Fasting serum levels of neuropeptide y in patients with schizophrenia on clozapine monotherapy.

OBJECTIVE

Neuropeptide Y (NPY) is one of the hypothalamic hormones that works by increasing appetite and decreasing metabolism, leading to weight gain. We checked whether NPY level in subjects with schizophrenia on clozapine is higher compared with healthy controls.

METHODS

We determined the fasting NPY levels of 24 subjects with schizophrenia on clozapine monotherapy and 24 age- and sex-matched healthy controls.

RESULTS

There was no difference for NPY between the clozapine group and the control group (mean [SD], 323.33 [138.50] vs 295.83 [25.28] pg/mL, P = 0.25). Neuropeptide Y was higher in women in the clozapine group (376.00 [162.15] vs 275.45 [96.99] pg/mL, P = 0.048) but not in the control group (P = 0.31) or in the whole study group (P = 0.20). We found no correlations between NPY and age, weight, body mass index, fat mass index, body circumferences, blood pressure, waist-to-hip ratio, levels of cholesterol, high-density lipoproteins, low-density lipoproteins, triglycerides, uric acid, calcium, homocysteine, glucose, insulin, insulin resistance, treatment duration, dose of clozapine, body composition, or basal metabolic rate.

CONCLUSIONS

We cannot conclude that treatment with clozapine is associated with increased level of NPY. We did not find previously described differences in NPY for obesity or associations between NPY and metabolic parameters.