Comparison of telomere length in schizophrenia patients using closapine

Background: In recent years, it has been suggested that schizophrenia may be associated with earlier biological aging. Telomeres protect chromosomal ends and are an important marker of cellular aging. Most of the studies found shorter telomere length in patients with schizophrenia however, there are conflicting results that showed longer telomeres. Studies including medications are also very limited. In this study we aimed to compare telomere length in schizophrenia patients with healthy controls and particularly to evaluate relationship between telomere length and clozapine which is the gold standard in treatment resistant patients. Method: The study included a total of 54 patients diagnosed with schizophrenia, 27 using clozapine and 27 not using clozapine, and 26 matched healthy controls. The patients were assessed using the CGI, PANSS, Brief Negative Symptom Scale, Calgary Depression Scale for Schizophrenia, Extrapyramidal Symptom Rating Scale, and the Personal and Social Performance Scale. Telomere length was measured using the Real-Time Quantitative PCR method. Results: In our study, we found significantly longer telomeres in patients with schizophrenia compared to healthy controls (p=0.01). The clozapine-treated group had longer telomeres than both the non-clozapine group (p=0.03) and healthy controls (p=0.001). No statistically significant difference in telomere length was found between the non-clozapine group and healthy controls (p=0.302). The same results were maintained when we controlled age, sex, body mass index, and other confounding variables. Regression analysis revealed significant relationship between only duration of disease and telomere length among the clinical variables. Conclusion: Our study found longer telomeres in patients than the controls, and telomere length was found to be associated with clozapine use. This suggests that clozapine treatment might have an effect on biological aging in schizophrenia patients. Further studies with more comprehensive design will aid to better understand this relationship and underlying mechanisms.