Association Between Serum Phosphate Levels and Stroke Risk in Patients Undergoing Hemodialysis: The Q-Cohort Study

Calcimimetics treatment strategy for serum calcium and phosphate management in patients with secondary hyperparathyroidism undergoing dialysis: A systematic review and meta-analysis of randomized studies

INTRODUCTION

Several calcimimetics, other than cinacalcet, are commercially available; however, their effects on calcium and phosphate levels have not yet been fully studied. We conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the impact of calcimimetics on the management of serum calcium and phosphate levels in patients with secondary hyperparathyroidism undergoing dialysis.

METHODS

A systematic literature search through October 2023 and a meta-analysis were conducted on the effects of upacicalcet, etelcalcetide, evocalcet, and cinacalcet on serum calcium and phosphate levels in patients with secondary hyperparathyroidism undergoing dialysis; we searched PubMed, Ovid MEDLINE, and the Cochrane Central Register of Controlled Trials, and 21 studies comprising 6371 patients undergoing dialysis were included.

RESULTS

Participants treated with calcimimetics had lower serum calcium and phosphate levels than placebo.

CONCLUSION

Calcimimetics significantly reduced serum calcium and phosphate levels compared to placebo in patients with secondary hyperparathyroidism undergoing dialysis, independent of therapeutic strategy or concomitant vitamin D treatment.

Disturbance in the potential cardiovascular-bone-skeletal muscle axis and morbidity and mortality in patients undergoing haemodialysis: the Q-Cohort Study

Background

Disturbances in the cardiovascular system, bone and skeletal muscle are independent risk factors for death among patients receiving haemodialysis (HD). However, the combined impact of disorders of these three organs on morbidity and mortality is unclear in the HD population.

Methods

A total of 3031 Japanese patients on maintenance HD were prospectively followed. The outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and bone fracture. Patients were divided into four groups (G1-G4) according to the baseline number of diseased organs represented as histories of cardiovascular disease and bone fractures and the presence of low skeletal muscle mass as follows: G1, no organ; G2, one organ; G3, two organs; G4, three organs. Multivariable-adjusted survival models were used to analyse associations between the number of diseased organs and outcomes.

Results

During a 4-year follow-up, 499 deaths, 540 MACE and 140 bone fractures occurred. In the Cox proportional hazards model, the risk for all-cause mortality was significantly higher in G2, G3 and G4 than in G1 as the reference {hazard ratio: G2, 2.16 [95% confidence interval (CI) 1.65-2.84], G3, 3.10 [95% CI 2.27-4.23] and G4, 3.11 [95% CI 1.89-5.14]}. Similarly, the risks for developing MACE and bone fractures were significantly elevated as the number of organ disorders increased.

Conclusions

Multiple disorders of the cardiovascular-bone-skeletal muscle axis are strong predictors of morbidity and mortality in patients undergoing HD.

Hyperphosphatemia in Chronic Kidney Disease: The Search for New Treatment Paradigms and the Role of Tenapanor

Hyperphosphataemia represents a significant challenge in the management of chronic kidney disease, exerting a pronounced influence on the pathogenesis of cardiovascular complications and mineral bone disorders. Traditional approaches to address hyperphosphataemia involve implementing dietary phosphate restrictions, administering phosphate binders, and, in cases of end-stage renal disease, resorting to dialysis. Unfortunately, these interventions frequently prove inadequate in maintaining phosphate levels within recommended ranges. Additionally, commonly employed pharmacological agents are not immune to eliciting adverse events, thereby limiting their prescription and therapeutic adherence. There is a growing focus on exploring novel therapeutic strategies in this context. The current discussion centres on tenapanor, a pharmacological agent predominantly acting as a selective inhibitor of sodium/hydrogen exchanger isoform 3 (NHE3). Its mechanism of action involves modulating tight junctions, resulting in reduced sodium absorption and intestinal paracellular permeability to phosphate. Furthermore, tenapanor downregulates sodium-dependent phosphate 2b transport protein (NaPi2b) expression, thereby impeding active transcellular phosphate transport. Clinical trials have elucidated the efficacy and safety profile of tenapanor. This evidence hints at a potential paradigm shift in the management of hyperphosphataemia. However, the burgeoning optimism surrounding tenapanor warrants tempered enthusiasm, as further research remains indispensable. The imperative lies in meticulously delineating its efficacy and safety contours within the crucible of clinical practice. In this review, we synthesize the intricate interplay between hyperphosphataemia and Chronic Kidney Disease-Mineral Bone Disorder, and we discuss the existing pharmacological interventions for hyperphosphataemia and explore emerging treatment paradigms that offer novel perspectives in managing elevated phosphate levels in CKD patients.

Mean Platelet Volume/Platelet Count Ratio as a Predictor of Both Incidence and Prognosis of Acute Ischemic Stroke in Hemodialysis Patients

Purpose

This study aimed to explore whether the mean platelet volume/platelet count ratio (MPR) has predictive value for the occurrence and prognosis of acute ischemic stroke (AIS) in hemodialysis patients.

Patients and Methods

A total of 402 patients undergoing maintenance hemodialysis were screened and 259 were enrolled in this study. The receiver operating characteristic curve and area under the curve (AUC) were used to evaluate the predictive power of the models. The patients enrolled in this study were divided into three groups based on the tertiles of the MPR value (Q1, Q2, and Q3). Kaplan-Meier curves were used to investigate the association between the MPR and AIS-free survival in hemodialysis patients. Chi-square analysis was performed to explore the association between the MPR and AIS outcomes in hemodialysis patients. And the AIS outcome was assessed using the modified Rankin Scale (mRS).

Results

MPR had a predictive value for the occurrence of AIS (AUC=0.814) in hemodialysis patients with a high sensitivity and specificity. AIS-free survival rates in the MPR Q1, MPR Q2, and MPR Q3 groups were 0.930, 0.701, and 0.360, respectively. The proportion of patients with good outcomes (mRS 0-2) was significantly greater among patients in the MPR Q1-Q2 group than in the MPR Q3 group (0.844 vs 0.745, p <0.001).

Conclusion

The MPR can be used as a good predictor of AIS in patients undergoing hemodialysis. Patients on hemodialysis with increased MPR levels had a higher incidence of AIS and poorer functional outcomes than those with low MPR levels.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Role of Chronic Kidney Disease (CKD)-Mineral and Bone Disorder (MBD) in the Pathogenesis of Cardiovascular Disease in CKD

Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD). Multiple factors account for the increased incidence of cardiovascular morbidity and mortality in patients with CKD. Traditional risk factors for atherosclerosis and arteriosclerosis, including age, hypertension, dyslipidemia, diabetes mellitus, and smoking, are also risk factors for CKD. Non-traditional risk factors specific for CKD are also involved in CVD pathogenesis in patients with CKD. Recently, CKD-mineral and bone disorder (CKD-MBD) has emerged as a key player in CVD pathogenesis in the context of CKD. CKD-MBD manifests as hypocalcemia and hyperphosphatemia in the later stages of CKD; however, it initially develops much earlier in disease course. The initial step in CKD-MBD involves decreased phosphate excretion in the urine, followed by increased circulating concentrations of fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH), which increase urinary phosphate excretion. Simultaneously, the serum calcitriol concentration decreases as a result of FGF23 elevation. Importantly, FGF23 and PTH cause left ventricular hypertrophy, arrhythmia, and cardiovascular calcification. More recently, calciprotein particles, which are nanoparticles composed of calcium, phosphate, and fetuin-A, among other components, have been reported to cause inflammation, cardiovascular calcification, and other clinically relevant outcomes. CKD-MBD has become one of the critical therapeutic targets for the prevention of cardiovascular events and is another link between cardiology and nephrology. In this review, we describe the role of CKD-MBD in the pathogenesis of cardiovascular disorders and present the current treatment strategies for CKD-MBD.

Investigation on maintenance hemodialysis patients with mineral and bone disorder in Anhui province, China

BACKGROUND

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a common comorbidity in patients with CKD. The study aims to describe the control rates of serum-corrected calcium (Ca), phosphate (P) and intact parathyroid hormone (iPTH) and its risk factors among maintenance hemodialysis (MHD) patients in Anhui Province of China.

METHODS

The study was conducted in 27 hemodialysis centers of Anhui Province between January 1st 2020 and December 31th 2020. Chi-square test was used to compare the control rates of serum-corrected Ca, P and iPTH between the present study and DOPPS 4 or Anhui Province in 2014. Binary logistic regression analysis was used to explore the risk factors of the control rates of serum-corrected Ca, P and iPTH.

