Rg. Barr et al., beta(2)-Adrenoceptor polymorphism and body mass index are associated with adult-onset asthma in sedentary but not active women, CHEST, 120(5), 2001, pp. 1474-1479
Citations number
30
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Study objective: beta (2)-Adrenoceptor Gly16 polymorphism has been associat
ed with asthma severity and beta (2)-adrenoceptor receptor downregulation,
but not with the diagnosis of asthma. Glu27 polymorphism may limit beta (2)
-adrenoceptor downregulation and predict body mass index (BMI), particularl
y among sedentary persons. In addition, BMI predicts asthma. We hypothesize
d that these DNA sequence variants predict adult-onset asthma only in seden
tary women.
Design: Nested case-control study.
Setting: Nurses' Health Study, a large, prospective cohort study with parti
cipants throughout the United States.
Participants: Among lifelong nonsmokers, 171 women with adult-onset, medica
tion-requiring asthma and 137 age-matched control subjects.
Measurements: Physical activity and BMI were self-reported by previously va
lidated questionnaire items. Genomic DNA was obtained from buccal brushings
collected via first-class mail.
Results: Of 76 sedentary women, the adjusted odds ratios of Gly16 allele we
re 7.4 (p=0.047) for asthma and 13.8 (p=0.02) for steroid-requiring asthma.
No similar associations were observed among 232 active women (p=0.91). Sed
entary individuals with both Gly16 and Glu27 alleles had a less elevated ri
sk for asthma. BMI was associated with asthma and Glu27 allele among sedent
ary women.
Conclusion: This exploratory analysis suggests an important gene/environmen
t interaction for asthma involving physical activity level. Further study i
n larger populations is warranted to confirm if sedentary lifestyle unmasks
a genetic risk for asthma.