Modification of additive effect between vitamins and ETS on childhood asthma risk according to GSTP1 polymorphism: a cross -sectional study.
BACKGROUND
Asthma is characterized by airway inflammation, and bronchial airways are particularly susceptible to oxidant-induced tissue damage.


OBJECTIVE
To investigate the effect of dietary antioxidant intake and environmental tobacco smoke (ETS) on the risk of childhood asthma according to genotypes susceptible to airway diseases.


METHODS
This cross-sectional study included 1124 elementary school children aged 7-12 years old. Asthma symptoms and smoking history were measured using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Intake of vitamin A (including retinol and β-carotene), C, and E was measured by a semi-quantitative food frequency questionnaire (FFQ). GSTP1 polymorphisms were genotyped from peripheral blood samples.


RESULTS
ETS was significantly associated with presence of asthma symptoms (adjusted odds ratio [aOR], 2.48; 95 % confidence interval [CI], 1.29-4.76) and diagnosis (aOR, 1.91; 95 % CI, 1.19-3.06). Dietary antioxidant intake was not associated with asthma symptoms, although ETS plus low vitamin A intake showed a significant positive association with asthma diagnosis (aOR, 2.23; 95 % CI, 1.10-4.54). Children with AA at nucleotide 1695 in GSTP1 who had been exposed to ETS and a low vitamin A intake have an increased risk of asthma diagnosis (aOR, 4.44; 95 % CI,1.58-12.52) compared with children who had not been exposed to the two risk factors. However, ETS exposure and low vitamin A intake did not significantly increase odds of asthma diagnosis in children with AG or GG genotypes.


CONCLUSIONS
Low vitamin A intake and ETS exposure may increase oxidative stress and thereby risk for childhood asthma. These relationships may be modified by gene susceptibility alleles of GSTP1.
Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, 39, Gwanpyeong-ro 138 beon-gil, Dongan-gu, Anyang, Gyeonggido, 431-828, South Korea. imipenem@hanmail.net.
So-Yeon
SY
Lee
Department of Pediatrics, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, South Korea. bskped@hanmail.net.
Bong-Seong
BS
Kim
Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, South Korea. kamelon@hanmail.net.
Sung-Ok
SO
Kwon
Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, South Korea. seyoung@khu.ac.kr.
Se-Young
SY
Oh
Research Center for Standardization of Allergic Diseases, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, South Korea. ysb1126@hanmail.net.
Hye Lim
HL
Shin
Department of Pediatrics, CHA Bundang Medical Center, CHA University School of Medicine, Yatap-dong Bundang-gu, Seongnam, Gyeonggido, 463-712, South Korea. youngdr1@naver.com.
Young-Ho
YH
Jung
Department of Pediatrics, Childhood Asthma Atopy Center, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea. unelee@hanmail.net.
Eun
E
Lee
Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, 39, Gwanpyeong-ro 138 beon-gil, Dongan-gu, Anyang, Gyeonggido, 431-828, South Korea. qjtjt222@naver.com.
Song-I
SI
Yang
Department of Pediatrics, Kosin University Gospel Hospital, Busan, South Korea. hawmok77@hanmail.net.
Hyung Young
HY
Kim
Department of Pediatrics, Korea Cancer Center Hospital, Seoul, South Korea. juheesea@hanmail.net.
Ju-Hee
JH
Seo
Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, South Korea. hbkim1126@naver.com.
Hyo-Bin
HB
Kim
Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, South Korea. pedas@naver.com.
Ji-Won
JW
Kwon
Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, 39, Gwanpyeong-ro 138 beon-gil, Dongan-gu, Anyang, Gyeonggido, 431-828, South Korea. drran@hallym.or.kr.
Hae-Ran
HR
Lee
Department of Pediatrics, Childhood Asthma Atopy Center, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea. sjhong@amc.seoul.kr.
Soo-Jong
SJ
Hong
D001205:Ascorbic Acid; D001249:Asthma / Q000453:epidemiology* / Q000235:genetics; D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data*; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D051549:Glutathione S-Transferase pi / Q000235:genetics*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*; D014801:Vitamin A; D014810:Vitamin E; D014815:Vitamins; D019207:beta Carotene
D014028:Tobacco Smoke Pollution; D014815:Vitamins; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D001205:Ascorbic Acid