RESULTS

A total of 3 025 MHD patients were recruited in this study, with a mean age of 54.8 (SD: 12.8) years, and 60.1% were males. According to the Chinese Diagnosis and Treatment Guidelines for CKD-MBD, the control rates of serum-corrected Ca, P and iPTH in the present study were 57.9%, 20.0% and 56.0%, respectively. Based on KDOQI guidelines (2003), the control rates of the above indicators were 43.1%, 35.3% and 22.3%, respectively. The control rates of serum-corrected Ca, P and iPTH in this study were lower than those of DOPPS 4 (P < 0.001). Compared to the results of Anhui Province in 2014, the control rate of corrected Ca was higher (P < 0.001) and the control rate of iPTH was lower (P = 0.005). Age, residential area, BMI, dialysis vintage, albumin and hemoglobin levels were factors of serum-corrected Ca, P and iPTH not within target range.

CONCLUSION

The control rates of serum-corrected Ca, P and iPTH in MHD patients in Anhui Province are relatively low. Monitoring and management should be strengthened to improve the prognosis of patients undergoing dialysis.

Risk factors for intracerebral hemorrhage in patients undergoing maintenance hemodialysis

Background

In patients undergoing hemodialysis, intracerebral hemorrhage (ICH) is the main cause of mortality among stroke subtypes. It is unclear whether, along with traditional cardiovascular risk factors, the risk factors unique to the uraemic environment, such as the abnormal metabolism of intact parathyroid hormone (iPTH), can contribute to the risk of ICH in these patients.

Methods

This retrospective case-control study included 25 patients undergoing hemodialysis with ICH at a single center between 30 June 2015 and 10 October 2022. The controls were 95 patients undergoing maintenance hemodialysis treated at the same dialysis center in July 2020. We compared the characteristics of patients with ICH with those of the control group to identify factors that contributed to the development of ICH.

Results

Intracerebral hemorrhage (ICH) was located in the basal ganglia (14/25), cerebellum (6/25), and brainstem (6/25) in 25 patients. A total of 17 patients died in the first 16 days due to neurological complications. Univariate analysis showed significant differences in systolic BP, diastolic BP, iPTH, and alkaline phosphatase between the two groups (p < 0.05). Multivariate logistic regression analysis showed that higher systolic BP (OR, 1.053; 95% CI, 1.018-1.090; p = 0.003) and higher iPTH (OR, 1.007; 95% CI, 1.003-1.012; p = 0.001) were associated with the onset of ICH. ICH was predicted by systolic BP and iPTH by receiver operating characteristic (ROC) curve analysis, with areas under the curve (AUCs) of 0.732 and 0.624, respectively. The optimal cutoffs for systolic BP and iPTH were 151.9 mmHg and 295.4 pg./ml, respectively. Restricted cubic spline showed that the shape of the association of iPTH with the risk of ICH was approximately J-shaped (P for non-linearity <0.05).

Conclusion

Higher systolic BP and abnormal iPTH metabolism might be associated with ICH in patients undergoing hemodialysis. Comprehensive control of hypertension and iPTH may be a fundamental preventive strategy for ICH in these patients.

Association between hyporesponsiveness to erythropoiesis-stimulating agents and risk of brain hemorrhage in patients undergoing hemodialysis: the Q-Cohort Study

BACKGROUND

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with increased risks of all cause and cardiovascular mortality in patients undergoing hemodialysis (HD). However, the impact of the hematopoietic response to ESAs on the development of stroke, including brain hemorrhage and infarction, remains unclear.

METHODS

In total, 2886 patients undergoing maintenance HD registered in the Q-Cohort Study who were treated with ESAs were prospectively followed up for 4 years. The hematopoietic response to ESAs was evaluated by the erythropoietin resistance index (ERI), calculated by dividing the weekly dose of ESA by post-HD weight and hemoglobin (U/kg/week/g/dL). The primary outcomes were the incidences of brain hemorrhage and infarction. Patients were divided into quartiles based on their ERI at baseline (Q1, ≤ 4.1; Q2, 4.2-7.0; Q3, 7.1-11.2; and Q4, ≥ 11.3). The risks of brain hemorrhage and infarction were estimated using Cox proportional hazards models, adjusting for potential confounders.

RESULTS

During the 4 year follow-up period, 71 patients developed brain hemorrhage and 116 developed brain infarction. In the multivariable analysis, the incidence of brain hemorrhage in the highest quartile (Q4) was significantly higher than that in the lowest quartile (Q1) (hazard ratio [95% confidence interval], 2.18 [1.08-4.42]). However, the association between the ERI and the incidence of brain infarction was not significant.

CONCLUSIONS

A higher ERI was associated with an increased risk of brain hemorrhage, but not brain infarction, in patients undergoing maintenance HD. A high ERI is thus an important risk factor for brain hemorrhage in these patients.

Impact of serum phosphate on severity and functional outcomes after ischemic stroke in young adults

BACKGROUND AND AIMS

Serum phosphate is an essential nutrient that plays multiple physiological roles in cardiovascular function. The aim of this study was to investigate the association between serum phosphate and stroke severity and prognosis in ischemic stroke and transient ischemic attack (TIA) among young adults.

METHODS AND RESULTS

We retrospectively recruited patients with acute ischemic stroke and TIA aged 18-45 years. The primary outcome was 90-day poor functional outcome (modified Rankin Scale score of 2-6). The secondary outcomes included stroke severity (NIHSS ≥5 was defined as moderate to severe stroke) and poor functional outcome at hospital discharge. A total of 687 patients with a mean age of 36.8 years were enrolled. Lower serum phosphate levels were significantly associated with more severe stoke (P for trend = 0.017). Compared with the fourth quartile, the odds ratio (95% CI) of the first quartile was 1.85 (1.19-3.22) for moderate to severe stroke. After adjusting for confounders other than stroke severity, the odds ratio (95% CI) of the first quartile was 1.74 (1.06-2.86) for poor functional outcome at hospital discharge and 1.90 (1.09-3.31) at 90-day follow-up compared with the fourth quartile. However, the significant association between serum phosphate and poor functional outcomes disappeared after stroke severity was further adjusted.

CONCLUSIONS

Serum phosphate is more likely a marker of stroke severity than a contributor to poor functional outcomes after ischemic stroke and TIA in young adults. Lower serum phosphate levels were associated with more severe stroke.

Sex Differences in Cause-specific Mortality in Japanese Dialysis Patients

Objective The survival advantage of females over males is lost in dialysis patients in many countries. Japanese female hemodialysis patients, however, have a survival advantage over their male counterparts. This study explored causes of death that contribute to sex differences in all-cause mortality in Japanese dialysis patients. Methods Data from the Japanese Society for Dialysis Therapy registry and National Vital Statistics from 2017 and 2018 were used. Standardized mortality ratios, male-to-female mortality rate ratios, and age-adjusted differences between sexes were calculated for all-cause, cardiovascular, and non-cardiovascular mortality, as well as cause-specific mortality, in dialysis patients and the general population. Results During the 2-year study period, 41,006 and 21,254 deaths occurred in 417,740 and 225,292 patient-years in male and female dialysis patients, respectively. The age-standardized all-cause mortality ratio was 1.21 (95% confidence interval, 1.20-1.23) for male patients compared to female patients. The male-to-female mortality rate ratio for cardiovascular disease was about 1.4 in younger age categories but closer to 1.0 in older age categories. Conversely, the ratio for non-cardiovascular disease was about 1.3 in older age categories but closer to 1.0 in younger age categories. Death from infectious disease, malignancy, and heart failure contributed to 38.4%, 22.7%, and 12.1%, respectively, of the male-to-female difference in all-cause mortality of dialysis patients. Conclusion Low cardiovascular mortality in younger age categories and low non-cardiovascular mortality in older age categories contributed to the survival advantage of female Japanese dialysis patients. Infectious disease was the greatest contributor to sex differences in all-cause mortality.

Phosphate in the Context of Cognitive Impairment and Other Neurological Disorders Occurrence in Chronic Kidney Disease

The nervous system and the kidneys are linked under physiological states to maintain normal body homeostasis. In chronic kidney disease (CKD), damaged kidneys can impair the central nervous system, including cerebrovascular disease and cognitive impairment (CI). Recently, kidney disease has been proposed as a new modifiable risk factor for dementia. It is reported that uremic toxins may have direct neurotoxic (astrocyte activation and neuronal death) and/or indirect action through vascular effects (cerebral endothelial dysfunction, calcification, and inflammation). This review summarizes the evidence from research investigating the pathophysiological effects of phosphate toxicity in the nervous system, raising the question of whether the control of hyperphosphatemia in CKD would lower patients’ risk of developing cognitive impairment and dementia.

Prevalence, treatment status, and predictors of anemia and erythropoietin hyporesponsiveness in Japanese patients with non-dialysis-dependent chronic kidney disease: a cross-sectional study

BACKGROUND

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) has been highlighted as a potential risk factor for cardiovascular disease in patients with chronic kidney disease (CKD).

