Choline metabolites and incident cardiovascular disease in a prospective cohort of adults: Coronary Artery Risk Development in Young Adults (CARDIA) Study

Relationship Between Level of Trimethylamine Oxide and the Risk of Recurrent Cardiovascular Events in Patients with Acute Myocardial Infarction

Background: This study investigated the value of trimethylamine oxide (TMAO) and its precursors in secondary prevention for patients with acute myocardial infarction (AMI). Methods: We retrospectively enrolled patients diagnosed with AMI. The associations of TMAO and its precursors with endpoint events were estimated by Cox proportional hazards models. Results: During a median follow-up of 6.4 years, 319 (32.0%) major adverse cardiovascular event (MACE) occurred in the 996 patients enrolled. After adjusting for traditional risk factors, the risk of MACE, cardiac death, and recurrent MI increased by 28% (HR 1.28, 95% CI 1.10-1.49), 44% (HR 1.44, 95% CI 1.12-1.84), and 27% (HR 1.27, 95% CI 1.04-1.55), respectively, per one increment in ln-transformed TMAO. After adjustment for the levels of its precursors, the relationship between TMAO and MACE was still significant. Choline was associated with MACEs, all-cause mortality, cardiac death, and risk of recurrent MI after adjusting for the levels of the remaining metabolites, in addition to traditional risk factors. The overall ability to predict all-cause mortality was better for the choline model than for the TMAO model (continuous NRI 0.185, p = 0.007; IDI 0.030, p = 0.020). Mediation effect analysis showed that the mediating effect of TMAO on choline and the risk of all-cause mortality was 11.39% (95% CI 0.0209-0.2200, p = 0.016), suggesting the existence of a choline activity pathway that is independent of the TMAO pathway. Conclusions: TMAO and choline were associated with an increased risk of MACE in patients with AMI, and choline had better predictive power.

Choline metabolism in ischemic stroke: An underappreciated "two-edged sword"

Ischemic stroke (IS) is an important cause of death and disability worldwide, but the molecular mechanisms involved are not fully understood. In this context, choline metabolism plays an increasingly important role in IS due to its multifaceted mechanisms involving neuroprotection, neuroregeneration, inflammatory response, immune regulation, and long-term health effects. With the deepening of the research on choline and its metabolites, such as trimethylamine-N-oxide (TMAO), scientists have gradually realized its key role in the occurrence, development and potential treatment of IS. This review summarizes the importance of choline in neuroprotection and long-term disease management, highlighting the complexity of choline metabolism affecting cerebrovascular health through gut microbes. Although choline and its metabolites exhibit a protective effect, excessive intake and increases in some metabolites may confer risk, suggesting the need to carefully balance dietary choline intake. The purpose of this review is to integrate the existing research results and provide a theoretical basis for further exploring the mechanism, prognosis evaluation and clinical intervention of choline metabolism in ischemic IS, hoping to provide a new perspective and enlightenment for the formulation of effective stroke prevention and treatment strategies, and promote a comprehensive understanding of heart and brain health and optimize intervention methods.

Betaine and aging: A narrative review of findings, possible mechanisms, research perspectives, and practical recommendations

The rapid aging of the global population necessitates addressing age-related conditions through innovative strategies. Nutritional supplements have emerged as potential interventions for preventing or slowing age-related changes, with betaine being a promising candidate. This systematic review aims to provide a comprehensive analysis of current literature on the impact of betaine on the aging process. Specifically, we summarize the mechanisms through which betaine is proposed to affect aging, we integrate existing findings, we identify gaps in the literature, and we discuss practical implications for promoting healthy aging. Evidence suggests that betaine may counteract aging-related changes in methylation potential by increasing concentration of S-adenosylmethionine, a key methyl donor. Additionally, betaine reduces homocysteine concentrations, potentially mitigating vascular, neurodegenerative, and oxidative damage. Betaine has also been shown to enhance mitochondrial function, to reduce oxidative stress, and to attenuate inflammation. It may serve as a preventive agent against sarcopenia by promoting anabolic signaling pathways and improving muscle strength in younger adults. Betaine may also exert an effect on bone remodeling and adipose tissue metabolism, with animal studies indicating enhanced fat oxidation and reduced fat synthesis. Although certain limited studies have suggested betaine's potential in mitigating age-related neurodegenerative diseases, the currently available evidence does not establish a clear link between dietary betaine intake and the incidence of cardiovascular diseases or type-2 diabetes. In conclusion, emerging evidence highlights the potential of betaine in attenuating age-related changes. However, further research is required to elucidate the efficacy and safety of betaine supplementation in older populations.

