Association of long-term exposure to traffic-related air pollution with blood pressure and hypertension in an adult population-based cohort in Spain (the REGICOR study).
ABSTRACT: BACKGROUND: Long-term exposure to traffic-related air pollution may increase blood pressure (BP) and induce hypertension. However, evidence supporting these associations is limited, and they may be confounded by exposure to traffic noise and biased due to inappropriate control for use of BP-lowering medications. OBJECTIVES: We evaluated the associations of long-term traffic-related air pollution with BP and prevalent hypertension, adjusting for transportation noise and assessing different methodologies to control for BP-lowering medications. METHODS: We measured systolic (SBP) and diastolic BP (DBP) at baseline (years 2003-2005) in 3,700 participants, 35-83 years of age, from a population-based cohort in Spain. We estimated home outdoor annual average concentrations of nitrogen dioxide (NO2) with a land-use regression model. We used multivariate linear and logistic regression. RESULTS: A 10-?g/m3 increase in NO2 levels was associated with 1.34 mmHg (95% CI: 0.14, 2.55) higher SBP in nonmedicated individuals, after adjusting for transportation noise. Results were similar in the entire population after adjusting for medication, as commonly done, but weaker when other methods were used to account for medication use. For example, when 10 mmHg were added to the measured SBP levels of medicated participants, the association was ? = 0.78 (95% CI: -0.43, 2.00). NO2 was not associated with hypertension. Associations of NO2 with SBP and DBP were stronger in participants with cardiovascular disease, and the association with SBP was stronger in those exposed to high traffic density and traffic noise levels ? 55 dB(A). CONCLUSIONS: We observed a positive association between long-term exposure to NO2 and SBP, after adjustment for transportation noise, which was sensitive to the methodology used to account for medication.
Project description:BACKGROUND: Traffic noise has been associated with prevalence of hypertension, but reports are inconsistent for blood pressure (BP). To ascertain noise effects and to disentangle them from those suspected to be from traffic-related air pollution, it may be essential to estimate people's noise exposure indoors in bedrooms. OBJECTIVES: We analyzed associations between long-term exposure to indoor traffic noise in bedrooms and prevalent hypertension and systolic (SBP) and diastolic (DBP) BP, considering long-term exposure to outdoor nitrogen dioxide (NO2). METHODS: We evaluated 1,926 cohort participants at baseline (years 2003-2006; Girona, Spain). Outdoor annual average levels of nighttime traffic noise (Lnight) and NO2 were estimated at postal addresses with a detailed traffic noise model and a land-use regression model, respectively. Individual indoor traffic Lnight levels were derived from outdoor Lnight with application of insulations provided by reported noise-reducing factors. We assessed associations for hypertension and BP with multi-exposure logistic and linear regression models, respectively. RESULTS: Median levels were 27.1 dB(A) (indoor Lnight), 56.7 dB(A) (outdoor Lnight), and 26.8 ?g/m3 (NO2). Spearman correlations between outdoor and indoor Lnight with NO2 were 0.75 and 0.23, respectively. Indoor Lnight was associated both with hypertension (OR = 1.06; 95% CI: 0.99, 1.13) and SBP (? = 0.72; 95% CI: 0.29, 1.15) per 5 dB(A); and NO2 was associated with hypertension (OR = 1.16; 95% CI: 0.99, 1.36), SBP (? = 1.23; 95% CI: 0.21, 2.25), and DBP (??= 0.56; 95% CI: -0.03, 1.14) per 10 ?g/m3. In the outdoor noise model, Lnight was associated only with hypertension and NO2 with BP only. The indoor noise-SBP association was stronger and statistically significant with a threshold at 30 dB(A). CONCLUSION: Long-term exposure to indoor traffic noise was associated with prevalent hypertension and SBP, independently of NO2. Associations were less consistent for outdoor traffic Lnight and likely affected by collinearity.
Project description:Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP.
Project description:BACKGROUND: Short-term exposure to air pollution has been associated with changes in blood pressure (BP) and emergency department visits for hypertension, but little is known about the effects of long-term exposure to traffic-related air pollution on BP and hypertension. OBJECTIVES: We studied whether long-term exposure to air pollution is associated with BP and hypertension. METHODS: In 1993-1997, 57,053 participants 50-64 years of age were enrolled in a population-based cohort study. Systolic and diastolic BP (SBP and DBP, respectively) were measured at enrollment. Self-reported incident hypertension during a mean follow-up of 5.3 years was assessed by questionnaire. We used a validated dispersion model to estimate residential long-term nitrogen oxides (NO(x)), a marker of traffic-related air pollution, for the 1- and 5-year periods prior to enrollment and before a diagnosis of hypertension. We conducted a cross-sectional analysis of associations between air pollution and BP at enrollment with linear regression, adjusting for traffic noise, measured short-term NO(x), temperature, relative humidity, and potential lifestyle confounders (n = 44,436). We analyzed incident hypertension with Cox regression, adjusting for traffic noise and potential confounders. RESULTS: A doubling of NO(x) exposure during 1- and 5-year periods preceding enrollment was associated with 0.53-mmHg decreases [95% confidence interval (CI): -0.88, -0.19 mmHg] and 0.50-mmHg decreases (95% CI: -0.84, -0.16 mmHg) in SBP, respectively. Long-term exposure also was associated with a lower prevalence of baseline self-reported hypertension (per doubling of 5-year mean NO(x): odds ratio = 0.96; 95% CI: 0.91, 1.00), whereas long-term NO(x) exposure was not associated with incident self-reported hypertension during follow-up. CONCLUSIONS: Long-term exposure to traffic-related air pollution was associated with a slightly lower prevalence of BP at baseline, but was not associated with incident hypertension.
