Effects of 6-month supplementation with β-hydroxy-β-methylbutyrate, glutamine and arginine on vascular endothelial function of older adults

Peculiarities of clinical signs, course and treatment of musculoskeletal system lesions in post-COVID syndrome

Introduction

Post-COVID syndrome (PCS) is a frequent phenomenon of patients who have suffered from an acute attack of COVID-19 infection, and it is characterized by a wide range of symptoms from different organs and systems including the musculoskeletal system (MSS). However, peculiarities of MSS lesions have not been sufficiently studied to date, in particular, in the aspect of the therapeutic process. We aimed to investigate peculiarities of MSS lesions in patients with PCS.

Material and methods

Observations were carried out in 142 patients with PCS and MSS lesions. The age of patients was 36-67 years. Up-to-date methods of disease verification were used. An acute period of COVID-19 in all the patients was of moderate severity without oxygen support.

Results

Musculoskeletal system lesions in patients with PCS were found to appear 1-4 weeks after the experienced acute period of COVID-19 infection. Against the background of significant arthralgia (100%) in 93 (65.5%) patients manifestations of acute arthritis were detected, the frequency of which increased with age. Musculoskeletal system lesions were found against the background of dominating PCS manifestations from the cardiovascular and digestive systems. Deterioration of the course and results of treatment of diseases caused by an age-related polymorbid background was determined. Certain difficulties in the treatment of MSS lesions by means of non-steroidal anti-inflammatory drugs and limitation in the use of glucocorticosteroids are caused by severe gastroduodenopathy and arterial hypertension. Long-term, up to 6 months, administration of L-arginine, L-carnitine and quercetin in the rehabilitation complex improved the overall results of treatment of PCS manifestations including arthropathy.

Conclusions

Musculoskeletal system lesions in patients with PCS are not the main constituent of this syndrome. Difficulties in the treatment of arthropathy are due to the signs of gastroduodenopathy and arterial hypertension. Additional administration of L-arginine, L-carnitine and quercetin is reasonable.

Long-term supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine, and glutamine for pressure ulcer in sedentary older adults: a retrospective matched case-control study

BACKGROUND

Growing evidence suggests that beta-hydroxy-beta-methylbutyrate (HMB), arginine (Arg), and glutamine (Gln) positively affect wound recovery. This study investigated the effects of long-term administration of HMB/Arg/Gln on pressure ulcer (PU) healing in sedentary older adults admitted to geriatric and rehabilitation care facilities.

METHODS

This was a pilot retrospective case (standard of care and HMB/Arg/Gln)-control (standard of care alone) clinical study. Outcome measures were relative healing rates and Pressure Ulcer Scale for Healing (PUSH) scores (calculated after 4, 8, 12, 16, and 20 weeks) and time to healing.

RESULTS

The study subpopulation was comprised of 14 participants (four males, 28.6%) with the median age of 85.5 years (interquartile range [IQR], 82.0-90.2 years). The control subpopulation was comprised of 31 participants (18 males, 58.1%) with the median age of 84.0 years (IQR, 78.0-90.0 years). At the beginning of follow-up, there were no statistically significant demographic (sex and age) and clinical (main diagnosis, baseline area, and PU perimeter) differences between the groups. During the study period, there were no significant differences in the relative healing rates and PUSH scores between the subpopulations. The median time to complete healing in the study and control populations was 170.0 days (95% confidence interval [CI], 85.7-254.3) and 218.0 days (95% CI, 149.2-286.7) (log-rank, chi-square=3.99; p<0.046), respectively.

CONCLUSION

More than 20 weeks of HMB/Arg/Gln supplementation had a positive effect on difficult PU healing in older adults with multiple comorbidities.

Glutamine Deficiency Promotes Immune and Endothelial Cell Dysfunction in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has caused the death of almost 7 million people worldwide. While vaccinations and new antiviral drugs have greatly reduced the number of COVID-19 cases, there remains a need for additional therapeutic strategies to combat this deadly disease. Accumulating clinical data have discovered a deficiency of circulating glutamine in patients with COVID-19 that associates with disease severity. Glutamine is a semi-essential amino acid that is metabolized to a plethora of metabolites that serve as central modulators of immune and endothelial cell function. A majority of glutamine is metabolized to glutamate and ammonia by the mitochondrial enzyme glutaminase (GLS). Notably, GLS activity is upregulated in COVID-19, favoring the catabolism of glutamine. This disturbance in glutamine metabolism may provoke immune and endothelial cell dysfunction that contributes to the development of severe infection, inflammation, oxidative stress, vasospasm, and coagulopathy, which leads to vascular occlusion, multi-organ failure, and death. Strategies that restore the plasma concentration of glutamine, its metabolites, and/or its downstream effectors, in conjunction with antiviral drugs, represent a promising therapeutic approach that may restore immune and endothelial cell function and prevent the development of occlusive vascular disease in patients stricken with COVID-19.

