Vascular Calcification Heterogeneity from Bench to Bedside: Implications for Manifestations, Pathogenesis, and Treatment Considerations

Vascular calcification (VC) is the ectopic deposition of calcium-containing apatite within vascular walls, exhibiting a high prevalence in older adults, and those with diabetes or chronic kidney disease. VC is a subclinical cardiovascular risk trait that increases mortality and functional deterioration. However, effective treatments for VC remain largely unavailable despite multiple attempts. Part of this therapeutic nihilism results from the failure to appreciate the diversity of VC as a pathological complex, with unforeseeable variations in morphology, risk associates, and anatomical and molecular pathogenesis, affecting clinical management strategies. VC should not be considered a homogeneous pathology because accumulating evidence refutes its conceptual and content uniformity. Here, we summarize the pathophysiological sources of VC heterogeneity from the intersecting pathways and networks of cellular, subcellular, and molecular crosstalk. Part of these pathological connections are synergistic or mutually antagonistic. We then introduce clinical implications related to the VC heterogeneity concept. Even within the same individual, a specific artery may exhibit the strongest tendency for calcification compared with other arteries. The prognostic value of VC may only be detectable with a detailed characterization of calcification morphology and features. VC heterogeneity is also evident, as VC risk factors vary between different arterial segments and layers. Therefore, diagnostic and screening strategies for VC may be improved based on VC heterogeneity, including the use of radiomics. Finally, pursuing a homogeneous treatment strategy is discouraged and we suggest a more rational approach by diversifying the treatment spectrum. This may greatly benefit subsequent efforts to identify effective VC therapeutics.

A combined circulating microRNA panel predicts the risk of vascular calcification in community-dwelling older adults with age strata differences

BACKGROUND

Older adults have a higher risk of developing vascular calcification (VC). Circulating miRNAs can be potential risk indicators. However, prior studies used single miRNA mostly, whereas miRNA panels were rarely evaluated. We aimed to examine whether a miRNA panel outperformed each miRNA alone, and analyzed whether advanced age affected VC risk predictive performance offered by the miRNA panel.

METHODS

We prospectively enrolled older adults (age ≥65 years) during their annual health checkup in 2017, and examined their VC severity followed by analyzing sera for VC regulatory miRNAs (miR-125b-5p, miR-125b-3p, and miR-378a-3p). We used multiple regression analyses to determine associations between each miRNA or a 3-combind panel and VC risk, followed by area under the receiver-operating-characteristics curve (AUROC) analysis. Participants were further divided to those of 65-75 and ≥75 years for comparison.

RESULTS

From 199 older adults screened, 169 (median age, 73.3 years) with available calcification assessment were analyzed, among whom 74.6 % having VC. Those with VC had significantly lower circulating miR-125b-5p, miR-125b-3p, and miR-378a-3p levels than those without. Regression analyses showed that the 3-combined miRNA panel exhibited significant associations with VC risk, with significantly higher AUROC than those of models based on individual miRNA. Importantly, in those ≥75 years, the miRNA-predicted risk of VC was more prominent than that in the 65-75 years group.

CONCLUSION

A miRNA panel for VC risk prediction might outperform individual miRNA alone in older adults, and advanced age modified the association between circulating miRNAs and the risk of VC.

The screening, diagnosis, and management of patients with autosomal dominant polycystic kidney disease: A national consensus statement from Taiwan

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of end-stage kidney disease (ESKD) worldwide. Guidelines for the diagnosis and management of ADPKD in Taiwan remains unavailable. In this consensus statement, we summarize updated information on clinical features of international and domestic patients with ADPKD, followed by suggestions for optimal diagnosis and care in Taiwan. Specifically, counselling for at-risk minors and reproductive issues can be important, including ethical dilemmas surrounding prenatal diagnosis and pre-implantation genetic diagnosis. Studies reveal that ADPKD typically remains asymptomatic until the fourth decade of life, with symptoms resulting from cystic expansion with visceral compression, or rupture. The diagnosis can be made based on a detailed family history, followed by imaging studies (ultrasound, computed tomography, or magnetic resonance imaging). Genetic testing is reserved for atypical cases mostly. Common tools for prognosis prediction include total kidney volume, Mayo classification and PROPKD/genetic score. Screening and management of complications such as hypertension, proteinuria, urological infections, intracranial aneurysms, are also crucial for improving outcome. We suggest that the optimal management strategies of patients with ADPKD include general medical care, dietary recommendations and ADPKD-specific treatments. Key points include rigorous blood pressure control, dietary sodium restriction and Tolvaptan use, whereas the evidence for somatostatin analogues and mammalian target of rapamycin (mTOR) inhibitors remains limited. In summary, we outline an individualized care plan emphasizing careful monitoring of disease progression and highlight the need for shared decision-making among these patients.

Interprofessional Differences in Multidimensional Self-Efficacy Associated With Professional Performance in Nephrology During Case-Based Learning

Introduction

Postgraduate medical education assumes rising importance in the rapidly advancing field of medicine. Case-based learning (CBL), a learner-centered pedagogy employing clinical cases to improve decision-making, is widely embraced in postgraduate medical education, including nephrology. Studies suggest that learning self-efficacy (SE) was closely associated with learning motivation and academic performance; however, very few studies examined this association in postgraduate nephrology education. None evaluated whether there were interprofessional differences concerning such association.

Methods

In 2022, we prospectively enrolled physicians and nurses participating in chronic kidney disease (CKD) care from institutions around Taiwan. They completed the Professional Medical Learning Self-efficacy (PMLS) questionnaire after attending >1 CBL session involving CKD care. We undertook confirmatory factor analysis (CFA), followed by structural equation modeling (SEM) to evaluate associations between 5 dimensions of learning SE (conceptual understanding [CU], higher-order cognitive skills [HC], practical work [PW], everyday application [EA], and medical science communication [MSC]) and their professional SE in nephrology according to participants' medical professions.

Results

A total of 513 healthcare providers were surveyed. The convergent and construct validity of our questionnaire were satisfied after analyses. We found that better perceived professional performance in the form of higher professional SE in nephrology was significantly associated with all 5 dimensions of learning SE among physicians and nurses. Only CU and PW were significantly associated with physicians' professional performance; whereas among nurses, only HC and MSC were significantly associated.

Conclusion

We showed that learning SE was an important determinant of nephrology professional performance. Different medical professions posed influences on major SE dimensions.

Epigenetically regulated inflammation in vascular senescence and renal progression of chronic kidney disease

Chronic kidney disease (CKD) and its complications, including vascular senescence and progressive renal fibrosis, are associated with inflammation. Vascular senescence, in particular, has emerged as an instrumental mediator of vascular inflammation that potentially worsens renal function. Epigenetically regulated inflammation involving histone modification, DNA methylation, actions of microRNAs and other non-coding RNAs, and their reciprocal reactions during vascular senescence and inflammaging are underappreciated. Their synergistic effects can contribute to CKD progression. Vascular senotherapeutics or pharmacological anti-senescent therapies based on epigenetic machineries can therefore be plausible options for ameliorating vascular aging and even halting the worsening of renal fibrosis. These include histone deacetylase modulators, histone methyltransferase modulators, other histone modification effectors, DNA methyltransferase inhibitors, telomerase reverse transcriptase enhancers, microRNA mimic delivery, and small molecules with microRNA-regulating potentials. Some of these molecules have already been tested and have shown anecdotal evidence for treating uremic vasculopathy and renal fibrosis, supporting the feasibility of this approach.

