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Joel Schwartz - One of the best experts on this subject based on the ideXlab platform.
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association of Outdoor Temperature with lung function in a temperate climate
European Respiratory Journal, 2019Co-Authors: Mary B Rice, Elissa H Wilker, Diane R Gold, George R Washko, Itai Kloog, Petros Koutrakis, Joel Schwartz, Antonella Zanobetti, Wenyuan LiAbstract:Acute exposure to cold dry air is a trigger of bronchoconstriction, but little is known about how daily Outdoor Temperature influences lung function. We investigated associations of Temperature from a model using satellite remote sensing data with repeated measures of lung function among 5896 participants of the Framingham Heart Study Offspring and Third Generation cohorts residing in the Northeastern US. We further tested if Temperature modified previously reported associations between pollution and lung function. We constructed linear mixed-effects models, and assessed departures from linearity using penalised splines. In fully adjusted linear models, 1-, 2- and 7-day average Temperatures were all associated with lower lung function: each 5°C higher previous-week Temperature was associated with a 20 mL lower (95% CI −34–−6) forced expiratory volume in 1 s. There was significant effect modification by season: negative associations of Temperature and lung function were present in winter and spring only. Negative associations between previous-day fine particulate matter and lung function were present during unseasonably warm but not unseasonably cool days, with a similar pattern for other pollutants. We speculate that Temperature-related differences in lung function may be explained by behavioural changes on relatively warm days, which may increase Outdoor exposures.
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lung function association with Outdoor Temperature and relative humidity and its interaction with air pollution in the elderly
Environmental Research, 2018Co-Authors: Petros Koutrakis, Joel Schwartz, David Sparrow, Pantel S Vokonas, Johanna Lepeule, Augusto A Litonjua, Antonio GasparriniAbstract:Abstract While the effects of weather variability on cardio-respiratory mortality are well described, research examining the effects on morbidity, especially for vulnerable populations, is warranted. We investigated the associations between lung function and Outdoor Temperature (T in Celsius degrees (°C)) and relative humidity (RH), in a cohort of elderly men, the Normative Aging Study. Our study included 1103 participants whose forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and weather exposures were assessed one to five times during the period 1995–2011 (i.e. 3162 observations). Temperature and relative humidity were measured at one location 4 h to 7 days before lung function tests. We used linear mixed-effects models to examine the associations with Outdoor T and RH. A 5-degree increase in the 3-day moving average T was associated with a significant 0.7% decrease (95%CI: −1.24, −0.20) in FVC and a 5% increase in the 7-day moving average RH was associated with a significant 0.2% decrease (95%CI: −0.40, −0.02) in FVC and FEV1. The associations with T were greater when combined with higher exposures of black carbon with a 1.6% decrease (95%CI −2.2; −0.9) in FVC and a 1% decrease (95%CI −1.7; −0.4) in FEV1. The relationships between T and RH and lung function were linear. No synergistic effect of T and RH was found. Heat and lung function are two predictors of mortality. Our findings suggest that increases in Temperature and relative humidity are related to decreases in lung function, and such observations might be amplified by high black carbon levels.
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ambient fine particulate matter Outdoor Temperature and risk of metabolic syndrome
American Journal of Epidemiology, 2017Co-Authors: Rachel Wallwork, Itai Kloog, Joel Schwartz, Pantel S Vokonas, Elena Colicino, Jia Zhong, Brent A Coull, Andrea BaccarelliAbstract:: Ambient air pollution and Temperature have been linked with cardiovascular morbidity and mortality. Metabolic syndrome and its components-abdominal obesity, elevated fasting blood glucose concentration, low high-density lipoprotein cholesterol concentration, hypertension, and hypertriglyceridemia-predict cardiovascular disease, but the environmental causes are understudied. In this study, we prospectively examined the long-term associations of air pollution, defined as particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (PM2.5), and Temperature with the development of metabolic syndrome and its components. Using covariate-adjustment Cox proportional hazards models, we estimated associations of mean annual PM2.5 concentration and Temperature with risk of incident metabolic dysfunctions between 1993 and 2011 in 587 elderly (mean = 70 (standard deviation, 7) years of age) male participants in the Normative Aging Study. A 1-μg/m3 increase in mean annual PM2.5 concentration was associated with a higher risk of developing metabolic syndrome (hazard ratio (HR) = 1.27, 95% confidence interval (CI): 1.06, 1.52), an elevated fasting blood glucose level (HR = 1.20, 95% CI: 1.03, 1.39), and hypertriglyceridemia (HR = 1.14, 95% CI: 1.00, 1.30). Our findings for metabolic syndrome and high fasting blood glucose remained significant for PM2.5 levels below the Environmental Protection Agency's health-safety limit (12 μg/m3). A 1°C increase in mean annual Temperature was associated with a higher risk of developing elevated fasting blood glucose (HR = 1.33, 95% CI: 1.14, 1.56). Men living in neighborhoods with worse air quality-with higher PM2.5 levels and/or Temperatures than average-showed increased risk of developing metabolic dysfunctions.
