A prospective study on symptom generation according to spicy food intake and TRPV1 genotypes in functional dyspepsia patients.
BACKGROUND
Capsaicin is an ingredient of red peppers that binds to transient receptor potential vanilloid subtype 1 (TRPV1), and Koreans eat more capsaicin-rich food than do Japanese. This study aimed to compare symptom generation according to TRPV1 genotypes and the intake of spicy foods.


METHODS
Consecutive functional dyspepsia (FD) patients who were evaluated at Konkuk University Medical Centre (Korea) and Keio University Hospital (Japan) were included. Questionnaires on spicy food intake, patient assessment of gastrointestinal symptoms (PAGI-SYM), patient assessment of quality of life, and hospital anxiety and depression scale were provided. Blood was sampled for the detection of TRPV1 polymorphisms, and upper gastrointestinal endoscopy was performed with biopsies.


RESULTS
Of 121 included subjects, 35 and 28 carried the TRPV1 CC and GG genotypes, respectively, with the prevalence rates not differing between Japan and Korea. The prevalence of FD subtypes did not differ with the spicy food intake, TRPV1 genotypes, or Helicobacter pylori infection. Neither TRPV1 polymorphisms nor H. pylori infections were related to scores on the PAGI-SYM questionnaires, but spicy food intake was positively correlated with the scores for stomach fullness (p = 0.001) and retching (p = 0.001). Using the linear regression analysis, stomach fullness was associated with spicy food intake (p = 0.007), whereas retching was related to younger age (p < 0.001) and female gender (p = 0.014).


CONCLUSIONS
Upper gastrointestinal symptoms are more common in subjects with a higher consumption of spicy foods, younger age and female gender, regardless of TRPV1 genotypes and the H. pylori infection status. Capsaicin-rich foods may induce stomach fullness.
Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
S-Y
SY
Lee
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
T
T
Masaoka
Department of Pathology, Konkuk University School of Medicine, Seoul, Korea.
H S
HS
Han
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
J
J
Matsuzaki
Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
M J
MJ
Hong
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
S
S
Fukuhara
Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
H S
HS
Choi
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.|Medical Education Center, Keio University School of Medicine, Tokyo, Japan.
H
H
Suzuki
D000328:Adult; D000367:Age Factors; D000368:Aged; D002211:Capsaicin; D004415:Dyspepsia / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D005260:Female; D005502:Food; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications* / Q000503:physiopathology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D012737:Sex Factors; D063189:Symptom Assessment; D050916:TRPV Cation Channels / Q000235:genetics*; D055815:Young Adult
D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D002211:Capsaicin
Capsaicin; Functional dyspepsia; Helicobacter pylori; TRPV1