Aortic arch calcification increases major adverse cardiac event risk, modifiable by echocardiographic left ventricular hypertrophy, in end-stage kidney disease patients

Background

The factors affecting cardiovascular risk associated with vascular calcification in patients with chronic kidney disease are less well addressed. Distinct risk factors may contribute synergistically to this elevated cardiovascular risk in this population.

Objectives

We aimed to determine whether echocardiographic left ventricular hypertrophy (LVH) affects the risk of major adverse cardiac events (MACE) associated with vascular calcification in end-stage kidney disease (ESKD) patients.

Methods

In this retrospective cohort study, ESKD patients underwent chest radiography and echocardiography to assess aortic arch calcification (AoAC) and LVH, respectively, and were classified into three groups accordingly: non-to-mild AoAC without LVH, non-to-mild AoAC with LVH, and moderate-to-severe AoAC. The risks of MACE, cardiovascular mortality, and overall mortality were assessed using Cox proportional hazard analysis.

Results

Of the 283 enrolled ESKD patients, 44 (15.5%) had non-to-mild AoAC without LVH, 117 (41.3%) had non-to-mild AoAC with LVH, and 122 (43.1%) had moderate-to-severe AoAC. After 34.1 months, 107 (37.8%) participants developed MACE, including 6 (13.6%), 40 (34.2%), and 61 (50%) from each respective group. Those with moderate-to-severe AoAC (Hazard ratio, 3.72; 95% confidence interval, 1.58-8.73) had a significantly higher risk of MACE than did those with non-to-mild AoAC without LVH or with non-to-mild AoAC and LVH (Hazard ratio, 2.73; 95% confidence interval, 1.16-6.46). A similar trend was observed for cardiovascular and overall mortality.

Conclusion

Echocardiographic LVH could modify the risk of adverse cardiovascular events associated with vascular calcification in ESKD patients. Interventions aiming to ameliorate both morbidities might be translated into a lower MACE risk in this population.

Literacy for Frailty among Undergraduate Medical Education: An Under-Recognized Opportunity to Improve Geriatric Care

Our society is aging much faster than it was before, and this phenomenon demands concerted action to optimize geriatric care. Presentations, clinical features, and management decision making are distinct between older adults and general population, and to enhance care quality, there remains unmet needs for undergraduate geriatric education. Among all geriatric syndromes that clinically matter, frailty is particularly instrumental, serving as the overarching phenotype that connects other geriatric conditions and predisposes individuals to adverse outcomes. However, understandings for frailty, or "literacy for frailty" is often poor among healthcare professionals, and misidentification, terminology confusion, and uncertainty surrounding the care of frail older adults, are not uncommon. This lack of frailty literacy undoubtedly contributes to the suboptimal geriatric care patients receive. We therefore propose a rationally designed, concise, and structured program for eliciting medical students' motivation for understanding frailty during their undergraduate period. Our increasing-frailty-literacy program includes 7 modules, accommodating the terminology, integrative pathogenesis, epidemiology of frailty, appropriate screening and identification tool selection, prognostication and patient communication, and individualization of treatment strategies. In combination with digital technologies and hands-on practice opportunities, we believe that our curriculum can promote medical students' learning efficacy for frailty and improve geriatric care for the current generation.

The Impact of Glucose-Lowering Strategy on the Risk of Increasing Frailty Severity among 49,519 Patients with Diabetes Mellitus: A Longitudinal Cohort Study

Patients with diabetes mellitus (DM) have a higher risk of incident and aggravating frailty over time. Frailty-initiating risk factors have been identified, but modulators of frail severity over time remain poorly defined. We aimed to explore the influences of glucose-lowering drug (GLD) strategy on DM patients' risk of increasing frail severity. We retrospectively identified type 2 DM patients between 2008 and 2016, dividing them into "no GLD", oral GLD (oGLD) monotherapy, oGLD combination, and those receiving insulin without or with oGLD at baseline. Increasing frail severity, defined as ≥1 FRAIL component increase, was the outcome of interest. Cox proportional hazard regression was utilized to analyze the risk of increasing frail severity associated with GLD strategy, accounting for demographic, physical data, comorbidities, medication, and laboratory panel. After screening 82,208 patients with DM, 49,519 (no GLD, 42.7%; monotherapy, 24.0%; combination, 28.5%; and insulin user, 4.8%) were enrolled for analysis. After 4 years, 12,295 (24.8%) had increasing frail severity. After multivariate adjustment, oGLD combination group exhibited a significantly lower risk of increasing frail severity (hazard ratio (HR) 0.90, 95% confidence interval (CI) 0.86 - 0.94), while the risk of insulin users increased (HR 1.11, 95% CI 1.02 - 1.21) than no GLD group. Users receiving more oGLD exhibited a trend of less risk reduction relative to others. In conclusion, we discovered that the strategy of oral glucose lowering drugs combination might reduce the risk of frail severity increase. Accordingly, medication reconciliation in frail diabetic older adults should take into account their GLD regimens.

Left Ventricular Hypertrophy Geometry and Vascular Calcification Co-Modify the Risk of Cardiovascular Mortality in Patients with End-Stage Kidney Disease: A Retrospective Cohort Study

AIM

Patients with end-stage kidney disease (ESKD) have an unparalleled risk of left ventricular hypertrophy (LVH) and vascular calcification (VC), both of which introduce excessive cardiovascular risk. However, it remains unclear whether LVH geometry co-modulates cardiovascular outcomes with VC in this population.

METHODS

A retrospective cohort study was conducted. Patients with ESKD requiring chronic hemodialysis were identified from Shin Kong Wu Ho-Su Memorial Hospital between October and December 2018, with echocardiographic LVH geometry and aortic arch calcification (AoAC) determined. They were divided into four groups according to AoAC severity and eccentric or concentric LVH. We used Kaplan-Meier analysis and Cox proportional hazard regression to analyze their cardiovascular and all-cause mortality after multivariate adjustment.

RESULTS

Overall, 223 patients with ESKD with LVH were analyzed, among whom 29.1%, 23.3%, 25.1%, and 22.4% had non-to-mild AoAC with eccentric and concentric LVH and moderate-to-severe AoAC with eccentric and concentric LVH, respectively. After 3.5 years of follow-up, patients with ESKD with moderate-to-severe AoAC and concentric LVH had a significantly higher risk of cardiovascular mortality than those with non-to-mild AoAC and eccentric LVH (hazard ratio 3.35, p=0.002). However, those with moderate-to-severe AoAC but eccentric LVH did not have higher cardiovascular mortality. Similarly, patients with ESKD with moderate-to-severe AoAC and concentric LVH had a significantly higher all-cause mortality than those with non-to-mild AoAC and eccentric LVH, whereas the other two groups did not have higher risk.

CONCLUSION

LVH geometry could help stratify the risk of patients with ESKD when they had severe VC, and co-existing severe VC and concentric LVH aggravated cardiovascular risk.

