Folate and homocysteine levels and their association with dietary intakes in Iranian patients infected with Helicobacter pylori: a case-control study.

The association between Helicobacter pylori (HP) infection and concentration of folate or homocysteine are still unclear. The aim of the present study was to assess the effect of  HP infection on folate and homocysteine concentrations in patients infected with HP and healthy participants. We also assessed dietary intakes of folate, vitamins B6 and B12 in two groups. In this case-control study, 44 participants with HP-infection and 46 healthy controls were studied. Participants were recruited from those referred to the central laboratory of Tabriz University of Medical Sciences. Blood samples were collected to determine serum folate and homocysteine levels. The presence of both IgG and IgA in serum was considered as HP positive. Dietary intakes were assessed in all participants by 24-hour dietary recalls by trained interviewers for three days. The mean concentration of serum folate was significantly lower in HP-positive patients than in controls (8.49 nmol/L vs. 10.95 nmol/L, respectively; P=0.01). Although the mean concentration of serum homocysteine differed between groups, statistical significance was missed (HP infected patients: 9.35 µmol/L; healthy participants: 8.96 µmol/L; P=0.064). Macro- and micronutrient intakes showed no significant difference between participants with and without HP infection. In logistic regression models, there was a negative correlation between folate concentration and HP infection even after controlling for confounding factors (OR=0.82; CI95%=0.79-0.97). In this study, authors showed that a negative association presents between HP infection and serum  folate concentrations, but the homocysteine status was not differed significantly between HP-positive and HP-negative participants.