Trimethylamine N-oxide in cardiovascular disease: Pathophysiology and the potential role of statins

Cardiovascular diseases are one of the leading causes of mortality and morbidity worldwide, with the total number of cases increasing to 523 million in 2019. Despite the advent of new drugs, cardiovascular mortality has increased at an alarming rate of 53.7 % from 12.1 million deaths in 1990. Recently, the role of gut microbiome metabolites, such as Trimethylamine N-Oxide (TMAO), in the pathogenesis of cardiovascular disease (CVD) has attracted significant attention. The gut microbiome is critical in various physiological processes including metabolism, immune function, and inflammation. Elevated TMAO levels are associated with atherosclerosis, heart failure, arrhythmia, and atrial fibrillation. TMAO accelerates atherosclerosis by promoting vascular inflammation and reducing reverse cholesterol transport, which leads to lipid accumulation and vessel narrowing. Previous research has indicated that a Mediterranean diet rich in fiber and phytochemicals can reduce TMAO levels by limiting precursors and fostering beneficial gut microbiota. Prebiotics and probiotics also decrease TMAO, while drugs such as meldonium, aspirin, and antibiotics have shown promise. However, recent studies have demonstrated major potential for the use of statins in reducing TMAO levels. Statin therapy can significantly reduce TMAO levels independent of their cholesterol-lowering effects. This reduction may involve direct interactions with the gut microbiome, changes in cholesterol metabolism, and changes in bile acid composition. This review aims to comprehensively evaluate the therapeutic potential of statins in reducing TMAO levels to improve CV outcomes.

Choline Metabolites, Genetic Susceptibility, and Incident Heart Failure

Background

Little is known about the associations between choline metabolites (total choline, phosphatidylcholine, and glycine) and the incidence of heart failure (HF).

Objectives

The purpose of this study was to assess the associations of choline metabolites with incident HF and examine the effect modification by genetic susceptibility.

Methods

This prospective cohort study followed 245,072 participants from the UK Biobank from baseline (2006-2010) until March 30, 2023. Participants were free of cardiovascular diseases at baseline. Circulating choline metabolites were quantitated using nuclear magnetic resonance spectrometer. Cox proportional hazards models were fitted to assess the association of choline metabolites and genetics with incident HF. Two-sample Mendelian randomization analyses were implemented to confirm the findings in observational analysis.

Results

During a median follow-up of 14.1 years, 5,468 incident HF cases were documented. Total choline and phosphatidylcholine were positively associated with HF risk (HR: 1.08 [95% CI: 1.04-1.12] and HR: 1.08 [95% CI: 1.05-1.12], per one SD increase, respectively). Compared with the lowest quartile group, the HR for the highest quartile group was 1.23 (95% CI: 1.12-1.35) for total choline and 1.23 (95% CI: 1.12-1.34) for phosphatidylcholine. Glycine was inversely associated with HF risk (HR: 0.97 [95% CI: 0.94-0.99], per one SD increase). Participants with high polygenic risk score and high total choline or phosphatidylcholine had the highest risk of HF, whereas participants with low polygenic risk score and high glycine had the lowest risk. No statistically significant interactions were observed between choline metabolites and genetic susceptibility to HF. The Mendelian randomization analysis supported the potential causal associations of total choline (OR: 1.71 [95% CI: 1.01-1.35]) and glycine (OR: 0.93 [95% CI: 0.88-0.99]) with HF.

Conclusions

Circulating choline metabolites were associated with the risk of incident HF, independent of genetic susceptibility. Whether targeting the metabolic pathway of choline might be a potential strategy for improving heart health warrants further validation.

Association of trimethylamine N-oxide and metabolites with kidney function decline in patients with chronic kidney disease

BACKGROUND

Trimethylamine N-oxide (TMAO) is a gut microbial metabolite derived from dietary l-carnitine and choline. High plasma TMAO levels are associated with cardiovascular disease and overall mortality, but little is known about the associations of TMAO and related metabolites with the risk of kidney function decline among patients with chronic kidney disease (CKD).