Extracellular MicroRNAs as Potential Biomarkers for Frail Kidney Phenotype: Progresses and Precautions

Frailty describes the cumulative subtle health deficits leading to an increased vulnerability to insults among older individuals or disease-laden ones. The prevalence of frailty increases substantially and relentlessly over declining renal function. Frailty in patients with chronic kidney disease (CKD) carries kidney-specific risk factors, clinical correlates and outcomes associations, hence alternatively termed frail kidney phenotype by researchers. Pathogenetically, miRNAs participate extensively in the development and aggravation of frailty, including the occurrence of frail kidney phenotype in CKD patients. These understandings spark profound interest in discovering biomarkers for identifying this detrimental phenotype, and extracellular miRNAs emerge as potentially useful ones. Pilot studies identify promising miRNA candidates for evaluating intermediates and surrogates of frail kidney phenotype, and more are underway. Several potential miRNA species in biologic fluids, such as circulating miR-29b and miR-223 (as inflammatory markers), exosomal miR-16-5p, miR-17/92 cluster members, and miR-106-5p (for uremic vasculopathy), serum exosomal miR-203a-3p (for uremic sarcopenia) have been examined and can be promising choices. Nonetheless, there remains research gap in affirming the direct connections between specific miRNAs and frail kidney phenotype. This stems partially from multiple limitations less well acknowledged before. From this perspective, we further outline the limitations and precautions prior to validating specific extracellular miRNA(s) for this purpose, from the definition of frailty definition, the functional and tissue specificity of miRNAs, the severity of CKD, and various technical considerations. It is expected that more affirmative studies can be produced for extending the utility of extracellular miRNAs in predicting frail kidney phenotype.

Vascular frailty, a proposal for new frailty type: A narrative review

Frailty is the incremental accumulation of minute defects that progressively impair health and performance. Frailty is commonly observed in older adults; however, secondary frailty may also occur in patients with metabolic disorders or major organ failure. In addition to physical frailty, several distinct types of frailty have been identified, including oral, cognitive, and social frailty, each of which is of practical importance. This nomenclature suggests that detailed descriptions of frailty can potentially advance relevant researches. In this narrative review, we first summarize the clinical value and plausible biological origin of frailty, as well as how to appropriately assess it using physical frailty phenotypes and frailty indexes. In the second part, we discuss the issue of vascular tissue as a relatively underappreciated organ whose pathologies contribute to the development of physical frailty. Moreover, when vascular tissue undergoes degeneration, it exhibits vulnerability to subtle injuries and manifests a unique phenotype amenable to clinical assessment prior to or accompanying physical frailty development. Finally, we propose that vascular frailty, based on an extensive set of experimental and clinical evidence, can be considered a new frailty type that requires our attention. We also outline potential methods for the operationalization of vascular frailty. Further studies are required to validate our claim and sharpen the spectrum of this degenerative phenotype.

Chest radiography deep radiomics-enabled aortic arch calcification interpretation across different populations

Earlier detection of aortic calcification can facilitate subsequent cardiovascular care planning. Opportunistic screening based on plain chest radiography is potentially feasible in various population. We used multiple deep convolutional neural network (CNN) transfer learning by fine-tuning pre-trained models followed by ensemble technique for aortic arch calcification on chest radiographs from a derivation and two external databases with distinct features. Our ensemble approach achieved 84.12% precision, 84.70% recall, and an area under the receiver-operating-characteristic curve (AUC) of 0.85 in the general population/older adult's dataset. We also obtained 87.5% precision, 85.56% recall, and an AUC of 0.86 in the pre-end-stage kidney disease (pre-ESKD) cohort. We identified discriminative regions for identifying aortic arch calcification between patients without and with pre-ESKD. These findings are expected to optimize cardiovascular risk prediction if our model is incorporated into the process of routine care.

Association of aortic arch and aortic valve calcifications with cardiovascular risk in patients on maintenance hemodialysis

Introduction

This study aimed to investigate the association of aortic arch calcification (AoAC) and aortic valve calcification (AVC) with major adverse cardiovascular events (MACE) and cardiovascular and all-cause mortality in patients on maintenance hemodialysis (MHD).

Methods

This study enrolled 297 adult patients with end-stage kidney disease who were on MHD. They were divided into those with an AoAC score <2 without AVC (n = 70, 23.6%), those with an AoAC score <2 with AVC (n = 96, 32.3%), and those with an AoAC score ≥2 regardless of AVC status (n = 131, 44.1%). We analyzed the risks of MACE, cardiovascular and overall mortality among the three groups using Cox proportional hazard analyses. Survival probabilities were estimated using the log-rank test via the Kaplan-Meier method.

Results

Kaplan-Meier analysis revealed that the MACE-free rate and the survival rates of cardiovascular and overall mortality were significantly higher in adult chronic hemodialysis patients with AoAC score <2 without AVC, followed by those with AoAC score <2 with AVC, and then those with AoAC score ≥2 (log-rank test; all p < 0.01). The grade of AoAC is a significant risk factor for MACE, cardiovascular mortality, and overall mortality after adjusting for age and gender Relative to AoAC score <2 without AVC, adult chronic hemodialysis patients with AoAC score ≥2 remained an independently significantly risk factor of MACE (adjusted hazard ratio, 2.17; 95% confidence interval 1.11-4.20; p = 0.023) after adjusting for age, sex, and all significant variables in baseline characteristics.

Conclusion

AoAC grade was positively correlated with a higher risk of MACE and cardiovascular and overall mortality. Furthermore, the presence of AVC modified the adverse cardiovascular risk associated with AoAC in patients on MHD.

Moving from tangibility toward digitalization: investigating team dynamics and facilitator support among medical students in conventional and digital small-group tutorials

BACKGROUND

Small group tutorials (SGT) promotes self-directed learning and is widely used in medical education. The coronavirus pandemic (COVID-19) has accelerated the trend toward SGT digitalization, with unclear effect. We hypothesize that team dynamics and facilitator support influence SGT satisfaction in digital versus conventional SGT.

METHODS

During the spring semester of year 2021, medical students (the second, third, and fourth year; n = 433) participating in conventional face-to-face and digital SGT curricula were enrolled. Participating students completed the collaborative learning attitude scale (including team dynamics, team acquaintance, and facilitator support dimensions) and teamwork satisfaction scale, previously validated for small-group collaborative learning, and chose preference between conventional or digital SGT in future curricula. Exploratory factor analysis (EFA) was performed to extract the essential structural factors of these scales. Paired t-tests were conducted to compare differences in different dimensions and satisfaction between the conventional and digital SGT settings. Two sets of multiple regression analyses were done; one with team satisfaction scale results and the other with preference for digital SGT as the dependent variable were used to evaluate determinants of these two variables.

RESULTS

The EFA results revealed that the original collaborative learning attitude scale was concentrated on two dimensions: team dynamics and facilitator support. No significant differences were noted between the SGT settings for the two dimensions and teamwork satisfaction. Regression analyses showed that teamwork dynamics was independently correlated with teamwork satisfaction in both conventional and digital SGT. Facilitator support was positively correlated with teamwork satisfaction in conventional, but not digital SGT. Higher teamwork satisfaction was an important determinant of preference for digital SGT among medical students.

CONCLUSIONS

Team dynamics were closely linked to teamwork satisfaction among medical students in both conventional and digital SGT, while the role of facilitator support became less obvious during digital SGT.

Effectiveness of tutor shadowing on faculty development in problem-based learning

BACKGROUND

To enhance tutors' teaching skills, tutor shadowing for novice tutors of problem-based learning (PBL) in addition to conventional faculty development (FD) was applied. This study aimed to develop a tutoring-skill scale (TS-scale) and evaluate the effect of shadowing on PBL tutors.

