Healthy Volunteers Study of the Effects of Olanzapine and Ziprasidone

A Randomized Comparison of the Acute Effects of Olanzapine and Ziprasidone on Whole Body Insulin Sensitivity in Healthy Volunteers

Primary Aim: To test the acute effects of olanzapine or ziprasidone administration, in comparison to placebo, on insulin sensitivity in antipsychotic-naïve healthy young men, measured as whole-body dextrose infusion rates (mg/kg/min), hepatic glucose production (glucose rate of appearance [Ra]), primarily muscle glucose utilization (glucose rate of disappearance [Rd]), and adipose tissue related free fatty acid production (glycerol rate of appearance [Ra]).

We hypothesize that olanzapine, but not ziprasidone, will result in acute decreases in insulin sensitivity.

Secondary Aim: To test the acute effects of olanzapine or ziprasidone on insulin signaling pathways in antipsychotic naïve healthy young men.

We hypothesize that olanzapine, but not ziprasidone, will result in acute alterations in insulin signaling.

See brief description

Inclusion Criteria:

• Males aged 18-45 years
• BMI approximately ≥ 25 and < 35
• insulin approximately ≥ 15 µU/ml or triglyceride approximately ≥ 130 mg/dl

Exclusion Criteria:

• Any DSM-IV Axis I diagnosis
• prisoners
• any serious medical disorder (i.e. metabolic diseases, type 1 or 2 diabetes mellitus, endocrine disease, coagulopathy, clinically significant anemia, acute infection)
• taking prescription medications
• non-sedentary lifestyle with > 3 hours of exercise per week