Project description: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.
Project description:BACKGROUND:Ambulatory blood pressure (BP) monitoring is the reference standard for out-of-clinic BP measurement. Thresholds for identifying ambulatory hypertension (daytime systolic BP [SBP]/diastolic BP [DBP] ?135/85 mm?Hg, 24-hour SBP/DBP ?130/80 mm?Hg, and nighttime SBP/DBP ?120/70 mm?Hg) have been derived from European, Asian, and South American populations. We determined BP thresholds for ambulatory hypertension in a US population-based sample of African American adults. METHODS:We analyzed data from the Jackson Heart Study, a population-based cohort study comprised exclusively of African American adults (n=5306). Analyses were restricted to 1016 participants who completed ambulatory BP monitoring at baseline in 2000 to 2004. Mean SBP and DBP levels were calculated for daytime (10:00 am-8:00 pm), 24-hour (all available readings), and nighttime (midnight-6:00 am) periods, separately. Daytime, 24-hour, and nighttime BP thresholds for ambulatory hypertension were identified using regression- and outcome-derived approaches. The composite of a cardiovascular disease or an all-cause mortality event was used in the outcome-derived approach. For this latter approach, BP thresholds were identified only for SBP because clinic DBP was not associated with the outcome. Analyses were stratified by antihypertensive medication use. RESULTS:Among participants not taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm?Hg were 134/85 mm?Hg, 130/81 mm?Hg, and 123/73 mm?Hg, respectively. The outcome-derived thresholds for daytime, 24-hour, and nighttime SBP corresponding to a clinic SBP ?140 mm?Hg were 138 mm?Hg, 134 mm?Hg, and 129 mm?Hg, respectively. Among participants taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm?Hg were 135/85 mm?Hg, 133/82 mm?Hg, and 128/76 mm?Hg, respectively. The corresponding outcome-derived thresholds for daytime, 24-hour, and nighttime SBP were 140 mm?Hg, 137 mm?Hg, and 133 mm?Hg, respectively, among those taking antihypertensive medication. CONCLUSIONS:On the basis of the outcome-derived approach for SBP and regression-derived approach for DBP, the following definitions for daytime, 24-hour, and nighttime hypertension corresponding to clinic SBP/DBP ?140/90 mm?Hg are proposed for African American adults: daytime SBP/DBP ?140/85 mm?Hg, 24-hour SBP/DBP ?135/80 mm?Hg, and nighttime SBP/DBP ?130/75 mm?Hg, respectively.
Project description:Air pollution causes hypertension, cardiovascular disease, and mortality. Asian dust (AD) reportedly induces asthma or acute myocardial infarction along with air pollution, but its impact on blood pressure (BP) is unknown. We investigated the association between short-term AD exposure and BP fluctuations in 300,952 individuals whose BP was measured during April 2005-March 2015 and divided them into AD and non-AD groups based on visitation for AD-related events. AD's occurrence, air pollutants' concentration (suspended particulate matter, SO2, NO2, photochemical oxidants), and meteorological variables (mean ambient temperature, relative humidity) were obtained from a monitoring station; AD events correlated with decreased visibility (< 10 km). We observed 61 AD days, with 3897 participants undergoing medical check-ups. Short-term AD exposure at lag day-0 was significantly associated with higher systolic BP (SBP), diastolic BP (DBP), and pulse rate (PR) risk (? = 1.85, 95% confidence interval (CI) 1.35-2.35 for SBP, ? = 2.24, 95% CI 1.88-2.61 for DBP, ? = 0.52, 95% CI 0.14-0.91 for PR) using multi-pollutant model. Population-attributable fractions exposed to AD were 11.5% for those with elevated SBP (SBP ? 120 mmHg) and 23.7% for those with hypertension (SBP ? 140 mmHg or DBP ? 90 mmHg). This study showed a strong association between short-term AD exposure and increased SBP and DBP.
