title: Homozygous TRPV1 315C influences the susceptibility to functional dyspepsia.
abstract: OBJECTIVE
  Capsaicin/vanilloid (transient receptor potential vanilloid 1, (TRPV1) receptor has been shown to be expressed in gastrointestinal tract and play a role as a member of sensory ion channel superfamily. The G315C polymorphism affects the TRPV1 gene and alters its protein level. We aimed to investigate the effect of TRPV1 G315C polymorphism on functional dyspepsia (FD) in a Japanese population.
  
  
  METHODS
  TRPV1 G315C polymorphism was genotyped in 98 subjects with no upper abdominal symptoms and 109 patients with FD. Severity of 7 upper gastrointestinal symptoms was assessed during cold water, and cold carbonated water drinking for randomly selected 20 healthy subjects.
  
  
  RESULTS
  We found a significant inverse association between TRPV1 315CC genotype and FD [CC vs. others; odds ratio (OR)=0.40, 95% confidence interval (CI)=0.38-0.82]. We also found that the same genotype held a lower risk of both epigastric pain syndrome (OR=0.25, 95% CI=0.09-0.73), postprandial syndrome (OR=0.27, 95% CI=0.07-0.96) according to Rome III, and Helicobacter pylori positive FD (OR=0.28, 95% CI=0.10-0.79). The evolution of symptom severity scale of 7 total symptoms (P=0.004), and heavy feeling in stomach (P=0.02) during cold carbonated water drinking were significantly lower among 315CC genotypes compared with others.
  
  
  CONCLUSIONS
  Homozygous TRPV1 315C influences the susceptibility to FD through altering the upper gastrointestinal sensation.
authors.affiliation: Department of Gastroenterology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan. tomomiccyu@yahoo.co.jp
authors.forename: Tomomitsu
authors.initials: T
authors.lastname: Tahara
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shibata
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yoshioka
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hirata
authors.forename: Tomiyasu
authors.initials: T
authors.lastname: Arisawa
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D004326:Drinking; D004415:Dyspepsia / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics; D016480:Helicobacter pylori / Q000302:isolation & purification; D006720:Homozygote; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D019518:Postprandial Period; D011446:Prospective Studies; D012720:Severity of Illness Index; D050916:TRPV Cation Channels / Q000235:genetics*; D055815:Young Adult
chemical_list: D050916:TRPV Cation Channels; C494482:TRPV1 protein, human