Metabolomics and cardiovascular imaging: a combined approach for cardiovascular ageing

Effects of short-term moderate intensity exercise on the serum metabolome in older adults: a pilot randomized controlled trial

BACKGROUND

We previously reported changes in the serum metabolome associated with impaired myocardial relaxation in an asymptomatic older community cohort. In this prospective parallel-group randomized control pilot trial, we subjected community adults without cardiovascular disease to exercise intervention and evaluated the effects on serum metabolomics.

METHODS

Between February 2019 to November 2019, thirty (83% females) middle-aged adults (53 ± 4 years) were randomized with sex stratification to either twelve weeks of moderate-intensity exercise training (Intervention) (n = 15) or Control (n = 15). The Intervention group underwent once-weekly aerobic and strength training sessions for 60 min each in a dedicated cardiac exercise laboratory for twelve weeks (ClinicalTrials.gov: NCT03617653). Serial measurements were taken pre- and post-intervention, including serum sampling for metabolomic analyses.

RESULTS

Twenty-nine adults completed the study (Intervention n = 14; Control n = 15). Long-chain acylcarnitine C20:2-OH/C18:2-DC was reduced in the Intervention group by a magnitude of 0.714 but increased in the Control group by a magnitude of 1.742 (mean difference -1.028 age-adjusted p = 0.004). Among Controls, alanine correlated with left ventricular mass index (r = 0.529, age-adjusted p = 0.018) while aspartate correlated with Lateral e' (r = -764, age-adjusted p = 0.016). C20:3 correlated with E/e' ratio fold-change in the Intervention group (r = -0.653, age-adjusted p = 0.004). Among Controls, C20:2/C18:2 (r = 0.795, age-adjusted p = 0.005) and C20:2-OH/C18:2-DC fold-change (r = 0.742, age-adjusted p = 0.030) correlated with change in E/A ratio.

CONCLUSIONS

Corresponding relationships between serum metabolites and cardiac function in response to exercise intervention provided pilot observations. Future investigations into cellular fuel oxidation or central carbon metabolism pathways that jointly impact the heart and related metabolic systems may be critical in preventive trials.

Longitudinal aortic strain, ventriculo-arterial coupling and fatty acid oxidation: novel insights into human cardiovascular aging

Aging-induced aortic stiffness has been associated with altered fatty acid metabolism. We studied aortic stiffness using cardiac magnetic resonance (CMR)-assessed ventriculo-arterial coupling (VAC) and novel aortic (AO) global longitudinal strain (GLS) combined with targeted metabolomic profiling. Among community older adults without cardiovascular disease, VAC was calculated as aortic pulse wave velocity (PWV), a marker of arterial stiffness, divided by left ventricular (LV) GLS. AOGLS was the maximum absolute strain measured by tracking the phasic distance between brachiocephalic artery origin and aortic annulus. In 194 subjects (71 ± 8.6 years; 88 women), AOGLS (mean 5.6 ± 2.1%) was associated with PWV (R = -0.3644, p < 0.0001), LVGLS (R = 0.2756, p = 0.0001) and VAC (R = -0.3742, p <0.0001). Stiff aorta denoted by low AOGLS <4.26% (25th percentile) was associated with age (OR 1.13, 95% CI 1.04-1.24, p = 0.007), body mass index (OR 1.12, 95% CI 1.01-1.25, p = 0.03), heart rate (OR 1.04, 95% CI 1.01-1.06, p = 0.011) and metabolites of medium-chain fatty acid oxidation: C8 (OR 1.005, p = 0.026), C10 (OR 1.003, p = 0.036), C12 (OR 1.013, p = 0.028), C12:2-OH/C10:2-DC (OR 1.084, p = 0.032) and C16-OH (OR 0.82, p = 0.006). VAC was associated with changes in long-chain hydroxyl and dicarboxyl carnitines. Multivariable models that included acyl-carnitine metabolites, but not amino acids, significantly increased the discrimination over clinical risk factors for prediction of AOGLS (AUC [area-under-curve] 0.73 to 0.81, p = 0.037) and VAC (AUC 0.78 to 0.87, p = 0.0044). Low AO GLS and high VAC were associated with altered medium-chain and long-chain fatty acid oxidation, respectively, which may identify early metabolic perturbations in aging-associated aortic stiffening. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02791139.