METHODS

We assessed cross-sectionally the prevalence, associated factors, and treatment status of anemia and ESA hyporesponsiveness in 4460 non-dialysis-dependent CKD patients enrolled in a multicenter cohort in Japan. Anemia was defined as a hemoglobin (Hb) level of less than 11 g/dL or receiving ESA therapy. ESA hyporesponsiveness was defined by the erythropoietin-resistance index (ERI), which was the erythropoietin dose per week divided by body weight and Hb level (U/kg/week/g/dl).

RESULTS

Of the 4460 patients, 1050 (23.5%) had anemia. ESAs were administered to 626 patients, reaching a percentage of 57.5% of patients with stage G5 CKD. However, the ESA treatment rate was only 49.0% in patients with a hemoglobin level of < 11 g/dL. The proportion of patients receiving iron supplementation was lower than that of patients receiving ESAs regardless of CKD stage or hemoglobin level, and a significant proportion of patients did not receive iron supplementation, even those with iron deficiency. The ERI increased with CKD stage progression, and the multiple regression analysis showed that age, female sex, body mass index, cholesterol, glomerular filtration rate, and intact parathyroid hormone level were independent contributors.

CONCLUSIONS

Our findings demonstrate that many Japanese patients with non-dialysis-dependent CKD receiving ESAs fail to maintain adequate hemoglobin levels. These results suggest the need for interventions for ESA hyporesponsiveness factors in addition to iron supplementation.

Correlation between a Bedridden Status and the Long-term Outcome in Hemodialysis Patients after Intracerebral Hemorrhaging

Objective The quality of life and activities of daily living (ADL) are generally poor among dialysis patients after intracerebral hemorrhaging, and their precise clinical course remains unclear. In addition, the association between the severity of cerebral hemorrhaging and the long-term prognosis in these patients has not been fully elucidated. This study aimed to evaluate the subsequent prognosis of hemodialysis patients who survived the acute phase of intracerebral hemorrhaging. Methods We included hemodialysis patients who were admitted to Nagasaki University Hospital between 2007 and 2015 for intracerebral hemorrhaging treatment. After excluding cases of in-hospital death, survivors were classified using the 5-point modified Rankin Scale (mRS), which specifically measures the ADL in patients with cerebrovascular diseases. The patients were followed up at the medical facilities to which they were transferred in the same medical zone until 2017. Results Out of 91 patients with cerebral hemorrhaging (65±11 years old, 66% men, hemodialysis duration 108±91 months), 62 survived until discharge. Twenty-one patients died during observation, largely due to infectious diseases, such as sepsis and pneumonia (n=16, 76%). Compared to patients with mRS 0-4 (n=31), those with mRS 5 (n=31) showed a significantly poorer prognosis. The hazard ratio adjusted for age and antiplatelets was 13.7 (95% confidence interval: 3.88-63.7, p<0.001). Conclusion Hemodialysis patients with intracerebral hemorrhaging who were bedridden showed poor outcomes. The major causes of death were infections. Therefore, these patients should be carefully monitored for infections in order to improve their prognosis.

Emerging cross-talks between chronic kidney disease-mineral and bone disorder (CKD-MBD) and malnutrition-inflammation complex syndrome (MICS) in patients receiving dialysis

Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a systemic disorder that affects multiple organs and systems and increases the risk of morbidity and mortality in patients with CKD, especially those receiving dialysis therapy. CKD–MBD is highly prevalent in CKD patients, and its treatment is gaining attention from healthcare providers who manage these patients. Additional important pathologies often observed in CKD patients are chronic inflammation and malnutrition/protein-energy wasting (PEW). These two pathologies coexist to form a vicious cycle that accelerates the progression of various other pathologies in CKD patients. This concept is integrated into the term “malnutrition–inflammation–atherosclerosis syndrome” or “malnutrition–inflammation complex syndrome (MICS)”. Recent basic and clinical studies have shown that CKD–MBD directly induces inflammation as well as malnutrition/PEW. Indeed, higher circulating levels of inorganic phosphate, fibroblast growth factor 23, parathyroid hormone, and calciprotein particles, as markers for critical components and effectors of CKD–MBD, were shown to directly induce inflammatory responses, thereby leading to malnutrition/PEW, cardiovascular diseases, and clinically relevant complications. In this short review, we discuss the close interplay between CKD–MBD and MICS and emphasize the significance of simultaneous control of these two seemingly distinct pathologies in patients with CKD, especially those receiving dialysis therapy, for better management of the CKD/hemodialysis population.

A Mobile App for Triangulating Strategies in Phosphate Education Targeting Patients with Chronic Kidney Disease in Malaysia: Development, Validation, and Patient Acceptance

Hyperphosphatemia afflicts end-stage chronic kidney disease (CKD) patients, contributing to comorbidities and mortality. Management strategies are dialysis, phosphate binder, and limiting dietary phosphate intake, but treatment barriers are poor patient compliance and low health literacy arising from low self-efficacy and lack of educational resources. This study describes developing and validating a phosphate mobile application (PMA). The PMA development based on the seven-stage Precaution Adoption Process Model prioritized titrating dietary phosphate intake with phosphate binder dose supported by educational videography. Experts (n = 13) first evaluated the PMA for knowledge-based accuracy, mobile heuristics, and clinical value. Adult HD patients validated the improved PMA using the seven-point mHealth App Usability Questionnaire (MAUQ). Patient feedback (n = 139) indicated agreement for ease of use (69.2%), interface and satisfaction (69.0%), and usefulness (70.1%), while 72.7% said they would recommend this PMA. The expectation confirmation for 25 PMA features ranged from 92.1% (lifestyle) up to 100.0% (language option); and the utilization rate of each feature varied from 21.6% (goal setting and feature-based log) to 91.4% (information on dietary phosphate and phosphate binder). The Conclusions: MyKidneyDiet-Phosphate Tracker PMA was acceptable to adult Malaysian HD patients as part of clinical phosphate management in low-resource settings.

Cardiometabolic risk factors associated with brain age and accelerate brain ageing

The structure and integrity of the ageing brain is interchangeably linked to physical health, and cardiometabolic risk factors (CMRs) are associated with dementia and other brain disorders. In this mixed cross-sectional and longitudinal study (interval mean = 19.7 months), including 790 healthy individuals (mean age = 46.7 years, 53% women), we investigated CMRs and health indicators including anthropometric measures, lifestyle factors, and blood biomarkers in relation to brain structure using MRI-based morphometry and diffusion tensor imaging (DTI). We performed tissue specific brain age prediction using machine learning and performed Bayesian multilevel modeling to assess changes in each CMR over time, their respective association with brain age gap (BAG), and their interaction effects with time and age on the tissue-specific BAGs. The results showed credible associations between DTI-based BAG and blood levels of phosphate and mean cell volume (MCV), and between T1-based BAG and systolic blood pressure, smoking, pulse, and C-reactive protein (CRP), indicating older-appearing brains in people with higher cardiometabolic risk (smoking, higher blood pressure and pulse, low-grade inflammation). Longitudinal evidence supported interactions between both BAGs and waist-to-hip ratio (WHR), and between DTI-based BAG and systolic blood pressure and smoking, indicating accelerated ageing in people with higher cardiometabolic risk (smoking, higher blood pressure, and WHR). The results demonstrate that cardiometabolic risk factors are associated with brain ageing. While randomized controlled trials are needed to establish causality, our results indicate that public health initiatives and treatment strategies targeting modifiable cardiometabolic risk factors may also improve risk trajectories and delay brain ageing.

Predictive model for diagnosing central lesions in emergency department patients with isolated dizziness who undergo diffusion-weighted magnetic resonance imaging

OBJECTIVES

Only 5% to 10% of patients who visit the emergency department (ED) with isolated dizziness without neurologic abnormalities may have central lesions; however, it is important to distinguish central lesions through brain imaging. This study was conducted to create a nomogram to provide an objective medical basis for selectively performing magnetic resonance imaging (MRI) among patients with isolated dizziness.

METHODS

This retrospective observational study enrolled patients who visited the ED of a tertiary hospital with isolated dizziness and underwent diffusion-weighted MRI and subsequently consulted with the departments of neurology, neurosurgery, or otorhinolaryngology. Multivariable logistic regression analysis was performed to identify risk factors in patients diagnosed with central lesions to create a nomogram with the significant variables.

RESULTS

Of the 1,078 patients who were screened, 119 were diagnosed with central lesions. Significant variables in the multivariable logistic regression analysis were albumin levels (odds ratio [OR] = 0.339, 95% confidence interval [CI] = 0.188 to 0.610, p = 0.0003), inorganic phosphate levels (OR = 0.891, 95% CI = 0.832 to 0.954, p = 0.0010), history of ischemic stroke (OR = 3.170, 95% CI = 1.807 to 5.560, p < 0.0001), presyncope (OR = 3.152, 95% CI = 1.184 to 8.389, p = 0.0216), and nystagmus (OR = 0.365, 95% CI = 0.237 to 0.561, p < 0.0001). The area under the receiver operating characteristic curve of the nomogram created with these variables was 0.7315 (95% CI = 0.6842 to 0.7788, p < 0.0001).

