β-Endorphin and Insulin/Glucose Responses to Different Meals in Obesity

Abstract

The responses of plasma β-endorphin, insulin and glucose to two different isocaloric mixed meals – high carbohydrate (CHO meal) and high fat (fat meal) – were assessed in women with android obesity before (n = 11) as well as after (n = 5) weight reduction, and in normal-weight controls (n = 8). Basal plasma β-endorphin concentrations in the obese subjects (7.7 ± 1.2 pmol/l) were significantly (p < 0.005) higher than in the controls (3.8 ± 0.5 pmol/l) and were not influenced by weight loss. Fasting plasma levels and the integrated releases of insulin and glucose, both after the CHO meal and after the fat meal were significantly higher in the obese subjects than in the controls. The fat meal induced no changes in β-endorphin levels in either group. After the CHO meal a significant decrease in plasma β-endorphin concentration was observed only in the obese group before weight reduction. An influence on β-endorphin release by macronutrients is hypothesized.