title: Physical activity, diet, and incident diabetes in relation to an ADRA2B polymorphism.
abstract: OBJECTIVE
  The 12Glu9 polymorphism of the alpha2B-adrenergic receptor gene may impair insulin secretion and modify the effects of a lifestyle intervention on the risk of type 2 diabetes, but the interaction with specific lifestyle components is unknown. We assessed the associations of leisure-time physical activity (LTPA), dietary changes, and weight loss on the risk of type 2 diabetes according to the 12Glu9 polymorphism in 481 participants of the Finnish Diabetes Prevention Study.
  
  
  RESULTS
  The lifestyle intervention decreased the risk of diabetes in 9Glu carriers (9Glu9, intervention vs control, relative risk (RR) = 0.23, 95% confidence interval (CI) 0.09-0.62), but not in 12Glu12 homozygotes. In the combined intervention and control groups, increased total LTPA as estimated with a questionnaire decreased the risk of diabetes in 12Glu carriers (12Glu12, upper vs lower third, RR = 0.12, 95% CI 0.03-0.53) but not in 9Glu9 homozygotes (P for the interaction 0.033). In contrast, favorable dietary changes, estimated using a dietary score, reduced the risk of diabetes in those with the 9Glu9 genotype (upper vs lower third, RR = 0.21, 95% CI 0.06-0.75) but not in those with the 12Glu allele. Weight loss significantly decreased the risk of diabetes only in 12Glu carriers.
  
  
  CONCLUSIONS
  Increased LTPA decreased the risk of type 2 diabetes more in those with the 12Glu allele of the ADRA2B gene, whereas dietary changes may have mediated the greater risk reduction of the lifestyle intervention in 9Glu homozygotes.
authors.affiliation: Department of Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: David E
authors.initials: DE
authors.lastname: Laaksonen
authors.forename: Niina
authors.initials: N
authors.lastname: Siitonen
authors.forename: Jaana
authors.initials: J
authors.lastname: Lindström
authors.forename: Johan G
authors.initials: JG
authors.lastname: Eriksson
authors.forename: Piritta
authors.initials: P
authors.lastname: Reunanen
authors.forename: Jaakko
authors.initials: J
authors.lastname: Tuomilehto
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
mesh_terms: D000483:Alleles; D001530:Belgium; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000235:genetics* / Q000517:prevention & control; D004032:Diet; D005260:Female; D015438:Health Behavior; D006801:Humans; D015994:Incidence; D007899:Leisure Activities; D008019:Life Style; D008297:Male; D009043:Motor Activity; D009752:Nutritional Status; D011110:Polymorphism, Genetic; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics*; D012306:Risk; D012307:Risk Factors
chemical_list: D018341:Receptors, Adrenergic, alpha-2