Fibrinogen genes modify the fibrinogen response to ambient particulate matter.
BACKGROUND
Ambient particulate matter has been associated with systemic inflammation indicated by blood markers such as fibrinogen, implicated in promoting atherothrombosis.


OBJECTIVE
This study evaluated whether single-nucleotide polymorphisms (SNPs) within the fibrinogen genes modified the relationship between ambient particles and plasma fibrinogen.


METHODS
In 854 myocardial infarction survivors from five European cities plasma fibrinogen levels were determined repeatedly (n = 5,082). City-specific analyses were conducted to assess the impact of particulate matter on fibrinogen levels, applying additive mixed models adjusting for patient characteristics, time trend, and weather. City-specific estimates were pooled by meta-analysis methodology.


RESULTS
Seven SNPs in the FGA and FGB genes shown to be associated with differences in fibrinogen levels were selected. Promoter SNPs within FGA and FGB were associated with modifications of the relationship between 5-day averages of particulate matter with an aerodynamic diameter below 10 microm (PM(10)) and plasma fibrinogen levels. The PM(10)-fibrinogen relationship for subjects with the homozygous minor allele genotype of FGB rs1800790 compared with subjects homozygous for the major allele was eightfold higher (P value for the interaction, 0.037).


CONCLUSIONS
The data suggest that susceptibility to ambient particulate matter may be partly genetically determined by polymorphisms that alter early physiological responses such as transcription of fibrinogen. Subjects with variants of these frequent SNPs may have increased risks not only due to constitutionally higher fibrinogen concentrations, but also due to an augmented response to environmental inflammatory stimuli such as ambient particulate matter.
Peters
Annette
A
Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology, Ingolstaedter Landstrasse, Neuherberg 85764, Germany. peters@helmholtz-muenchen.de
Greven
Sonja
S
Heid
Iris M
IM
Baldari
Fiammetta
F
Breitner
Susanne
S
Bellander
Tom
T
Chrysohoou
Christina
C
Illig
Thomas
T
Jacquemin
Bénédicte
B
Koenig
Wolfgang
W
Lanki
Timo
T
Nyberg
Fredrik
F
Pekkanen
Juha
J
Pistelli
Riccardo
R
Rückerl
Regina
R
Stefanadis
Christodoulos
C
Schneider
Alexandra
A
Sunyer
Jordi
J
Wichmann
H Erich
HE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004781:Environmental Exposure / Q000009:adverse effects; D005060:Europe / Q000453:epidemiology; D005260:Female; D005340:Fibrinogen / Q000032:analysis* / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006720:Homozygote; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology; D052638:Particulate Matter; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D014505:Urban Population
D052638:Particulate Matter; D005340:Fibrinogen