Comparison of Metabolic Syndrome Incidence Among Schizophrenia Patients Treated With Aripiprazole Versus Olanzapine or Placebo

Background: Metabolic syndrome is a strong determinant of new-onset diabetes and coronary heart disease in general populations. Given the higher prevalence of metabolic syndrome among mentally ill patients, the syndrome poses a greater health risk to this population. Atypical antipsychotic treatment may exacerbate this condition. We compared both the rate and incidence of metabolic syndrome among schizophrenia patients (DSM-IV criteria) treated with the atypical antipsychotics aripiprazole or olanzapine or placebo from 4 double-blind, randomized, controlled clinical trials.

Method: Metabolic syndrome was defined according to the Third Adult Treatment Panel (ATP III) Guidelines as the presence on follow-up of 3 of the following abnormalities: waist circumference > 102 cm if male and > 88 cm if female, high density lipoprotein (HDL) < 40 mg/dL if male and = 85 mm Hg or systolic blood pressure >= 130 mm Hg, fasting triglycerides >= 150 mg/dL, fasting plasma glucose >= 110 mg/dL. Both the rate of metabolic syndrome and the person-time incidence were computed from the on-treatment follow-up.

Results: In the placebo-controlled trials, the rate of metabolic syndrome was 25.8% among 155 placebo patients and 19.9% for 267 aripiprazole patients (p = .466 by stratified log rank). The incidence of metabolic syndrome was 14.3% for 91 placebo patients versus 5.3% for 151 aripiprazole patients (p < .001). In the active comparator trials, patients treated with olanzapine (N = 373) versus aripiprazole (N = 380) exhibited rates of 41.6% and 27.9%, respectively (p = .0002). Incidence rates were 27.4% for 212 olanzapine patients versus 15.7% for 198 aripiprazole patients (p = .0055).

Conclusion: Both the rate and incidence of clinically relevant metabolic syndrome differ according to the choice of antipsychotic agent. The association between metabolic syndrome and treatment warrants careful consideration in the choice of antipsychotic agents.