METHODS

We prospectively followed 152 nondialysis patients with CKD stages 3-5 and measured plasma TMAO and related metabolites (trimethylamine [TMA], choline, carnitine, and γ-butyrobetaine) via liquid chromatography‒mass spectrometry. An estimated glomerular filtration rate (eGFR) slope >3 ml/min/per 1.73 m2 per year was defined as a rapid decline. We performed logistic regression to determine the probability of rapid or slow eGFR decline, with each metabolite as the main predictor. The gut microbiota was profiled via whole metagenomic sequencing.

RESULTS

The participants had a median age of 66 years, 41.4 % were women, 39.5 % had diabetes, and the median eGFR was 23 mL/min/1.73 m2. A rapid decrease in the eGFR occurred in 65 patients (42.8 %) over a median follow-up of 3.3 years. After adjustment for baseline eGFR, proteinuria, and clinical factors, plasma TMAO levels were independently associated with increased odds of rapid eGFR decline (odds ratio, 2.42; 95 % CI, 1.36-4.32), whereas plasma TMA, choline, carnitine, and γ-butyrobetaine levels were not. Patients who exhibited rapid eGFR decline had a distinct gut microbial composition characterized by increased α-diversity and an abundance of TMA-producing bacteria, including those of the genera Desulfovibrio and Collinsella tanakaei, as well as increased expression of the TMA-producing enzymes bbuA and cutC.

CONCLUSION

Our findings suggest the relevance of plasma TMAO in the progression of kidney disease among patients with CKD.

Choline Metabolites and 15-Year Risk of Incident Diabetes in a Prospective Cohort of Adults: Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

The potential for choline metabolism to influence the development of diabetes has received increased attention. Previous studies on circulating choline metabolites and incident diabetes have been conducted in samples of older adults, often with a high prevalence of risk factors.

RESEARCH DESIGN AND METHODS

Participants were from year 15 of follow-up (2000-2001) in the Coronary Artery Risk Development in Young Adults (CARDIA) Study (n = 3,133, aged 33-45 years) with plasma choline metabolite (choline, betaine, and trimethylamine N-oxide [TMAO]) data. We quantified associations between choline metabolites and 15-year risk of incident diabetes (n = 387) among participants free of diabetes at baseline using Cox proportional hazards regression models adjusted for sociodemographics, health behaviors, and clinical variables.

RESULTS

Betaine was inversely associated with 15-year risk of incident diabetes (hazard ratio 0.76 [95% CI 0.67, 0.88] per 1-SD unit betaine), and TMAO was positively associated with 15-year risk of incident diabetes (1.11 [1.01, 1.22] per 1-SD unit). Choline was not significantly associated with 15-year risk of incident diabetes (1.05 [0.94, 1.16] per 1-SD).

CONCLUSIONS

Our findings are consistent with other published literature supporting a role for choline metabolism in diabetes. Our study extends the current literature by analyzing a racially diverse population-based cohort of early middle-aged individuals in whom preventive activities may be most relevant.

Association of Serum Trimethylamine-N-Oxide Concentration from Childhood to Early Adulthood with Age and Sex

BACKGROUND

Primary prevention is the cornerstone of cardiometabolic health. In the randomized, controlled Special Turku Coronary Risk Factor Intervention Project (STRIP), dietary counseling intervention was given to children from infancy to 20 years of age and a follow-up was completed at age 26 years. We investigated the associations of age, sex, gut microbiome, and dietary intervention with the gut metabolite and the cardiac biomarker trimethylamine-N-oxide (TMAO).

METHODS

Overall, 592 healthy participants (females 46%) from STRIP were investigated. Compared to the control group, the intervention group had received dietary counseling between ages 7 months and 20 years focused on low intakes of saturated fat and cholesterol and the promotion of fruit, vegetable, and whole-grain consumption. TMAO serum concentrations were measured by a liquid chromatography-tandem mass spectrometry method at ages 11, 13, 15, 17, 19, and 26 years. Microbiome composition was assessed using 16S rRNA gene sequencing at 26 years of age.

RESULTS

TMAO concentrations increased from age 11 to 26 years in both sexes. At all measurement time points, males showed significantly higher serum TMAO concentrations compared to females, but concentrations were similar between the intervention and control groups. A direct association between TMAO concentrations and reported fiber intake was found in females. Gut microbiome analysis did not reveal associations with TMAO.

CONCLUSIONS

TMAO concentration increased from childhood to early adulthood but was not affected by the given dietary intervention. In females, TMAO concentrations could be directly associated with higher fiber intake suggesting sex-specific differences in TMAO metabolism.