defined hypertension. Inequalities were found across the SBP distribution in both datasets-below and above the hypertension threshold-yet were larger at the upper tail; in HSE, median SBP differences were 2.8 mmHg (1.7, 3.9) yet 5.6 mmHg (4.9, 6.4) at the 90th quantile. Adjustment for antihypertensive medication use had little impact on the magnitude of inequalities; in contrast, associations were largely attenuated after adjustment for body mass index. Finally, cohort data suggested that disadvantage in early and adult life had cumulative independent associations with BP: cohort-pooled differences in SBP were 5.0 mmHg (3.8, 6.1) in a score combining early life social class and own education, yet were 3.4 mmHg (2.4, 4.4) for education alone.

CONCLUSION

Socioeconomic inequalities in BP have persisted from 1989 to 2016 in Britain/England, despite improved detection and treatment of high BP. To achieve future reductions in BP inequalities, policies addressing the wider structural determinants of high BP levels are likely required, particularly those curtailing the obesogenic environment-targeting detection and treatment alone is unlikely to be sufficient.

Age differences in the relationships between risk factors and loss of kidney function: a general population cohort study

BACKGROUND

Annual decline in kidney function is a widely applied surrogate outcome of renal failure. It is important to understand the relationships between known risk factors and the annual decline in estimated glomerular filtration rate (eGFR) according to baseline age; however, these remain unclear.

METHODS

A community-based retrospective cohort study of adults who underwent annual medical examinations between 1999 and 2013 was conducted. The participants were stratified into different age groups (40-49, 50-59, 60-69, 70-79, and ≥ 80 years) to assess the risk for loss of kidney function. A mixed-effects model was used to estimate the association between risk factors and annual changes in eGFR.

RESULTS

In total, 51,938 participants were included in the analysis. The age group of ≥80 years included 8127 individuals. The mean annual change in eGFR was - 0.39 (95% confidence interval: - 0.41 to - 0.37) mL/min/1.73 m² per year. Older age was related to faster loss of kidney function. In the older age group, higher systolic blood pressure, proteinuria, and current smoking were related to faster loss of kidney function (p trend < 0.01, 0.03, and < 0.01, respectively). Conversely, each age group showed similar annual loss of kidney function related to lower hemoglobin levels and diabetes mellitus (p trend 0.47 and 0.17, respectively).

CONCLUSIONS

Higher systolic blood pressure, proteinuria, and smoking were related to faster loss of kidney function, and a greater effect size was observed in the older participants. More risk assessments for older people are required for personalized care.

Mid- to Late-Life Time-Averaged Cumulative Blood Pressure and Late-Life Cardiac Structure, Function, and Heart Failure

Limited data exist regarding systolic blood pressure (SBP) through mid- to late-life and late-life cardiac function and heart failure (HF) risk. Among 4578 HF-free participants in the ARIC study (Atherosclerosis Risk in Communities) attending the fifth visit (2011-2013; age 75±5 years), time-averaged cumulative SBP was calculated as the sum of averaged SBPs from adjacent consecutive visits (visits 1-5) indexed to total observation time (24±1 years). Calculations were performed using measured SBPs and also incorporating antihypertensive medication specific effect constants (underlying SBP). Outcomes included comprehensive echocardiography at visit 5 and post-visit 5 incident HF, HF with preserved ejection fraction, and reduced ejection fraction. Higher cumulative SBP was associated with greater left ventricular mass and worse diastolic measures (all P<0.001), associations that were stronger with underlying compared with cumulative SBP (all P<0.05). At 5.6±1.2 years follow-up post-visit 5, higher cumulative measured and underlying SBP were associated with incident HF (hazard ratio per 10 mm Hg for measured: 1.12 [1.01-1.24]; underlying: 1.19 [95% CI, 1.10-1.30]) and HF with preserved ejection fraction (measured: 1.15 [1.00-1.33]; underlying: 1.28 [1.14-1.45]), but not HF with reduced ejection fraction (measured: 1.11 [0.94-1.32]; underlying: 1.11 [0.96-1.24]). Associations with HF and HF with preserved ejection fraction were more robust with cumulative underlying compared with measured SBP (all P<0.05). Time-averaged cumulative SBP in mid to late life is associated with worse cardiac function and risk of incident HF, especially HF with preserved ejection fraction, in late life. These associations were stronger considering underlying as opposed to measured SBP, highlighting the importance of prevention and effective treatment of hypertension to prevent late-life cardiac dysfunction and HF.

