1. ¹Department of Clinical Pharmacoepidemiology, Division of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
2. ²Department of Clinical Pharmacy, Wilhelmina Hospital Assen, Assen, The Netherlands
3. ³Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
4. ⁴Department of Clinical Pharmacy, Martini Hospital Groningen, Groningen, The Netherlands
5. ⁵Department of Psychotic Disorders, Mental Health Services Drenthe, Assen, The Netherlands
6. ⁶Mental Health Services Drenthe, Assen, The Netherlands
7. ⁷Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht, The Netherlands

Correspondence: Professor Dr ACG Egberts, Department of Clinical Pharmacoepidemiology, Division of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, TB Utrecht 3508, The Netherlands. E-mail: A.C.G.Egberts@pharm.uu.nl

Received 21 February 2006; Revised 23 August 2006; Accepted 24 August 2006; Published online 3 October 2006.

Abstract

The use of antipsychotics is associated with an increased risk of obesity. This consideration makes it important to search for determinants that can predict the risk for antipsychotic-induced obesity. In this cross-sectional study, we investigated whether polymorphisms in the HTR2C gene were associated with obesity (body mass index >30 kg/m²) in patients using antipsychotics. We examined polymorphisms in the promoter region of the HTR2C gene ((HTR2C:c.1–142948(GT)_n, rs3813928 (-997 G/A), rs3813929 (-759 C/T), rs518147 (-697 G/C)) and an intragenic polymorphism (rs1414334:C>G). The results of the logistic regression were expressed as adjusted odds ratios (OR). In total, we included 127 patients mainly diagnosed with schizophrenia or schizoaffective disorder (89%). The results indicate that a combined genotype carrying the variant HTR2C:c.1–142948(GT)_n 13 repeat allele, the common allele rs3813929 C, the variant allele rs518147 C and the variant allele rs1414334 C is significantly related to an increased risk of obesity (OR 3.71 (95% confidence interval: 1.24–11.12)).