Project description:OBJECTIVES:To explore relationships between patients' self-monitoring of blood pressure (BP) and their concurrent self-reports of medication intake, well-being, stress, physical activity and symptoms. DESIGN:This study is a secondary analysis of a prospective study exploring the 8-week effectiveness of a mobile phone-based self-management support system for patients with hypertension. SETTING:Four primary healthcare centres situated in urban and suburban communities in Sweden. PARTICIPANTS:50 patients undergoing treatment for hypertension. PRIMARY AND SECONDARY OUTCOME MEASURES:Associations between systolic (SBP) and diastolic blood pressure (DBP) and 10 self-report lifestyle-related variables were analysed using linear mixed effects modelling. RESULTS:Medication intake, better well-being, less stress and greater physical activity were associated variously with lower same-day SBP and DBP. The single strongest association was found between medication intake and SBP, where failure to take medications was associated with an estimated 7.44 mm Hg higher SBP. To a lesser degree, medication intake was also associated with DBP, where DBP was 4.70 mm Hg higher in cases where medications were not taken. Well-being and stress were consistently associated with SBP and DBP, whereas physical activity was associated with only SBP. None of the symptoms-dizziness, headache, restlessness, fatigue or palpitations-were significantly associated with BP. CONCLUSIONS:Our findings that BP was associated with patients' BP management behaviours and experiences of well-being and stress, but not symptoms suggest that enabling persons with hypertension to monitor and track their BP in relation to medication intake, physical activity, well-being, stress and symptoms may be a fruitful way to help them gain first-hand understanding of the importance of adherence and persistence to treatment recommendations. TRIAL REGISTRATION NUMBER:NCT01510301; Pre-results.
Project description:To investigate trends in blood pressure (BP) and hypertension prevalence in Korea.Based on the Korean National Health and Nutrition Examination Survey (KNHANES) I (1998), II (2001), III (2005), IV (2007-2009), V (2010-2012), and VI (2013-2014), 56077 participants (23974 men and 32103 women) were included.Mean systolic BP (SBP) and diastolic BP (DBP) decreased in both sexes (male SBP: 128.1 to 120.2 mm Hg, male DBP: 82.0 to 78.5 mm Hg; female SBP: 125.7 to 116.0 mm Hg and female DBP: 77.4 to 73.2 mm Hg from the KNHANES I-VI). The age-standardized prevalence of hypertension was significantly decreased in both sexes (male; 33.3% to 30.3%, female; 28.7% to 22.7%, all p for trend <0.001). Regardless of taking anti-hypertensive medication or not, SBP and DBP declined universally in both sexes. Compared to the KNHANES I, the odds ratios (95% confidence intervals) of the KNHANES II to VI for less-than-normotensive and less-than-hypertensive BP increased in both sexes.Mean BP levels in both sexes and hypertension prevalence showed downward trends during the 16-year period.
Project description:Both genomics and environmental stressors play a significant role in increases in blood pressure (BP). In an attempt to further explain the hypertension (HTN) disparity among African Americans (AA), both genetic underpinnings (selected candidate genes) and stress due to perceived racial discrimination (as reported in the literature) have independently been linked to increased BP among AAs. Although Gene x Environment interactions on BP have been examined, the environmental component of these investigations has focused more on lifestyle behaviors such as smoking, diet, and physical activity, and less on psychosocial stressors such as perceived discrimination.The present study uses candidate gene analyses to identify the relationship between Everyday Discrimination (ED) and Major Life Discrimination (MLD) with increases in systolic BP (SBP) and diastolic BP (DBP) among AA in the Jackson Heart Study. Multiple linear regression models reveal no association between discrimination and BP after adjusting for age, sex, body mass index (BMI), antihypertensive medication use, and current smoking status.Subsequent candidate gene analysis identified 5 SNPs (rs7602215, rs3771724, rs1006502, rs1791926, and rs2258119) that interacted with perceived discrimination and SBP, and 3 SNPs (rs2034454, rs7602215, and rs3771724) that interacted with perceived discrimination and DBP. Most notably, there was a significant SNP?×?discrimination interaction for 2 SNPs on the SLC4A5 gene: rs3771724 (MLD: SBP P = .034, DBP P = .031; ED: DBP: P = .016) and rs1006502 (MLD: SBP P?=?.034, DBP P?=?.030; ED: DBP P?=?.015).This study supports the idea that SNP?×?discrimination interactions combine to influence clinically relevant traits such as BP. Replication with similar epidemiological samples is required to ascertain the role of genes and psychosocial stressors in the development and expression of high BP in this understudied population.
Project description:The metabolic syndrome is associated with higher ambulatory blood pressure. The authors studied the association of metabolic syndrome and masked hypertension (MHT) among African Americans with clinic-measured systolic/diastolic blood pressure (SBP/DBP) <140/90 mm Hg in the Jackson Heart Study. MHT was defined as daytime, nighttime, or 24-hour hypertension on ambulatory blood pressure monitoring. Among 359 participants not taking antihypertensive medication, the metabolic syndrome was associated with MHT (prevalence ratio, 1.38; 95% confidence interval, 1.10-1.74]). When metabolic syndrome components (clinic SBP/DBP 130-139/85-89 mm Hg, abdominal obesity, impaired glucose, low high-density lipoprotein cholesterol, high triglycerides) were analyzed separately, only clinic SBP/DBP 130-139/85-89 mm Hg was associated with MHT (prevalence ratio, 1.90; 95% confidence interval, 1.56-2.32]). The metabolic syndrome was not associated with MHT among participants not taking antihypertensive medication with SBP/DBP 130-139/85-89 and <130/85 mm Hg, separately, or among participants taking antihypertensive medication (n=393). Ambulatory blood pressure monitoring screening for MHT among African Americans should be considered based on clinic BP, not metabolic syndrome.