Serum metabolite signatures of cardiac function and morphology in individuals from a population-based cohort

BACKGROUND

Changes in serum metabolites in individuals with altered cardiac function and morphology may exhibit information about cardiovascular disease (CVD) pathway dysregulations and potential CVD risk factors. We aimed to explore associations of cardiac function and morphology, evaluated using magnetic resonance imaging (MRI) with a large panel of serum metabolites.

METHODS

Cross-sectional data from CVD-free individuals from the population-based KORA cohort were analyzed. Associations between 3T-MRI-derived left ventricular (LV) function and morphology parameters (e.g., volumes, filling rates, wall thickness) and markers of carotid plaque with metabolite profile clusters and single metabolites as outcomes were assessed by adjusted multinomial logistic regression and linear regression models.

RESULTS

In 360 individuals (mean age 56.3 years; 41.9% female), 146 serum metabolites clustered into three distinct profiles that reflected high-, intermediate- and low-CVD risk. Higher stroke volume (relative risk ratio (RRR): 0.53, 95%-CI [0.37; 0.76], p-value < 0.001) and early diastolic filling rate (RRR: 0.51, 95%-CI [0.37; 0.71], p-value < 0.001) were most strongly protectively associated against the high-risk profile compared to the low-risk profile after adjusting for traditional CVD risk factors. Moreover, imaging markers were associated with 10 metabolites in linear regression. Notably, negative associations of stroke volume and early diastolic filling rate with acylcarnitine C5, and positive association of function parameters with lysophosphatidylcholines, diacylphosphatidylcholines, and acylalkylphosphatidylcholines were observed. Furthermore, there was a negative association of LV wall thickness with alanine, creatinine, and symmetric dimethylarginine. We found no significant associations with carotid plaque.

CONCLUSIONS

Serum metabolite signatures are associated with cardiac function and morphology even in individuals without a clinical indication of CVD.

Characteristics of pulmonary artery strain assessed by cardiovascular magnetic resonance imaging and associations with metabolomic pathways in human ageing

Background

Pulmonary artery (PA) strain is associated with structural and functional alterations of the vessel and is an independent predictor of cardiovascular events. The relationship of PA strain to metabolomics in participants without cardiovascular disease is unknown.

Methods

In the current study, community-based older adults, without known cardiovascular disease, underwent simultaneous cine cardiovascular magnetic resonance (CMR) imaging, clinical examination, and serum sampling. PA global longitudinal strain (GLS) analysis was performed by tracking the change in distance from the PA bifurcation to the pulmonary annular centroid, using standard cine CMR images. Circulating metabolites were measured by cross-sectional targeted metabolomics analysis.

Results

Among n = 170 adults (mean age 71 ± 6.3 years old; 79 women), mean values of PA GLS were 16.2 ± 4.4%. PA GLS was significantly associated with age (β = -0.13, P = 0.017), heart rate (β = -0.08, P = 0.001), dyslipidemia (β = -2.37, P = 0.005), and cardiovascular risk factors (β = -2.49, P = 0.001). Alanine (β = -0.007, P = 0.01) and proline (β = -0.0009, P = 0.042) were significantly associated with PA GLS after adjustment for clinical risk factors. Medium and long-chain acylcarnitines were significantly associated with PA GLS (C12, P = 0.027; C12-OH/C10-DC, P = 0.018; C14:2, P = 0.036; C14:1, P = 0.006; C14, P = 0.006; C14-OH/C12-DC, P = 0.027; C16:3, P = 0.019; C16:2, P = 0.006; C16:1, P = 0.001; C16:2-OH, P = 0.016; C16:1-OH/C14:1-DC, P = 0.028; C18:1-OH/C16:1-DC, P = 0.032).

Conclusion

By conventional CMR, PA GLS was associated with aging and vascular risk factors among a contemporary cohort of older adults. Metabolic pathways involved in PA stiffness may include gluconeogenesis, collagen synthesis, and fatty acid oxidation.