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the relationship between indoor and Outdoor Temperature apparent Temperature relative humidity and absolute humidity
Indoor Air, 2014Co-Authors: Jennifer Nguyen, Joel Schwartz, Douglas W. DockeryAbstract:Many studies report an association between Outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to Outdoor ambient weather. The average indoor Temperature, apparent Temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 to April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and Outdoor Temperatures is nonlinear. At warmer Outdoor Temperatures, there is a strong correlation between indoor and Outdoor Temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler Temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for Outdoor apparent Temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). Absolute humidity exhibited the strongest indoor-to-Outdoor correlation (r = 0.96, β = 0.69). Indoor and Outdoor Temperatures correlate well only at warmer Outdoor Temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with Outdoor AH year-round.
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relationship between Outdoor Temperature and blood pressure
Occupational and Environmental Medicine, 2011Co-Authors: Jaana I Halonen, Antonella Zanobetti, David Sparrow, Pantel S Vokonas, Joel SchwartzAbstract:Objectives Cardiovascular mortality has been linked to changes in Outdoor Temperature. However, the mechanisms behind these effects are not well established. We aimed to study the effect of Outdoor Temperature on blood pressure, as increased blood pressure is a risk factor for cardiovascular death. Methods The study population consisted of men aged 53e100 years living in the Boston area. We used a mixed effects model to estimate the effect of three Temperature variables: ambient, apparent and dew point Temperature (DPT), on repeated measures (every 3e5 years) of diastolic (DBP) and systolic blood pressure (SBP). Random intercepts for subjects and several possible confounders were used in the models, including black carbon and barometric pressure. Results We found modest associations between DBP and ambient and apparent Temperature. In the basic models, DBP in association with a 58C decrease in 7-day moving averages of Temperatures increased by 1.01% (95% CI � 0.06% to 2.09%) and 1.55% (95% CI 0.61% to 2.49%) for ambient and apparent Temperature, respectively. Excluding extreme Temperatures strengthened these associations (2.13%, 95% CI 0.66% to 3.63%, and 1.65%, 95% CI 0.41% to 2.90%, for ambient and apparent Temperature, respectively). Effect estimates for DPT were close to null. The effect of apparent Temperature on SBP was similar (1.30% increase (95% CI 0.32% to 2.29%) for a 58C decrease in 7-day moving average). Conclusions Cumulative exposure to decreasing ambient and apparent Temperature may increase blood pressure. These findings suggest that an increase in blood pressure could be a mechanism behind coldrelated, but not heat-related, cardiovascular mortality.
Zheng Bian - One of the best experts on this subject based on the ideXlab platform.
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The association of Outdoor Temperature with blood pressure, and its influence on future cardio-cerebrovascular disease risk in cold areas.
