Subjects were recruited from an urban community mental health clinic. Each subject underwent a series of anthropometric measures and an indirect calorimetry measure. A fasting blood sample was taken for plasma glucose, serum insulin, and lipid profile.
Seventy-one subjects (54 male, 17 female) were included in the study. There was a significant positive relationship between REE and fasting serum insulin level (r = .39, p = .001). Stepwise multiple regression analysis was performed with various characteristics such as age, race, antipsychotic agent used, fat-free mass, BMI, waist circumference, waist–hip ratio, physical activity level, and fasting serum insulin as candidate predictors for REE. Only fat-free mass and insulin were able to enter into the regression model, which indicates that higher fat-free mass and higher fasting serum insulin level predict increased REE.
A higher fasting serum insulin level is associated with an increased REE, which may prevent further weight gain in nondiabetic patients with schizophrenia.