Abnormal lactate metabolism is linked to albuminuria and kidney injury in diabetic nephropathy

Diabetic nephropathy (DN) is characterized by abnormal kidney energy metabolism, but its causes and contributions to DN pathogenesis are not clear. To examine this issue, we carried out targeted metabolomics profiling in a mouse model of DN that develops kidney disease resembling the human disorder. We found a distinct profile of increased lactate levels and impaired energy metabolism in kidneys of mice with DN, and treatment with an angiotensin-receptor blocker (ARB) reduced albuminuria, attenuated kidney pathology and corrected many metabolic abnormalities, restoring levels of lactate toward normal while increasing kidney ATP content. We also found enhanced expression of lactate dehydrogenase isoforms in DN. Expression of both the LdhA and LdhB isoforms were significantly increased in kidneys of mice, and treatment with ARB significantly reduced their expression. Single-cell sequencing studies showed specific up-regulation of LdhA in the proximal tubule, along with enhanced expression of oxidative stress pathways. There was a significant correlation between albuminuria and lactate in mice, and also in a Southeast Asian patient cohort consisting of individuals with type 2 diabetes and impaired kidney function. In the individuals with diabetes, this association was independent of ARB and angiotensin-converting enzyme inhibitor use. Furthermore, urinary lactate levels predicted the clinical outcomes of doubling of serum creatinine or development of kidney failure, and there was a significant correlation between urinary lactate levels and biomarkers of tubular injury and epithelial stress. Thus, we suggest that kidney metabolic disruptions leading to enhanced generation of lactate contribute to the pathogenesis of DN and increased urinary lactate levels may be a potential biomarker for risk of kidney disease progression.

Fluoride induced metabolic disorder of endothelial cells

Endemic fluorosis is a global public health problem. Cardiovascular diseases caused by fluoride are closely related to endothelial cell injury. Metabolism disorder of endothelial cells (ECs) are recognized as the key factor of endothelial dysfunction which has been a hot topic in recent years. However, the toxic effect of fluoride on vascular endothelium has not been elucidated. The aim of this study was to explore the alteration of endothelial cell metabolites in Human Umbilical Vein Endothelial Cells (HUVECs) exposed to NaF using LC-MS/MS technique. The screening conditions were Variable Importance for the Projection (VIP) > 1 and P < 0.05. It was found that the expression of the metabolites Lumichrome and S-Methyl-5'-thioadenosine was upregulated and of the other metabolites, such as Creatine, L-Glutamate, Stearic acid was downregulated. Differential metabolites were found to be primarily related to FoxO、PI3K/Akt and apoptosis signaling pathways by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. From the perspective of metabolism, this study explored the possible mechanism of fluoride induced endothelial cell injury which providing theories and clues for subsequent studies.

Cardio-sarcopenia: A syndrome of concern in aging

Cardiac alterations in structure and function, namely, the left ventricle, have been intensely studied for decades, in association with aging. In recent times, there has been keen interest in describing myocardial changes that accompany skeletal muscle changes in older adults. Initially described as a cardio-sarcopenia syndrome where alterations in myocardial structure were observed particularly among older adults with skeletal muscle sarcopenia, investigations into this syndrome have spurred a fresh level of interest in the cardiac-skeletal muscle axis. The purpose of this perspective is to summarize the background for this "syndrome of concern," review the body of work generated by various human aging cohorts, and to explore future directions and opportunities for understanding this syndrome.

Metabolomics study of the effect of Danggui Buxue Tang on rats with chronic fatigue syndrome

Danggui Buxue Tang (DBT), a traditional Chinese medicine formula for "invigorating qi and enriching blood", has been reported to produce a good effect on chronic fatigue syndrome (CFS). However, the related mechanism remains largely unresolved. In this study, a metabolomics approach with gas chromatography coupled to mass spectrometry combined with pattern recognition was devised to estimate the extent to which DBT alleviated CFS induced by food restriction and force swimming in rats. After four weeks of treatment, the endurance capability of rats was significantly better and the motionless time was significantly shorter in the DBT group than in CFS model group. Moreover, the activities of SOD and GSH-Px were increased, while the levels of MDA, IL-6 and TNF-α were decreased in the DBT treatment group. Fifteen significantly changed metabolites were observed in the serum of rats with CFS, which was reversed markedly by DBT treatment. Metabolic pathway analysis showed that DBT could possibly alleviate CFS in rats by regulating phenylalanine, tyrosine and tryptophan biosynthesis, glycine, serine and the metabolism of threonine, glycerolipid, glyoxylate, dicarboxylate and tyrosine. It was observed that the metabolism of glycine, serine and threonine was most closely related to the improvement of CFS by DBT treatment. This study showed that DBT could improve CFS effectively and metabolomics was a powerful means to gain insights into the traditional Chinese medicine formulas against CFS.