Journal of Hypertension, 2020Co-Authors: Bo Yu, Chi Wang, Xue Zhou, Zhen Tang, Qing Luan, Zheng BianAbstract:OBJECTIVES: To explore whether lower Outdoor Temperature increases cardio-cerebrovascular disease risk through regulating blood pressure and whether indoor heating in winter is beneficial to prevent cardio-cerebrovascular disease in cold areas. METHODS: We analyzed the data of 38 589 participants in Harbin from the China Kadoorie Biobank (CKB) during 2004-2008, with an average of 7.14-year follow-up. Linear regression analysis was performed to estimate the relationship between Outdoor Temperature and blood pressure. Cox regression analysis and logistic regression analysis were used to analyze the association of blood pressure with cardio-cerebrovascular event risk. Mediation analysis was performed to explore the role of blood pressure in the association between Outdoor Temperature and cardio-cerebrovascular events risk. RESULTS: There was an increase of 6.7 mmHg in SBP and 2.1 mmHg in DBP for each 10 °C decrease in Outdoor Temperature when Outdoor Temperature was higher than 5 °C. There was an inverse association between Outdoor Temperature and cardio-cerebrovascular event morbidity. The increases in blood pressure and cardio-cerebrovascular event morbidity were attenuated in months when central heating was fully provided. Participants with hypertension have higher risks of cardio-cerebrovascular disease (hazard ratio 1.347; 95% CI 1.281--1.415), CVD (hazard ratio 1.347; 95% CI 1.282--1.416), MACE (hazard ratio 1.670; 95% CI 1.560--1.788) and stroke (hazard ratio 1.683; 95% CI 1.571--1.803). Mediation analysis demonstrated that the association between Outdoor Temperature and cardio-cerebrovascular events risk was potentially mediated by blood pressure. CONCLUSION: Temperature-driven blood pressure potentially mediates the association between Outdoor Temperature and cardio-cerebrovascular events risk. Indoor heating in winter is probably beneficial to cardio-cerebrovascular disease prevention by inhibition of blood pressure increase.
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Outdoor Temperature blood pressure and cardiovascular disease mortality among 23 000 individuals with diagnosed cardiovascular diseases from china
European Heart Journal, 2015Co-Authors: Ling Yang, Zheng Bian, Sarah Lewington, Liming Li, Paul Sherliker, Rory Collins, R Peto, Rong Yang, Yongrui Zhang, Guangchun LiAbstract:Introduction Blood pressure is a major cause of cardiovascular disease (CVD) and both may increase as Outdoor Temperatures fall. However, there are still limited data about seasonal variation in blood pressure and CVD mortality among patients with prior-CVD. Methods We analysed data on 23 000 individuals with prior-CVD who were recruited from 10 diverse regions into the China Kadoorie Biobank during 2004–8. After 7 years of follow-up, 1484 CVD deaths were recorded. Baseline survey data were used to assess seasonal variation in systolic blood pressure (SBP) and its association with Outdoor Temperature. Cox regression was used to examine the association of usual SBP with subsequent CVD mortality, and seasonal variation in CVD mortality was assessed by Poisson regression. All analyses were adjusted for age, sex, and region. Results Mean SBP was significantly higher in winter than in summer (145 vs. 136 mmHg, P < 0.001), especially among those without central heating. Above 5°C, each 10°C lower Outdoor Temperature was associated with 6.2 mmHg higher SBP. Systolic blood pressure predicted subsequent CVD mortality, with each 10 mmHg higher usual SBP associated with 21% (95% confidence interval: 16–27%) increased risk. Cardiovascular disease mortality varied by season, with 41% (21–63%) higher risk in winter compared with summer. Conclusion Among adult Chinese with prior-CVD, there is both increased blood pressure and CVD mortality in winter. Careful monitoring and more aggressive blood pressure lowering treatment in the cold months are needed to help reduce the winter excess CVD mortality in high-risk individuals.
