title: Relationship between vitamin B12, folate and homocysteine levels and H. pylori infection in patients with functional dyspepsia: a cross-section study.
abstract: BACKGROUND
  H. pylori infection has been associated with many micronutrient deficiencies. There is a dearth of data from communities with nutritional deficiencies and high prevalence of H. pylori infection. The aim of this study was to determine the impact of H. pylori infection on serum levels of vitamin B(12), folate and homocysteine in patients with functional dyspepsia (FD).
  
  
  METHODS
  One hundred and thirty-two patients with FD undergoing gastroscopy were enrolled. The serum was analyzed for B(12), folate and homocysteine levels before gastroscopy. H. pylori infection was diagnosed by histopathological examination of gastric biopsies and urea breath test. An independent sample t-test and the Mann-Whitney test were used to compare mean serum concentrations of biomarkers between H. pylori-positive and H. pylori-negative groups of patients. A Chi-square test was performed to assess the differences among proportions, while Spearman's rho was used for correlation analysis between levels of B(12) and homocysteine.
  
  
  RESULTS
  The mean age of the group was 40.3 ± 11.5 (19-72) years. Folate deficiency was seen in 43 (34.6%), B(12) deficiency in 30 (23.1%) and hyperhomocysteinemia in 60 (46.2%) patients. H. pylori was present in 80 (61.5%) patients with FD while it was absent in 50 (38.5%). Mean serum levels of B(12), folate and homocysteine in the H. pylori-positive group of patients were not significantly different from the levels in the H. pylori-negative group (357 ± 170 vs. 313 ± 136 pg/mL; p = 0.13), (4.35 ± 1.89 vs. 4.42 ± 1.93 ng/mL; p = 0.84); (15.88 ± 8.97 vs. 16.62 ± 7.82 μmol/L; p = 0.24); respectively.B(12) deficiency (≤200 pg/mL) was 23.8% in the H. pylori-positive patients versus 22.0% in the H. pylori-negative patients. Folate deficiency (≤3.5 ng/mL) was 33.8% in the H. pylori-positive group versus 36% in the H. pylori-negative group. Hyperhomocysteinemia (>15 μmol/L) was present in 46.2% of H. pylori-positive patients compared to 44% in the H. pylori-negative group. Correlation analysis indicated that serum B(12) levels were inversely associated with serum levels of homocysteine in patients with FD (rho = -0.192; p = 0.028).
  
  
  CONCLUSIONS
  This study demonstrated an inverse relationship between serum levels of B(12) and homocysteine in patients with FD. Moreover, no impact of the presence of H. pylori was found on B(12), folate and homocysteine levels in such patients.
authors.affiliation: Section of Gastroenterology, Department of Medicine, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Shahid
authors.initials: S
authors.lastname: Rasool
authors.forename: Shahab
authors.initials: S
authors.lastname: Abid
authors.forename: Mohammad Perwaiz
authors.initials: MP
authors.lastname: Iqbal
authors.forename: Naseema
authors.initials: N
authors.lastname: Mehboobali
authors.forename: Ghulam
authors.initials: G
authors.lastname: Haider
authors.forename: Wasim
authors.initials: W
authors.lastname: Jafri
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004415:Dyspepsia / Q000097:blood* / Q000150:complications / Q000382:microbiology; D005260:Female; D005492:Folic Acid / Q000097:blood*; D016481:Helicobacter Infections / Q000097:blood* / Q000150:complications / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12