Surplus dietary tryptophan inhibits stress hormone kinetics and induces insulin resistance in pigs

Recently we have shown that surplus dietary tryptophan (TRP) reduced the plasma concentrations of cortisol and noradrenaline in pigs. Stress hormones are known to affect insulin sensitivity and metabolism. We now investigated the long-term effects of surplus dietary TRP on 1) plasma and urinary stress hormone kinetics, 2) insulin sensitivity for glucose and amino acid clearance, and 3) whole body nitrogen balance. Pigs were fed for 3 weeks a high (13.2%) vs normal (3.4%) TRP to large neutral amino acids (LNAA) diet, leading to reduced fasting (14 h) plasma cortisol (17.1 ± 3.0 vs 28.9 ± 4.3 ng/mL, p