Urinary metabolites and risk of coronary heart disease: A prospective investigation among urban Chinese adults

Association between tryptophan concentrations and the risk of developing cardiovascular diseases: a systematic review and meta-analysis

BACKGROUND

Metabolic regulation of various amino acids have been proven to be effective in preventing cardiovascular disease (CVD). The impact of tryptophan, an essential amino acid, on the risk of developing CVD has not been fully elucidated.

AIMS

The aim of this meta-analysis was to systematically review evidence of the effects of tryptophan on CVD risk.

METHODS

The PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases were searched to collect relevant trials from inception to August 2024. The means and hazard ratios (HRs) were extracted and pooled. Subgroup analysis was performed to identify pooled effect estimates, and sensitivity analysis was conducted to assess the robustness of the pooled estimates.

RESULTS

Data were collected from 34,370 people under follow-up for CVD events in 13 studies, including cohort studies and case-control studies. They were categorized into three groups on the basis of sample type and indicators: the plasma tryptophan level group, the plasma tryptophan CVD hazard group, and the urinary tryptophan CVD hazard group. The CVD included in this study were coronary artery disease, heart failure, and peripheral artery disease. Twelve studies on plasma tryptophan were meta-analyzed. The plasma tryptophan levels in CVD patients were generally lower than those in individuals without CVD (SMD = -8.57, 95%CI (-15.77, -1.37), P = 0.02). Decreased circulating tryptophan levels are associated with cardiovascular disease risk (HR = 0.85, 95%CI (0.78, 0.92), P < 0.00001).

CONCLUSIONS

Decreased circulating tryptophan levels are associated with an increased risk of CVD events. Intervention in circulating tryptophan levels may be indicated to help prevent CVD.

Identification of diagnostic biomarkers used in the diagnosis of cardiovascular diseases and diabetes mellitus: A systematic review of quantitative studies

AIMS

To perform a systematic review of studies that sought to identify diagnostic biomarkers for the diagnosis of cardiovascular diseases (CVDs) and diabetes mellitus (DM), which could be used in low- and middle-income countries (LMICs) where there is a lack of diagnostic equipment, treatments and training.

MATERIALS AND METHODS

Papers were sourced from six databases: the British Nursing Index, Google Scholar, PubMed, Sage, Science Direct and Scopus. Articles published between January 2002 and January 2023 were systematically reviewed by three reviewers and appropriate search terms and inclusion/exclusion criteria were applied.

RESULTS

A total of 18 studies were yielded, as well as 234 diagnostic biomarkers (74 for CVD and 160 for DM). Primary biomarkers for the diagnosis of CVDs included growth differentiation factor 15 and neurogenic locus notch homologue protein 1 (Notch1). For the diagnosis of DM, alpha-2-macroglobulin, C-peptides, isoleucine, glucose, tyrosine, linoleic acid and valine were frequently reported across the included studies. Advanced analytical techniques, such as liquid chromatography mass spectrometry, enzyme-linked immunosorbent assays and vibrational spectroscopy, were also repeatedly reported in the included studies and were utilized in combination with traditional and alternative matrices such as fingernails, hair and saliva.

CONCLUSIONS

While advanced analytical techniques are expensive, laboratories in LMICs should carry out a cost-benefit analysis of their use. Alternatively, laboratories may want to explore emerging techniques such as infrared, Fourier transform-infrared and near-infrared spectroscopy, which allow sensitive noninvasive analysis.

Inosine: A bioactive metabolite with multimodal actions in human diseases

The nucleoside inosine is an essential metabolite for purine biosynthesis and degradation; it also acts as a bioactive molecule that regulates RNA editing, metabolic enzyme activity, and signaling pathways. As a result, inosine is emerging as a highly versatile bioactive compound and second messenger of signal transduction in cells with diverse functional abilities in different pathological states. Gut microbiota remodeling is closely associated with human disease pathogenesis and responses to dietary and medical supplementation. Recent studies have revealed a critical link between inosine and gut microbiota impacting anti-tumor, anti-inflammatory, and antimicrobial responses in a context-dependent manner. In this review, we summarize the latest progress in our understanding of the mechanistic function of inosine, to unravel its immunomodulatory actions in pathological settings such as cancer, infection, inflammation, and cardiovascular and neurological diseases. We also highlight the role of gut microbiota in connection with inosine metabolism in different pathophysiological conditions. A more thorough understanding of the mechanistic roles of inosine and how it regulates disease pathologies will pave the way for future development of therapeutic and preventive modalities for various human diseases.

