Atypical antipsychotics (AAPs) are known to increase the risk of metabolic syndrome (MetS), a predictor for cardiovascular disease and diabetes. This risk differs according to the AAPs.

The objective of this analysis was to examine the incidence of MetS in schizophrenia patients treated with asenapine or olanzapine.

The aim was to estimate the incidence of MetS among schizophrenia patients (DSM-IV criteria) after 52 weeks of exposure to asenapine or olanzapine.

Pooled data from patients completing 52-week extension of randomized trials (041512, 041513, 25544 and A7501014) were included. Patients were treated with asenapine or olanzapine.

The National Cholesterol Education Program, Adult Treatment Panel III (NCEP ATP III) definition of MetS was used, defined as 3 or more of the 5 following risk determinants: waist circumference > 102 cm for male and > 88 cm for female, triglycerides = 150 mg/dL, HDL cholesterol < 40 mg/dL for male and < 50 mg/dL for female, sitting blood pressure ≥ 130/85 mm Hg, or fasting glucose ≥ 110 mg/dL.

Incidence (i.e. new metabolic cases in patients without MetS at baseline) was calculated at week 52.

741 patients were included in this analysis of 52-week studies (asenapine 397, olanzapine 344). After 52 weeks of treatment exposure, the incidence of MetS was significantly higher in olanzapine-treated patients than in asenapine-treated patients (19.44% versus 11.46%, p = 0.01).

These post-hoc analyses confirmed a higher risk of developing a MetS with olanzapine. The incidence of MetS after 52 weeks of treatment with asenapine was found to be significantly lower.