Vitamin D status and intermediate vascular and bone outcomes in chronic kidney disease: a secondary post hoc analysis of IMPROVE-CKD.

BACKGROUND AND AIMS: Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD) and has been associated with abnormalities of mineral metabolism and vascular calcification. Vitamin D influences parathyroid hormone values and calcium and phosphate metabolism, and may play a role in vascular function and bone health. We aimed to test our hypothesis that vitamin D deficiency is associated with arterial stiffness, aortic calcification and lower bone mineral density (BMD) in patients with CKD. METHODS: A cross-sectional analysis was performed using baseline data from the IMpact of Phosphate Reduction On Vascular Endpoints in CKD (IMPROVE-CKD) study cohort. Clinical and laboratory parameters were compared between those with and without vitamin D deficiency, defined as 25-hydroxyvitamin D (25(OH)D) <50 nmol/L. Univariable and multivariable linear regression analyses were performed to assess associations between serum 25(OH)D levels and pulse wave velocity (PWV), augmentation index (AIx), abdominal aortic calcification (measured by the Agatston score) and lumbar spine BMD. RESULTS: Baseline 25(OHD) values were available in 208 out of 278 IMPROVE-CKD study participants, with a mean value of 70.1 ± 30.7 nmol/L. Of these, 57 (27%) patients had vitamin D deficiency. Those with 25(OH)D deficiency were more likely to have diabetes (56% vs 38%), cardiovascular disease (54% vs 36%) and lower serum calcium (2.29 ± 0.13 vs 2.34 ± 0.13 mmol/L). On univariable and multivariable regression analyses, baseline 25(OH)D values were not associated with PWV, the AIx, Agatston score or BMD. CONCLUSION: Baseline 25(OH)D levels were not associated with intermediate markers of vascular function and BMD in patients with CKD stages 3b and 4.

Kidney transplantation in people living with human immunodeficiency virus: An overview of the Australian experience.

Kidney transplantation in people living with HIV (PLWHIV) is occurring with increasing frequency. Limited international data suggest comparable patient and graft survival in kidney transplant recipients with and without HIV. All PLWHIV aged ≥18 years who received a kidney transplant between 2000 and 2020 were identified by retrospective data initially extracted from Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), with additional HIV-specific clinical data extracted from linked local health-care records. Twenty-five PLWHIV and kidney failure received their first kidney transplant in Australia between January 2000 and December 2020. Majority were male (85%), with median age 54 years (interquartile range, IQR 43-57). Focal segmental glomerulosclerosis was the most common primary kidney disease (20%), followed by polycystic kidney disease (16%). 80% of patients underwent induction with basiliximab and none with anti-thymocyte globulin (ATG). Participants were followed for median time of 3.5 years (IQR 2.0-6.5). Acute rejection occurred in 24% of patients. Two patients lost their allografts and three died. Virological escape occurred in 28% of patients, with a maximum viral load of 190 copies/mL. In conclusion, kidney transplantation in PLWHIV in Australia is occurring with increasing frequency. Acute rejection is more common than in Australia's general transplant population, but this does not appear to be associated with higher rates of graft failure or mortality out to four years.

Factors Influencing Kidney Transplantation Experiences for Patients From Culturally and Linguistically Diverse Backgrounds: A Qualitative Study.

BACKGROUND: Disparities in aspects of chronic kidney disease progression and management exist for patients from culturally and linguistically diverse (CALD) backgrounds, including with treatment and outcomes for kidney transplantation. OBJECTIVE: This study aimed to explore factors that impact kidney transplant outcomes from the perspective of kidney transplant recipients (KTRs) from CALD backgrounds and their family caregivers. METHODS: A descriptive qualitative design was utilised. Participants were recruited from two tertiary hospitals in Victoria, Australia. Semi-structured interviews were conducted with KTRs who were born overseas in countries where English is not the primary language. Interviews were also conducted with family caregivers. Analysis was guided by the Framework Method, and emergent subcategories were mapped into the categories identified in Andersen's Health Service Utilisation Model. RESULTS: Data from 21 KTRs and five caregivers were grouped under the categories of Population Characteristics, Environment, Health Behaviour and Outcomes. KTRs believed that neither culture nor religious beliefs impacted how they managed their transplant or healthcare utilisation. KTRs expressed satisfaction with their care, felt no inequity with how they were treated by health professionals and expressed gratitude for the Australian healthcare system. Language did not necessarily impact transplant outcomes, but there was a reliance on interpreters for non-English-speaking patients as most written information was in English. Caregivers were instrumental in providing support but discussed the challenges involved. CONCLUSION: This study explored factors influencing kidney transplantation for KTRs from a CALD background. The study provided insight into how to deliver quality healthcare to these patients, highlighting the importance of health services providing information that is written in the patient's own language and respectively asking KTRs about their health beliefs or customs. Caregivers were instrumental in supporting KTRs, but there is a need to better prepare them for this role. PATIENT OR PUBLIC CONTRIBUTION: Patient and public involvement was integrated into the design and delivery of the study. KTRs from CALD backgrounds assisted with framing the research questions and offering advice on the recruitment and data collection process.

