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Objective: Excess sodium intake is associated with volume overload and increased blood pressure. Therefore, to prevent future cardiovascular events, a sodium-restricted diet is strongly recommended for patients on maintenance hemodialysis (HD). However, only one formula for estimating dietary sodium intake in HD patients is available, and its validity has not been adequately evaluated. This study aimed to measure daily sodium intake using the duplicate portion method and provide a new formula for estimating dietary sodium intake., Design and Methods: Nineteen Japanese patients undergoing HD were enrolled in this cross-sectional multicenter study. The daily sodium intake of these patients was measured directly using the duplicate portion method. Two formulas for estimating sodium intake were developed by stepwise regression analysis. Their validities were compared with the validity of the previous formula. Furthermore, using these new formulas, we estimated the daily consumption of sodium in a large number of Japanese HD patients., Results: The previous formula underestimated true sodium intake using Bland-Altman diagrams. No significant correlation was noted between the measured sodium intake and the estimated intake (r = 0.30, P = .23, Fisher's Z-transformation). The new formulas 1 and 2, which included age, predialysis and postdialysis serum sodium levels, predialysis body weight, and interdialytic body weight gain, accurately estimated sodium consumption. The coefficients of correlation between the estimated values and the true sodium intake were r = 0.858 and r = 0.805, respectively. The simulation model using data from the Japanese Society for Dialysis Therapy showed that the distribution of the estimated sodium intake using the previous formula shifted left compared with that using the new formulas., Conclusions: The new formulas accurately estimated the daily sodium consumption in HD patients. Further longitudinal studies are required to determine whether the estimated sodium intake level calculated using the new formulas would serve as a potential marker and/or therapeutic target to prevent cardiovascular events in HD patients., (Copyright © 2021 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

A non-enzymatic reaction between reducing sugars and the amino groups of proteins, lipids and nucleic acids is known as the "Maillard reaction". The reactions have progressed in a normal aging process and at an accelerated rate under hyperglycemic, inflammatory, and/or oxidative stress conditions, thus leading to the formation and accumulation of advanced glycation end products (AGEs). Cross-linking modification of organic matrix proteins such as collagen by AGEs not only leads to an increase in vascular and myocardial stiffness, but also deteriorates structural integrity and physiological function of multiple organ systems. Furthermore, there is a growing body of evidence that interaction of AGEs with a cell surface receptor RAGE elicits oxidative stress generation and subsequently evokes inflammatory, thrombogenic and fibrotic reactions, thereby being involved in the development and progression of various age- or diabetes-related disorders, including cardiovascular disease (CVD), Alzheimer's disease, osteoporosis, cancer growth and metastasis. Skin AGE levels measured in biopsy specimens are associated with the development and progression of diabetic microangiopathy. Recently, accumulation levels of AGEs in the skin can be measured non-invasively by autofluorescence. Accumulating evidence has suggested that skin autofluorescence (SAF) is correlated with the presence and severity of vascular complications of diabetes and could predict future cardiovascular events and death in patients with diabetes. This review summarizes the pathophysiological role of tissue accumulation levels of AGEs in vascular damage in high-risk patients, especially focusing on the association between SAF and cardiorenal disorder., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Advanced glycation end products (AGEs) are a heterogenous group of molecules formed during a non-enzymatic reaction between proteins and sugar residues. Recently, AGEs and their receptor (receptor for AGEs; RAGE) play a central role in the pathogenesis of cardiovascular disease (CVD), which accounts for disability and high mortality rate in patients with diabetes. AGEs initiate diabetic micro- and macrovascular complications through the structural modification and functional alteration of the extracellular matrix proteins as well as intracellular signaling molecules. Engagement of RAGEs with AGEs elicits intracellular reactive oxygen species (ROS) generation and subsequently activates mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling, followed by production of several inflammatory and/or profibrotic factors such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), plasminogen activator inhibitor-1 (PAI-1) and monocyte chemoattractant protein-1 (MCP-1), thereby being involved in the progression of atherosclerosis. Administration of soluble form of RAGE (sRAGE) could work as a decoy receptor for AGEs and might inhibit the binding of AGEs to RAGE, preventing the development and progression of atherosclerosis in animal models. Furthermore, AGEs/high mobility group box-1 (HMGB-1)-RAGE interaction is involved in heart failure, abdominal aortic aneurysm (AAA) and vascular calcification as well. Thus, blockade of the AGEs/HMGB-1-RAGE system may be a promising therapeutic target for preventing diabetes- and/or age-related CVD. We review here the pathological role of the AGEs/HMGB-1-RAGE system in various types of CVD.

