The Moderating Impact of Ethnicity on Metabolic Outcomes During Treatment With Olanzapine and Aripiprazole in Patients With Schizophrenia

Objective: Race is strongly associated with risk for metabolic dysfunction, but there is limited prospective data concerning the impact of race on antipsychotic metabolic outcomes among patients with schizophrenia.

Method: This study is a post hoc analysis of data from a 26-week, double-blind, randomized trial of aripiprazole (N = 155) and olanzapine (N = 159) conducted from April 2000 through June 2001 in patients aged ≥18 years with acute schizophrenia according to DSM-IV criteria. The data were analyzed on the basis of racial breakdown: white and black/Hispanic. Between-drug and within-drug outcomes were analyzed separately for each racial cohort across weight, lipid, and glucose parameters.

Results: For white subjects (N = 167), olanzapine significantly worsened all metabolic parameters except high-density lipoprotein (HDL) cholesterol and fasting glucose, and this was significantly different than aripiprazole for every outcome except fasting glucose. In the black/Hispanic cohort (N = 137), olanzapine treatment resulted in adverse metabolic outcomes, and these changes were significantly different from aripiprazole for adiposity, total cholesterol, and non-HDL cholesterol. Aripiprazole decreased the odds of endpoint metabolic syndrome compared with olanzapine for all subjects (OR = 0.33, 95% CI = 0.19 to 0.55), the white cohort (OR = 0.20, 95% CI = 0.10 to 0.41), and black/Hispanic subjects (OR = 0.53, 95% CI = 0.25 to 1.12), but the black/Hispanic result was not statistically significant (p =.096). Within the aripiprazole group, white subjects had significantly lower risk for metabolic syndrome, but there was no significant difference in metabolic syndrome between white and black/Hispanic subjects exposed to olanzapine.

Conclusion: Race may be an important moderator of metabolic risk during atypical antipsychotic therapy. Olanzapine treatment is associated with greater effects on adiposity and lipids than aripiprazole in both white and black/Hispanic subjects, suggesting that antipsychotic choice and intensive monitoring are important in minimizing metabolic risk, especially in nonwhite patients.

J Clin Psychiatry 2009;70(3):318-325