Plasma asymmetric dimethylarginine, L-arginine and left ventricular structure and function in a community-based sample

Asymmetric dimethylarginine correlates with indicators of prethrombotic state in patients with nonvalvular atrial fibrillation

OBJECTIVE

The mechanism of asymmetric dimethylarginine (ADMA) in thrombosis in patients with nonvalvular atrial fibrillation (NVAF) is still unclear. Our aim was to investigate the relationship between ADMA and indicators of prethrombotic state in NVAF patients and to analyze the predictive role of ADMA in NVAF thrombosis.

METHODS

A total of 192 NVAF patients were continuously selected from January 2023 to October 2023. Plasma ADMA levels were measured by high-performance liquid chromatography. P-selectin (P-sel), von Willebrand factor (vWF), D-dimer (D-D), and plasminogen activator inhibitor-1 (PAI-1) levels were measured by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) levels were measured by the nitrate reductase assay for plasma nitrite/nitrate, then the Griess method (Shanghai Hailian Biotechnology Co., Shanghai, China) was used to calculate plasma NO levels.

RESULTS

In our study, ADMA levels were significantly elevated and positively correlated with P-sel, vWF, D-D, and PAI-1, whereas NO levels were significantly negatively correlated with these prethrombotic factors in NVAF. Furthermore, multifactorial logistic regression analysis showed that ADMA and LA diameter were independent predictors of high thrombosis risk (CHA2DS2-VASc ≥2 score) in patients with NVAF.

CONCLUSIONS

Our findings suggested that ADMA correlated with the prethrombotic state in NVAF and that reduction of ADMA levels in NVAF patients may be a novel therapeutic strategy for thrombosis risk reduction.

The role of asymmetric dimethylarginine in endothelial dysfunction and abnormal nitric oxide metabolism in systemic sclerosis: results from a pilot study

INTRODUCTION/OBJECTIVES

Systemic sclerosis (SSc) is characterized by generalized vasculopathy affecting mainly small vessels while macrovascular involvement is less investigated. The aim of this study was to examine associations between asymmetric dimethylarginine (ADMA) - a biomarker of atherosclerosis - and assessments of macrovascular endothelial function in patients with SSc.

METHODS

This was a cross-sectional study including consecutive SSc patients attending the Scleroderma Outpatient Clinic. ADMA measurement in serum samples was based on an enzyme immunoassay technique. Participants underwent blood pressure measurement according to 2018 ESC/ESH Guidelines, applanation tonometry for the evaluation of arterial stiffness, and carotid ultrasound for the measurement of the intima-media thickness (cIMT).

RESULTS

Eighty-one Caucasians (82.3% female) SSc individuals with mean age 55.44 ± 13.4 years were included in this analysis. The correlation analysis of ADMA levels (unadjusted and adjusted values) with functional and morphological parameters of atherosclerosis revealed no statistically significant associations. Subgroup analysis based on disease duration (≤ 4 years), immunologic profile (SCL-70 and ACA antibodies), disease type (limited, diffuse), and inflammatory status (erythrocyte sedimentation rate [ESR] > 25 mm/h and C-reactive protein [CRP] > 5 mg/L) showed no associations, except from a significant positive correlation between ADMA levels and cΙΜΤ_mean (r = 0.370, p = 0.044) in individuals with early SSc.

CONCLUSIONS

The results of the study suggest that ADMA may be related with accelerated atherosclerosis in early stages of the disease. However, the lack of association between other morphological and functional parameters of endothelial dysfunction may suggest that other regulators of nitric oxide metabolism may contribute to macrovascular injury in SSc in various phases of the disease. Key Points • ADMA is a biomarker of atherosclerosis and has been linked with microvascular complications of SSc. •ADMA was not correlated with morphological and functional parameters of atherosclerosis in the population of the study. •The demonstrated association between ADMA and cIMT in patients with early SSc may suggest a role of NO/ADMA pathway in the initiation of macrovascular injury in SSc.

Asymmetric dimethylarginine, related arginine derivatives, and incident atrial fibrillation

BACKGROUND

Oxidative stress plays an important role in the development of atrial fibrillation (AF). Arginine derivatives including asymmetric dimethylarginine (ADMA) are central to nitric oxide metabolism and nitrosative stress. Whether blood concentrations of arginine derivatives are related to incidence of AF is uncertain.

METHODS AND RESULTS

In 3,310 individuals (mean age 58 ± 10 years, 54% women) from the community-based Framingham Study, we prospectively examined the relations of circulating levels of ADMA, l-arginine, symmetric dimethylarginine (SDMA), and the ratio of l-arginine/ADMA to incidence of AF using proportional hazards regression models. Over a median follow-up time of 10 years, 247 AF cases occurred. Using age- and sex-adjusted regression models, ADMA was associated with a hazard ratio of 1.15 per 1-SD increase in loge-biomarker concentration (95% CI 1.02-1.29, P = .02) for AF, which was no longer significant after further risk factor adjustment (hazard ratio 1.09, 95% CI 0.97-1.23, P = .15). Neither l-arginine nor SDMA was related to new-onset AF. A clinical model comprising clinical risk factors for AF (for age, sex, height, weight, systolic blood pressure, diastolic blood pressure, current smoking, diabetes, hypertension treatment, myocardial infarction, and heart failure; c statistic = 0.781; 95% CI 0.753-0.808) was not improved by the addition of ADMA (0.782; 95% CI 0.755-0.809).