CONCLUSIONS

Albumin, inorganic phosphate, previous stroke, presyncope, and nystagmus were associated with the predictive diagnosis of central lesions among patients admitted to the ED with isolated dizziness. The novel nomogram created using these variables can help in objectively determining the need for MRI in patients presenting with isolated dizziness to the ED.

Interactions Between Kidney Function and Cerebrovascular Disease: Vessel Pathology That Fires Together Wires Together

The kidney and the brain, as high-flow end organs relying on autoregulatory mechanisms, have unique anatomic and physiological hemodynamic properties. Similarly, the two organs share a common pattern of microvascular dysfunction as a result of aging and exposure to vascular risk factors (e.g., hypertension, diabetes and smoking) and therefore progress in parallel into a systemic condition known as small vessel disease (SVD). Many epidemiological studies have shown that even mild renal dysfunction is robustly associated with acute and chronic forms of cerebrovascular disease. Beyond ischemic SVD, kidney impairment increases the risk of acute cerebrovascular events related to different underlying pathologies, notably large artery stroke and intracerebral hemorrhage. Other chronic cerebral manifestations of SVD are variably associated with kidney disease. Observational data have suggested the hypothesis that kidney function influences cerebrovascular disease independently and adjunctively to the effect of known vascular risk factors, which affect both renal and cerebral microvasculature. In addition to confirming this independent association, recent large-scale human genetic studies have contributed to disentangling potentially causal associations from shared genetic predisposition and resolving the uncertainty around the direction of causality between kidney and cerebrovascular disease. Accelerated atherosclerosis, impaired cerebral autoregulation, remodeling of the cerebral vasculature, chronic inflammation and endothelial dysfunction can be proposed to explain the additive mechanisms through which renal dysfunction leads to cerebral SVD and other cerebrovascular events. Genetic epidemiology also can help identify new pathological pathways which wire kidney dysfunction and cerebral vascular pathology together. The need for identifying additional pathological mechanisms underlying kidney and cerebrovascular disease is attested to by the limited effect of current therapeutic options in preventing cerebrovascular disease in patients with kidney impairment.

Association between phosphate and long-term outcome in CAD patients underwent coronary intervention

Phosphate has been linked to higher cardiovascular (CV) risk. However, whether phosphate is associated with poor outcomes for patients with coronary artery disease (CAD) after percutaneous coronary interventions (PCIs) remained undetermined. 2,894 CAD patients (2,220 male, aged 71.6 ± 12.2), who received PCI at TVGH from 2006 to 2015, with phosphate measurement, were enrolled. The primary outcome was the composite of major adverse CV events [MACE, comprising of CV death, nonfatal MI, and nonfatal stroke] and heart failure hospitalization (HHF). The key secondary outcome was MACE. There was a J-curve association between phosphate and CV events after adjusted for comorbidities and renal function. Phosphate around 3.2 ± 0.1 mg/dL was associated with the lowest CV risk. In Cox analysis, each 1 mg/dL increases in phosphate was associated with a higher risk of MACE + HHF (HR: 1.12, 95% CI: 1.05–1.21): CV death (HR: 1.37, 95% CI: 1.22–1.55) and HHF (HR: 1.12, 95% CI: 1.02–1.23). Subgroup analyses showed more prominent association between phosphate and MACE + HHF in male, age > 65, bare-metal stents (BMSs), LVEF < 50%, eGFR < 60, LDL > 70 mg/dL, and emergent PCI. Phosphate has a significant association with the risk of CV events in CAD patients undergoing PCI that was independent of comorbidities and renal function.

Association between Multimorbidity and Kidney Function among Patients with Non-Dialysis-Dependent CKD

Aim: Individuals with chronic kidney disease (CKD) have a high prevalence of comorbidities, including cardiovascular disease (CVD) and its risk factors. However, epidemiological results to assess the association between multimorbidity and kidney function among the CKD population remains limited.

Methods: We performed a cross-sectional analysis of the association between 23 comorbid conditions and reduced kidney function in 4,476 patients with non-dialysis-dependent CKD enrolled in a multicenter cohort in Japan. Reduced kidney function was defined as an estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m².

Results: The mean age of patients was 67 years (male, 56.0%). The prevalence of hypertension, diabetes mellitus, dyslipidemia, prior CVD, cancer, and bone fracture, which are the major comorbidities, was 83.3%, 28.7%, 45.9%, 23.3%, 12.7%, and 6.3%, respectively. Multivariable-adjusted analyses revealed that age, male sex, hypertension, dyslipidemia, prior CVD, body mass index, urinary protein excretion, and underlying kidney disease were independent factors associated with reduced kidney function. Importantly, the odds ratios (ORs) for reduced kidney function increased linearly as the number of major comorbid conditions increased (OR for 1–2 conditions: 2.22, 95% confidence interval [CI]: 1.65–2.97; OR for 3–4 conditions: 3.04, 95% CI: 2.12–4.37; OR for ≥ 5 conditions: 4.37, 95% CI: 1.75–10.9). The upward trend in OR was more pronounced with cardiovascular comorbidities but not significant with non-cardiovascular comorbidities.

Conclusions: In conclusion, we observed an independent association between cardiovascular comorbidity and its risk factors and reduced kidney function. The results of this study highlight the importance of managing multimorbidity among patients with CKD.

Association between Serum Phosphate Levels and the Development of Aortic Stenosis in Patients Undergoing Hemodialysis

We aimed to investigate the factors associated with the development of aortic stenosis (AS) in patients undergoing hemodialysis (HD), and to elucidate the prognosis of HD patients with AS. Patients on HD that had also undergone echocardiography at Nagasaki Renal Center between July 2011 and June 2012 were included. Patients with AS at the time of inclusion were excluded. The diagnosis of AS was based on an annual routine or additional echocardiography. The patients were followed up until June 2021. The association between patient background and AS was also evaluated. Of the 302 patients (mean age, 67.4 ± 13.3 years; male, 58%; median dialysis history, 4.7 years), 60 developed AS and 10 underwent aortic valve replacement. A Cox proportional hazards model revealed that age (hazard ratio (HR), 1.07; 95% confidential interval (CI), 1.04–1.10; p < 0.001) and serum phosphate levels (HR, 1.40; 95%CI, 1.16–1.67, p < 0.001) were independent risk factors for developing AS. Incidentally, there was no significant mortality difference between patients with AS and those without (p = 0.53). Serum phosphate levels are a risk factor for developing AS and should be controlled. Annual echocardiography may contribute to the early detection of AS and improves the prognosis of patients undergoing HD.

Association Between Admission Serum Phosphate Level and All-Cause Mortality Among Patients with Spontaneous Intracerebral Hemorrhage

Background

Hypophosphatemia was reported to frequently occur in patients with nontraumatic intracranial hemorrhage (ICH); however, the correlation between hypophosphatemia and outcomes of ICH remains unclear. This study aimed to examine the association between admission serum phosphate and all-cause mortality among patients with mild–moderate spontaneous ICH (sICH).

Methods

A total of 851 patients with sICH were enrolled. Serum phosphate was acquired within 24 hours on admission, and participants were divided according to phosphate quartiles. The primary outcome was all-cause mortality within 90 days, and univariate and multivariate models were employed to estimate the mortality risk.

Results

There were significant differences among sICH patients with different phosphate quartiles in terms of age, diastolic blood pressure (DBP), activated partial thromboplastin time (APTT), platelet count, and incidence of respiratory failure events on admission (P < 0.05). Log rank test showed a significant difference in the mortality risk among sICH patients with each phosphate quartile. Univariate Cox regression analysis revealed that age, smoking, DBP, APTT, NIH stroke scale (NIHSS) score, hematoma volume and serum phosphate might be associated with the 90-day all-cause mortality in patients with sICH (P < 0.05). Multivariable Cox regression analysis showed that the crude mortality was 4.3-fold greater in sICH patients with serum phosphate Q1 than those with Q4 (P < 0.001), and remained 3.18-fold higher after adjusting for age, smoking, DBP, APTT, NIHSS score, hematoma volume and early withdrawal of life-sustaining therapy (P = 0.011). Representative operating curve (ROC) analysis showed that admission serum phosphate was predictable for all-cause mortality within 90 days in patients with sICH (area under the ROC = 0.628, P < 0.001).

Conclusion

Low admission serum phosphate is strongly associated with a high risk of mortality in patients with mild–moderate sICH, and hypophosphatemia may be a prognostic marker for all-cause mortality in patients with mild–moderate sICH.