METHODS

This study employed a before-and-after study design with three phases. In phase 1, a TS-scale was elaborated. A validity examination was performed in phase 2. Phase 3 was a study of the effectiveness using a TS-scale survey of novice PBL tutors before and after the FD course. The FD course for novice PBL tutors included an FD workshop and PBL shadowing activities.

RESULTS

A TS-scale with a 32-item questionnaire of self-rated confidence for PBL tutors was identified in phase 1. In phase 2, 7 experienced specialists in medical education were invited to evaluate the content validity of the scale. The item content validity index (I-CVI) ranged from 0.86 to 1, and the scale-CVI (S-CVI) was 0.95. A total of 85 novice PBL tutors completed the TS-scale before the FD course, yielding a Cronbach's alpha of 0.98. An exploratory factor analysis with varimax rotation was performed. The twenty-four items with significant loadings greater than 0.5 were incorporated into a new TS-scale and were grouped into three factors: student contact, medical expertise, and teaching expertise. In phase 3, 76 novice PBL tutors completed the 24-item TS-scale before (pretest) and after (posttest) the FD course. Their self-rated confidence improved significantly across the three factors after the FD course. The pretest and posttest scores did not differ according to the tutors' gender, the grades they taught, or their specialty background.

CONCLUSIONS

Novice PBL tutors benefit from FD that incorporates tutor shadowing in the 3 key domains of tutoring competencies. The TS-scale developed in this study can be applied in future research on FD design.

The down-regulation of XBP1, an unfolded protein response effector, promotes acute kidney injury to chronic kidney disease transition

Background

The activation of the unfolded protein response (UPR) is closely linked to the pathogenesis of renal injuries. However, the role of XBP1, a crucial regulator of adaptive UPR, remains unclear during the transition from acute kidney injury (AKI) to chronic kidney disease (CKD).

Methods

We characterized XBP1 expressions in different mouse models of kidney injuries, including unilateral ischemia–reperfusion injury (UIRI), unilateral ureteral obstruction, and adenine-induced CKD, followed by generating proximal tubular XBP1 conditional knockout (XBP1^cKO) mice for examining the influences of XBP1. Human proximal tubular epithelial cells (HK-2) were silenced of XBP1 to conduct proteomic analysis and investigate the underlying mechanism.

Results

We showed a tripartite activation of UPR in injured kidneys. XBP1 expressions were attenuated after AKI and inversely correlated with the severity of post-AKI renal fibrosis. XBP1^cKO mice exhibited more severe renal fibrosis in the UIRI model than wide-type littermates. Silencing XBP1 induced HK-2 cell cycle arrest in G2M phase, inhibited cell proliferation, and promoted TGF-β1 secretion. Proteomic analysis identified TNF receptor associated protein 1 (Trap1) as the potential downstream target transcriptionally regulated by XBP1s. Trap1 overexpression can alleviate silencing XBP1 induced profibrotic factor expressions and cell cycle arrest.

Conclusion

The loss of XBP1 in kidney injury was profibrotic, and the process was mediated by autocrine and paracrine regulations in combination. The present study identified the XBP1-Trap1 axis as an instrumental mechanism responsible for post-AKI fibrosis, which is a novel regulatory pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00828-9.

Frailty as an Independent Risk Factor for Depression in Patients With End-Stage Renal Disease: A Cross-Sectional Study

Background

Depression confers substantial disease burden globally, especially among those with chronic kidney disease (CKD). The presence of depression significantly impairs one's quality of life. Risk factors for depression in patients with CKD remain under-appreciated, and whether frailty, a geriatric phenotype, constitutes a risk factor for depression in this population is unknown.

Methods

We prospectively enrolled patients with end-stage renal disease (ESRD) undergoing hemodialysis for >3 months from National Taiwan University Hospital Yunlin Branch between 2019 and 2021. Clinical, physical, functional, and performance parameters were recorded, followed by frailty/sarcopenia assessment. Depression was screened for using the Geriatric Depression Scale. We analyzed the independent relationship between frailty and depression in these patients, using multiple regression analyses.

Results

Totally 151 patients with ESRD were enrolled (mean 61.1 years, 66.9% male), among whom 16.6% had screening-identified depression. ESRD participants with depression did not differ from those without regarding most parameters except serum creatinine, functional indices, and sarcopenia/frailty status. We found that having greater frail severities was independently associated with a higher probability of depression; having FRAIL- (odds ratio [OR] 5.418) and SOF-based (OR 2.858) frailty independently correlated with a higher depression probability. A linear relation exists between a greater frail severity and the probability of depression. Using a more relaxed criterion for detecting depression, higher SOF scores remained significantly associated with an increased depression risk.

Conclusions

In patients with CKD, frailty independently correlated with a higher probability of having depression. Strategies aiming to attenuate frailty may be able to benefit those with depression simultaneously in this population.

The Dynamics and Plasticity of Epigenetics in Diabetic Kidney Disease: Therapeutic Applications Vis-à-Vis

Chronic kidney disease (CKD) refers to the phenomenon of progressive decline in the glomerular filtration rate accompanied by adverse consequences, including fluid retention, electrolyte imbalance, and an increased cardiovascular risk compared to those with normal renal function. The triggers for the irreversible renal function deterioration are multifactorial, and diabetes mellitus serves as a major contributor to the development of CKD, namely diabetic kidney disease (DKD). Recently, epigenetic dysregulation emerged as a pivotal player steering the progression of DKD, partly resulting from hyperglycemia-associated metabolic disturbances, rising oxidative stress, and/or uncontrolled inflammation. In this review, we describe the major epigenetic molecular mechanisms, followed by summarizing current understandings of the epigenetic alterations pertaining to DKD. We highlight the epigenetic regulatory processes involved in several crucial renal cell types: Mesangial cells, podocytes, tubular epithelia, and glomerular endothelial cells. Finally, we highlight epigenetic biomarkers and related therapeutic candidates that hold promising potential for the early detection of DKD and the amelioration of its progression.

Early elimination of uremic toxin ameliorates AKI-to-CKD transition

Acute kidney injury (AKI)-related fibrosis is emerging as a major driver of chronic kidney disease (CKD) development. Aberrant kidney recovery after AKI is multifactorial and still poorly understood. The accumulation of indoxyl sulfate (IS), a protein-bound uremic toxin, has been identified as a detrimental factor of renal fibrosis. However, the mechanisms underlying IS-related aberrant kidney recovery after AKI is still unknown. The present study aims to elucidate the effects of IS on tubular damage and its involvement in the pathogenesis of AKI-to-CKD transition. Our results showed that serum IS started to accumulate associated with the downregulation of tubular organic anion transporter but not observed in the small-molecule uremic toxins of the unilateral ischemia-reperfusion injury (UIRI) without a contralateral nephrectomy model. Serum IS is positively correlated with renal fibrosis and binding immunoglobulin protein (BiP) and CAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) expression induction in the UIRI with a contralateral nephrectomy model (UIRI+Nx). To evaluate the effects of IS in the AKI-to-CKD transition, we administered indole, a precursor of IS, at the early stage of UIRI. Our results demonstrated IS potentiates renal fibrosis, senescence-associated secretory phenotype (SASP), and activation of endoplasmic reticulum (ER) stress, which is attenuated by synergistic AST-120 administration. Furthermore, we clearly demonstrated that IS exposure potentiated hypoxia-reperfusion (H/R) induced G2/M cell cycle arrest, epithelial-mesenchymal transition (EMT) and aggravated ER stress induction in vitro. Finally, the ER chemical chaperon, 4-phenylbutyric acid (4-PBA), successfully reversed the above-mentioned AKI-to-CKD transition. Taken together, early IS elimination in the early stage of AKI is likely to be a useful strategy in the prevention and/or treatment of the AKI-to-CKD transition.

