Seasonal variation of effect of air pollution on blood pressure

Construction of a Composite Hospital Admission Index Using the Aggregated Weights of Criteria

“…However, there is some evidence that both cold and hot temperature for hospital admission vary by location. For example, several recent studies conducted in North America have found that hospital admission is generally higher in warm period as compared with the cool period (Peng et al 2005;Ren & Tong 2006a;Stafoggia et al 2008), while studies in Asian countries have provided inconsistent result; hospital admission increased in cool months (Chena et al 2010;Kan et al 2008;Liang et al 2009) and others have reported increment in warmer months (Choi et al 2007;Yi et al 2010).…”

Particulate Matter, Hypertension, and the Metabolic Syndrome

“…This possibly suggests that control of heart rate with a beta -blocker and/or conditions naturally associated with a low heart rate (e.g., low sympathetic ANS tone) are protective. More recently, two much larger studies by Choi et al (2007) in Incheon, South Korea ( n = 10,459) and by Auchincloss et al among 5112 participants of the Multi -Ethnic Study of Atherosclerosis (MESA) also reported positive fi ndings (Auchincloss et al, 2008 ). In the MESA cohort, the previous 30 -day PM 2.5 levels and metrics of traffi c exposure were most strongly associated with elevated systolic BP.…”

“…Eleven studies have reported positive fi ndings, while four have been negative (Linn et al, 1999 ;Brauer et al, 2001 ;Ibald -Mulli et al, 2001, 2004Zanobetti et al, 2004 ;Chuang et al, 2005 ;Santos et al, 2005 ;Harrabi et al, 2006 ;Madsen and Nafstad, 2006 ;Choi et al, 2007 ;Liu et al, 2007 ;McCracken et al, 2007 ;Auchincloss et al, 2008 ;Dvonch et al, 2009 ;Brook et al, 2010 ). However, it is important to emphasize that most of the published studies have been retrospective analyses of existing cohorts and were not designed with the explicit aim of evaluating the relationship between PM and BP.…”

“…One important biological mechanism contributing to these associations is an air pollution -mediated pro -hypertensive response (Brook, 2007 ). Epidemiological studies demonstrate that present -day levels of PM are capable of elevating arterial blood pressure (BP) within a period of a few days (Linn et al, 1999 ;Brauer et al, 2001 ;Ibald -Mulli et al, 2001, 2004Zanobetti et al, 2004 ;Chuang et al, 2005 ;Santos et al, 2005 ;Harrabi et al, 2006 ;Madsen and Nafstad, 2006 ;Choi et al, 2007 ;Liu et al, 2007 ;McCracken et al, 2007 ;Auchincloss et al, 2008 ;Dvonch et al, 2009 ;Brook et al, 2010 ). Controlled human and animal experiments have corroborated the veracity of this relationship under certain scenarios whereby BP can increase within only hours of exposure (Gong et al, 2003 ;Mills et al, 2005Mills et al, , 2007Mills et al, , 2008Urch et al, 2005 ;Dales et al, 2007 ;Br ä uner et al, 2008 ;Fang et al, 2008 ;Shah et al, 2008 ;Brook et al, 2009 ).…”

Winter Hypertension : Potential Mechanisms

“…[79] In another study , found a significant association between O 3 and blood pressure in the cold-weather season. [80] A number of biological mechanisms have been proposed to explain this association Exposure to air pollution has been shown to cause arterial vasoconstriction. [81] A study on the acute effect of inhaled urban air-pollution particles in the rat showed increased plasma levels of endothelin-1, which is thought to have an active role in the maintenance of basal systemic vascular tone.…”