Lack of association between the -759C/T polymorphism of the 5-HT2C receptor gene and olanzapine-induced weight gain among Korean schizophrenic patients.
BACKGROUND
Weight gain can be an adverse effect of antipsychotics that significantly affects long-term health and treatment compliance. Many reports have suggested that the 5-HT2C receptor gene (HTR2C) is related to appetite and eating behaviours associated with body weight change. We hypothesized that there was a relationship between the HTR2C -759C/T polymorphism and olanzapine-induced weight gain.


METHODS
Seventy-nine Korean schizophrenic patients were examined. Their weight was measured before starting olanzapine and after long-term treatment for at least 3 months. We controlled the use of drugs other than olanzapine except benzodiazepines and anticholinergics. Genotyping for the HTR2C -759C/T polymorphism was performed on all participants.


RESULTS
We found that long-term treatment with olanzapine resulted in mean gains in weight and BMI of 5.2 kg and 1.93 kg/m(2), respectively. However, body weight changes from baseline to the study endpoint were not significantly associated with genotypes. The frequency of the T allele did not differ significantly between subjects with weight gains below and above a clinically significant cutoff, defined as 7% relative to baseline (chi(2) = 0.213, P = 0.445), indicating that the T allele had no protective effect against olanzapine-induced weight gain.


CONCLUSIONS
The findings from this study do not support the presence of a relationship between the -759C/T polymorphism of the HTR2C gene and weight gain in Korean schizophrenic patients receiving olanzapine treatment.
Park
Y-M
YM
Department of Neuropsychiatry, Inje University College of Medicine, Goyang, South Korea.
Cho
J-H
JH
Kang
S-G
SG
Choi
J-E
JE
Lee
S-H
SH
Kim
L
L
Lee
H-J
HJ
D000328:Adult; D000483:Alleles; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001569:Benzodiazepines / Q000009:adverse effects*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007723:Korea; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D011110:Polymorphism, Genetic; D044405:Receptor, Serotonin, 5-HT2C / Q000235:genetics*; D012559:Schizophrenia / Q000188:drug therapy*; D015430:Weight Gain / Q000187:drug effects* / Q000235:genetics
D014150:Antipsychotic Agents; D044405:Receptor, Serotonin, 5-HT2C; D001569:Benzodiazepines; D000077152:Olanzapine