ORIGINAL PAPER Homocysteine Levels in Patients with Schizophrenia on Clozapine

Abstract We tested the hypothesis that homocysteine levels are higher in blood of schizophrenic subjects on clozapine monotherapy than in healthy controls and they correlate with anthropometric measurements, laboratory tests and results of bioimpedance analysis of body com-position. Data for 24 subjects with schizophrenia treated with clozapine and 24 age- and sex-matched healthy vol-unteers was analyzed. Regarding the whole group, homo-cysteine levels were significantly higher in men (17.0 ± 3.4 vs. 12.1 ± 4.0 lmol/L, p = 0.009). Homocysteine levels correlated with waist circumference (R = 0.58, p = 0.003), waist-to-hip ratio (R = 0.57, p = 0.003), basal metabolic rate (R = 0.48, p = 0.01), lean body mass [kg] (R = 0.53, p = 0.008), body water [L] (R = 0.53, p = 0.008) and triglycerides (R = 0.57, p = 0.003). There were no significant differences of homocysteine levels for impaired fasting glucose, abdominal obesity, obesity/ overweight, and dyslipidemia. Homocysteine levels did not correlate with age, treatment duration, clozapine dose, weight, body mass index, abdominal circumference, blood pressure, total body fat, cholesterol, high density lipopro-teins, low density lipoproteins, uric acid, calcium, glucose, insulin, homoeostasis model assessment of insulin resis-tance 1, and homoeostasis model assessment of insulin resistance 2. We did not find significant differences in blood homocysteine levels between subjects with schizo-phrenia and controls. Association with waist circumference may support homocysteine role as an important cardio-vascular risk factor. Association with lean weight may explain why men have higher levels of homocysteine than women