Gravidity, parity, blood pressure and mortality among women in Bangladesh from the HEALS cohort

OBJECTIVES

Despite a hypothesised connection of reproductive history with hypertension and mortality, the nature of this association is poorly characterised. We evaluated the association of parity and gravidity with blood pressure, hypertension and all-cause mortality.

DESIGN

Prospective cohort study.

SETTING

Health Effects of Arsenic Longitudinal Study cohort in rural Bangladesh.

PARTICIPANTS

There were 21 634 Bangladeshi women recruited in 2000-2002, 2006-2008 and 2010-2014 included in the present analysis.

METHODS

Reproductive history was ascertained through an interviewer-administered questionnaire at the baseline visit. Blood pressure was measured by a trained study physician following a standard protocol at the baseline visit. Vital status was ascertained at the biennial follow-up of study participants through June 2017. Linear and logistic regression models estimated the relationship between parity and gravidity with blood pressure and hypertension, respectively. Cox proportional hazards models estimated the relationship with all-cause mortality only among women aged >45 years.

RESULTS

Diastolic blood pressure was lowest in women with parity one (reference) and elevated in nulliparous women (adjusted % change=3.12; 95% CI 1.93 to 4.33) and women with parity >2 (adjusted % change=1.71; 95% CI 1.12 to 2.31). The associations with nulliparity were stronger for women aged >45 years. Similar association patterns were observed with hypertension. Further, in nulliparous women aged >45 years, 265 deaths (6.6%) were ascertained during the follow-up period (median follow-up time=8 years), and we observed suggestive elevated risks of all-cause mortality (adjusted HR 3.83; 95% CI 0.74 to 19.78). The relationships between reproductive history, blood pressure, hypertension and mortality were similar when modelling reproductive history as gravidity rather than parity.

CONCLUSIONS

For women in rural Bangladesh, nulliparity and nulligravidity appear to be associated with higher blood pressure and subsequent elevated risk of mortality.

Biological Pathways of Long-Term Visit-to-Visit Blood Pressure Variability in the American Population: Cardiovascular Health Study and Women’s Health Initiatives

Studies reported a positive relationship between visit-to-visit blood pressure variability (VVBPV) and cardiovascular morbidity and mortality independently of the mean arterial blood pressure across clinical visits. The literature is scarce on the genes and biological mechanisms that regulate long-term VVBPV. We sought to identify biological pathways that regulate visit-to-visit blood pressure variability. We used phenotypic and genotype data from the Women’s Health Initiatives and Cardiovascular Health Studies. We defined VVBPV of systolic and diastolic blood pressure phenotypes as the standard deviation about the participant’s regression line with systolic and diastolic blood pressure regressed separately across visits. We imputed missing genotypes and then conducted a genome-wide association analysis to identify genomic variants related to the VVBPV and detect biological pathways. For systolic VVBPV, we identified a neurological pathway, the GABAergic pathway (P values = 1.1E − 2), and a vascular pathway, the RAP1 signaling pathway (P values = 5.8E − 2). For diastolic VVBPV, the hippo signaling (P values = 4.1E − 2), CDO myogenesis (P values = 7.0E − 2), and O-glycosylation of TSR domain-containing protein pathways (P values = 9.0E − 2) were the significant pathways. Future studies are warranted to validate these results. Further understanding of the roles of the genes regulating the identified pathways will help researchers to improve future pharmacological interventions to treat VVBPV in clinical practice.

The association of traffic-related air and noise pollution with maternal blood pressure and hypertensive disorders of pregnancy in the HOME study cohort