Fully digital problem-based learning for undergraduate medical students during the COVID-19 period: Practical considerations

Digital problem-based learning (PBL) was originally introduced as a means to improve student engagement and increase flexibility. However, its use becomes mandatory during the coronavirus disease 2019 (COVID-19) period, accelerating changes in medical education. Few elaborated on the implementation details of digital PBL curricula. Technical guidance can be important but under-recognized prerequisite of a successful digital PBL session. In National Taiwan University College of Medicine, we established a digital PBL curriculum and previously validated a confidence questionnaire for surveying undergraduate students receiving digital PBL sessions. In this opinion piece, we gleaned multiple procedural details from our experiences based on students'/tutors' feedback, which we summarized in a 5″W″ recommendations (Who), timing/duration (When), location (Where), software/hardware/topics (What), and evaluation aspects (Why). Suggestions on how to optimally prepare for digital PBL session are also provided. We believe that these tips can further facilitate the wide adoption of digital PBL.

Chronic Kidney Disease: Strategies to Retard Progression

Chronic kidney disease (CKD), defined as the presence of irreversible structural or functional kidney damages, increases the risk of poor outcomes due to its association with multiple complications, including altered mineral metabolism, anemia, metabolic acidosis, and increased cardiovascular events. The mainstay of treatments for CKD lies in the prevention of the development and progression of CKD as well as its complications. Due to the heterogeneous origins and the uncertainty in the pathogenesis of CKD, efficacious therapies for CKD remain challenging. In this review, we focus on the following four themes: first, a summary of the known factors that contribute to CKD development and progression, with an emphasis on avoiding acute kidney injury (AKI); second, an etiology-based treatment strategy for retarding CKD, including the approaches for the common and under-recognized ones; and third, the recommended approaches for ameliorating CKD complications, and the final section discusses the novel agents for counteracting CKD progression.

Independent Determinants of Appetite Impairment among Patients with Stage 3 or Higher Chronic Kidney Disease: A Prospective Study

Protein-energy wasting (PEW) is an important complication resulting from chronic kidney disease (CKD). Appetite impairment contributes significantly to PEW in these patients, but risk factors associated with having appetite impairment in patients with CKD remain elusive. Patients with an estimated glomerular filtration rate <60 mL/min/1.73 m² for ≥2 times at least three months apart were prospectively enrolled during 2017, with their demographic features, comorbidities, anthropometric parameters, physical and performance indices, functional status, frailty, sensory organ integrity, and laboratory data collected. Their appetite status was measured using the Council on Nutrition Appetite Questionnaire (CNAQ). We examined independent determinants of appetite impairment in these CKD patients using multiple regression analyses. Among 78 patients with CKD, 42.3% had CNAQ-identified impaired appetite. Those with an impaired appetite also had poorer physical performance, a higher degree of functional impairment, higher frail severities, lower serum sodium levels, less intact oral cavity, and a trend toward having less intact nasal structures than those without. Multiple regression analyses revealed that a higher frail severity, in the forms of increasing Study of Osteoporotic Fractures (SOF) scores (odds ratio (OR), 2.74; 95% confidence interval (CI), 1.15–6.57) and a less intact nasal structure (OR, 0.96; 95% CI, 0.92–0.995) were associated with a higher probability of having an impaired appetite, while higher serum sodium (OR, 0.76; 95% CI, 0.6–0.97) correlated with a lower probability. Based on our findings, in patients with CKD, the severity of frailty, serum sodium, and nasal structural integrity might modify appetite status. Therapies targeting these factors might be beneficial for appetite restoration in patients with CKD.

Gender-Related Differences in Chronic Kidney Disease-Associated Vascular Calcification Risk and Potential Risk Mediators: A Scoping Review

Vascular calcification (VC) involves the deposition of calcium apatite in vascular intima or media. Individuals of advanced age, having diabetes mellitus or chronic kidney disease (CKD) are particularly at risk. The pathogenesis of CKD-associated VC evolves considerably. The core driver is the phenotypic change involving vascular wall constituent cells toward manifestations similar to that undergone by osteoblasts. Gender-related differences are observed regarding the expressions of osteogenesis-regulating effectors, and presumably the prevalence/risk of CKD-associated VC exhibits gender-related differences as well. Despite the wealth of data focusing on gender-related differences in the risk of atherosclerosis, few report whether gender modifies the risk of VC, especially CKD-associated cases. We systematically identified studies of CKD-associated VC or its regulators/modifiers reporting data about gender distributions, and extracted results from 167 articles. A significantly higher risk of CKD-associated VC was observed in males among the majority of original investigations. However, substantial heterogeneity exists, since multiple large-scale studies yielded neutral findings. Differences in gender-related VC risk may result from variations in VC assessment methods, the anatomical segments of interest, study sample size, and even the ethnic origins of participants. From a biological perspective, plausible mediators of gender-related VC differences include body composition discrepancies, alterations involving lipid profiles, inflammatory severity, diversities in matrix Gla protein (MGP), soluble Klotho, vitamin D, sclerostin, parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), and osteoprotegerin levels. Based on our findings, it may be inappropriate to monotonously assume that male patients with CKD are at risk of VC compared to females, and we should consider more background in context before result interpretation.

A combined microRNA and target protein-based panel for predicting the probability and severity of uraemic vascular calcification: a translational study

AIMS

Vascular calcification (VC) increases the future risk of cardiovascular events in uraemic patients, but effective therapies are still unavailable. Accurate identification of those at risk of developing VC using pathogenesis-based biomarkers is of particular interest and may facilitate individualized risk stratification. We aimed to uncover microRNA (miRNA)-target protein-based biomarker panels for evaluating uraemic VC probability and severity.

METHODS AND RESULTS

We created a three-tiered in vitro VC model and an in vivo uraemic rat model receiving high phosphate diet to mimic uraemic VC. RNAs from the three-tiered in vitro and in vivo uraemic VC models underwent miRNA and mRNA microarray, with results screened for differentially expressed miRNAs and their target genes as biomarkers. Findings were validated in original models and additionally in an ex vivo VC model and human cells, followed by functional assays of identified miRNAs and target proteins, and tests of sera from end-stage renal disease (ESRD) and non-dialysis-dependent chronic kidney disease (CKD) patients without and with VC. Totally 122 down-regulated and 119 up-regulated miRNAs during calcification progression were identified initially; further list narrowing based on miRNA-mRNA pairing, anti-correlation, and functional enrichment left 16 and 14 differentially expressed miRNAs and mRNAs. Levels of four miRNAs (miR-10b-5p, miR-195, miR-125b-2-3p, and miR-378a-3p) were shown to decrease throughout all models tested, while one mRNA (SULF1, a potential target of miR-378a-3p) exhibited the opposite trend concurrently. Among 96 ESRD (70.8% with VC) and 59 CKD patients (61% with VC), serum miR-125b2-3p and miR-378a-3p decreased with greater VC severity, while serum SULF1 levels increased. Adding serum miR-125b-2-3p, miR-378a-3p, and SULF1 into regression models for VC substantially improved performance compared to using clinical variables alone.

