The purpose of this study is to determine whether atypical antipsychotic drugs (commonly prescribed for treating schizophrenia) induce changes in anthropometry and metabolism, including alteration in insulin sensitivity and/or insulin secretion by the pancreas, when given to lean, non-diabetic, individuals who are antipsychotic drug(s)-naïve, and free of metabolic syndrome at enrollment.

Atypical antipsychotic drugs (AADs) induce weight gain, truncal adiposity and may engender a metabolic syndrome which may progress to IFG/IGT or DM. AADs effects in lean schizophrenic patients without metabolic syndrome are not documented, especially the relationship between weight gain and changes in insulin sensitivity (S), beta-cell function (β), and circulating adiponectin. We prospectively determined the outcome of 9-month therapy with AADs on anthropometrics, metabolism and adiponectin, including HOMA-modeling of S, β, and βxS (hyperbolic product, assessing individual β adjusted for S)in 36 schizophrenic subjects (M:F 24:12; Caucasian n=23; North-African n=12; South-Asian n=1) aged 35±9 years (mean±1SD) free of MetS (NCEP-ATPIII).

Inclusion Criteria:

• age 18-55 years
• body mass index <25.0 kg/m²
• waist circumference <102 (men) and <88 cm (women)
• absence of a metabolic syndrome according to NCEP ATPIII criteria
• normoglycaemic (fasting plasma glucose levels <100 mg/dl)

Exclusion Criteria:

• previous use of antipsychotic drugs
• concomitant therapy with drugs known to possess an inherent potential to increase weight and/or to alter glucose metabolism (including antihistaminic drugs, glucocorticoids, β-blockers, antiepileptic drugs and mirtazapine)