CT scanning-based phenotypes vary with ADRB2 polymorphisms in chronic obstructive pulmonary disease.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by varying degrees of involvement of airway and lung parenchyma. Although cigarette smoke is the major risk factor for COPD, the principal determining factors of involvement of the airway or lung parenchyma have not been clearly defined. Genetic variability in COPD patients might influence the varying degrees of involvement of airway and parenchyma. We therefore studied whether airway and parenchyma involvement might be associated with the ADRB2 genotype, which has been reported to be associated with COPD susceptibility and the bronchodilator response.


METHODS
One hundred and eleven COPD subjects, whose post-bronchodilator FEV(1)/FVC values were less than 0.7, and who had histories of smoking exceeding 10 pack-years, were prospectively recruited from pulmonology clinics of 11 hospitals in Seoul, Korea. The degrees of involvement of airway and parenchyma were evaluated by volumetric computed tomography (CT) scans. In-house software automatically calculated luminal areas, airway wall areas, percentages of wall areas in segmental bronchi, emphysema indices, and mean lung densities in the whole lung parenchyma. The ADRB2 genotypes at codon 16 were determined for all patients.


RESULTS
Gly16 was associated with lumen diameter, luminal area, and percentage of wall area in patients with COPD (p=0.02), whereas neither wall area nor wall thickness differed with ADRB2 genotype. Neither emphysema index nor mean lung density was associated with ADRB2 genotype.


CONCLUSIONS
Gly16 variant in ADRB2 gene was associated with airway wall phenotypes measured using CT scanning in COPD patients.
Kim
Woo Jin
WJ
Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, South Korea.
Oh
Yeon-Mok
YM
Sung
Joohon
J
Lee
Young Kyung
YK
Seo
Joon Beom
JB
Kim
NamKug
N
Kim
Tae-Hyung
TH
Huh
Jin Won
JW
Lee
Ji-Hyun
JH
Kim
Eun-Kyung
EK
Lee
Jin Hwa
JH
Lee
Sang-Min
SM
Lee
Sangyeub
S
Lim
Seong Yong
SY
Shin
Tae Rim
TR
Yoon
Ho Il
HI
Kwon
Sung-Youn
SY
Lee
Sang Do
SD
D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005541:Forced Expiratory Volume; D005838:Genotype; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000503:physiopathology; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D012306:Risk; D012907:Smoking / Q000473:pathology; D014057:Tomography, X-Ray Computed
D018343:Receptors, Adrenergic, beta-2