CONCLUSION

Using a translational approach, we discovered a novel panel of biomarkers for gauging the probability/severity of uraemic VC based on miRNAs/target proteins, which improved the diagnostic accuracy.

Frailty is associated with a higher risk of developing delirium and cognitive impairment among patients with diabetic kidney disease: A longitudinal population-based cohort study

AIMS

Delirium, a form of acute brain failure, exhibits a high incidence among older adults. Recent studies have implicated frailty as an under-recognized complication of diabetes mellitus. Whether the presence of frailty increases the risk of delirium/cognitive impairment among patients with diabetic kidney disease (DKD) remains unclear.

METHODS

From the longitudinal cohort of diabetes patients (LCDP) (n = 840,000) in Taiwan, we identified adults with DKD, dividing them into those without and with different severities of frailty based on a modified FRAIL scale. Cox proportional hazard regression was utilized to examine the frailty-associated risk of delirium/cognitive impairment, identified using approaches validated by others.

RESULTS

Totally 149,145 patients with DKD (mean 61.0 years, 44.2% female) were identified, among whom 31.0%, 51.7%, 16.0% and 1.3% did not have or had 1, 2 and >2 FRAIL items at baseline. After 3.68 years, 6613 (4.4%) developed episodes of delirium/cognitive impairment. After accounting for demographic/lifestyle factors, co-morbidities, medications and interventions, patients with DKD and 1, 2 and >2 FRAIL items had a progressively higher risk of developing delirium/cognitive impairment than those without (for those with 1, 2 and >2 items, hazard ratio 1.18, 1.26 and 1.30, 95% confidence interval 1.08-1.28, 1.14-1.39 and 1.10-1.55, respectively). For every FRAIL item increase, the associated risk rose by 9%.

CONCLUSIONS

Frailty significantly increased the risk of delirium/cognitive impairment among patients with DKD. Frailty screening in these patients may assist in delirium risk stratification.

Muscle relaxant use and the associated risk of incident frailty in patients with diabetic kidney disease: a longitudinal cohort study

Background:

Patients with diabetic kidney disease (DKD) are at an increased risk of frailty. The exposure to muscle relaxants frequently leads to adverse effects despite their modest therapeutic efficacy, but whether muscle relaxants predispose users to frailty remains unclear.

Methods:

Patients with DKD from a population-based cohort, the Longitudinal Cohort of Diabetes Patients, were identified between 2004 and 2011 (N = 840,000). Muscle relaxant users were propensity score-matched to never-users in a 1:1 ratio based on demographic features, comorbidities, outcome-relevant medications, and prior major interventions. Incident frailty, the study endpoint, was measured according to a modified FRAIL scale. We used Kaplan–Meier analyses and Cox proportional hazard regression to analyze the association between cumulative muscle relaxant use (⩾ 28 days) and the risk of incident frailty.

Results:

Totally, 11,637 users and matched never-users were enrolled, without significant differences regarding baseline clinical features. Cox proportional hazard regression showed that patients with DKD and received muscle relaxants had a significantly higher risk of incident frailty than never-users [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.04–1.53]. This increase in frailty risk paralleled that in cumulative muscle relaxant dosages (quartile 1 versus 2 versus 3 versus 4, HR 0.91 versus 1.22 versus 1.38 versus 1.45, p = 0.0013 for trend) and in exposure durations (quartile 1 versus 2 versus 3 versus 4, HR 1.12 versus 1.33 versus 1.23 versus 1.34, p = 0.0145 for trend) of muscle relaxants.

Conclusion:

We found that cumulative muscle relaxant exposure might increase frailty risk. It is prudent to limit muscle relaxant prescription in patients with DKD.

Plain language summary

Does cumulative muscle relaxant exposure increase the risk of incident frailty among patients with diabetic kidney disease?

Background: Frailty denotes a degenerative feature that adversely influences one’s survival and daily function. Patients with diabetes and chronic kidney disease are at a higher risk of developing frailty, but whether concurrent medications, especially muscle relaxants, aggravate this risk remains undefined.

Methods: In this population-based study including 11,637 muscle relaxant users and matched never-users with diabetic kidney disease, we used a renowned frailty-assessing tool, FRAIL scale, to assess frailty severity and examined the incidence of frailty brought by muscle relaxant exposure.

Results: We found that users exhibited a 26% higher risk of developing incident frailty compared with never-users, and the probability increased further if users were prescribed higher doses or longer durations of muscle relaxants.

Conclusion: We concluded that in those with diabetic kidney disease, cumulative muscle relaxant use was associated with a higher risk of incident frailty, suggesting that moderation of muscle relaxant use in this population can be of potential importance.

Uremic Toxins and Frailty in Patients with Chronic Kidney Disease: A Molecular Insight

The accumulation of uremic toxins (UTs) is a prototypical manifestation of uremic milieu that follows renal function decline (chronic kidney disease, CKD). Frailty as a potential outcome-relevant indicator is also prevalent in CKD. The intertwined relationship between uremic toxins, including small/large solutes (phosphate, asymmetric dimethylarginine) and protein-bound ones like indoxyl sulfate (IS) and p-cresyl sulfate (pCS), and frailty pathogenesis has been documented recently. Uremic toxins were shown in vitro and in vivo to induce noxious effects on many organ systems and likely influenced frailty development through their effects on multiple preceding events and companions of frailty, such as sarcopenia/muscle wasting, cognitive impairment/cognitive frailty, osteoporosis/osteodystrophy, vascular calcification, and cardiopulmonary deconditioning. These organ-specific effects may be mediated through different molecular mechanisms or signal pathways such as peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), mitogen-activated protein kinase (MAPK) signaling, aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Runt-related transcription factor 2 (RUNX2), bone morphogenic protein 2 (BMP2), osterix, Notch signaling, autophagy effectors, microRNAs, and reactive oxygen species induction. Anecdotal clinical studies also suggest that frailty may further accelerate renal function decline, thereby augmenting the accumulation of UTs in affected individuals. Judging from these threads of evidence, management strategies aiming for uremic toxin reduction may be a promising approach for frailty amelioration in patients with CKD. Uremic toxin lowering strategies may bear the potential of improving patients’ outcomes and restoring their quality of life, through frailty attenuation. Pathogenic molecule-targeted therapeutics potentially disconnect the association between uremic toxins and frailty, additionally serving as an outcome-modifying approach in the future.

Frailty increases the risk for developing urinary tract infection among 79,887 patients with diabetic mellitus and chronic kidney disease

Background

Patients with diabetic mellitus (DM) and chronic kidney disease (CKD) are at an increased risk of urinary tract infection (UTI) due to their altered immunological integrity. These patients are similarly prone to developing frailty, a state of cumulative health deficits involving multiple domains and leading to adverse outcomes. Whether frailty predisposes affected individuals to UTI among patients with DM and CKD remains unclear.

Methods

A population-based cohort of patients with DM and CKD (n = 79,887) were assembled from the Longitudinal Cohort of Diabetes Patients, with their baseline frailty status measured by a  modified FRAIL scale. We analyzed their risk of developing UTI depending on their severity of frailty, after accounting demographic profiles, lifestyle factors, comorbidities, concurrent medications, and major interventions. A secondary analysis focused on the risk of urosepsis related to frailty.

