Low serum tryptophan predicts higher mortality in cardiovascular disease

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 conce...

Full description

Saved in:
Bibliographic Details
Main Authors: Murr, Christian (Author) , Grammer, Tanja B. (Author) , Kleber, Marcus E. (Author) , März, Winfried (Author)
Format: Article (Journal)
Language:English
Published: March 2015
In: European journal of clinical investigation
Year: 2015, Volume: 45, Issue: 3, Pages: 247-254
ISSN:1365-2362
DOI:10.1111/eci.12402
Online Access:Verlag, Volltext: http://dx.doi.org/10.1111/eci.12402
Verlag, Volltext: https://onlinelibrary-wiley-com.ezproxy.medma.uni-heidelberg.de/doi/abs/10.1111/eci.12402
Get full text
Author Notes:Christian Murr, Tanja B. Grammer, Marcus E. Kleber, Andreas Meinitzer, Winfried März and Dietmar Fuchs
Description
Summary: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.
Item Description:Gesehen am 03.12.2018
Physical Description:Online Resource
ISSN:1365-2362
DOI:10.1111/eci.12402