CONCLUSIONS

Asymmetric dimethylarginine and related arginine derivatives were not associated with incident AF in the community after accounting for other clinical risk factors and confounders. Its role in the pathogenesis of AF needs further refinement.

Increased left atrial size in obese children and its association with insulin resistance: a pilot study

Subclinical cardiac abnormalities represent predisposing factors for cardiovascular disease (CVD) in obese subjects. The aim of this study was to evaluate early cardiac abnormalities in obese youth and the potential association with insulin resistance (IR). Thirty obese (12 males (M)/18 females (F); age = 11.5 ± 2.4 years; body mass index (BMI)-standard deviation score (SDS) = +2.1 ± 0.5) and 15 normal weight (10 M/5 F; age = 12.8 ± 3.1 years; BMI-SDS = +0.3 ± 0.9) children and adolescents underwent Doppler two-dimensional echocardiographic assessments of left atrial (LA) and ventricular (LV) geometry and LV diastolic function (peak early [E] and late waves, E wave deceleration time, myocardial flow velocities). Homeostasis model assessment of IR (HOMA-IR) was used as an IR index. LA size was increased in obese children, as indicated by higher LA diameter (4.9 ± 0.5 vs 4.1 ± 0.4 cm, p < 0.001), area (14.3 ± 2.5 vs 10.7 ± 2.0 cm(2), p < 0.001), and volume (33.8 ± 10.6 vs 23.7 ± 6.4 ml, p = 0.003). LV mass was also increased in obese children (87.0 ± 16.6 vs 68.8 ± 13.2 g, p = 0.003), who also showed subtle diastolic dysfunctions, as indicated by higher values of E (97.1 ± 14.3 vs 86.2 ± 11.9 cm/s, p = 0.02). All the above parameters were significantly associated with BMI-SDS (p < 0.05). In addition, HOMA-IR was independently associated with LA diameter, area, and volume (β = 0.314, p = 0.040; β = 0.415, p = 0.008; β = 0.535, p = 0.001).

CONCLUSION

Obese children feature increased LA size, which emerged to be mainly correlated to, and possibly driven by IR, suggesting an increased CVD risk.

WHAT IS KNOWN

Left atrial and ventricular alterations have been reported in obese adults, and they represent predisposing factors for cardiovascular disease. There is some evidence suggesting that obese children show increased left ventricular mass and also increased atrial size, although with conflicting results.

WHAT IS NEW

Obese normotensive children showed a moderately increased atrial size, subtle alterations in left cardiac diastolic function, and ventricular mass. An association between insulin resistance and left cardiac changes was found, although its mechanism remains to be determined.

Translating metabolomics to cardiovascular biomarkers

Metabolomics is the systematic study of the unique chemical fingerprints of small molecules or metabolite profiles that are related to a variety of cellular metabolic processes in a cell, organ, or organism. Although messenger RNA gene expression data and proteomic analyses do not tell the whole story of what might be happening in a cell, metabolic profiling provides direct and indirect physiologic insights that can potentially be detectable in a wide range of biospecimens. Although not specific to cardiac conditions, translating metabolomics to cardiovascular biomarkers has followed the traditional path of biomarker discovery from identification and confirmation to clinical validation and bedside testing. With technological advances in metabolomic tools (such as nuclear magnetic resonance spectroscopy and mass spectrometry) and more sophisticated bioinformatics and analytical techniques, the ability to measure low-molecular-weight metabolites in biospecimens provides a unique insight into established and novel metabolic pathways. Systemic metabolomics may provide physiologic understanding of cardiovascular disease states beyond traditional profiling and may involve descriptions of metabolic responses of an individual or population to therapeutic interventions or environmental exposures.

Inflammation and asymmetric dimethylarginine for predicting death and cardiovascular events in ESRD patients

BACKGROUND

Endothelial dysfunction as assessed by asymmetric dimethylarginine (ADMA) and inflammation has been consistently linked to atherosclerosis, death, and cardiovascular (CV) events in ESRD patients. Inflammation amplifies the effect of ADMA on the severity of atherosclerosis in ESRD patients, but it is still unknown whether inflammation and ADMA interact in the high risk of death and CV events in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a cohort of 225 hemodialysis patients, we investigated the interaction between inflammatory biomarkers (C-reactive protein and IL-6) and ADMA as predictors of death and CV events over an extended follow-up (13 years).

RESULTS

During follow-up, 160 patients died, and 123 had CV events. With crude and multiple Cox regression analyses, an interaction was found between inflammation biomarkers and ADMA for explaining death and CV events in ESRD patients. The adjusted hazard ratios (HRs) for death (HR, 2.18; 95% confidence interval [CI], 1.34 to 3.54) and CV outcomes (HR, 2.59; 95% CI, 1.47 to 4.55) of patients with C-reactive protein and ADMA above the median were higher than expected in the absence of interaction under the additive model (1.15 and 1.97, respectively) and significantly higher than in patients with only one biomarker above the median. Data analyses carried out by stratifying patients according to IL-6 provided similar results.

CONCLUSIONS

These data support the hypothesis that inflammation amplifies the risk of death and CV events associated with high ADMA levels in ESRD. These analyses further emphasize the need for intervention studies to attenuate inflammation and high ADMA levels in this population.