Association of serum retinol-binding protein 4 with insulin resistance and metabolic parameters during olanzapine therapy.

ABSTRACT

OBJECTIVE: Retinol-binding protein 4 (RBP4) has been shown to be associated with insulin resistance (IR), metabolic indices and metabolic syndrome (MetS) in various patient populations and in obesity. We investigated the association between metabolic parameters, IR and RBP4 during olanzapine therapy. DESIGN: A prospective study. PATIENTS Thirty-seven participants with psychiatric disorder who were atypical antipsychotic naive and newly initiated on olanzapine were assessed. MEASUREMENTS Fasting RBP4, anthropometric and metabolic variables were measured before and after 3 months of olanzapine therapy. RESULTS: Participants who developed MetS showed higher RBP4 levels compared with those without MetS, although not significant (P = 0·053). The variation in RBP4 level was correlated with changes in systolic blood pressure (r = 0·423, P = 0·009), diastolic blood pressure (r = 0·390, P = 0·017), total cholesterol (r = 0·446, P = 0·006) and low-density lipoprotein (LDL) (r = 0·407, P = 0·012). Multiple linear regression analysis illustrated that end-point log insulin level was the most significant independent predictor of final log RBP4 levels (standardized ß = 0·353, P = 0·024). CONCLUSIONS: Our results suggest that RBP4 levels might be associated with at least some olanzapine-induced metabolic abnormalities and cardiovascular disease risk factors.