Evaluation of the recovery after heart surgery following preoperative supplementation with a combination of beta-hydroxy-beta-methylbutyrate, L-arginine, and L-glutamine: a double-blind randomized placebo-controlled clinical trial

BACKGROUND

The preoperative period is a good time to improve nutrition status, compensate for nutrient deficiencies, and optimize immune function in patients' underlying surgery. In some medical conditions, supplementation with a combination of L-glutamine (Gln), β-hydroxy-β-methylbutyrate (HMB), and L-arginine (Arg) had promising effects on improving recovery. The present study aimed to evaluate the effect of supplementation with Gln/Arg/HMB in patients undergoing heart surgery.

METHODS

This randomized clinical trial was conducted on 70 patients undergoing cardiac surgery. Participants were requested to consume 2 sachets of a combination of 7 g L-arginine, 7 g L-glutamine, and 1.5 g daily HMB or placebo 30 days before operation. At the baseline and end of the study, left ventricular ejection fraction and the serum levels of troponin, creatine phosphokinase (CPK), CPK-MB, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin were measured. Also, the Sequential Organ Failure Assessment (SOFA) score, time of stay in hospital and intensive care unit (ICU), and postoperative complications were recorded after surgery.

RESULTS

In total, 60 preoperative patients (30 in each group) with a mean age of 53.13 ± 14.35 years completed the study (attrition rate = 85.7%). Subjects in the Gln/Arg/HMB group had lower serum levels of CPK-MB (median [IQR] = 49 [39.75] vs. 83 [64.55]; P = 0.011), troponin (median [IQR] = 2.13 [1.89] vs. 4.34 [1.99]; P < 0.001), bilirubin (median [IQR] = 0.50 [0.20] vs. 0.40 [0.22]; P < 0.001), and SOFA score (median [IQR] = 2 [2] vs. 5 [2]; P < 0.001) at end of the study compared to the placebo. Also, the time of stay in the hospital (median [IQR] = 5 [1] vs. 6 [3]; P < 0.001) and ICU (median [IQR] = 2.50 [1.00] vs. 3.50 [1.50]; P = 0.002) was lower in the Gln/Arg/HMB group.

CONCLUSION

The present study showed that perioperative supplementation with a combination of Gln, Arg, and HMB enhances the recovery, reduces myocardial injury, and decreases the time of hospital and ICU stay in cardiac surgery patients. These results need to be confirmed in a larger trial.

TRIAL REGISTRATION

IRCT.ir IRCT20120913010826N31. Registered on 13 October 2020.

l-Glutamine supplementation enhances glutathione peroxidase and paraoxonase-1 activities in HDL of exercising older individuals

BACKGROUND

Oxidative stress is an important factor in the formation of atherosclerotic plaques. High-density lipoprotein (HDL) harbors paraoxonase-1 (PON-1) and glutathione peroxidase (GPx), key enzymes in the protection against the harmful effects of oxidative stress. Although exercise training can increase both HDL-c content and its antioxidant action, and glutamine (Gln) intake also promotes GPx-based defenses, the association between exercise training and Gln in the regulation of PON-1 activity was not explored. Therefore, the objective of this study was to investigate the effects of Gln supplementation on the redox balance and on the total HDL antioxidant capacity by evaluation of the activity of PON-1 and GPx enzymes in physically exercised elderly individuals compared to non-exercised ones.

METHODS

Fifty-one practitioners of a combined exercise training program (CET, age: 71.9 ± 5.7 years) and 32 non-practitioners (NP, age: 73 ± 6.3 years) participated in the study. CET and NP groups were separated into 2 subgroups according to the supplementation: Gln, 0.3 g/kg/day + 10 g maltodextrin (CET-Gln, n = 26; and NP-Gln, n = 16) or placebo, 10 g maltodextrin (CET-PL, n = 25; and NP-PL, n = 16). Blood samples were drawn at baseline and after 30 days after commencement of the supplementation for biochemical and enzyme activity analyses.

