title: Ambient temperature and cardiovascular biomarkers in a repeated-measure study in healthy adults: A novel biomarker index approach.
abstract: Associations of ambient temperature with cardiovascular morbidity and mortality have been well documented in numerous epidemiological studies, but the underlying pathways remain unclear. We investigated whether systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function may be the mechanistic pathways associated with ambient temperature.
  
  
  
  Forty study participants underwent repeated blood collections for 12 times in Beijing, China in 2010-2011. Ambient temperature and air pollution data were measured in central monitors close to student residences. We created five indices as the sum of weighted biomarker percentiles to represent the overall levels of 15 cardiovascular biomarkers in five pathways (systemic inflammation: hs-CRP, TNF-α and fibrinogen; coagulation: fibrinogen, PAI-1, tPA, vWF and sP-selectin; systemic oxidative stress: Ox-LDL and sCD36: antioxidant activity: EC-SOD and GPX1; and endothelial function: ET-1, E-selectin, ICAM-1 and VCAM-1). We used generalized mixed-effects models to estimate temperature effects controlling for air pollution and other covariates.
  
  
  
  There were significant decreasing trends in the adjusted means of biomarker indices over the lowest to the highest quartiles of daily temperatures before blood collection. A 10°C decrease at 2-d average daily temperature were associated with increases of 2.5% [95% confidence interval (CI): 0.7, 4.2], 1.6% (95% CI: 0.1, 3.1), 2.7% (95% CI: 0.5, 4.8), 5.5% (95% CI: 3.8, 7.3) and 2.0% (95% CI: 0.3, 3.8) in the indices for systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function, respectively. In contrast, the associations between ambient temperature and individual biomarkers had substantial variation in magnitude and strength.
  
  
  
  The altered cardiovascular biomarker profiles in healthy adults associated with ambient temperature changes may help explain the temperature-related cardiovascular morbidity and mortality. The biomarker index approach may serve as a novel tool to capture ambient temperature effects.
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Shaowei
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Di
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Pan
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Shan
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Wei
authors.affiliation: Institute of Reproductive & Child Health, School of Public Health, Peking University, Beijing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Baccarelli
authors.affiliation: Department of Public Health, Hyogo College of Medicine, Hyogo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shima
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China. Electronic address: lotus321321@126.com.
authors.forename: Furong
authors.initials: F
authors.lastname: Deng
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, No. 38 Xueyuan Road, Beijing, China. Electronic address: guoxb@bjmu.edu.cn.
authors.forename: Xinbiao
authors.initials: X
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000975:Antioxidants / Q000378:metabolism; D000068476:Beijing / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology* / Q000401:mortality; D004781:Environmental Exposure; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000453:epidemiology / Q000401:mortality; D008297:Male; D009017:Morbidity; D018384:Oxidative Stress; D013696:Temperature; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers
keywords: Cardiovascular health; Coagulation; Endothelial function; Inflammation; Oxidative stress; Temperature