Objectives: We investigated the associations of the LEP-2548A/G and HTR2C-759C/T polymorphisms with long-term clozapine-induced weight changes and baseline BMI in chronic patients with schizophrenia.
Materials and methods: A total of 113 patients receiving clozapine for at least 1 year were enrolled. Body weight was measured cross-sectionally and data on body weight just before starting clozapine were retrospectively extracted from medical records.
Results: Clozapine-induced change in BMI was correlated inversely with the baseline BMI (P<0.001, ρ=-0.347). The LEP-2548A/G polymorphism was associated significantly with the change in BMI (F=4.380, P=0.015) during clozapine use; those with the AA genotype had the highest BMI gain (1.4±3.1 kg/m), followed by those with the AG (-0.2±3.3 kg/m) and GG (-1.6±3.4 kg/m) genotypes. We also found a significant association between the leptin genotype and BMI at baseline (F=3.499, P=0.034); those with the AA genotype had the lowest baseline BMI (23.4±4.3 kg/m), followed by those with the AG (24.1±4.4 kg/m) and GG (28.8±7.3 kg/m) genotypes. In the case of the HTR2C-759C/T polymorphism, we found a trend in which T alleles were more prevalent in male patients with up to 7% increase in BMI than in those with a greater than 7% increase in BMI [12/54 (22.7%) vs. 1/27 (3.7%); Fisher's exact test: P=0.051].
Conclusion: This study shows an inverse correlation between the baseline BMI and change in BMI during long-term clozapine use in patients with schizophrenia, and the LEP-2548A/G polymorphism was associated significantly with both these measures.