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season and Outdoor Temperature in relation to detection and control of hypertension in a large rural chinese population
International Journal of Epidemiology, 2014Co-Authors: Danting Su, Zheng Bian, Liming Li, Huaidong Du, Xinwei Zhang, Yijian Qian, Lingli Chen, Yaping Chen, Zhengming Chen, Min YuAbstract:Background: In many Western populations, blood pressure varies moderately with season and Outdoor Temperature. Relatively little is known about effects of seasonal changes in blood pressure on the detection and control of hypertension in general populations, especially in low- and middle-income countries. Methods: We analysed cross-sectional data of 57 375 (42% men) participants aged 30–79 (mean 52.3) years who were enrolled during 2004–08, as part of the China Kadoorie Biobank, from a rural county in the south-east costal Zhejiang Province. Analyses related daily mean Outdoor Temperature, obtained from local Meteorological Bureau, to mean systolic (SBP) and diastolic blood pressure (DBP), rate of newly detected hypertension and, among those with self-reported physician-diagnosed hypertension, rate of adequate blood pressure control, using multiple linear and logistic regression models. Results: The overall mean blood pressure was 135.9 mmHg for SBP and 80.5 mmHg for DBP. Daily Outdoor Temperature ranged between � 2.9 and 33.7 � C, with July being the hottest month (mean 29.4 � C) and January the coldest (mean 4.0 � C). Comparing January (the coldest month) with July (the warmest), the differences in the adjusted SBP/DBP were 19.2/7.7 mmHg. Each 10 � C lower ambient Temperature was associated with 6.9/2.9 mmHg
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seasonal variation in blood pressure and its relationship with Outdoor Temperature in 10 diverse regions of china the china kadoorie biobank
Journal of Hypertension, 2012Co-Authors: Sarah Lewington, Zheng Bian, Liming Li, Paul Sherliker, Iona Y Millwood, Gary Whitlock, Liuqing Yang, R Collins, Jingzhou Chen, Xianping WuAbstract:OBJECTIVES: Mean blood pressure varies moderately with Outdoor air Temperature in many western populations. Substantial uncertainty exists, however, about the strength of the relationship in other populations and its relevance to age, adiposity, medical treatment, climate and housing conditions. METHODS: To investigate the relationship of blood pressure with season and Outdoor Temperature, we analysed cross-sectional data from the China Kadoorie Biobank study of 506,673 adults aged 30-79 years recruited from 10 diverse urban and rural regions in China. Analyses related mean blood pressure - overall and in various subgroups - to mean local Outdoor Temperature. RESULTS: The mean difference in SBP between summer (June-August) and winter (December-February) was 10 mmHg overall, and was more extreme, on average, in rural than in urban areas (12 vs. 8 mmHg; P for interaction <0.0001). Above 5°C, SBP was strongly inversely associated with Outdoor Temperature in all 10 areas studied, with 5.7 (SE 0.04) mmHg higher SBP per 10°C lower Outdoor Temperature. The association was stronger in older people and in those with lower BMI. At lower Temperatures, there was no evidence of an association among participants who reported having central heating in their homes. CONCLUSION: Blood pressure was strongly inversely associated with Outdoor Temperature in Chinese adults across a range of climatic conditions, although access to home central heating appeared to remove much of the association during the winter months. Seasonal variation in blood pressure should be considered in the clinical management of hypertension.
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Seasonal variation in blood pressure and its relationship with Outdoor Temperature in 10 diverse regions of China: the China Kadoorie Biobank.
Journal of Hypertension, 2012Co-Authors: Sarah Lewington, Zheng Bian, Liming Li, Paul Sherliker, Iona Y Millwood, Gary Whitlock, Liuqing Yang, R Collins, Jingzhou ChenAbstract:OBJECTIVES: Mean blood pressure varies moderately with Outdoor air Temperature in many western populations. Substantial uncertainty exists, however, about the strength of the relationship in other populations and its relevance to age, adiposity, medical treatment, climate and housing conditions. METHODS: To investigate the relationship of blood pressure with season and Outdoor Temperature, we analysed cross-sectional data from the China Kadoorie Biobank study of 506,673 adults aged 30-79 years recruited from 10 diverse urban and rural regions in China. Analyses related mean blood pressure - overall and in various subgroups - to mean local Outdoor Temperature. RESULTS: The mean difference in SBP between summer (June-August) and winter (December-February) was 10 mmHg overall, and was more extreme, on average, in rural than in urban areas (12 vs. 8 mmHg; P for interaction
Mohamad Firdaus Basrawi - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Outdoor Temperature on the Performance of a Split-Unit Type Air Conditioner Using R22 Refrigerant
MATEC Web of Conferences, 2018Co-Authors: Mohd Hazwan Yusof, Sulaiman Mohd Muslim, Muhammad Fadhli Suhaimi, Mohamad Firdaus BasrawiAbstract:To maintain the Temperature setup on an air conditioner, the compressor will use more or less energy based on the Outdoor Temperature. Therefore, there is a need to understand the performance of the air conditioner if the Outdoor Temperature is varied. In this research, a used small capacity split-unit air conditioner using R-22 refrigerant is used to study the effect of Outdoor Temperature on the performance of the air conditioner. From the results, it can be understood that lower Outdoor Temperature requires less work from the compressor. The cooling capacity and coefficient of performance drop as the Outdoor Temperature increases.
