Objective: The primary purpose of this 8-week double-blind, placebo-controlled trial of rosiglitazone 4 mg/day was to examine its effect on insulin sensitivity index (SI) and glucose utilization (SG) in clozapine-treated subjects with schizophrenia with insulin resistance.
Method: Eighteen subjects were randomized and accessed with a Frequently Sampled Intravenous Glucose Tolerance Test (FSIVGTT) at baseline and at week 8 to estimate SG and SI.
Results: Controlling for the baseline, comparing the rosiglitazone group with placebo group, there was a non-significant improvement in SG (0.016 +/- 0.006-0.018 +/- 0.008, effect size = 0.23, P = 0.05) with a trend of improvement in SI in the rosiglitazone group (4.6 +/- 2.8-7.8 +/- 6.7, effect size = 0.18, P = 0.08). There was a significant reduction in small low-density lipoprotein cholesterol (LDL-C) particle number (987 +/- 443-694 +/- 415, effect size = 0.30, P = 0.04).
Conclusion: Rosiglitazone may have a role in addressing insulin resistance and lipid abnormalities associated with clozapine.