Prenatal Particulate Matter/Tobacco Smoke Increases Infants' Respiratory Infections: COCOA Study.
OBJECTIVE
To investigate whether prenatal exposure to indoor fine particulate matter (PM₂.₅) and environmental tobacco smoke (ETS) affects susceptibility to respiratory tract infections (RTIs) in infancy, to compare their effects between prenatal and postnatal exposure, and to determine whether genetic factors modify these environmental effects.


METHODS
The study population consisted of 307 birth cohort infants. A diagnosis of RTIs was based on parental report of a physician's diagnosis. Indoor PM₂.₅ and ETS levels were measured during pregnancy and infancy. TaqMan was used for genotyping of nuclear factor erythroid 2-related factor (Nrf2) (rs6726395), glutathione-S-transferase-pi (GSTP) 1 (rs1695), and glutathione-S-transferase-mu (GSTM) 1. Microarrays were used for genome-wide methylation analysis.


RESULTS
Prenatal exposure to indoor PM₂.₅ increased the susceptibility of lower RTIs (LRTIs) in infancy (adjusted odds ratio [aOR]=2.11). In terms of combined exposure to both indoor PM₂.₅ and ETS, prenatal exposure to both pollutants increased susceptibility to LRTIs (aOR=6.56); however, this association was not found for postnatal exposure. The Nrf2 GG (aOR=23.69), GSTM1 null (aOR=8.18), and GSTP1 AG or GG (aOR=7.37) genotypes increased the combined LRTIs-promoting effects of prenatal exposure to the 2 indoor pollutants. Such effects of prenatal indoor PM₂.₅ and ETS exposure were not found for upper RTIs.


CONCLUSIONS
Prenatal exposure to both indoor PM₂.₅ and ETS may increase susceptibility to LRTIs. This effect can be modified by polymorphisms in reactive oxygen species-related genes.
Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
Song I
SI
Yang
Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Byoung Ju
BJ
Kim
Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
So Yeon
SY
Lee
Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
Hyo Bin
HB
Kim
Institute of Environmental and Industrial Medicine, Hanyang University, Seoul, Korea.
Cheol Min
CM
Lee
Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Jinho
J
Yu
Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Mi Jin
MJ
Kang
Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Ho Sung
HS
Yu
Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Eun
E
Lee
Department of Pediatrics, Bundang CHA Medical Center, CHA University School of Medicine, Seongnam, Korea.
Young Ho
YH
Jung
Department of Pediatrics, Pusan National University Yangsan Hospital, Yangsan, Korea.
Hyung Young
HY
Kim
Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea.
Ju Hee
JH
Seo
Department of Pediatrics, Seoul National University Bundang Hospital, Seungnam, Korea.
Ji Won
JW
Kwon
Department of Pediatrics, College of Medicine, Korea University, Seoul, Korea.
Dae Jin
DJ
Song
Department of Pediatrics, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea.
Gwangcheon
G
Jang
Department of Pediatrics and the Allergy and Respiratory Research Laboratory, Inje University Seoul Paik Hospital, Seoul, Korea.
Woo Kyung
WK
Kim
Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
Jung Yeon
JY
Shim
Department of Pediatrics, Ajou University School of Medicine, Suwon, Korea.
Soo Young
SY
Lee
Department of Pediatrics, Soonchunhyang University College of Medicine, Seoul, Korea.
Hyeon Jong
HJ
Yang
Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
Dong In
DI
Suh
Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Seo Ah
SA
Hong
Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Kil Yong
KY
Choi
Department of Pediatrics, Gangnam CHA Medical Center, CHA University College of Medicine, Seoul, Korea.
Youn Ho
YH
Shin
Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Kangmo
K
Ahn
Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
Kyung Won
KW
Kim
Division of Allergy and Chronic Respiratory diseases, Center for of Biomedical Sciences, Korea National Institute of Health, Korea Centers for Disease Control and Prevention, Osong, Korea.
Eun Jin
EJ
Kim
Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. sjhong@amc.seoul.kr.
Soo Jong
SJ
Hong
Prenatal exposure; methylation; particulate matter; polymorphism; respiratory tract infections; tobacco smoke