RESULTS

Increased HDL-c, total peroxidase (PRx), and GPx activities were found in both CET-Gln and NP-Gln after the supplementation period, compared to baseline, in opposition to CET-PL and NP-PL groups. PON-1 activity increased only in CET-Gln. In both CET-Gln and NP-Gln groups, there was a reduction of the total peroxides/PRx, iron/PRx, and total peroxides/GPX ratios after supplementation. In CET-Gln, thiobarbituric acid-reactive substances (TBARS)/PRx and TBARS/GPx ratios were also lower after supplementation. CET-Gln and CET-PL subgroups had lower glycemia than NP-Gln and NP-PL, either at baseline or after the supplementation periods. The other parameters were unchanged after supplementation [total cholesterol, LDL-c, triglycerides, non-HDL cholesterol, total peroxides, TBARS, iron serum, Trolox-equivalent antioxidant capacity (TEAC), and uric acid].

CONCLUSIONS

Gln supplementation can increase glutathione peroxidase activity regardless the individuals were physically active or sedentary, but the PON-1 activity only increased in physically active individuals. These results show the potential of Gln supplementation in the maintenance of the vascular redox balance, with potential implications for atherogenesis protection.

Metabolic Alterations Identified in Urine, Plasma and Aortic Smooth Muscle Cells Reflect Cardiovascular Risk in Patients with Programmed Coronary Artery Bypass Grafting

Atherosclerosis is the predominant pathology associated to premature deaths due to cardiovascular disease. However, early intervention based on a personalized diagnosis of cardiovascular risk is very limited. We have previously identified metabolic alterations during atherosclerosis development in a rabbit model and in subjects suffering from an acute coronary syndrome. Here we aim to identify specific metabolic signatures which may set the basis for novel tools aiding cardiovascular risk diagnosis in clinical practice. In a cohort of subjects with programmed coronary artery bypass grafting (CABG), we have performed liquid chromatography and targeted mass spectrometry analysis in urine and plasma. The role of vascular smooth muscle cells from human aorta (HA-VSMCs) was also investigated by analyzing the intra and extracellular metabolites in response to a pro-atherosclerotic stimulus. Statistically significant variation was considered if p value < 0.05 (Mann-Whitney test). Urinary trimethylamine N-oxide (TMAO), arabitol and spermidine showed higher levels in the CVrisk group compared with a control group; while glutamine and pantothenate showed lower levels. The same trend was found for plasma TMAO and glutamine. Plasma choline, acetylcholine and valine were also decreased in CVrisk group, while pyruvate was found increased. In the secretome of HA-VSMCs, TMAO, pantothenate, glycerophosphocholine, glutathion, spermidine and acetylcholine increased after pro-atherosclerotic stimulus, while secreted glutamine decreased. At intracellular level, TMAO, pantothenate and glycerophosphocholine increased with stimulation. Observed metabolic deregulations pointed to an inflammatory response together with a deregulation of oxidative stress counteraction.

Molecular Signature of Multisystem Cardiometabolic Stress and Its Association With Prognosis

Importance

Cardiometabolic disease is responsible for decreased longevity and poorer cardiovascular outcomes in the modern era. Metabolite profiling provides a specific measure of global metabolic function to examine specific metabolic mechanisms and pathways of cardiometabolic disease beyond its clinical definitions.

Objectives

To define a molecular basis for cardiometabolic stress and assess its association with cardiovascular prognosis.

Design, Setting, and Participants

A prospective observational cohort study was conducted in a population-based setting across 2 geographically distinct centers (Boston Puerto Rican Health Study [BPRHS], an ongoing study of individuals enrolled between June 1, 2004, and October 31, 2009; and Atherosclerosis Risk in Communities [ARIC] study, whose participants were originally sampled between November 24, 1986, and February 10, 1990, and followed up through December 31, 2017). Participants in the BPRHS were 668 Puerto Rican individuals with metabolite profiling living in Massachusetts, and participants in the ARIC study were 2152 individuals with metabolite profiling and long-term follow-up for mortality and cardiovascular outcomes. Statistical analysis was performed from October 1, 2018, to March 13, 2020.

Exposure

The primary exposure was metabolite profiles across both cohorts.

Main Outcomes and Measures

Outcomes included associations with multisystem cardiometabolic stress and all-cause mortality and incident coronary heart disease (in the ARIC study).

