Open AccessDNA Hypomethylation, Ambient Particulate Matter, and Increased Blood Pressure: Findings From Controlled Human Exposure Experiments
Author(s) -
Bellavia Andrea,
Urch Bruce,
Speck Mary,
Brook Robert D.,
Scott Jeremy A.,
Albetti Benedetta,
Behbod Behrooz,
North Michelle,
Valeri Linda,
Bertazzi Pier Alberto,
Silverman Frances,
Gold Diane,
A. Baccarelli Andrea
Publication year - 2013
Publication title -
journal of the american heart association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.494
H-Index - 85
ISSN - 2047-9980
DOI - 10.1161/jaha.113.000212
Subject(s) - medicine , blood pressure , methylation , dna methylation , particulates , diastole , endocrinology , gene expression , biology , gene , genetics , ecology
Background Short‐term exposures to fine (<2.5 μm aerodynamic diameter) ambient particulate‐matter ( PM ) have been related with increased blood pressure ( BP ) in controlled‐human exposure and community‐based studies. However, whether coarse (2.5 to 10 μm) PM exposure increases BP is uncertain. Recent observational studies have linked PM exposures with blood DNA hypomethylation, an epigenetic alteration that activates inflammatory and vascular responses. No experimental evidence is available to confirm those observational data and demonstrate the relations between PM , hypomethylation, and BP . Methods and Results We conducted a cross‐over trial of controlled‐human exposure to concentrated ambient particles ( CAP s). Fifteen healthy adult participants were exposed for 130 minutes to fine CAP s, coarse CAP s, or HEPA ‐filtered medical air (control) in randomized order with ≥2‐week washout. Repetitive‐element ( Alu , long interspersed nuclear element‐1 [ LINE ‐1]) and candidate‐gene ( TLR4 , IL‐12 , IL‐6 , iNOS ) blood methylation, systolic and diastolic BP were measured pre‐ and postexposure. After adjustment for multiple comparisons, fine CAP s exposure lowered Alu methylation (β‐standardized=−0.74, adjusted‐ P =0.03); coarse CAP s exposure lowered TLR4 methylation (β‐standardized=−0.27, adjusted‐ P =0.04). Both fine and coarse CAP s determined significantly increased systolic BP (β=2.53 mm Hg, P =0.001; β=1.56 mm Hg, P =0.03, respectively) and nonsignificantly increased diastolic BP (β=0.98 mm Hg, P =0.12; β=0.82 mm Hg, P =0.11, respectively). Decreased Alu and TLR4 methylation was associated with higher postexposure DBP (β‐standardized=0.41, P =0.04; and β‐standardized=0.84, P =0.02; respectively). Decreased TLR4 methylation was associated with higher postexposure SBP (β‐standardized=1.45, P =0.01). Conclusions Our findings provide novel evidence of effects of coarse PM on BP and confirm effects of fine PM . Our results provide the first experimental evidence of PM ‐induced DNA hypomethylation and its correlation to BP .