Results

Among all participants, 36.1 %, 50.3 %, 12.8 %, and 0.8 % did not have or had 1, 2, and ≥ 3 FRAIL items, respectively, at baseline. After 3.51 years, 11,175 UTI events occurred. Kaplan-Meier analysis showed that participants with DM, CKD and an increasing number of FRAIL items had successively higher incidence of UTI than those without any FRAIL items (log rank p < 0.001). Cox proportional hazard modeling revealed that after accounting for all confounders, those with more severe frailty exhibited a significantly higher risk of incident UTI (for groups of 1, 2, and ≥ 3 FRAIL items, hazard ratio 1.19, 1.24, and 1.43, respectively; all p < 0.001) than those without. An 11 % risk elevation for UTI could be observed for every FRAIL item increase. Participants with more severe frailty exhibited a trend of having higher risk of urosepsis as well.

Conclusions

Having frailty predicted a higher risk of developing UTI in the future in patients with DM and CKD. It would be prudent to screen for frailty in these patients and provide optimal frailty-directed management to attenuate their risk of UTI and improve their outcomes.

Frailty increases the risk for developing urinary tract infection among 79,887 patients with diabetic mellitus and chronic kidney disease

BACKGROUND

Patients with diabetic mellitus (DM) and chronic kidney disease (CKD) are at an increased risk of urinary tract infection (UTI) due to their altered immunological integrity. These patients are similarly prone to developing frailty, a state of cumulative health deficits involving multiple domains and leading to adverse outcomes. Whether frailty predisposes affected individuals to UTI among patients with DM and CKD remains unclear.

METHODS

A population-based cohort of patients with DM and CKD (n = 79,887) were assembled from the Longitudinal Cohort of Diabetes Patients, with their baseline frailty status measured by a  modified FRAIL scale. We analyzed their risk of developing UTI depending on their severity of frailty, after accounting demographic profiles, lifestyle factors, comorbidities, concurrent medications, and major interventions. A secondary analysis focused on the risk of urosepsis related to frailty.

RESULTS

Among all participants, 36.1 %, 50.3 %, 12.8 %, and 0.8 % did not have or had 1, 2, and ≥ 3 FRAIL items, respectively, at baseline. After 3.51 years, 11,175 UTI events occurred. Kaplan-Meier analysis showed that participants with DM, CKD and an increasing number of FRAIL items had successively higher incidence of UTI than those without any FRAIL items (log rank p < 0.001). Cox proportional hazard modeling revealed that after accounting for all confounders, those with more severe frailty exhibited a significantly higher risk of incident UTI (for groups of 1, 2, and ≥ 3 FRAIL items, hazard ratio 1.19, 1.24, and 1.43, respectively; all p < 0.001) than those without. An 11 % risk elevation for UTI could be observed for every FRAIL item increase. Participants with more severe frailty exhibited a trend of having higher risk of urosepsis as well.

CONCLUSIONS

Having frailty predicted a higher risk of developing UTI in the future in patients with DM and CKD. It would be prudent to screen for frailty in these patients and provide optimal frailty-directed management to attenuate their risk of UTI and improve their outcomes.

Impact of a kidney-specific disease-specific care certification program on the institutional performance indicators of hospitals caring for patients with chronic kidney disease: A national data analysis

AIM

The prevalence of chronic kidney disease (CKD) is on the rise due to population aging and multimorbidity. Taiwan is particularly afflicted by this prevailing ailment. Although multidisciplinary pre-dialysis care has been implemented to halt CKD progression and reduce health-care utilization in Taiwan, more is needed to reduce the local burden of CKD.

METHODS

The Taiwan Joint Commission initiated a kidney-care disease-specific care (DSC) certification program since 2017, aiming to improve participating hospitals' quality of care for kidney disease and to synchronize the quality of kidney care across Taiwan. We analysed the trend of changes over time among the kidney DSC certification program participating institutes during the period before, during, and after DSC certification program implementation, using the Generalized Estimating Equation methods.

RESULTS

A total of 20 institutes participated in the DSC certification program focusing on kidney diseases between January 2018 and March 2020, among which 70% were medical centres. DSC certification program was shown to significantly reduce the annual incidence of arteriovenous fistula reconstruction while increase the levels of serum albumin and haemoglobin among patients with end-stage renal disease (ESRD) under haemodialysis over time. For parameters related to peritoneal dialysis (PD), participating in the kidney-care DSC certification program significantly increased serum albumin levels among these patients with ESRD over time.

CONCLUSION

In this study, we discovered that a kidney-care DSC certification program significantly improved multiple performance indicators of participating institutes including patients' haemoglobin, albumin, and shunt re-creation probability among patients with end-stage renal disease.

The risk trajectory of different cardiovascular morbidities associated with chronic kidney disease among patients with newly diagnosed diabetes mellitus: a propensity score-matched cohort analysis

Background

Chronic kidney disease (CKD) introduces an increased cardiovascular risk among patients with diabetes mellitus (DM). The risk and tempo of cardiovascular diseases may differ depending upon their type. Whether CKD differentially influences the risk of developing each cardiovascular morbidity in patients with newly diagnosed DM remains unexplored.

Methods

We identified patients with incident DM from the Longitudinal Cohort of Diabetes Patients (LCDP) cohort (n = 429,616), and uncovered those developing CKD after DM and their propensity score-matched counterparts without. After follow-up, we examined the cardiovascular morbidity-free rates of patients with and without CKD after DM, followed by Cox proportional hazard regression analyses. We further evaluated the cumulative risk of developing each outcome consecutively during the study period.

Results

From LCDP, we identified 55,961 diabetic patients with CKD and matched controls without CKD. After 4.2 years, patients with incident DM and CKD afterward had a significantly higher risk of mortality (hazard ratio [HR] 1.1, 95% confidence interval [CI] 1.06–1.14), heart failure (HF) (HR 1.282, 95% CI 1.19–1.38), acute myocardial infarction (AMI) (HR 1.16, 95% CI 1.04–1.3), and peripheral vascular disease (PVD) (HR 1.277, 95% CI 1.08–1.52) compared to those without CKD. The CKD-associated risk of mortality, HF and AMI became significant soon after DM occurred and remained significant throughout follow-up, while the risk of PVD conferred by CKD did not emerge until 4 years later. The CKD-associated risk of ischemic, hemorrhagic stroke and atrial fibrillation remained insignificant.

Conclusions

The cardiovascular risk profile among incident DM patients differs depending on disease type. These findings can facilitate the selection of an optimal strategy for early cardiovascular care for newly diagnosed diabetic patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01279-6.

Circulating microRNA-125b Levels Are Associated With the Risk of Vascular Calcification in Healthy Community-Dwelling Older Adults

Background: Vascular calcification (VC) is a subclinical manifestation of vascular disease burden among older adults, conferring an elevated mortality risk. Biomarkers capable of detecting and risk-stratifying VC associated with advanced age remains unavailable, impeding our effort to provide optimal care to geriatric patients.

Objectives: In this study, we aimed to investigate whether circulating miR-125b served as a potential indicator for VC in relatively healthy older adults.

Methods: Community-dwelling older adults (age ≥65) were prospectively recruited during 2017, followed by clinical features documentation and VC rating based on aortic arch calcification (AAC) and abdominal aortic calcification (AbAC). Multiple logistic regression was done to evaluate the relationship between circulating miR-125b levels, VC presence and severity, followed by selecting the optimal cutoff point for VC diagnosis.

