Biochemical Markers of Folate Metabolism Disorders in Schizophrenia in the Russian Population

Abstract—A range of foreign studies have shown that, in schizophrenia, hyperhomocysteinemia occurs more frequently than in the general population. Hyperhomocysteinemia may be an integrated marker of folate metabolism disorders (as a result of vitamin deficiency and/or genetic predisposition) or involved in the pathogenesis of the disease through several possible molecular mechanisms. In Russia, similar studies have not been conducted. In addition, there are conflicting results of studies on genetic factors involved in folate and homocysteine metabolism in schizophrenia. The aim of this study was to evaluate an association of serum homocysteine, folate, and cobalamin levels with schizophrenia in the Central part of Russia (Nizhny Novgorod region). For this purpose, 50 patients with schizophrenia and 36 healthy volunteers were randomly selected. The levels of homocysteine, folates and cobalamin (B12) were measured in blood serum. The concentration of homocysteine was measured using the Сobas analyzer (Roche Diagnostics) with an enzymatic assay. The content of folate and vitamin B12 was determined by chemiluminescent microparticle immunoassay (Architect, Abbott lab. S.A). It was found that the level of homocysteine was significantly higher in the patients than in the control group (p = 0.0041), and folate levels were significantly lower (p = 0.0072). The level of homocysteine in the patients had a weak negative statistically significant correlation with both folate level (ρ = –0.38; p = 0.0063) and with B12 level (ρ = –0.36; p = 0.0082). Homocysteine level was significantly higher in men than in women in the entire studied population (Z = –2.1068, p = 0.0351), as well as in subgroups of patients (Z = –2.11; p = 0.035) and healthy controls (z = 3.4; p = 0.00067). The data suggest the need for further investigation of hyperhomocysteinemia and other biochemical markers of folate metabolism disorders in schizophrenia in the Russian population and the development of ways to correct them to optimize the treatment of this mental disorder.