Clinical epidemiological analysis of cohort studies investigating the pathogenesis of kidney disease

In recent years, large cohort studies of patients with chronic kidney disease (CKD) have been established all over the world. These studies have attempted to analyze the pathogenesis of CKD using a large body of published evidence. The design of cohort studies is characterized by the measurement of the exposure prior to the occurrence of the outcome, which has the advantage of clarifying the temporal relationship between predictors and outcomes and estimating the strength of the causal relationship between predictors and multiple outcomes. Recent advances in biostatistical analysis methods, such as propensity scores and risk prediction models, are facilitating causal inference using higher quality evidence with greater precision in observational studies. In this review, we will discuss clinical epidemiological research of kidney disease based on the analysis of observational cohort data sets, with a focus on our previous studies.

Serum Alkaline Phosphatase Levels and Increased Risk of Brain Hemorrhage in Hemodialysis Patients: The Q-Cohort Study

Aim: Elevated serum alkaline phosphatase (ALP) levels have been associated with increased risks of all-cause and cardiovascular mortality in patients receiving hemodialysis. However, little is known about the impact of serum ALP levels on the development of stroke, such as brain hemorrhage and infarction.

Methods: A total of 3,497 patients receiving maintenance hemodialysis registered in the multicenter observational Q-Cohort Study were analyzed. The primary outcomes were the incidences of brain hemorrhage and infarction. The covariate of interest was serum ALP levels. Patients were divided into tertiles based on their serum ALP levels (U/L) at baseline (T1, ＜69.3; T2, 69.3–98.4; T3, ＞98.4). The risks of brain hemorrhage, brain infarction, and composite stroke were estimated using Cox proportional hazards models and competing risk models with all-cause death as a competing risk.

Results: A total of 89 patients developed brain hemorrhage and 195 patients developed brain infarction during the 4-year follow-up period. The risk of brain hemorrhage in the highest tertile (T3) was significantly higher than that in the lowest tertile (T1) (multivariable-adjusted hazard ratio [95% confidence interval], 1.93 [1.12–3.35], subdistribution hazard ratio, 1.91 [1.10–3.30]). However, there was no significant association between serum ALP levels and the risk of brain infarction or composite stroke.

Conclusions: Higher serum ALP levels are associated with an increased risk of brain hemorrhage, but not brain infarction, in patients receiving maintenance hemodialysis. High serum ALP level is thus an important risk factor for brain hemorrhage in hemodialysis patients.

Causes of death in patients undergoing maintenance hemodialysis in Japan: 10-year outcomes of the Q-Cohort Study

BACKGROUND

Although the mortality rate in patients on hemodialysis remains extremely high, detailed information on causes of death over long-term periods is limited. The aim of this study was to clarify the underlying causes of death in patients undergoing maintenance hemodialysis in Japan.

METHODS

This was a 10-year, multicenter, observational study of 3528 outpatients undergoing maintenance hemodialysis in Japan. Clinical outcomes were analyzed and causes of death were classified into six broad categories including cardiovascular diseases, infectious diseases, malignant neoplasms, cachexia, trauma/accidents, and other diseases, and more detailed subcategories.

RESULTS

During the 10-year follow-up period, 1748 (49.5%) patients died. The most frequent causes of death were cardiovascular diseases (36.1%), followed by infectious diseases (25.8%) and malignant neoplasms (13.5%). In a detailed classification, sudden death, pulmonary infection, and lung cancer were the most common causes of death in cardiovascular diseases, infectious diseases, and malignant neoplasms, respectively.

CONCLUSION

Our study determined details on causes of death in Japanese hemodialysis patients during the 10-year follow-up period. Cardiovascular disease, especially sudden death is noticeable cause of death among patients on hemodialysis.

Serum Phosphate and 1-Year Outcome in Patients With Acute Ischemic Stroke and Transient Ischemic Attack

Objective: To determine the association between serum phosphate level and 1-year clinical outcomes in patients with acute ischemic stroke and transient ischemic attack.

Methods: We included 7,353 patients with acute ischemic stroke and transient ischemic attack from the China National Stroke Registry III for analysis. Participants were divided into 4 groups according to serum phosphate quartiles. Composite end point included recurrent stroke, myocardial infarction, other ischemic vascular events, and all-cause mortality. Poor functional outcome is defined as modified Rankin Scale score of 3 to 6. Multivariable Cox regression or logistic regression was used to evaluate the independent association of serum phosphate with 1-year all-cause mortality, recurrent stroke, composite end point and poor functional outcome.

Results: The mean age of the included 7,353 patients was 62.5 years, and 68.6% of them were men. Plotting hazard ratios over phosphate levels suggested a U-shaped association especially for recurrent stroke and composite end point, and therefore the third quartile group was set as reference group. Compared with the third quartile of phosphate (1.06–1.20 mmol/L), the adjusted hazard ratios/odds ratios (95% CI) of the lowest quartile (<0.94 mmol/L) were 0.98 (0.67–1.42) for all-cause mortality, 1.31 (1.05–1.64) for stroke recurrence, 1.26 (1.02–1.57) for composite end point, and 1.27 (1.01–1.61) for poor functional outcome, and the adjusted odds ratio of the highest quartile (≥1.2 mmol/L) was 1.40 (1.11–1.77) for poor functional outcome.

Conclusions: Serum phosphate may be an independent predictor of stroke recurrence, composite end point and poor functional outcome after ischemic stroke.

Association between geriatric nutritional risk index and stroke risk in hemodialysis patients: 10-Years outcome of the Q-Cohort study

BACKGROUNDS AND AIMS

The geriatric nutritional risk index (GNRI), which is calculated using the serum albumin level and body mass index, is a nutritional marker associated with an increased risk of cardiovascular events in patients who are receiving hemodialysis. However, no studies have examined the association between the GNRI level and the incidence of stroke in this population.

METHODS

Three thousand forty-five patients were registered in the Q-Cohort Study, which is a multicenter, observational cohort of hemodialysis patients. The main outcomes were brain infarction and brain hemorrhage. The main exposure was GNRI levels at baseline. Patients were divided into quartiles on the basis of baseline GNRI levels: Q1, <90.7; Q2, 90.7-95.5; Q3, 95.6-99.8; Q4, >99.8. The risk of brain infarction or hemorrhage was estimated using the multivariable-adjusted Cox proportional hazard risk models and restricted cubic spline analyses.

RESULTS

During the 10-year follow-up period, 326 patients developed brain infarction and 149 patients developed brain hemorrhage. Cox proportional hazard risk models showed that the risk of brain infarction and hemorrhage in Q1 was significantly higher than that in Q4 group. The hazard ratios [95% confidence intervals] were 1.49 [1.05-2.12] and 1.89 [1.11-3.20], respectively. Restricted cubic spline curves showed that a lower GNRI was incrementally associated with an increased risk for both brain infarction and brain hemorrhage.

CONCLUSIONS

Our results suggest that a lower GNRI is an independent risk factor for both brain infarction and hemorrhage in patients who are receiving maintenance hemodialysis.

Predictive value of ankle-brachial index for long-term events of ischemic stroke in hemodialysis patients

OBJECTIVES

The ankle-brachial index is a noninvasive modality to evaluate atherosclerosis and is a predictive role for future cardiovascular events and mortality. However, few studies have evaluated its relation to long-term future ischemic stroke in hemodialysis patients. Therefore, we examined the relationship between ankle-brachial index and ischemic stroke events among hemodialysis patients in a seven-year follow-up.

METHODS

A total of 84 patients were enrolled. Ankle-brachial index was assessed in January 2009. Primary outcomes included ischemic stroke. An ankle-brachial index < 0.9 was considered abnormal and 1.4 ≥ ankle-brachial index ≥ 0.9 to be normal ankle-brachial index.

RESULTS

Mean values for ankle-brachial index were 0.98 ± 0.21at study entrance. In addition, 28 patients encountered ischemic stroke in the seven-year follow-up. In univariate Cox regression analysis, old age (hazard ratio (HR): 1.065, 95% confidence interval (CI): 1.030-1.102, p < 0.001), low seven-year averaged serum phosphate levels (HR: 0.473, 95% CI: 0.306-0.730, p = 0.001), and abnormal ankle-brachial index (HR: 0.035, 95% CI: 0.009-0.145, p < 0.001) were risk factors for ischemic stroke. In multivariate Cox regression analysis for significant variables in univariate analysis, abnormal ankle-brachial index (HR: 0.058, 95% CI: 0.012-0.279, p < 0.001) and low seven-year averaged serum phosphate levels (HR: 0.625, 95% CI: 0.404-0.968, p = 0.035) remained the risk factors for ischemic stroke. The risk of ischemic stroke was 3.783-fold in patients with abnormal ankle-brachial index compared with patients with normal ankle-brachial index (HR: 3.783, 95% CI: 1.731-8.269, p = 0.001).

CONCLUSIONS

These findings suggest that ankle-brachial index is an impressive predictor of future ischemic stroke among hemodialysis patients.