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The Effect of Refrigerant Charge and Outdoor Temperature on the Condenser and Evaporator of a Split-Unit Type Air Conditioner Using R22 Refrigerant
MATEC Web of Conferences, 2018Co-Authors: Mohd Hazwan Yusof, Sulaiman Mohd Muslim, Muhammad Fadhli Suhaimi, Mohamad Firdaus BasrawiAbstract:To maintain the Temperature setup on an air conditioner, the compressor will use more or less energy based on the Outdoor Temperature. Therefore, there is a need to understand the performance of the air conditioner if the Outdoor Temperature is varied. In this research, a used small capacity split-unit air conditioner using R-22 refrigerant is used to study the effect of Outdoor Temperature on the performance of the air conditioner. From the results, it can be understood that lower Outdoor Temperature requires less work from the compressor. The cooling capacity and coefficient of performance drop as the Outdoor Temperature increases.
Diyu Yang - One of the best experts on this subject based on the ideXlab platform.
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indoor clothing insulation and thermal history a clothing model based on logistic function and running mean Outdoor Temperature
Building and Environment, 2018Co-Authors: Diyu Yang, Xiong Shen, Peizhi YangAbstract:Abstract Predicting the pattern of clothing adjustment to climate change can provide important basis for thermal comfort and energy consumption analysis. This study proposed a clothing model (IC-RM model) to predict indoor clothing insulation based on people's thermal history. In the IC-RM model, the running mean (RM) Outdoor Temperature (exponentially weighted running mean of the past Outdoor Temperatures) was used as the Outdoor climate index to reflect the thermal history. Different from the existing models, the IC-RM model adopted a four parameters logistic function to fit the relation between indoor clothing insulation and the RM Outdoor Temperature. A longitudinal thermal comfort survey (13 months) was conducted in two different types of naturally ventilated building in Changsha China. The decreased freedom of clothing adjustment at high/low Outdoor Temperatures and notable effects of the past Outdoor Temperatures on the indoor clothing insulation were observed. The IC-RM model was implemented using 1427 useful clothing records collected during the survey. The high R2 value (>0.9) for the IC-RM model indicated that the proposed model provides an effective method to quantify the change of indoor clothing insulation based on the effect of thermal history. Compared with linear, exponential and power functions, the logistic function exhibited better performance in quantifying the tendency for the variation in the indoor clothing insulation with the RM Outdoor Temperature.
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adjustments of the adaptive thermal comfort model based on the running mean Outdoor Temperature for chinese people a case study in changsha china
Building and Environment, 2017Co-Authors: Diyu Yang, Jing XiongAbstract:Abstract A method to develop an adaptive thermal comfort model based on the running mean Outdoor Temperature for Chinese people was proposed. The determination of two important parameters (neutral Temperature and Outdoor Temperature) in the adaptive thermal comfort model was the focus of this work. A longitudinal survey was conducted from Jan. 2010 to Feb. 2011 in two naturally ventilated office buildings located in Changsha, China. During the survey, the thermal sensation of the subjects was investigated, and the indoor Temperature was measured daily. Based on the field data, the neutral Temperature and the running mean Outdoor Temperature were determined. Further, an adaptive thermal comfort model was established by quantifying the relationship between the neutral Temperature and the running mean Outdoor Temperature. The results show that the adaptive thermal comfort model based on the running mean Outdoor Temperature can well reflect the change of neutral Temperature in the two office buildings with the climate of Changsha China. This study provides a reliable method to adjust the adaptive thermal comfort model based on the running mean Temperature for Chinese people.
