title: Effect of caffeine-containing beverage consumption on serum alanine aminotransferase levels in patients with chronic hepatitis C virus infection: a hospital-based cohort study.
abstract: BACKGROUND
  To date, there have been no prospective studies examining the effect of coffee consumption on serum alanine aminotransferase (ALT) level among individuals infected with the hepatitis C virus (HCV). We conducted a hospital-based cohort study among patients with chronic HCV infection to assess an association between baseline coffee consumption and subsequent ALT levels for 12 months.
  
  
  METHODS
  From 1 August 2005 to 31 July 2006, total 376 HCV-RNA positive patients were recruited. A baseline questionnaire elicited information on the frequency of coffee consumption and other caffeine-containing beverages. ALT level as a study outcome was followed through the patients' medical records during 12 months. The association between baseline beverage consumption and subsequent ALT levels was evaluated separately among patients with baseline ALT levels within normal range (≤45 IU/L) and among those with higher ALT levels (>45 IU/L).
  
  
  RESULTS
  Among 229 patients with baseline ALT levels within normal range, 186 (81%) retained normal ALT levels at 12 months after recruitment. Daily drinkers of filtered coffee were three times more likely to preserve a normal ALT level than non-drinkers (OR=2.74; P=0.037). However, decaffeinated coffee drinkers had a somewhat inverse effect for sustained normal ALT levels, with marginal significance (OR=0.26; P=0.076). In addition, among 147 patients with higher baseline ALT levels, 39 patients (27%) had ALT reductions of ≥20 IU/L at 12 months after recruitment. Daily drinkers of filtered coffee had a significantly increased OR for ALT reduction (OR=3.79; P=0.034). However, in decaffeinated coffee drinkers, OR could not be calculated because no patients had ALT reduction.
  
  
  CONCLUSIONS
  Among patients with chronic HCV infection, daily consumption of filtered coffee may have a beneficial effect on the stabilization of ALT levels.
authors.affiliation: Department of Gerontological Nursing, Graduate School of Nursing, Osaka City University, Osaka, Japan ; Department of Public Health, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Yachiyo
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Department of Public Health, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Ohfuji
authors.affiliation: Department of Public Health, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Wakaba
authors.initials: W
authors.lastname: Fukushima
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tamori
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Enomoto
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan ; Department of Medical Nutrition, Graduate School of Human Life Science, Osaka City University, Osaka, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Habu
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Iwai
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Sawako
authors.initials: S
authors.lastname: Uchida-Kobayashi
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Fujii
authors.affiliation: Department of Nuclear Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Shiomi
authors.affiliation: Department of Hepatology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Norifumi
authors.initials: N
authors.lastname: Kawada
authors.affiliation: Department of Public Health, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirota
mesh_terms: D000368:Aged; D000410:Alanine Transaminase / Q000097:blood*; D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D061215:Energy Drinks; D005260:Female; D005500:Follow-Up Studies; D019698:Hepatitis C, Chronic / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine; D000410:Alanine Transaminase