Traffic-related air and noise pollution may increase the risk for cardiovascular disorders, especially among susceptible populations like pregnant women. The objective of this study was to evaluate the association of exposure to traffic-related air pollution and traffic noise with blood pressure in pregnant women. We extracted systolic blood pressure (SBP) and diastolic blood pressure (DBP) at ≥20 weeks gestation, as well as hypertensive disorders of pregnancy from medical records in the HOME Study, a prospective pregnancy and birth cohort from Cincinnati, OH (n = 370). We estimated exposure to elemental carbon attributable to traffic (ECAT),1 a marker of traffic-related air pollution, at women's residences at ~20 weeks gestation using a validated land use regression model and traffic noise using a publicly available transportation noise model. We used linear mixed models and modified Poisson regression adjusted for covariates to examine associations of ECAT and traffic noise with blood pressure and hypertensive disorders of pregnancy risk, respectively. In adjusted models, we found a 1.6 (95% CI = 0.02, 3.3; p = 0.048) mm Hg increase in SBP associated with an interquartile range increase in ECAT concentration; the association was stronger after adjusting for traffic noise (1.9 mm Hg, 95% = 0.1, 3.7; p = 0.035). ECAT concentrations were not significantly associated with DBP or hypertensive disorders of pregnancy, and traffic noise was not associated with SBP, DBP, or hypertensive disorders of pregnancy. There was no evidence of a joint effect of traffic noise and ECAT on any outcome. In this cohort, higher residential traffic-related air pollution exposure at ~20 weeks gestation was associated with higher SBP in late pregnancy. It is important for future studies of traffic-related air or noise pollution to jointly consider both exposures and neighborhood characteristics given their correlation and potential cumulative impact on cardiovascular health.

Antihypertensive treatment and blood pressure trends among South African adults: A repeated cross-sectional analysis of a population panel survey

BACKGROUND

Recent findings suggest a decline in mean blood pressure and prevalence of uncontrolled hypertension in the South African adult population in the last decade, in contrast with the increase previously observed. This study aimed at quantifying the contribution of antihypertensive treatment to this decline.

METHODS

We used data from the four waves of the National Income Dynamics Study between 2008 and 2015 and analysed changes in systolic (SBP) and diastolic blood pressure (DBP) and prevalence of uncontrolled hypertension among South African adults (15 years and above). We compared the observed changes with a counterfactual scenario in which the impact of antihypertensive treatment was estimated by censored regression and removed, with and without adjustment for BMI, waist circumference, alcohol use and smoking.

RESULTS

During the study period, the prevalence of antihypertensive treatment rose from 13.1% to 17.6% among women and from 5.3% to 8.2% among men. Concurrently-despite worsening trends in major biobehavioural risk factors for elevated blood pressure-mean SBP decreased in both genders, DBP decreased among women and was stable among men. The odds of uncontrolled hypertension decreased by 4%/year among women and 1%/year among men. After removing the treatment effect, the downward trend in the odds of uncontrolled hypertension was reduced to 1%/year among women and completely offset among men. Among those 55 years and older, but not among younger subjects, treatment effects also explained most of the observed decreases in mean SBP and DBP.

CONCLUSIONS

Among South African adults, we infer that diffusion of antihypertensive treatment contributed substantially to the downward trend in the prevalence of uncontrolled hypertension observed between 2008 and 2015. The marked decrease in SBP and uncontrolled hypertension found among younger participants could not be explained by treatment nor by the changing distribution of the measured risk factors available in this study, and requires further investigation.

FGF23 (Fibroblast Growth Factor-23) and Incident Hypertension in Young and Middle-Aged Adults: The CARDIA Study

Blacks have the highest prevalence of hypertension in the United States. Higher levels of FGF23 (fibroblast growth factor-23) have been associated with worse cardiovascular outcomes. Whether FGF23 is associated with rising blood pressure (BP) and racial differences in incident hypertension is unclear. We studied 1758 adults (45.0±3.7 years; 57.8% female; 36.9% black) without hypertension or cardiovascular disease who participated in the year 20 (2005-2006) follow-up examination of the CARDIA study (Coronary Artery Risk Development in Young Adults). We investigated the associations of baseline (year 20) cFGF23 (C-terminal FGF23) levels with longitudinal BP patterns and incident hypertension (defined as being on antihypertensive medication, systolic BP ≥130 or diastolic BP ≥80 mm Hg) during 2 follow-up visits (years 25 and 30). During follow-up, 35.2% of participants developed hypertension. In multivariable linear mixed models, there were greater increases in systolic BP from year 20 to 25 and year 25 to 30 in the highest FGF23 quartile relative to the lowest quartile (+2.1 mm Hg, P=0.0057 and +2.2 mm Hg, P=0.0108, respectively for each time period), whereas there were greater increases in diastolic BP from year 20 to 25 in the highest quartile relative to the lowest (+1.6 mm Hg; P=0.0024). In multivariable modified Poisson regression analyses, the highest FGF23 quartile was associated with a 45% greater risk of developing hypertension during follow-up compared with the lowest quartile (relative risk, 1.45 [1.18-1.77]). Results did not vary by race (Pinteraction=0.1523). Higher FGF23 levels are independently associated with rising BP over time and an increased risk of incident hypertension but not racial differences in hypertension.