Results: A total of 343 relatively healthy older adults (median age, 73.8 years; 40% male; 59.8% having AAC) were enrolled, with a median circulating miR-125b level of 0.012 (interquartile range, 0.003–0.037). Those with more severe AAC had progressively decreasing miR-125b levels (p<0.001). Multiple regression analyses showed that having higher miR-125b levels based on the median value were associated with a substantially lower risk of AAC [odds ratio (OR) 0.022, 95% confidence interval (CI) 0.011–0.044] compared to those having lower ones. An optimal cutoff of miR-125b for identifying AAC in older adults was 0.008, with a sensitivity and specificity of 0.86 and 0.80, respectively. Similar findings were obtained when using AbAC as the endpoint.

Conclusions: We found that miR-125b serves as an independent indicator for VC in relatively healthy older adults, and may potentially be linked with VC pathophysiology.

Superoxide Dismutase 2 (SOD2) in Vascular Calcification: A Focus on Vascular Smooth Muscle Cells, Calcification Pathogenesis, and Therapeutic Strategies

Vascular calcification (VC) describes the pathophysiological phenotype of calcium apatite deposition within the vascular wall, leading to vascular stiffening and the loss of compliance. VC is never benign; the presence and severity of VC correlate closely with the risk of myocardial events and cardiovascular mortality in multiple at-risk populations such as patients with diabetes and chronic kidney disease. Mitochondrial dysfunction involving each of vascular wall constituents (endothelia and vascular smooth muscle cells (VSMCs)) aggravates various vascular pathologies, including atherosclerosis and VC. However, few studies address the pathogenic role of mitochondrial dysfunction during the course of VC, and mitochondrial reactive oxygen species (ROS) seem to lie in the pathophysiologic epicenter. Superoxide dismutase 2 (SOD2), through its preferential localization to the mitochondria, stands at the forefront against mitochondrial ROS in VSMCs and thus potentially modifies the probability of VC initiation or progression. In this review, we will provide a literature-based summary regarding the relationship between SOD2 and VC in the context of VSMCs. Apart from the conventional wisdom of attenuating mitochondrial ROS, SOD2 has been found to affect mitophagy and the formation of the autophagosome, suppress JAK/STAT as well as PI₃K/Akt signaling, and retard vascular senescence, all of which underlie the beneficial influences on VC exerted by SOD2. More importantly, we outline the therapeutic potential of a novel SOD2-targeted strategy for the treatment of VC, including an ever-expanding list of pharmaceuticals and natural compounds. It is expected that VSMC SOD2 will become an important druggable target for treating VC in the future.

Uremic Vascular Calcification: The Pathogenic Roles and Gastrointestinal Decontamination of Uremic Toxins

Uremic vascular calcification (VC) commonly occurs during advanced chronic kidney disease (CKD) and significantly increases cardiovascular morbidity and mortality. Uremic toxins are integral within VC pathogenesis, as they exhibit adverse vascular influences ranging from atherosclerosis, vascular inflammation, to VC. Experimental removal of these toxins, including small molecular (phosphate, trimethylamine-N-oxide), large molecular (fibroblast growth factor-23, cytokines), and protein-bound ones (indoxyl sulfate, p-cresyl sulfate), ameliorates VC. As most uremic toxins share a gut origin, interventions through gastrointestinal tract are expected to demonstrate particular efficacy. The “gastrointestinal decontamination” through the removal of toxin in situ or impediment of toxin absorption within the gastrointestinal tract is a practical and potential strategy to reduce uremic toxins. First and foremost, the modulation of gut microbiota through optimizing dietary composition, the use of prebiotics or probiotics, can be implemented. Other promising strategies such as reducing calcium load, minimizing intestinal phosphate absorption through the optimization of phosphate binders and the inhibition of gut luminal phosphate transporters, the administration of magnesium, and the use of oral toxin adsorbent for protein-bound uremic toxins may potentially counteract uremic VC. Novel agents such as tenapanor have been actively tested in clinical trials for their potential vascular benefits. Further advanced studies are still warranted to validate the beneficial effects of gastrointestinal decontamination in the retardation and treatment of uremic VC.

Astaxanthin Counteracts Vascular Calcification In Vitro Through an Early Up-Regulation of SOD2 Based on a Transcriptomic Approach

Vascular calcification (VC) is a critical contributor to the rising cardiovascular risk among at-risk populations such as those with diabetes or renal failure. The pathogenesis of VC involves an uprising of oxidative stress, for which antioxidants can be theoretically effective. However, astaxanthin, a potent antioxidant, has not been tested before for the purpose of managing VC. To answer this question, we tested the efficacy of astaxanthin against VC using the high phosphate (HP)-induced vascular smooth muscle cell (VSMC) calcification model. RNAs from treated groups underwent Affymetrix microarray screening, with intra-group consistency and inter-group differential expressions identified. Candidate hub genes were selected, followed by validation in experimental models and functional characterization. We showed that HP induced progressive calcification among treated VSMCs, while astaxanthin dose-responsively and time-dependently ameliorated calcification severities. Transcriptomic profiling revealed that 3491 genes exhibited significant early changes during VC progression, among which 26 potential hub genes were selected based on closeness ranking and biologic plausibility. SOD2 was validated in the VSMC model, shown to drive the deactivation of cellular senescence and enhance antioxidative defenses. Astaxanthin did not alter intracellular reactive oxygen species (ROS) levels without HP, but significantly lowered ROS production in HP-treated VSMCs. SOD2 knockdown prominently abolished the anti-calcification effect of astaxanthin on HP-treated VSMCs, lending support to our findings. In conclusion, we demonstrated for the first time that astaxanthin could be a potential candidate treatment for VC, through inducing the up-regulation of SOD2 early during calcification progression and potentially suppressing vascular senescence.

Elevated Red Cell Distribution Width Is Independently Associated With a Higher Frailty Risk Among 2,932 Community-Dwelling Older Adults

Background: Older adults are at an increased risk of frailty, but laboratory surrogates for identifying frailty in this population remain controversial and clinicians frequently encounter difficulty during frailty screening. We examined whether having a high red cell distribution width (RDW) was associated with an increased probability of frailty in older adults.

Methods: We prospectively included community-dwelling older adults between 2013 and 2016 from a single institute, with their clinical features/laboratory parameters documented. We used the Study of Osteoporotic Fractures index (malnutrition, poor physical performance, and fatigue) to delineate frailty, and harnessed multiple logistic regression to investigate whether having a high RDW (≥ 15.7%) was associated with an increased risk of having frailty among these participants.

Results: A total of 2,932 older adults (mean 73.5 ± 6.7 years; 44.6% male) were included, among whom 113 (3.9%) and 76 (2.6%) had a high RDW and presented frailty, respectively. Older adults with a high RDW were more likely to be frail (p = 0.002) and had more positive SOF items than those with normal RDW levels (p = 0.013). Those with a high RDW exhibited a significantly higher risk of having frailty (odds ratio [OR] 2.689, 95% confidence interval [CI] 1.184–6.109) compared to those without. Sensitivity analyses using RDW as a continuous variable similarly showed that RDW levels were positively associated with frailty risk (OR 1.223 per 1% RDW higher).

Conclusions: In older adults, higher RDW can be regarded as a frailty indicator, and the readiness in RDW assessment supports its screening utility.