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Controlled exposure to particulate matter from urban street air is associated with decreased vasodilation and heart rate variability in overweight and older adults.

Hemmingsen JG, Rissler J, Lykkesfeldt J, Sallsten G, Kristiansen J, Møller P P, Loft S - Part Fibre Toxicol (2015)

Bottom Line: Elderly and obese subjects may be particularly susceptible, although short-term effects are poorly described.Moreover, HRV measurements showed that the high and low frequency domains were significantly decreased and increased, respectively.Redox and inflammatory status did not change significantly based on the above measures.

View Article: PubMed Central - PubMed

Affiliation: Department of Public Health, Section of Environmental Health, Faculty of Health and Medical Sciences, University of Copenhagen, Øster Farimagsgade 5A, DK-1014, Copenhagen K, Denmark. jehe@sund.ku.dk.

ABSTRACT

Background: Exposure to particulate matter (PM) is generally associated with elevated risk of cardiovascular morbidity and mortality. Elderly and obese subjects may be particularly susceptible, although short-term effects are poorly described.

Methods: Sixty healthy subjects (25 males, 35 females, age 55 to 83 years, body mass index>25 kg/m2) were included in a cross-over study with 5 hours of exposure to particle- or sham-filtered air from a busy street using an exposure-chamber. The sham- versus particle-filtered air had average particle number concentrations of ~23.000 versus ~1800/cm3 and PM2.5 levels of 24 versus 3 μg/m3, respectively. The PM contained similar fractions of elemental and black carbon (~20-25%) in both exposure scenarios. Reactive hyperemia and nitroglycerin-induced vasodilation in finger arteries and heart rate variability (HRV) measured within 1 h after exposure were primary outcomes. Potential explanatory mechanistic variables included markers of oxidative stress (ascorbate/dehydroascorbate, nitric oxide-production cofactor tetrahydrobiopterin and its oxidation product dihydrobiopterin) and inflammation markers (C-reactive protein and leukocyte differential counts).

Results: Nitroglycerin-induced vasodilation was reduced by 12% [95% confidence interval: -22%; -1.0%] following PM exposure, whereas hyperemia-induced vasodilation was reduced by 5% [95% confidence interval: -11.6%; 1.6%]. Moreover, HRV measurements showed that the high and low frequency domains were significantly decreased and increased, respectively. Redox and inflammatory status did not change significantly based on the above measures.

Conclusions: This study indicates that exposure to real-life levels of PM from urban street air impairs the vasomotor function and HRV in overweight middle-aged and elderly adults, although this could not be explained by changes in inflammation, oxidative stress or nitric oxide-cofactors.

No MeSH data available.


Related in: MedlinePlus

Individual and median vasodilation induced by reactive hyperemia (n = 60) before and after and nitroglycerin (NTG) (n = 40) only after exposure to particle filtered air versus non-filtered air from an urban street in 60 middle-aged and elderly overweight subjects.
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Fig2: Individual and median vasodilation induced by reactive hyperemia (n = 60) before and after and nitroglycerin (NTG) (n = 40) only after exposure to particle filtered air versus non-filtered air from an urban street in 60 middle-aged and elderly overweight subjects.

Mentions: Vasodilation was measured as induced by reactive hyperemia (RHI: reactive hyperemia index) and an NO donor (NTG-I: nitroglycerin-induced vasodilation index), representing endothelium dependent and independent mechanisms, respectively (Figure 2). RHI was 5% (95% CI: −11.6; 1.6) lower after 5-h exposure to PM as compared with the response after filtered air although not being statistically significant (P = 0.128). However, the NTG-I was statistically significantly reduced by 12% (95% CI: −22; −1.0) after the exposure to PM from urban street air (P = 0.033), although only 40 participants had this measurement due to a history of possible migraine or limited availability of medical supervision.Figure 2


Controlled exposure to particulate matter from urban street air is associated with decreased vasodilation and heart rate variability in overweight and older adults.

Hemmingsen JG, Rissler J, Lykkesfeldt J, Sallsten G, Kristiansen J, Møller P P, Loft S - Part Fibre Toxicol (2015)

Individual and median vasodilation induced by reactive hyperemia (n = 60) before and after and nitroglycerin (NTG) (n = 40) only after exposure to particle filtered air versus non-filtered air from an urban street in 60 middle-aged and elderly overweight subjects.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4374502&req=5

Fig2: Individual and median vasodilation induced by reactive hyperemia (n = 60) before and after and nitroglycerin (NTG) (n = 40) only after exposure to particle filtered air versus non-filtered air from an urban street in 60 middle-aged and elderly overweight subjects.
Mentions: Vasodilation was measured as induced by reactive hyperemia (RHI: reactive hyperemia index) and an NO donor (NTG-I: nitroglycerin-induced vasodilation index), representing endothelium dependent and independent mechanisms, respectively (Figure 2). RHI was 5% (95% CI: −11.6; 1.6) lower after 5-h exposure to PM as compared with the response after filtered air although not being statistically significant (P = 0.128). However, the NTG-I was statistically significantly reduced by 12% (95% CI: −22; −1.0) after the exposure to PM from urban street air (P = 0.033), although only 40 participants had this measurement due to a history of possible migraine or limited availability of medical supervision.Figure 2

Bottom Line: Elderly and obese subjects may be particularly susceptible, although short-term effects are poorly described.Moreover, HRV measurements showed that the high and low frequency domains were significantly decreased and increased, respectively.Redox and inflammatory status did not change significantly based on the above measures.

View Article: PubMed Central - PubMed

Affiliation: Department of Public Health, Section of Environmental Health, Faculty of Health and Medical Sciences, University of Copenhagen, Øster Farimagsgade 5A, DK-1014, Copenhagen K, Denmark. jehe@sund.ku.dk.

ABSTRACT

Background: Exposure to particulate matter (PM) is generally associated with elevated risk of cardiovascular morbidity and mortality. Elderly and obese subjects may be particularly susceptible, although short-term effects are poorly described.

Methods: Sixty healthy subjects (25 males, 35 females, age 55 to 83 years, body mass index>25 kg/m2) were included in a cross-over study with 5 hours of exposure to particle- or sham-filtered air from a busy street using an exposure-chamber. The sham- versus particle-filtered air had average particle number concentrations of ~23.000 versus ~1800/cm3 and PM2.5 levels of 24 versus 3 μg/m3, respectively. The PM contained similar fractions of elemental and black carbon (~20-25%) in both exposure scenarios. Reactive hyperemia and nitroglycerin-induced vasodilation in finger arteries and heart rate variability (HRV) measured within 1 h after exposure were primary outcomes. Potential explanatory mechanistic variables included markers of oxidative stress (ascorbate/dehydroascorbate, nitric oxide-production cofactor tetrahydrobiopterin and its oxidation product dihydrobiopterin) and inflammation markers (C-reactive protein and leukocyte differential counts).

Results: Nitroglycerin-induced vasodilation was reduced by 12% [95% confidence interval: -22%; -1.0%] following PM exposure, whereas hyperemia-induced vasodilation was reduced by 5% [95% confidence interval: -11.6%; 1.6%]. Moreover, HRV measurements showed that the high and low frequency domains were significantly decreased and increased, respectively. Redox and inflammatory status did not change significantly based on the above measures.

Conclusions: This study indicates that exposure to real-life levels of PM from urban street air impairs the vasomotor function and HRV in overweight middle-aged and elderly adults, although this could not be explained by changes in inflammation, oxidative stress or nitric oxide-cofactors.

No MeSH data available.


Related in: MedlinePlus