Background: It is important to assess cardiovascular risk factors to properly verify the potential consequences of atypical antipsychotic-related weight gain. The objective of the present study was to evaluate whether 2 atypical antipsychotics differ regarding their impact on the cardiovascular disease risk profile compared with a reference group.

Method: We conducted a cross-sectional, multicenter study to assess anthropometric indices of obesity and to obtain a comprehensive fasting metabolic risk profile. Either risperidone or olanzapine had to be prescribed as the first and only antipsychotic for a minimum of 6 months. Patients were compared with a reference group of nondiabetic men. Data were collected from August 1999 to August 2001.

Results: Eighty-seven patients treated with olanzapine (N = 42) or risperidone (N = 45) were evaluated. Olanzapine-treated patients had significantly higher plasma triglyceride concentrations (2.01 ± 1.05 vs. 1.34 ± 0.65 mmol/L, p <= .05), lower high-density lipoprotein (HDL)-cholesterol levels (0.92 ± 0.17 vs. 1.04 ± 0.21 mmol/L, p <= .05), higher cholesterol/HDL-cholesterol ratios (5.62 ± 1.70 vs. 4.50 ± 1.44, p <= .05), higher apolipoprotein B levels (1.07 ± 0.35 vs. 0.92 ± 0.27 g/L, p <= .05), smaller low-density lipoprotein peak particle diameters (252.6 ± 4.1 vs. 255.2 ± 4.3 Š, p < .01), and higher fasting insulin concentrations (103.9 ± 67.6 vs. 87.5 ± 56.1 pmol/L, p <= .05) than risperidone-treated patients. Moreover, 33% of olanzapine-treated patients were carriers of 3 atherogenic features of the metabolic syndrome as opposed to a prevalence of only 11% of risperidone-treated patients.

Conclusion: These results suggest that olanzapine-treated patients are characterized by a more deteriorated metabolic risk factor profile compared with risperidone-treated patients. These observations raise concerns about the potential differential long-term deleterious effects of some antipsychotics, such as olanzapine, on cardiovascular health.