Background: A non-enzymatic reaction between reducing sugars and amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules, whose process has been known to progress at an accelerated rate under hyperglycemic and/or oxidative stress conditions. Over a course of days to weeks, early glycation products undergo further reactions such as rearrangements and dehydration to become irreversibly cross-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs)., Scope of Review: In this paper, we review the role of AGE-oxidative stress axis and its therapeutic interventions in vascular complications in diabetes., Major Conclusions: AGEs elicit oxidative stress generation and subsequently cause inflammatory and thrombogenic reactions in various types of cells via interaction with a receptor for AGEs (RAGE), thereby being involved in vascular complications in diabetes. In addition, mitochondrial superoxide generation has been shown to play an important role in the formation and accumulation of AGEs under diabetic conditions. Further, we have recently found that a pathophysiological crosstalk between AGE-RAGE axis and renin-angiotensin system (RAS) could contribute to the progression of vascular damage in diabetes., General Significance: These observations suggest that inhibition of AGE-RAGE-oxidative stress axis or blockade of its interaction with RAS is a novel therapeutic strategy for preventing vascular complications in diabetes., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Diabetes is associated with an increase risk for cardiovascular disease (CVD). Recently, macrovascular complications of diabetes have been shown to start before the development of diabetes. Indeed, several clinical studies have confirmed the increased risk of CVD in patients with impaired glucose tolerance (IGT). Since postprandial hyperglycemia and insulin resistance are thought to play a central role in the development and progression of CVD in patients with IGT, amelioration of postprandial hyperglycemia as well as insulin resistance is a therapeutic target for the prevention of CVD in these high-risk patients. Acarbose, an alpha-glucosidase inhibitor, delays the absorption of carbohydrate from the small intestine, thereby reducing postprandial hyperglycemia. Further, recently, acarbose has been shown to improve insulin resistance in vivo. These findings suggest that acarbose is a promising metabolic modifier that could reduce the risk of CVD in patients with the metabolic syndrome. In this paper, we review the clinical utility of acarbose in various cardiometabolic disorders.

Endothelial dysfunction due to the reduced bioavailability of nitric oxide (NO) is involved in the course of atherosclerotic cardiovascular disease as well as chronic kidney disease (CKD). NO is synthesized from L-arginine via the action of NO synthase, which is blocked by endogenous L-arginine analogues such as asymmetric dimethylarginine (ADMA). ADMA is a naturally occurring amino acid found in plasma and various types of tissues. The plasma level of ADMA is reported to be associated with cardiovascular risk factors such as hypertension, diabetes, hyperlipidemia, and CKD, and is a strong predictor for cardiovascular disease and the progression of CKD. In this review, we discuss the biology of ADMA, the molecular mechanisms of the elevation of ADMA levels in CKD, and the pathological role of ADMA in patients with CKD.

Late-onset hypogonadism (LOH) and depression contribute to cardiovascular disease (CVD) in male hemodialysis (HD) patients. Carnitine deficiency is frequently observed in HD patients, playing a role in CVD. We examined whether carnitine deficiency was independently associated with LOH and depression in these patients. Twenty-six male HD patients underwent determinations of serum levels of free carnitine and testosterone. Status of LOH and depression were evaluated by questionnaires using aging male symptoms' (AMS) scale and self-rating depression scale (SDS), respectively. Free carnitine and testosterone levels in male HD patients were significantly lower than those in age-matched healthy male subjects. Linear regression analysis showed that AMS scale was positively associated with SDS. Univariate regression analysis revealed that total carnitine (inversely), free carnitine (inversely) and HD duration were correlated with AMS scale. Multiple stepwise regression analysis revealed that free carnitine was an independent determinant of AMS scale. Furthermore, free carnitine was also independently correlated with SDS in male HD patients. This study demonstrated that decreased free carnitine levels were independently associated with AMS scale and SDS in male HD patients. The observations suggest that decreased free carnitine levels could be a marker and therapeutic target of LOH and depression in uremic men with HD. [ABSTRACT FROM AUTHOR]

