BACKGROUND: The essential amino acid tryptophan is required for protein synthesis and formation of the neurotransmitter serotonin and may exert immunoregulatory functions. An accelerated tryptophan breakdown rate is associated with inflammation and immune activation. MATERIALS AND METHODS: Serum concentrations of free tryptophan, neopterin and high-sensitivity C-reactive protein (hsCRP) were measured in 1196 patients with coronary artery disease (CAD) derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study. RESULTS: Tryptophan concentrations did not differ between patients with (mean ± SD: 40.1 ± 9.8 μM) or without (42.3 ± 23.9 μM; not significant, Welch's test) angiographic CAD, but patients with CAD had higher neopterin (9.1 ± 8.2 nM) and hsCRP (9.3 ± 18.5 mg/L) concentrations compared to patients without (neopterin: 7.6 ± 4.7 nM, hsCRP: 5.8 ± 7.6 mg/L; both P < 0.0001). There existed an inverse correlation between serum tryptophan and neopterin (Spearman's rank correlation: rs = -0.273) and hsCRP (rs = -0.163; both P < 0.0001) concentrations. Median observation time was 10.5 years, and 385 patients had died, including 244 patients due to cardiovascular and 132 due to noncardiovascular causes. After adjustments for cardiovascular risk factors and other possible confounders, the hazard ratio (with 95% CI) in the first tryptophan quartile of the study population was 1.51 (1.19-1.90; P = 0.0006) for total mortality, 1.41 (1.05-1.89; P = 0.0224) for cardiovascular and 1.79 (1.20-2.67; P = 0.0042) for noncardiovascular mortalities, respectively, thus indicating a significantly higher risk of death in patients with tryptophan concentrations < 34 μM. CONCLUSIONS: Low serum tryptophan in patients with CAD is associated with immune activation and indicates reduced life expectancy.
BACKGROUND: The essential amino acid tryptophan is required for protein synthesis and formation of the neurotransmitter serotonin and may exert immunoregulatory functions. An accelerated tryptophan breakdown rate is associated with inflammation and immune activation. MATERIALS AND METHODS: Serum concentrations of free tryptophan, neopterin and high-sensitivity C-reactive protein (hsCRP) were measured in 1196 patients with coronary artery disease (CAD) derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study. RESULTS:Tryptophan concentrations did not differ between patients with (mean ± SD: 40.1 ± 9.8 μM) or without (42.3 ± 23.9 μM; not significant, Welch's test) angiographic CAD, but patients with CAD had higher neopterin (9.1 ± 8.2 nM) and hsCRP (9.3 ± 18.5 mg/L) concentrations compared to patients without (neopterin: 7.6 ± 4.7 nM, hsCRP: 5.8 ± 7.6 mg/L; both P < 0.0001). There existed an inverse correlation between serum tryptophan and neopterin (Spearman's rank correlation: rs = -0.273) and hsCRP (rs = -0.163; both P < 0.0001) concentrations. Median observation time was 10.5 years, and 385 patients had died, including 244 patients due to cardiovascular and 132 due to noncardiovascular causes. After adjustments for cardiovascular risk factors and other possible confounders, the hazard ratio (with 95% CI) in the first tryptophan quartile of the study population was 1.51 (1.19-1.90; P = 0.0006) for total mortality, 1.41 (1.05-1.89; P = 0.0224) for cardiovascular and 1.79 (1.20-2.67; P = 0.0042) for noncardiovascular mortalities, respectively, thus indicating a significantly higher risk of death in patients with tryptophan concentrations < 34 μM. CONCLUSIONS: Low serum tryptophan in patients with CAD is associated with immune activation and indicates reduced life expectancy.
Authors: Edward Yu; Miguel Ruiz-Canela; Marta Guasch-Ferré; Yan Zheng; Estefania Toledo; Clary B Clish; Jordi Salas-Salvadó; Liming Liang; Dong D Wang; Dolores Corella; Montse Fitó; Enrique Gómez-Gracia; José Lapetra; Ramón Estruch; Emilio Ros; Montserrat Cofán; Fernando Arós; Dora Romaguera; Lluis Serra-Majem; Jose V Sorlí; Frank B Hu; Miguel A Martinez-Gonzalez Journal: J Nutr Date: 2017-02-08 Impact factor: 4.798
Authors: Hui Xing Lau; Sarah El-Heis; Qai Ven Yap; Yiong Huak Chan; Cheryl Pei Ting Tan; Neerja Karnani; Karen Mei Ling Tan; Elizabeth Huiwen Tham; Anne Eng Neo Goh; Oon Hoe Teoh; Kok Hian Tan; Johan Gunnar Eriksson; Yap Seng Chong; Mary Foong-Fong Chong; Hugo Van Bever; Bee Wah Lee; Lynette P Shek; Keith M Godfrey; Evelyn Xiu Ling Loo Journal: Clin Exp Allergy Date: 2021-06-24 Impact factor: 5.018