Results

Participants in the BPRHS (N = 668; 491 women; mean [SD] age, 57.0 [7.4] years; mean [SD] body mass index [calculated as weight in kilograms divided by height in meters squared], 32.0 [6.5]) had higher prevalent cardiometabolic risk relative to those in the ARIC study (N = 2152; 599 African American individuals; 1213 women; mean [SD] age, 54.3 [5.7] years; mean [SD] body mass index, 28.0 [5.5]). Multisystem cardiometabolic stress was defined for 668 Puerto Rican individuals in the BPRHS as a multidimensional composite of hypothalamic-adrenal axis activity, sympathetic activation, blood pressure, proatherogenic dyslipidemia, insulin resistance, visceral adiposity, and inflammation. A total of 260 metabolites associated with cardiometabolic stress were identified in the BPRHS, involving known and novel pathways of cardiometabolic disease (eg, amino acid metabolism, oxidative stress, and inflammation). A parsimonious metabolite-based score associated with cardiometabolic stress in the BPRHS was subsequently created; this score was applied to shared metabolites in the ARIC study, demonstrating significant associations with coronary heart disease and all-cause mortality after multivariable adjustment at a 30-year horizon (per SD increase in metabolomic score: hazard ratio, 1.14; 95% CI, 1.00-1.31; P = .045 for coronary heart disease; and hazard ratio, 1.15; 95% CI, 1.07-1.24; P < .001 for all-cause mortality).

Conclusions and Relevance

Metabolites associated with cardiometabolic stress identified known and novel pathways of cardiometabolic disease in high-risk, community-based cohorts and were associated with coronary heart disease and survival at a 30-year time horizon. These results underscore the shared molecular pathophysiology of metabolic dysfunction, cardiovascular disease, and longevity and suggest pathways for modification to improve prognosis across all linked conditions.

Blood biomarkers indicate that the preclinical stages of Alzheimer's disease present overlapping molecular features

It is still debated whether non-specific preclinical symptoms of Alzheimer's disease (AD) can have diagnostic relevance. We followed the evolution from cognitively normal to AD by NMR-based metabolomics of blood sera. Multivariate statistical analysis of the NMR profiles yielded models that discriminated subjective memory decline (SMD), mild cognitive impairment (MCI) and AD. We validated a panel of six statistically significant metabolites that predicted SMD, MCI and AD in a blind cohort with sensitivity values ranging from 88 to 95% and receiver operating characteristic values from 0.88 to 0.99. However, lower values of specificity, accuracy and precision were observed for the models involving SMD and MCI, which is in line with the pathological heterogeneity indicated by clinical data. This excludes a "linear" molecular evolution of the pathology, pointing to the presence of overlapping "gray-zones" due to the reciprocal interference of the intermediate stages. Yet, the clear difference observed in the metabolic pathways of each model suggests that pathway dysregulations could be investigated for diagnostic purposes.

Arginine supplementation and cardiometabolic risk

PURPOSE OF REVIEW

Because arginine is the substrate for nitric oxide synthesis, which is pivotal to vascular homeostasis and linked to the insulin response, it has long been posited that supplemental arginine could benefit cardiometabolic health.

RECENT FINDINGS

Recent data have supported the view that supplemental arginine could alleviate the initiation and development of endothelial dysfunction and also shown that it may reduce the risk of type 2 diabetes. One important finding is that these effects may indeed vary as a function of the amount of arginine, its form and notably the metabolic status of the population. Some studies have shown that low doses of slow-release arginine are better used for nitric oxide synthesis and beneficial in individuals with abnormal arginine metabolism/bioavailability. Pathophysiological data in rodents have emphasized the importance of arginase activation during the development of cardiometabolic risk, which lends credence to a potential benefit for arginine supplements. Likewise, epidemiological evidence suggests that alterations to arginine bioavailability are important regarding the cardiometabolic risk. However, other metabolic mechanisms linked to the multiple pathways of arginine metabolism may also play a role.

SUMMARY

Further studies are needed to confirm and analyze how and when supplemental arginine is beneficial to cardiometabolic health.

The Emerging Role of l-Glutamine in Cardiovascular Health and Disease

Emerging evidence indicates that l-glutamine (Gln) plays a fundamental role in cardiovascular physiology and pathology. By serving as a substrate for the synthesis of DNA, ATP, proteins, and lipids, Gln drives critical processes in vascular cells, including proliferation, migration, apoptosis, senescence, and extracellular matrix deposition. Furthermore, Gln exerts potent antioxidant and anti-inflammatory effects in the circulation by inducing the expression of heme oxygenase-1, heat shock proteins, and glutathione. Gln also promotes cardiovascular health by serving as an l-arginine precursor to optimize nitric oxide synthesis. Importantly, Gln mitigates numerous risk factors for cardiovascular disease, such as hypertension, hyperlipidemia, glucose intolerance, obesity, and diabetes. Many studies demonstrate that Gln supplementation protects against cardiometabolic disease, ischemia-reperfusion injury, sickle cell disease, cardiac injury by inimical stimuli, and may be beneficial in patients with heart failure. However, excessive shunting of Gln to the Krebs cycle can precipitate aberrant angiogenic responses and the development of pulmonary arterial hypertension. In these instances, therapeutic targeting of the enzymes involved in glutaminolysis such as glutaminase-1, Gln synthetase, glutamate dehydrogenase, and amino acid transaminase has shown promise in preclinical models. Future translation studies employing Gln delivery approaches and/or glutaminolysis inhibitors will determine the success of targeting Gln in cardiovascular disease.