Association of hyperphosphatemia with an increased risk of sudden death in patients on hemodialysis: Ten-year outcomes of the Q-Cohort Study

BACKGROUND AND AIMS

Sudden death is one of the most common causes of death among patients on hemodialysis. Although hyperphosphatemia is a well-known risk factor for cardiovascular and all-cause deaths, the studies focusing on the relationship between serum phosphate levels and the risk of sudden death are limited. This study aimed to clarify the relationship between serum phosphate levels and the risk of sudden death in patients on hemodialysis.

METHODS

This is a multicenter, longitudinal, and observational study. A total of 3505 patients, registered in the Q-Cohort Study, who underwent maintenance hemodialysis, and were followed up for 10 years, were included. Patients were divided into quartiles on the basis of baseline serum phosphate levels: Q1 (n = 886), <4.2 mg/dL; Q2 (n = 837), 4.2-4.8 mg/dL; Q3 (n = 908), 4.9-5.6 mg/dL; and Q4 (n = 874), ≥5.7 mg/dL. Associations between baseline serum phosphate levels and sudden death were analyzed using the Cox proportional hazards model and the Fine-Gray regression model.

RESULTS

During the follow-up period, 227 patients died from sudden death. The risk for sudden death was significantly higher in the highest quartile (Q4) than in the lowest quartile (Q1) as the reference group (multivariable-adjusted hazard ratios and 95% confidence intervals: Q1, 1.00; Q2, 1.15 [0.77-1.70], Q3, 1.31 [0.89-1.93], and Q4, 1.72 [1.14-2.59]; hazard ratio for every 1-mg/dL increase in the serum phosphate level, 1.23 [1.09-1.39]; p < 0.001).

CONCLUSIONS

Hyperphosphatemia is independently associated with an elevated risk of sudden death in patients on hemodialysis.

Renal-Cerebral Pathophysiology: The Interplay Between Chronic Kidney Disease and Cerebrovascular Disease

OBJECTIVES

Cerebrovascular disease has increasingly been linked to overall vascular health. Pathologic conditions like diabetes, hypertension, and kidney disease have been shown to affect brain health and cerebrovascular and nervous systems. Acute kidney injury (AKI) and chronic Kidney Disease (CKD) represent a variety of vascular insults that can adversely affect cerebral health. Hypertension, fluctuations in blood pressure, and diabetic vasculopathy are known risk factors for cerebrovascular disease associated with CKD. Other emerging areas of interest include endothelial dysfunction, vascular calcification due to calcium and phosphorus metabolism dysregulation, and uremic neuropathy present the next frontier of investigation in CKD and cerebrovascular health.

METHODS

It has become apparent that the interrelation of AKI and CKD with vascular health, chemical homeostasis, and hormonal regulation upset many aspects of cerebral health and functioning. Stroke is an obvious connection, with CKD patients demonstrating a higher proclivity for cerebrovascular accidents. Cerebral bleeding risk, uremic neuropathies, sodium dysregulation with impacts on nervous system, vascular calcification, and endothelial dysfunction are the next salient areas of research that are likely to reveal key breakthroughs in renal-cerebral pathophysiology.

RESULTS

In this review nephrological definition are discussed in a neuro-centric manner, and the areas of key overlap between CKD and cerebrovascular pathology are discussed. The multifaceted effects of renal function on the health of the brain are also examined.

CONCLUSION

This review article aims to create the background for ongoing and future neurological-nephrological collaboration on understanding the special challenges in caring for patients with cerebrovascular disease who also have CKD.

Cerebro-renal interaction and stroke

Stroke is an event causing a disturbance in cerebral function leading to death and disability worldwide. Both acute kidney injury and chronic kidney disease (CKD) are associated with an increased risk of stroke and cerebrovascular events. The underlying mechanistic approach between impaired renal function and stroke is limitedly explored and has attracted researchers to learn more for developing therapeutic intervention. Common risk factors such as hypertension, hyperphosphatemia, atrial fibrillation, arteriosclerosis, hyperhomocysteinemia, blood-brain barrier disruption, inflammation, etc. are observed in the general population, but are high in renal failure patients. Also, risk factors like bone mineral metabolism, uremic toxins, and anemia, along with the process of dialysis in CKD patients, eventually increases the risk of stroke. Therefore, early detection of risks associated with stroke in CKD is imperative, which may decrease the mortality associated with it. This review highlights mechanisms by which kidney dysfunction can lead to cerebrovascular events and increase the risk of stroke in renal impairment.

Association of dietary patterns with serum phosphorus in maintenance haemodialysis patients: a cross-sectional study

Sources of dietary phosphate differentially contribute to hyperphosphatemia in maintenance haemodialysis (MHD) patients. This cross-sectional study in Malaysia investigated association between dietary patterns and serum phosphorus in MHD patients. Dietary patterns were derived by principal component analysis, based on 27 food groups shortlisted from 3-day dietary recalls of 435 MHD patients. Associations of serum phosphorus were examined with identified dietary patterns. Three dietary patterns emerged: Home foods (HF_dp), Sugar-sweetened beverages (SSB_dp), and Eating out noodles (EO-N_dp). The highest tertile of patients in HF (T3-HF_dp) pattern significantly associated with higher intakes of total protein (p = 0.002), animal protein (p = 0.001), and animal-based organic phosphate (p < 0.001), whilst T3-SSB_dp patients had significantly higher intakes of total energy (p < 0.001), inorganic phosphate (p < 0.001), and phosphate:protein ratio (p = 0.001). T3-EO-N_dp patients had significantly higher intakes of total energy (p = 0.033), total protein (p = 0.003), plant protein (p < 0.001), but lower phosphate:protein ratio (p = 0.009). T3-SSB_dp patients had significantly higher serum phosphorus (p = 0.006). The odds ratio of serum phosphorous > 2.00 mmol/l was significantly 2.35 times higher (p = 0.005) with the T3-SSB_dp. The SSB_dp was associated with greater consumption of inorganic phosphate and higher serum phosphorus levels.

Cerebrovascular disease: how serum phosphorus, vitamin D, and uric acid levels contribute to the ischemic stroke

Background

Associations between serum phosphorus level and the incidence of ischemic stroke are not clear. This study aimed to measure serum phosphorus, vitamin D3, and uric acid levels in ischemic stroke patients compared to a population without ischemic stroke.

Methods

In this cross-sectional study, 133 patients admitted to a neurology ward with the diagnosis of ischemic stroke were compared with a control group comprising 133 age- and gender-matching individuals. The presence of ischemic stroke was confirmed by a neurologist based on clinical signs, symptoms, brain CT scan, and MRI. Blood samples were taken from all patients in the first 24 h of admission to measure serum phosphorus, vitamin D3, calcium, and uric acid levels.

Results

According to the results of this study, uric acid medians in patients with stroke and controls were 4.9 [3.8–6.4] and 3.9 [3.5–4.9] mg/dL, respectively (p < 0.001). Median phosphorus and vitamin D levels were significantly lower in stroke patients than the controls (3.6 [3.02–4.21] vs. 4.2 [3.8–4.6]) and (15.1 [8.2–27.9] vs. 22.7 [10.4–39.2]), respectively. Multiple logistic regression analysis showed that the ischemic stroke was positively associated with the vitamin D level and negatively correlated with the uric acid level. The phosphorus level was not significantly predictive of ischemic stroke.

Conclusion

Lower serum levels of vitamin D3 and higher levels of uric acid were associated with ischemic stroke. There are still unknowns about the role of these indicators on ischemic stroke and it requires further studies.

Risk Factors and Outcomes of Cerebral Stroke in End-Stage Renal Disease Patients Receiving Hemodialysis

OBJECTIVE

Dialysis patients have a higher incidence of stroke, and outcomes are often poor. Diabetic nephropathy (DN) is a stroke risk-factor, but the importance is unclear in dialysis patients. This study investigated the stroke features and risk factors in hemodialysis (HD) patients.

METHODS

All end-stage renal disease patients undergoing HD at Teraoka Memorial Hospital dialysis center were identified, with 195 recruited. Baseline clinical characteristics were collected, and the clinical outcomes and related factors of stroke in HD patients were retrospectively analyzed. The incidence rate of stroke and mortality were calculated using Kaplan-Meier survival analysis. Factors potentially related to stroke were analyzed by the log-rank test and Cox proportional hazards model for univariate and multivariate analysis.

RESULTS

In total, 21.0% (41 of 195) patients developed stroke. The incidence rates of stroke per 1000 patient-years were 53.6, 65.2, and 34.0 in all HD patients, DN patients, and non-DN patients, respectively. The cumulative incidence rates of stroke in all HD patients, DN patients, and non-DN patients per 5 years, and per 10 years were 22.6%, 43.5%; 28.8%, 59.6%; and 17.6%, 31.1%, respectively. The incidence rate of stroke in the DN patients was significantly higher than in the non-DN patients (P = .013). DN was the significant risk factor for stroke by multivariate analysis (hazard ratio 2.63, 95% confidence interval 1.08-7.85; P = .032).

CONCLUSIONS

This study revealed the trends of stroke in HD patients at a single institution in Japan. DN was shown to be a significant risk factor for stroke in HD patients.

