Schizophrenia is a devastating mental illness associated with obesity and diabetes mellitus rates that far exceed those of the general population.
The aim was to evaluate changes in positive energy balance (serum insulin, leptin and ghrelin) and hormones involved in neuroendocrine regulations (serum cortisol, growth hormone and prolactin) before treatment with atypical antypsyhotics (SGA) in normal weight patients with schizophrenia.
Thirty patients with schizophrenia (13 males, mean age 28.9±1.3 years and BMI, 23.3±0.6 kg/m2) treated with antypsyhotics first generation were investigated in this study. They had neither other diseases. The control group included 27 healthy subjects (9 males, mean age 30.7±1.9 years, BMI od 22.8±0.6 kg/m2). Positive family history for diabetes mellitus was similar between groups.
A oral glucose tolerance test (OGTT) with measuring glycemia, insulin, growth hormone and ghrelin was performed in all patients. Fasting samples for leptin, cortisol and prolactin were taken. Patients had normal fasting glucose levels but significantly higher peak glucose levels during OGTT as well as glucose area under the curve (AUC) than control subjects (746±25 vs 650±26 mmol/L/120 min; P<0.01). Fasting insulin levels, as well as insulin AUC did not differ from control subjects at baseline (P>0.05) but peak insulin values were significantly higher in patients with schizophrenia (95.1±14.8 vs 52.2±6.5 mU/L, P<0.05). Growth hormone (GH) and ghrelin levels during OGTT, and leptin concentrations did not differ between patients and control subjects (P>0.05). Cortisol levels (513.3±29.1 vs 441.9±24.3 nmol/L; P<0.05) were higher in patients. Prolactin levels were higher in patients with schizophrenia than in control subjects (821±135 vs 353±45 mU/L; P< 0.01).
Normal weight patients with schizophrenia have already some abnormalities in glucose metabolism therapy and neuroendocrine responses (cortisol, prolactin) before SGA. Thus, shizophrenia could be per se risk factor for diabetes mellitus.