Pantel S Vokonas - One of the best experts on this subject based on the ideXlab platform.
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lung function association with Outdoor Temperature and relative humidity and its interaction with air pollution in the elderly
Environmental Research, 2018Co-Authors: Petros Koutrakis, Joel Schwartz, David Sparrow, Pantel S Vokonas, Johanna Lepeule, Augusto A Litonjua, Antonio GasparriniAbstract:Abstract While the effects of weather variability on cardio-respiratory mortality are well described, research examining the effects on morbidity, especially for vulnerable populations, is warranted. We investigated the associations between lung function and Outdoor Temperature (T in Celsius degrees (°C)) and relative humidity (RH), in a cohort of elderly men, the Normative Aging Study. Our study included 1103 participants whose forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and weather exposures were assessed one to five times during the period 1995–2011 (i.e. 3162 observations). Temperature and relative humidity were measured at one location 4 h to 7 days before lung function tests. We used linear mixed-effects models to examine the associations with Outdoor T and RH. A 5-degree increase in the 3-day moving average T was associated with a significant 0.7% decrease (95%CI: −1.24, −0.20) in FVC and a 5% increase in the 7-day moving average RH was associated with a significant 0.2% decrease (95%CI: −0.40, −0.02) in FVC and FEV1. The associations with T were greater when combined with higher exposures of black carbon with a 1.6% decrease (95%CI −2.2; −0.9) in FVC and a 1% decrease (95%CI −1.7; −0.4) in FEV1. The relationships between T and RH and lung function were linear. No synergistic effect of T and RH was found. Heat and lung function are two predictors of mortality. Our findings suggest that increases in Temperature and relative humidity are related to decreases in lung function, and such observations might be amplified by high black carbon levels.
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ambient fine particulate matter Outdoor Temperature and risk of metabolic syndrome
American Journal of Epidemiology, 2017Co-Authors: Rachel Wallwork, Itai Kloog, Joel Schwartz, Pantel S Vokonas, Elena Colicino, Jia Zhong, Brent A Coull, Andrea BaccarelliAbstract:: Ambient air pollution and Temperature have been linked with cardiovascular morbidity and mortality. Metabolic syndrome and its components-abdominal obesity, elevated fasting blood glucose concentration, low high-density lipoprotein cholesterol concentration, hypertension, and hypertriglyceridemia-predict cardiovascular disease, but the environmental causes are understudied. In this study, we prospectively examined the long-term associations of air pollution, defined as particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (PM2.5), and Temperature with the development of metabolic syndrome and its components. Using covariate-adjustment Cox proportional hazards models, we estimated associations of mean annual PM2.5 concentration and Temperature with risk of incident metabolic dysfunctions between 1993 and 2011 in 587 elderly (mean = 70 (standard deviation, 7) years of age) male participants in the Normative Aging Study. A 1-μg/m3 increase in mean annual PM2.5 concentration was associated with a higher risk of developing metabolic syndrome (hazard ratio (HR) = 1.27, 95% confidence interval (CI): 1.06, 1.52), an elevated fasting blood glucose level (HR = 1.20, 95% CI: 1.03, 1.39), and hypertriglyceridemia (HR = 1.14, 95% CI: 1.00, 1.30). Our findings for metabolic syndrome and high fasting blood glucose remained significant for PM2.5 levels below the Environmental Protection Agency's health-safety limit (12 μg/m3). A 1°C increase in mean annual Temperature was associated with a higher risk of developing elevated fasting blood glucose (HR = 1.33, 95% CI: 1.14, 1.56). Men living in neighborhoods with worse air quality-with higher PM2.5 levels and/or Temperatures than average-showed increased risk of developing metabolic dysfunctions.