Modified creatinine index and risk for long-term infection-related mortality in hemodialysis patients: ten-year outcomes of the Q-Cohort Study

Modified creatinine (Cr) index, calculated by age, sex, pre-dialysis serum Cr concentration, and Kt/V for urea, is an indicator of skeletal muscle mass in hemodialysis (HD) patients. It remains unknown whether the modified Cr index predicts infection-related mortality in this population. We investigated the association between the modified Cr index and infection-related mortality. A total of 3046 patients registered in the Q-Cohort Study, a multicenter, observational study of HD patients, were analyzed. Associations between sex-specific quartiles (Q1–Q4) of the modified Cr index and the risk for infection-related mortality were analyzed by Cox proportional hazard model. During a median follow-up of 8.8 years, 387 patients died of infection. The estimated risk for infection-related mortality was significantly higher in the lower quartiles (Q1, Q2, and Q3) than in the highest quartile (Q4) as the reference group (hazard ratios and 95% confidence intervals [CI]: Q1, 2.89 [1.70–5.06], Q2, 2.76 [1.72–4.62], and Q3, 1.79 [1.12–2.99]). The hazard ratio (95% CI) for a 1 mg/kg/day decrease in the modified Cr index was 1.18 (1.09–1.27, P < 0.01) for infection-related mortality. In conclusion, a lower modified Cr index is associated with an increased risk for long-term infection-related mortality in the HD population.

Lower serum calcium and pre-onset blood pressure elevation in cerebral hemorrhage patients undergoing hemodialysis

BACKGROUND

Asymptomatic blood pressure (BP) elevation may be associated with cerebral hemorrhage (CH); however, few studies have investigated this association. We aimed to evaluate BP elevation before CH in hemodialysis (HD) patients and elucidate its associated factors.

METHODS

We reviewed HD patients treated for CH at our hospital between 2008 and 2019 (CH group). The control group comprised HD patients treated at Nagasaki Renal Center between 2011 and 2012. Data were obtained from medical records and three consecutive HD charts, made immediately before CH. HD1 was the session closest to onset, followed by HD2 and HD3. Systolic and mean BP were evaluated at the beginning of HD, and factors associated with BP elevation were investigated.

RESULTS

The CH and control groups included 105 and 339 patients, respectively. Systolic and mean BP at HD1 were significantly higher than those at baseline (HD2 + HD3) in the CH group by 5 and 3 mmHg, respectively (P < 0.001). Multiple linear regression analysis showed that lower calcium levels were significantly associated with BP elevation in the CH group (P < 0.05). The CH group was sub-divided by June 2013; the latter group had lower calcium levels (9.2 mg/dL) and a marked systolic BP difference from baseline (+ 10 mmHg) compared with the former (9.5 mg/dL and - 4 mmHg).

CONCLUSION

Asymptomatic BP elevation was observed in HD patients before CH; this elevation was associated with lower serum calcium levels and observed more frequently in the recent era. The precise mechanism underlying this effect remains unknown.

Disentangling the multiple links between renal dysfunction and cerebrovascular disease

Chronic kidney disease (CKD) has a rapidly rising global prevalence, affecting as many as one-third of the population over the age of 75 years. CKD is a well-known risk factor for cardiovascular disease and, in particular, there is a strong association with stroke. Cohort studies and trials indicate that reduced glomerular filtration rate increases the risk of stroke by about 40% and that proteinuria increases the risk by about 70%. In addition, CKD is also strongly associated with subclinical cerebrovascular abnormalities, vascular cognitive impairment and dementia. The mechanisms responsible for these associations are currently unclear. CKD is associated with traditional risk factors such as hypertension, diabetes mellitus and atrial fibrillation, but non-traditional risk factors such as uraemia, oxidative stress, mineral and bone abnormalities, and dialysis-related factors, such as changes in cerebral blood flow or cardiac structure, are also postulated to play a role. Kidney disease can also impact and complicate the treatments used in acute stroke and in secondary prevention. In this review, we will outline our current understanding of the epidemiology and pathophysiology of cerebrovascular disease in CKD.

Hemoglobin concentration and the risk of hemorrhagic and ischemic stroke in patients undergoing hemodialysis: the Q-cohort study

Background

The contribution of the hemoglobin concentration to the incidence of hemorrhagic or ischemic stroke in patients undergoing hemodialysis is unclear.

Methods

In total, 3436 patients undergoing prevalent hemodialysis were followed up for 4 years. The primary outcome was the first development of hemorrhagic or ischemic stroke. The baseline hemoglobin concentration was divided into quartiles [hemoglobin (g/dL): Q1, ≤9.7; Q2, 9.8-10.5; Q3, 10.6-11.1; Q4, ≥11.2]. The association between the hemoglobin concentration and each type of stroke was examined using the Kaplan-Meier method and a Cox proportional hazards model.

Results

During the follow-up period, 76 (2.2%) patients developed hemorrhagic stroke and 139 (4.0%) developed ischemic stroke. The 4-year incidence rate of hemorrhagic stroke was significantly higher in patients with lower hemoglobin concentrations. Compared with the quartile of patients with the highest hemoglobin concentrations (Q4), the multivariable-adjusted hazard ratios for hemorrhagic stroke were 1.18 (95% confidence interval, 0.56-2.51), 1.59 (0.82-3.21) and 2.31 (1.16-4.73) in patients in Q3, Q2 and Q1, respectively. No association was identified between the 4-year incidence rate of ischemic stroke and the hemoglobin concentration. Compared with the quartile of patients with the lowest hemoglobin concentrations (Q1), the multivariable-adjusted hazard ratios for ischemic stroke were 1.17 (95% confidence interval, 0.73-1.89), 0.88 (0.51-1.51) and 1.10 (0.66-1.83) in patients in Q2, Q3 and Q4, respectively.

Conclusions

Our results suggest that low hemoglobin concentrations are associated with a high risk of hemorrhagic stroke, but not of ischemic stroke, in patients undergoing hemodialysis.

Renal replacement modality and stroke risk in end-stage renal disease-a national registry study

Background

The risk of stroke in end-stage renal disease (ESRD) on renal replacement therapy (RRT) is up to 10-fold greater than the general population. However, whether this increased risk differs by RRT modality is unclear.

Methods

We used data contained in the Scottish Renal Registry and the Scottish Stroke Care Audit to identify stroke in all adult patients who commenced RRT for ESRD from 2005 to 2013. Incidence rate was calculated and regression analyses were performed to identify variables associated with stroke. We explored the effect of RRT modality at initiation and cumulative dialysis exposure by time-dependent regression analysis, using transplant recipients as the reference group.

Results

A total of 4957 patients commenced RRT for ESRD. Median age was 64.5 years, 41.5% were female and 277 patients suffered a stroke (incidence rate was 18.6/1000 patient-years). Patients who had stroke were older, had higher blood pressure and were more likely to be female and have diabetes. On multivariable regression older age, female sex, diabetes and higher serum phosphate were associated with risk of stroke. RRT modality at initiation was not. On time-dependent analysis, haemodialysis (HD) exposure was independently associated with increased risk of stroke.

Conclusions

In patients with ESRD who initiate RRT, HD use independently increases risk of stroke compared with transplantation. Use of peritoneal dialysis did not increase risk on adjusted analysis.

Phosphate, the forgotten mineral in hypertension

PURPOSE OF REVIEW

The purpose of this study is to review the current literature related to the role of inorganic phosphate in the pathogenesis of hypertension.

RECENT FINDINGS

An increasing number of publications have revealed a detrimental role of inorganic phosphate, which is commonly used as a flavor enhancer or preservative in the processed food, in promoting hypertension in otherwise healthy individuals. Animal experimental data indicate that dietary phosphate excess engages multiple mechanisms that promote hypertension, including overactivation of the sympathetic nervous system, increased vascular stiffness, impaired endothelium-dependent vasodilation, as well as increased renal sodium absorption or renal injury. These effects may be explained by direct effects of high extracellular phosphate levels or increase in phosphaturic hormones such as fibroblast growth factor 23, or downregulation of klotho, a transmembrane protein expressed in multiple organs which possess antiaging property.

SUMMARY

Dietary phosphate, particularly inorganic phosphate, is an emerging risk factor for hypertension which is ubiquitous in the western diet. Large randomized clinical trials are needed to determine if lowering dietary phosphate content constitutes an effective nonpharmacologic intervention for prevention and treatment of hypertension.

Association between serum calcium levels and prognosis, hematoma volume, and onset of cerebral hemorrhage in patients undergoing hemodialysis

BACKGROUND

High serum calcium levels should be avoided in patients on hemodialysis (HD) because they can induce cardiovascular diseases and worsen the patient's prognosis. In contrast, low serum calcium levels worsen the prognosis of patients with cerebral hemorrhage in the general population. So far, whether serum calcium levels in patients on HD are associated with cerebral hemorrhage remains unknown. This study aimed to reveal the association between serum calcium and cerebral hemorrhage in patients on HD, including in-hospital death, volume of hematoma, and onset of cerebral hemorrhage.