ABSTRACT: Aim: There is accumulating evidence that advanced glycation end products (AGE) play a role in cardiovascular disease (CVD) in patients with haemodialysis (HD). Carnitine deficiency is frequently observed in HD patients, which may also contribute to CVD. In this study, we examined whether carnitine deficiency was independently associated with increased tissue accumulation levels of AGE in HD patients. Methods: One hundred and twenty-nine HD patients underwent determinations of blood chemistries including serum level of carnitine. Tissue AGE levels were evaluated by measuring skin autofluorescence with an AGE-reader. Results: Serum carnitine levels were significantly lower, while skin AGE levels were significantly higher in HD patients compared with healthy controls ( P < 0.001). In univariate analysis, β2-microglobulin (β2-MG) and carnitine (inversely) were correlated with skin AGE levels. Multiple stepwise regression analysis revealed that carnitine levels were one of the independent determinants of skin AGE levels ( P = 0.024). When β2-MG-adjusted skin AGE levels were stratified by serum carnitine levels, a statistical significance and dose-response relationship were observed ( P = 0.043). Furthermore, skin AGE levels were one of the independent determinants of serum carnitine levels as well ( P = 0.012). Conclusion: The present study demonstrated that decreased carnitine levels were independently associated with increased skin AGE levels in HD patients. Since carnitine is reported to inhibit the formation of AGE in vitro, our study suggests that supplementation of carnitine may be a therapeutic target for preventing the accumulation of tissue AGE and subsequently reducing the risk of CVD in HD patients. [ABSTRACT FROM AUTHOR]

C-reactive protein (CRP) level predicts future cardiovascular events in patients on haemodialysis (HD). Advanced glycation end products (AGE) play a role in cardiovascular disease (CVD) in HD patients. However, which variables including tissue AGE levels are independently associated with CRP remains unknown. Therefore, whether tissue AGE and CRP levels were correlated with atherosclerosis in HD patients was examined. Fifty-four HD patients underwent determinations of blood chemistries and tissue AGE. Tissue AGE levels were evaluated by measuring skin autofluorescence. Pulsatility index (PI) in the carotid artery was measured using a Doppler ultrasonography. Univariate analyses showed that age, white blood cells, serum albumin (inversely), alkaline phosphatase (inversely), tartrate-resistant acid phosphatase 5b (TRAP5b) (inversely) and skin AGE levels were significantly correlated with high-sensitivity CRP (hsCRP). Multiple stepwise regression analysis revealed that serum albumin, TRAP5b and skin AGE levels were independent determinants of hsCRP. Further, PI was highest among HD patients with high skin AGE and high hsCRP levels. The present study suggests that tissue AGE level is one of the independent determinants of hsCRP in HD patients. Tissue AGE and hsCRP levels may be correlated with each other, which could in concert contribute to the progression of atherosclerosis in these subjects. This study demonstrates the association between tissue advanced glycation end products (AGE) level and high-sensitivity C-reactive protein (hsCRP) in haemodialysis patients. In addition, tissue AGE and hsCRP levels could in concert contribute to the progression of atherosclerosis in these subjects. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is a public health concern that affects approximately 10% of the global population. CKD is associated with poor outcomes due to high frequencies of comorbidities such as heart failure and cardiovascular disease. Uremic toxins are compounds that are usually filtered and excreted by the kidneys. With the decline of renal function, uremic toxins are accumulated in the systemic circulation and tissues, which hastens the progression of CKD and concomitant comorbidities. Gut microbial dysbiosis, defined as an imbalance of the gut microbial community, is one of the comorbidities of CKD. Meanwhile, gut dysbiosis plays a pathological role in accelerating CKD progression through the production of further uremic toxins in the gastrointestinal tracts. Therefore, the gut-kidney axis has been attracting attention in recent years as a potential therapeutic target for stopping CKD. Trimethylamine N-oxide (TMAO) generated by gut microbiota is linked to the progression of cardiovascular disease and CKD. Also, advanced glycation endproducts (AGEs) not only promote CKD but also cause gut dysbiosis with disruption of the intestinal barrier. This review summarizes the underlying mechanism for how gut microbial dysbiosis promotes kidney injury and highlights the wide-ranging interventions to counter dysbiosis for CKD patients from the view of uremic toxins such as TMAO and AGEs. [ABSTRACT FROM AUTHOR]