Effects of 5-HTR2C Gene Polymorphisms on Glucolipid Metabolism in Schizophrenia Patients Treated with Olanzapine

OBJECTIVE To investigate the effects of -759 C/T and -697 G/C polymorphisms of 5-hydroxytryptamine 2 C receptor gene(5-HTR2 C) on glucolipid metabolism in schizophrenia patients treated with olanzapine.METHODS A total of 184 schizophrenia patients who treated with olanzapine alone were recruited. Fasting blood glucose(FBG), triglyceride(TG), total cholesterol(TC), low density lipoprotein(LDL) and high density lipoprotein(HDL) were measured at baseline and the end of 6 th week of treatment. The -759 C/T and -697 G/C polymorphisms of 5-HTR2 C gene were detected by improved multiple ligase detection reaction(iMLDR), and then the changes in glycolipid levels before and after treatment for each genotype were compared by covariance analysis.RESULTS There was no significant difference in baseline glucolipid levels between -759 C/T and -697 G/C genotypes of 5-HTR2 C gene. There were significant differences in net increase of FBG and TG between -759 C/T genotypes after 6 weeks of treatment(F=4.862, P=0.009; F=3.397, P=0.036). The net increase of FBG in patients with wild CC genotype was higher than that in patients with CT or TT genotypes(P=0.038, P=0.010), and the net increase of TG in patients with wild CC genotype was higher than that with TT genotype(P=0.010). There was significant difference in the net increase of FBG between -697 G/C genotypes(F=4.385, P=0.014), and patients with wild GG genotype was higher than that with CC genotype(P=0.006). The combined analysis of the two loci also found that the net increase of FBG in patients with wild CC/GG genotype was higher than that in patients with CT+TT/GC+CC genotype(P=0.021).CONCLUSION The -759 C/T and -697 G/C polymorphisms of 5-HTR2 C gene are associated with abnormal glucolipid metabolism in schizophrenia treated with olanzapine.