METHODS

This cross-sectional case-control study included 99 patients on HD with cerebral hemorrhage at a single center between July 1, 2007 and December 31, 2017. Controls included 339 patients on HD at a single HD center between July 1, 2011 and June 30, 2012. Data on serum calcium level, patient demographics, and comorbid conditions were collected, and associations between cerebral hemorrhage and subsequent death were evaluated by multivariate logistic regression analysis. Further, the association of these backgrounds and hematoma volume was evaluated by multiple regression analysis.

RESULTS

Of the 99 patients, 32 (32%) died from cerebral hemorrhage. The corrected serum calcium level (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.43-4.35; P < 0.001) and antiplatelet drug use (OR, 3.95; 95% CI, 1.50-10.4; P = 0.005) had significant effects on the prognosis. Moreover, the corrected serum calcium (P = 0.003) and antiplatelet drug use (P = 0.01) were significantly correlated with hematoma volume. In the patients, the corrected serum calcium level (OR, 1.54; 95% CI, 1.07-2.22; P = 0.02) was associated with the onset of cerebral hemorrhage, as was pre-hemodialysis systolic blood pressure (per 10 mmHg) (OR, 1.40; 95% CI, 1.23-1.59; P < 0.001).

CONCLUSIONS

Although the precise mechanisms remain unknown, a high serum calcium level is associated with cerebral hemorrhage in patients on HD. Thus, we should pay attentions to a patient's calcium level.

Detecting high-risk chronic kidney disease-mineral bone disorder phenotypes among patients on dialysis: a historical cohort study

BACKGROUND

The clinical management of chronic kidney disease-mineral bone disorder (CKD-MBD) remains extremely challenging, partially due to difficulties in defining high-risk phenotypes based on serum biomarkers. We evaluated the prevalence and outcomes of 27 mutually exclusive CKD-MBD phenotypes in a large, multi-national cohort of chronic dialysis patients over a 5-year follow-up study.

METHODS

In this historical cohort study, we enrolled all haemodialysis patients registered in EuCliD® on 1 July 2011 across 28 Europe, the Middle East and Africa (EMEA) and South American countries. We created 27 mutually exclusive phenotypes based on combinations of serum parathyroid hormone (PTH), phosphorus (P) and calcium (Ca) 6-month averages (L, low; T, target; H, high). We tested the association between CKD-MBD phenotypes and 5-year mortality and hospitalization risk by outcome risk score-adjusted proportional hazard regression.

RESULTS

We enrolled 35 721 eligible patients. Eastern European and South American countries generally achieved poorer CKD-MBD control when compared with Western European countries (prevalence ratio: 0.79; P < 0.001). There were 15 795 deaths [126.7 deaths/1000 person-years; 95% confidence interval (CI) 124.7-128.7]; 18 014 had at least one hospitalization (203.9 hospitalizations/1000 person-years; 95% CI 201.0-206.9); the incidence of the composite endpoint was 280.0 events/1000 person-years (95% CI 276.6-283.5). In the fully adjusted model, relative mortality risk ranged from hazard ratio (HR) = 1.07 (PTH/Ca/P: TLT) to HR = 1.59 (PTH/Ca/P: LTL), whereas the relative composite endpoint risk ranged from HR = 1.07 (PTH/Ca/P: TTH) to HR = 1.36 (PTH/Ca/P: LTL).

CONCLUSION

We identified several CKD-MBD phenotypes associated with reduced hospitalization-free survival and increased mortality. Ranking of relative risk estimates or excess events concurs in informing healthcare priority setting.

Prognostic value of pre-dialysis blood pressure and risk threshold on clinical outcomes in hemodialysis patients: The Q-Cohort Study

The influence of pre-dialysis blood pressure (BP) on the prognosis of hemodialysis (HD) patients is still inconclusive.A total of 3436 HD patients were prospectively followed up for 4 years. The patients were divided into quintiles of pre-dialysis systolic BP (SBP) and diastolic BP (DBP) levels [mm Hg]: Quintile 1 (Q1), SBP <134, DBP <66; Q2, SBP 134 to 147, DBP 66 to 72; Q3, SBP 148 to 158, DBP 73 to 79; Q4, SBP 159 to 171, DBP 80 to 85; Q5, SBP ≥172, DBP ≥86. The association between the pre-dialysis BP and outcomes were examined using a Cox proportional hazards model.During a 4-year follow-up period, 564 (16.4%) patients died of any cause and 590 (17.2%) developed cardiovascular (CV) events. The lowest level of pre-dialysis SBP group (Q1) showed a significantly increased risk of all-cause mortality (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.40-2.39) and the highest group (Q5) significantly increased risk of CV events (HR 1.31, 95% CI 1.02-1.68) compared with the reference group (Q3), respectively. The highest level of pre-dialysis DBP group was significantly associated with increased risk for both all-cause mortality and CV events. Restricted cubic spline analysis for BP and outcomes suggested the optimal pre-dialysis BP value associated with the lowest risk of outcomes was SBP 152 mm Hg for all-cause mortality, SBP 143 mm Hg for CV events, and DBP 68 mm Hg for all-cause mortality.Our results suggested that pre-dialysis BP was independently associated with all-cause mortality and CV events among Japanese HD patients.

Significant association of anti-platelet factor 4/heparin antibody with cardiovascular disease in hemodialysis patients: a longitudinal 7-year study

BACKGROUND

Hemodialysis patients have a high incidence of anti-platelet factor 4/heparin antibody (PF4-H Ab) and are at a high risk of cardiovascular disease. This study determines the association between PF4-H Ab and cardiovascular events including coronary artery disease (CAD), ischemic stroke (IS), and native arteriovenous fistula thrombosis (AVFT), in a longitudinal 7-year follow-up.

PATIENTS AND METHODS

84 hemodialysis patients were enrolled. Data collection included chart reviews and assessments of laboratory records. PF4-H Ab was evaluated by ELISA and a titer ≥ 0.4 was defined to have PF4-H Ab.

RESULTS

30 patients were PF4-H Ab positive, 30 patients had CAD, 29 patients had IS, and 43 patients had AVFT. In Cox proportional hazard regression analysis, PF4-H Ab (HR 2.72, p = 0.01) was a significant risk factor for CAD. Age (HR 1.06, p = 0.003), PF4-H Ab (HR 4.53, p < 0.001), 7-year averaged serum phosphate levels (HR 0.53, p = 0.012), and 7-year averaged blood platelet count (HR 1.01, p = 0.029) were risk factors for IS. Age (HR 1.03, p = 0.047), PF4-H Ab (HR 3.57, p < 0.001), and 7-year averaged serum triglyceride levels (HR 1.01, p = 0.005) were risk factors for AVFT. In PF4-H Ab-positive groups, thrombocytopenia was not associated with CAD, IS, and AVFT by Fisher's test analysis.

CONCLUSION

This study reveals that PF4-H Ab is a risk factor for developing CAD, IS, and AVFT among hemodialysis patients.

Modified creatinine index and risk for cardiovascular events and all-cause mortality in patients undergoing hemodialysis: The Q-Cohort study

BACKGROUND AND AIMS

The modified creatinine (Cr) index, calculated by age, sex, pre-dialysis serum Cr levels, and Kt/V for urea, reflects skeletal muscle mass in patients on hemodialysis. Whether the modified Cr index is associated with cardiovascular events and all-cause mortality remains unknown.

METHODS

A total of 3027 patients registered in the Q-Cohort Study, a multicenter, prospective study of patients on hemodialysis in Japan, were analyzed. The main outcomes were cardiovascular events and all-cause mortality. Associations between sex-specific quartiles of the modified Cr index and outcomes were analyzed by the Cox proportional hazard models and the Fine-Gray proportional subdistribution hazards model.

RESULTS

The modified Cr index was correlated with known nutritional and inflammatory markers. During a 4-year follow-up, 499 patients died of any cause, 372 experienced heart disease, and 194 developed stroke. The risk for all-cause mortality was significantly higher in the lower quartiles (Q1 and Q2) than in the highest quartile (Q4) as the reference group (hazard ratios and 95% confidence intervals: Q1, 2.65 [1.69-4.25], Q2, 1.92 [1.27-2.94], and Q3, 1.31 [0.87-2.02]). The risk of heart disease was significantly higher in Q1 than in Q4 (hazard ratios and 95% confidence intervals: Q1, 1.64 [1.04-2.61], Q2, 1.34 [0.91-2.00], and Q3, 1.04 [0.71-1.52]). The risk of stroke was not associated with the modified Cr index.

CONCLUSIONS

A lower modified Cr index is associated with an increased risk for heart disease and all-cause mortality, but not with the risk for stroke in patients on hemodialysis.