A combination of chicken embryo extract and a nutritional supplement protect a rat model of aging againstd-galactose-induced dysfunction of mitochondria and autophagy

The aging process is usually associated with increased oxidative stress and deficiency of tissues and organs, which causes a decline in the life quality of individuals.

Comprehensive metabolic profiling of chronic low-grade inflammation among generally healthy individuals

BACKGROUND

Inflammation occurs as an immediate protective response of the immune system to a harmful stimulus, whether locally confined or systemic. In contrast, a persisting, i.e., chronic, inflammatory state, even at a low-grade, is a well-known risk factor in the development of common diseases like diabetes or atherosclerosis. In clinical practice, laboratory markers like high-sensitivity C-reactive protein (hsCRP), white blood cell count (WBC), and fibrinogen, are used to reveal inflammatory processes. In order to gain a deeper insight regarding inflammation-related changes in metabolism, the present study assessed the metabolic patterns associated with alterations in inflammatory markers.

METHODS

Based on mass spectrometry and nuclear magnetic resonance spectroscopy we determined a comprehensive panel of 613 plasma and 587 urine metabolites among 925 apparently healthy individuals. Associations between inflammatory markers, namely hsCRP, WBC, and fibrinogen, and metabolite levels were tested by linear regression analyses controlling for common confounders. Additionally, we tested for a discriminative signature of an advanced inflammatory state using random forest analysis.

RESULTS

HsCRP, WBC, and fibrinogen were significantly associated with 71, 20, and 19 plasma and 22, 3, and 16 urine metabolites, respectively. Identified metabolites were related to the bradykinin system, involved in oxidative stress (e.g., glutamine or pipecolate) or linked to the urea cycle (e.g., ornithine or citrulline). In particular, urine 3'-sialyllactose was found as a novel metabolite related to inflammation. Prediction of an advanced inflammatory state based solely on 10 metabolites was well feasible (median AUC: 0.83).

CONCLUSIONS

Comprehensive metabolic profiling confirmed the far-reaching impact of inflammatory processes on human metabolism. The identified metabolites included not only those already described as immune-modulatory but also completely novel patterns. Moreover, the observed alterations provide molecular links to inflammation-associated diseases like diabetes or cardiovascular disorders.

Effects of an L-arginine-based multi ingredient product on endothelial function in subjects with mild to moderate hypertension and hyperhomocysteinemia - a randomized, double-blind, placebo-controlled, cross-over trial

Background

Nutrition plays an important role in prevention and management of cardiovascular diseases (CVD) in early stages. Recent research demonstrated beneficial effects of various nutritional ingredients on vascular health. The aim of the current study was to evaluate the effects of an L-arginine-based multi ingredient product (AbMIP) on vascular function.

Methods

Twenty-five male and female subjects, aged between 45 and 65 years with elevated blood pressure and hyperhomocysteinemia were included in this cross-over trial. Subjects were randomly assigned to one of the two sequence groups (AbMIP -placebo or placebo – AbMIP). AbMIP and placebo were taken for 4 weeks, each. Endothelial function under fasting conditions, blood pressure, postprandial endothelial function after consumption of a high fat meal, homocysteine, asymmetric dimethyl arginine (ADMA) and Hba1c were determined.

Results

AbMIP significantly improved fasting endothelial function determined by EndoPAT™ when compared to placebo (p = 0.047). Similarly, homocysteine levels were significantly decreased after verum supplementation when compared to placebo (p < 0.0001). Systolic blood pressure decreased significantly under AbMIP (p = 0.002) and the reduction was more pronounced when compared to placebo. However, due to placebo-effects no significant difference could be found between groups (p = 0.586). The effects on postprandial endothelial function were stronger for AbMIP when compared with placebo but did not reach significance (p = 0.201). No significant effects of AbMIP were observed regarding HbA1c, ADMA and diastolic blood pressure.

Conclusions

Due to improvement on endothelial function, decrease of elevated homocysteine levels and excellent tolerability, AbMIP was demonstrated to be a beneficial option for dietary treatment of endothelial dysfunction and hyperhomocysteinemia in early stages of CVD.

Trial registration

The clinical trials.gov identifier is NCT02392767, November 14, 2014.