Combined HTR2C-LEP genotype as a determinant of obesity in patients using antipsychotic medication.

Obesity is one of the most serious common somatic adverse effects of atypical antipsychotic agents. Genetic factors partly determine the individual patients risk of developing obesity during treatment. As weight-regulating mechanisms, such as the leptinergic and serotonergic system, may be interdependent, genetic polymorphisms in these systems also may show interactions. To determine whether combined HTR2CLEP genotype or HTR2C-LEPR genotype are associated with obesity in patients using atypical antipsychotic drugs, a cross-sectional study design was used. The study population included 200 patients aged between 18 and 65 years of age, diagnosed with a psychotic disorder, all of whom had been using an atypical antipsychotic for at least 3 months. Primary outcome measure was presence of obesity (body mass index, >30). Determinants were the combined (HTR2C -759C/T-LEPR Q223R), (HTR2C -759C/T-LEP -2548G/A, (HTR2C rs1414334-LEPR Q223R) and (HTR2C rs1414334-LEP -2548G/A) genotypes. Of the 200 included patients, 61 (31%) were obese. In patients without the HTR2C -759T allele, presence of the LEP -2548G allele was associated with obesity (odds ratio, 2.88; 95% confidence interval, 1.05-7.95). The results of the other analyses showed some nonsignificant trends. The combined (HTR2C -759C/TYLEP -2548G/A) genotype may be a determinant of obesity in patients during treatment with atypical antipsychotic drugs.