Tryptophan was metabolized into beneficial metabolites against coronary heart disease or prevented from producing harmful metabolites by the in vitro drug screening model based on Clostridium sporogenes

In our previous study of 2,130 Chinese patients with coronary heart disease (CHD), we found that tryptophan (TRP) metabolites contributed to elevated risks of death. Many TRP-derived metabolites require the participation of intestinal bacteria to produce, and they play an important role in the pathogenesis of metabolic diseases such as CHD. So it is necessary to metabolize TRP into beneficial metabolites against CHD or prevent the production of harmful metabolites through external intervention. Indole-3-butyric acid (IBA) may be a key point of gut microbiota that causes TRP metabolism disorder and affects major adverse cardiovascular events in CHD. Therefore, this study aimed to develop a method based on in vitro culture bacteria to evaluate the effects of IBA on specific microbial metabolites quickly. We detected the concentrations of TRP and its metabolites in 11 bacterial strains isolated from feces using liquid chromatography–mass spectrometry, and selected Clostridium sporogenes as the model strain. Then, IBA was used in our model to explore its effect on TRP metabolism. Results demonstrated that the optimal culture conditions of C. sporogenes were as follows: initial pH, 6.8; culture temperature, 37°C; and inoculum amount, 2%. Furthermore, we found that IBA increases the production of TRP and 5-HIAA by intervening TRP metabolism, and inhibits the production of KYNA. This new bacteria-specific in vitro model provides a flexible, reproducible, and cost-effective tool for identifying harmful agents that can decrease the levels of beneficial TRP metabolites. It will be helpful for researchers when developing innovative strategies for studying gut microbiota.

[Correlation of plasma N-acetyl-neuraminic acid level with TIMI risk stratification and clinical outcomes in patients with acute coronary syndrome]

OBJECTIVE

To explore the correlation of plasma N-acetyl-neuraminic acid level with Thrombolysis In Myocardial Infarction (TIMI) risk score and clinical outcomes of patients with acute coronary syndrome (ACS).

METHODS

We consecutively enrolled 708 consecutive patients (401 male and 307 female, mean age 63.6±10.6 years) undergoing coronary angiography in our hospital between October, 2018 and July, 2019, including 597 patients with ACS and 111 without ACS (control group). The patients with ACS group were divided into high (n=104), moderate (n=425) and low (n=68) risk groups according to their TIMI risk scores. All the participants were examined for plasma Neu5Ac level using liquid chromatography-tandem mass spectrometry and underwent coronary angiography with their Gensini scores calculated. The patients with ACS were followed up after discharge for a mean of 15 months for the occurrence of major adverse cardiac events (Mace). Binary logistic regression analysis was performed to identify the risk factors of Mace in these patients.

RESULTS

Plasma Neu5Ac levels were significantly higher in ACS group than in the control group (P < 0.05). ROC curve analysis showed that plasma Neu5Ac level could assist in the diagnosis of ACS (0.648 [0.597-0.699]) with a sensitivity of 39.2% and a specificity of 86.5% at the cutoff value of 288.50 ng/mL. In the ACS patients, plasma Neu5Ac level was significantly higher in the high-risk group than in the moderate-risk and low-risk groups (P < 0.05) and could assist in the diagnosis of a high risk (0.645 [0.588-0.703]) with a sensitivity of 42.3% and a specificity of 80.1% at the cutoff value of 327.50 ng/ mL. Plasma Neu5Ac was positively correlated with age, serum uric acid, creatinine, lipoprotein a, Ddimer, C-reactive protein, MB isoform of creatine kinase and Gensini score and negatively correlated with high-density lipoprotein level. During the followup, 80 ACS patients experienced Mace, who had significantly higher plasma Neu5Ac level than those without Mace (n=517). Logistic regression analysis showed that plasma Neu5Ac level and a history of previous stroke were independent risk factors for the occurrence of Mace.

CONCLUSIONS

Plasma Neu5Ac level can provide assistance in the diagnosis and risk stratification of ACS and is an independent risk factor for prognosis of ACS patients.