title: Postprandial plasma lipid levels are influenced by the interaction of functional polymorphisms in the microsome triglyceride transfer protein and beta3 adrenergic receptor genes.
abstract: BACKGROUND
  The effects of polymorphisms in the genes encoding microsome triglycerides transfer protein (MTP) and beta3-adrenergic receptor (beta3-AR) on lipid and glucose metabolism were investigated.
  
  
  METHODS
  Clinical phenotypes related to lipid and glucose metabolism were evaluated during dietary loading (17 g of fat, 750 Cal) and glucose loading (75 g glucose). MTP and beta3-AR genotypes were determined by restriction fragment length polymorphism.
  
  
  RESULTS
  Subjects with the Arg64 beta3-AR gene (Arg+) polymorphism showed significantly higher fasting (FTG) and postprandial (PTG) triglyceride levels, fasting plasma glucose (FPG), fasting plasma immuno-reactive insulin (FIRI) and HOMA-R in comparison with Trp64 homozygotes. Subjects with the T allele (T +) of MTP -164T/G polymorphism (with T allele) showed significantly lower levels of FPG, FIRI, HOMA-R and PTG than did subjects without the T allele (T-). To evaluate the interaction of the polymorphisms, we divided our subjects into four groups. T-/Arg-, T-/Arg+, T+/Arg- and T+/Arg+. In these four groups, only T-/Arg+ showed significantly higher PTG levels. Plasma glucose levels were significantly higher at 60 and 120 min after oral glucose loading in in the T-/Arg+ subjects.
  
  
  CONCLUSIONS
  In this study, we identified an example of genotypic interactions that influence the clinical phenotype in multi-factorial diseases.
authors.affiliation: Department of Medicine, Division of Nephrology and Endocrinology, Nihon University School of Medicine, Tokyo, Japan. tueno@med.nihon-u.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ueno
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Taro
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsunemi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Tahira
authors.forename: Noboru
authors.initials: N
authors.lastname: Fukuda
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Soma
authors.forename: Koichi
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D011110:Polymorphism, Genetic; D019518:Postprandial Period; D051381:Rats; D022702:Receptors, Adrenergic, beta-3 / Q000235:genetics* / Q000378:metabolism; D014280:Triglycerides / Q000097:blood*
chemical_list: D002352:Carrier Proteins; D022702:Receptors, Adrenergic, beta-3; D014280:Triglycerides; C106092:microsomal triglyceride transfer protein; D005947:Glucose