title: Tumor necrosis factor-beta gene NcoI polymorphism decreases insulin resistance in Japanese men.
abstract: Given that the NcoI polymorphism of the tumor necrosis factor-beta (TNF-beta) gene has been shown to be associated with tumor necrosis factor-alpha (TNF-alpha) secretory capacity, we know that this TNF-beta gene polymorphism may influence insulin resistance. In Caucasians, 2 polymorphisms of the TNF-alpha promoter region (positions -308 and -238) have been reported to be associated with insulin resistance. Thus, we investigated how genetic variation in the TNF-beta and TNF-alpha genes was associated with insulin resistance in 211 Japanese men. The frequency of the TNF-beta gene polymorphism was 0.41, and insulin resistance, estimated by homeostasis model assessment (HOMA), was significantly lower in variant homozygotes versus wild-type allele. The frequencies of the -308 and -238 polymorphisms were 0.01 and 0.02, respectively, and these polymorphisms were not associated with insulin resistance. Our results suggest that the TNF-beta gene polymorphism decreases insulin resistance, and that the -308 and -238 polymorphisms of the TNF-alpha promoter region are not a major contributing factor to insulin resistance in Japanese men.
authors.affiliation: First Department of Internal Medicine, School of Medicine, Kanazawa University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Nagai
authors.forename: M
authors.initials: M
authors.lastname: Taniguchi
authors.forename: H
authors.initials: H
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Takamura
authors.forename: T
authors.initials: T
authors.lastname: Abe
authors.forename: G
authors.initials: G
authors.lastname: Nomura
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D000368:Aged; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics; D006801:Humans; D006949:Hyperlipidemias / Q000235:genetics; D007333:Insulin Resistance / Q000235:genetics*; D007564:Japan; D008233:Lymphotoxin-alpha / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics; D011110:Polymorphism, Genetic
chemical_list: D008233:Lymphotoxin-alpha; C052380:endodeoxyribonuclease NcoI; D015252:Deoxyribonucleases, Type II Site-Specific