Left Atrial Phasic Function in Older Adults Is Associated with Fibrotic and Low-Grade Inflammatory Pathways

INTRODUCTION

Concomitant risk factors challenge the mechanistic understanding of cardiac aging. We determined the degree to which the left atrial function could be distinguished by advanced cardiac magnetic resonance (CMR) imaging in older adults and assessed associations between the left atrial function and the plasma biomarkers related to biological aging and cardiovascular disease [serum monocyte chemoattractant protein-1 (MCP1), matrix metallopeptidase 9 (MMP-9), B-type natriuretic peptides (BNPs), galectin-3 (Gal-3), high-sensitivity cardiac troponin I (hsTn1), high-sensitivity C-reactive protein (hs-CRP), and soluble urokinase plasminogen activator receptor (sUPAR)].

METHODS

Among a cross-sectional population-based cohort of older adults, longitudinal LA strain including reservoir strain (εs), conduit strain (εe), and booster strain (εa) as well as peak strain rates (SRs, SRe, SRa) were determined using CMR and studied in association with blood biomarkers.

RESULTS

We studied 243 community adults (42.8% female, mean age 70.3 ± 9.5 years). In bivariate analysis, εe and SRe were reduced in gradation with increasing risk factors (all p values <0.0001). Corresponding levels of sUPAR (ng/mL) were quantitatively higher in older adults with <2 risk factors (2.5 ± 1.6 vs. 1.7 ± 1.3, p = 0.0005), in those with ≥2 risk factors (3.3 ± 2.4 vs. 1.7 ± 1.3, p < 0.0001), compared to young adults; including between older adults with ≥2 risk factors and older adults with <2 risk factors (3.3 ± 2.4 vs. 2.5 ± 1.6, p = 0.017). Based on multivariate analysis, sUPAR was significantly associated with both εe (OR 1.52, p = 0.006) and SRe decline (OR 1.5, p = 0.019). The associations between Gal-3 and εe reduction (OR 1.2, p = 0.022) and between BNP and SRe decline were generally weaker (OR 1.03, p = 0.027). The addition of sUPAR to a model consisting of age, risk factors, Gal-3, and BNPs increased the area under the curve of εe from 0.72 to 0.77 (p = 0.015).

CONCLUSION

By advanced CMR imaging, a panel of circulating biomarkers comprising galectin, MMP-9 and sUPAR were associated with left atrial dysfunction in older adults. Higher levels of Gal-3 and MMP-9 may be suggestive of fibrotic mechanisms in left atrial aging while impairments in left atrial strain seen in association with circulating sUPAR may be related to immune activation in the left atrium in response to left atrial remodeling and fibrotic processes.

Cardiovascular Aging and Physical Activity: Insights From Metabolomics

The purpose of this review is to explore how metabolomics can help uncover mechanisms through which physical activity may influence the progression of cardiovascular aging. Cardiovascular aging is a process of functional and structural changes in older adults which can progress to cardiovascular disease. Metabolomics profiling is an investigative tool that can track the diverse changes which occur in human biochemistry with physical activity and aging. This mini review will summarize published investigations in metabolomics and physical activity, with a specific focus on the metabolic pathways that connect physical activity with cardiovascular aging.

Metabolomics and cardiovascular imaging: a combined approach for cardiovascular ageing

The purpose of this review is to explore how metabolomics can help uncover new biomarkers and mechanisms for cardiovascular ageing. Cardiovascular ageing refers to cardiovascular structural and functional alterations that occur with chronological ageing and that can lead to the development of cardiovascular disease. These alterations, which were previously only detectable on tissue histology or corroborated on blood samples, are now detectable with modern imaging techniques. Despite the emergence of powerful new imaging tools, clinical investigation into cardiovascular ageing is challenging because ageing is a life course phenomenon involving known and unknown risk factors that play out in a dynamic fashion. Metabolomic profiling measures large numbers of metabolites with diverse chemical properties. Metabolomics has the potential to capture changes in biochemistry brought about by pathophysiologic processes as well as by normal ageing. When combined with non-invasive cardiovascular imaging tools, metabolomics can be used to understand pathological consequences of cardiovascular ageing. This review will summarize previous metabolomics and imaging studies in cardiovascular ageing. These methods may be a clinically relevant and novel approach to identify mechanisms of cardiovascular ageing and formulate or personalize treatment strategies.