TV watching modifies obesity risk linked to the 27Glu polymorphism of the ADRB2 gene in girls.
OBJECTIVE
A matched case-control study was conducted in a population of Spanish children and adolescents (5-18 years old), to assess the interaction between the Gln27Glu polymorphism of the ADRB2 and television (TV) watching on obesity risk.


METHODS
Obese (n=165) and control subjects (n=165) matched by sex and age were recruited and classified according to Spanish reference data. Results. Using conditional logistic regression, we calculated the obesity risk linked to the polymorphism. A statistically significant association was found for 27Glu carrier allele girls (OR = 1.95; 95% CI = 1.02-3.70), but no association was apparent among boys. In the fully adjusted model, the odds ratio for obesity linked to the genotype Glu27Glu in the female population rose to 4.84 (95% CI = 1.37-17.10). Moreover, we found a significant negative interaction between hours of TV watching and the Gln27Glu polymorphism for obesity risk in girls. Surprisingly, among 27Glu carrier subjects, even girls with a low level of TV watching ( < 12.5 h/week) had a high obesity risk (OR = 4.60; 95% CI = 1.01-20.02), which was not very different to the odds ratio values for sedentary girls carrying the 27 Glu allele watching TV more than 12.5 h/week (OR = 6.05; 95% CI = 1.31-27.71). Conclusion. A higher risk of obesity was found for girls carrying the 27Glu allele of the ADRB2 gene even when they spent less than 12.5 h/week watching TV. In addition, our results suggest that the effect of sedentary lifestyle on obesity risk may depend on the genotype of the subject.
Ochoa
M C
MC
Department of Physiology and Nutrition, University of Navarra, Pamplona, Spain.
Moreno-Aliaga
M J
MJ
Martínez-González
M A
MA
Martínez
J A
JA
Marti
A
A
D000293:Adolescent; D015992:Body Mass Index; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008019:Life Style; D016015:Logistic Models; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D016017:Odds Ratio; D010641:Phenotype; D011110:Polymorphism, Genetic; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics* / Q000378:metabolism; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D013690:Television / Q000706:statistics & numerical data*; D013997:Time Factors
D018343:Receptors, Adrenergic, beta-2