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relationship between Outdoor Temperature and blood pressure
Occupational and Environmental Medicine, 2011Co-Authors: Jaana I Halonen, Antonella Zanobetti, David Sparrow, Pantel S Vokonas, Joel SchwartzAbstract:Objectives Cardiovascular mortality has been linked to changes in Outdoor Temperature. However, the mechanisms behind these effects are not well established. We aimed to study the effect of Outdoor Temperature on blood pressure, as increased blood pressure is a risk factor for cardiovascular death. Methods The study population consisted of men aged 53e100 years living in the Boston area. We used a mixed effects model to estimate the effect of three Temperature variables: ambient, apparent and dew point Temperature (DPT), on repeated measures (every 3e5 years) of diastolic (DBP) and systolic blood pressure (SBP). Random intercepts for subjects and several possible confounders were used in the models, including black carbon and barometric pressure. Results We found modest associations between DBP and ambient and apparent Temperature. In the basic models, DBP in association with a 58C decrease in 7-day moving averages of Temperatures increased by 1.01% (95% CI � 0.06% to 2.09%) and 1.55% (95% CI 0.61% to 2.49%) for ambient and apparent Temperature, respectively. Excluding extreme Temperatures strengthened these associations (2.13%, 95% CI 0.66% to 3.63%, and 1.65%, 95% CI 0.41% to 2.90%, for ambient and apparent Temperature, respectively). Effect estimates for DPT were close to null. The effect of apparent Temperature on SBP was similar (1.30% increase (95% CI 0.32% to 2.29%) for a 58C decrease in 7-day moving average). Conclusions Cumulative exposure to decreasing ambient and apparent Temperature may increase blood pressure. These findings suggest that an increase in blood pressure could be a mechanism behind coldrelated, but not heat-related, cardiovascular mortality.
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Outdoor Temperature is associated with serum hdl and ldl
Environmental Research, 2011Co-Authors: Jaana I Halonen, Antonella Zanobetti, David Sparrow, Pantel S Vokonas, Joel SchwartzAbstract:Background While exposures to high and low air Temperatures are associated with cardiovascular mortality, the underlying mechanisms are poorly understood. The risk factors for cardiovascular disease include high levels of total cholesterol and low-density lipoprotein (LDL), and low levels of high-density lipoprotein (HDL). We investigated whether Temperature was associated with changes in circulating lipid levels, and whether this might explain part of the association with increased cardiovascular events.
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associations between Outdoor Temperature and markers of inflammation a cohort study
Environmental Health, 2010Co-Authors: Jaana I Halonen, Antonella Zanobetti, David Sparrow, Pantel S Vokonas, Joel SchwartzAbstract:Associations between ambient Temperature and cardiovascular mortality are well established. This study investigated whether inflammation could be part of the mechanism leading to Temperature-related cardiovascular deaths. The study population consisted of a cohort of 673 men with mean age of 74.6 years, living in the greater Boston area. They were seen for examination roughly every 4 years, and blood samples for inflammation marker analyses were drawn in 2000-2008 (total of 1254 visits). We used a mixed effects model to estimate the associations between ambient Temperature and a variety of inflammation markers (C-reactive protein, white blood cell count, soluble Vascular Cell Adhesion Molecule-1, soluble Intercellular Adhesion Molecule-1, tumor necrosis factor alpha, and interleukins -1β, -6 and -8). Random intercept for each subject and several possible confounders, including combustion-related air pollution and ozone, were used in the models. We found a 0 to 1 day lagged and up to 4 weeks cumulative responses in C-reactive protein in association with Temperature. We observed a 24.9% increase [95% Confidence interval (CI): 7.36, 45.2] in C-reactive protein for a 5°C decrease in the 4 weeks' moving average of Temperature. We observed similar associations also between Temperature and soluble Intercellular Adhesion Molecule-1 (4.52%, 95% CI: 1.05, 8.10, over 4 weeks' moving average), and between Temperature and soluble Vascular Cell Adhesion Molecule-1 (6.60%, 95% CI: 1.31, 12.2 over 4 weeks' moving average). Penalized spline models showed no deviation from linearity. There were no associations between Temperature and other inflammation markers. Cumulative exposure to decreased Temperature is associated with an increase in inflammation marker levels among elderly men. This suggests that inflammation markers are part of intermediate processes, which may lead to cold-, but not heat-, related cardiovascular deaths.
