Indoor particles affect vascular function in the aged: an air filtration-based intervention study.
BACKGROUND
Exposure to particulate matter is associated with risk of cardiovascular events, possibly through endothelial dysfunction, and indoor air may be most important.


OBJECTIVE
We investigated effects of controlled exposure to indoor air particles on microvascular function (MVF) as the primary endpoint and biomarkers of inflammation and oxidative stress as secondary endpoints in a healthy elderly population.


METHODS
A total of 21 nonsmoking couples participated in a randomized, double-blind, crossover study with two consecutive 48-hour exposures to either particle-filtered or nonfiltered air (2,533-4,058 and 7,718-12,988 particles/cm(3), respectively) in their homes.


RESULTS
MVF was assessed noninvasively by measuring digital peripheral artery tone after arm ischemia. Secondary endpoints included hemoglobin, red blood cells, platelet count, coagulation factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F(2alpha), and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence interval, 0.4-16.3%), and the particulate matter (diameter < 2.5 mum) mass of the indoor particles was more important than the total number concentration (10-700 nm) for these effects. MVF was significantly associated with personal exposure to iron, potassium, copper, zinc, arsenic, and lead in the fine fraction. After Bonferroni correction, none of the secondary biomarkers changed significantly.


CONCLUSIONS
Reduction of particle exposure by filtration of recirculated indoor air for only 48 hours improved MVF in healthy elderly citizens, suggesting that this may be a feasible way of reducing the risk of cardiovascular disease.
Bräuner
Elvira Vaclavik
EV
D. Institute of Public Health, Department of Environmental and Occupational Health, Øster Farimagsgade 5A, DK-1014 Copenhagen K, Denmark.
Forchhammer
Lykke
L
Møller
Peter
P
Barregard
Lars
L
Gunnarsen
Lars
L
Afshari
Alireza
A
Wåhlin
Peter
P
Glasius
Marianne
M
Dragsted
Lars Ove
LO
Basu
Samar
S
Raaschou-Nielsen
Ole
O
Loft
Steffen
S
D000280:Administration, Inhalation; D000367:Age Factors; D000368:Aged; D016902:Air Pollution, Indoor / Q000032:analysis / Q000517:prevention & control*; D050197:Atherosclerosis / Q000097:blood / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D016001:Confidence Intervals; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004784:Environmental Monitoring; D005260:Female; D005374:Filtration / Q000379:methods; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D019570:Inhalation Exposure; D008297:Male; D008851:Micropore Filters; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis; D018384:Oxidative Stress; D052638:Particulate Matter / Q000633:toxicity*; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014657:Vasculitis / Q000097:blood / Q000209:etiology / Q000517:prevention & control*
D018836:Inflammation Mediators; D052638:Particulate Matter; D009585:Nitrogen Dioxide