Vitamin D Therapy in Adults With CKD: A Systematic Review and Meta-analysis.

RATIONALE & OBJECTIVE: Vitamin D is widely used to manage chronic kidney disease-mineral and bone disorder (CKD-MBD). We evaluated the effects of vitamin D therapy on mortality, cardiovascular, bone, and kidney outcomes in adults with CKD. STUDY DESIGN: Systematic review of randomized controlled trials (RCT) with highly sensitive searching of MEDLINE, Embase, and CENTRAL, through February 25, 2023. SETTING & STUDY POPULATIONS: Adults with stage 3, 4, or 5 CKD, including kidney failure treated with dialysis. Recipients of a kidney transplant were excluded. SELECTION CRITERIA FOR STUDIES: RCTs with≥3 months of follow-up evaluating a vitamin D compound. DATA EXTRACTION: Data were extracted independently by three investigators. ANALYTICAL APPROACH: Treatment estimates were summarized using random effects meta-analysis. Primary review endpoints were all-cause death, cardiovascular death, and fracture. Secondary outcomes were major adverse cardiovascular events, hospitalization, bone mineral density, parathyroidectomy, progression to kidney failure, proteinuria, estimated glomerular filtration rate, hypercalcemia, hyperphosphatemia, biochemical markers of CKD-MBD, and various intermediate outcome measures of cardiovascular disease. Risk of bias was assessed using the Cochrane Risk of Bias (RoB) 2 tool. Evidence certainty was adjudicated using GRADE. RESULTS: Overall, 128 studies involving 11,270 participants were included. Compared with placebo, vitamin D therapy probably had no effect on all-cause death (relative risk [RR], 1.04; 95% CI, 0.84-1.24); and uncertain effects on fracture (RR, 0.68; 95% CI, 0.37-1.23) and cardiovascular death (RR, 0.73; 95% CI, 0.31-1.71). Compared with placebo, vitamin D therapy lowered serum parathyroid hormone and alkaline phosphatase, but increased serum calcium. LIMITATIONS: Data were limited by trials with short-term follow-up periods, small sample size, and the suboptimal quality. CONCLUSIONS: Vitamin D therapy did not reduce the risk of all-cause death in people with CKD. Effects on fracture and cardiovascular and kidney outcomes were uncertain. TRIAL REGISTRATION: Registered at PROSPERO with study number CRD42017057691. PLAIN-LANGUAGE SUMMARY: Chronic kidney disease (CKD) is associated with increased risk of death, cardiovascular disease, and fractures. This excess risk is thought to be related to changes in bone and mineral metabolism, leading to the development of CKD-mineral and bone disorder (CKD-MBD) which is characterized by vascular calcification and reduced bone quality. Vitamin D is commonly used in the treatment of this condition. We reviewed randomized controlled trials examining the effect of vitamin D therapy in CKD. We found that vitamin D therapy affects serum biomarkers, including an increase in serum calcium. However, it probably has no effect on risk of all-cause death in CKD, and the effects on other clinical bone, cardiovascular, and kidney outcomes are uncertain.

Effect of the phosphate binder sucroferric oxyhydroxide in dialysis patients on endogenous calciprotein particles, inflammation, and vascular cells.

BACKGROUND: Calciprotein particles (CPPs), colloidal mineral-protein nanoparticles, have emerged as potential mediators of phosphate toxicity in dialysis patients, with putative links to vascular calcification, endothelial dysfunction and inflammation. We hypothesized that phosphate binder therapy with sucroferric oxyhydroxide (SO) would reduce endogenous CPP levels and attenuate pro-calcific and pro-inflammatory effects of patient serum towards human vascular cells in vitro. METHODS: This secondary analysis of a randomised controlled crossover study compared the effect of 2-week phosphate binder washout with high-dose (2000 mg/day) and low-dose (250 mg/day) SO therapy in 28 haemodialysis patients on serum CPP levels, inflammatory cytokine/chemokine arrays and human aortic smooth muscle cell (HASMC) and coronary artery endothelial cell (HCAEC) bioassays. RESULTS: In our cohort (75% male, 62 ± 12 years) high-dose SO reduced primary (amorphous) and secondary (crystalline) CPP levels {-62% [95% confidence interval (CI) -76 to -44], P < .0001 and -38% [-62 to -0.14], P < .001, respectively} compared with washout. Nine of 14 plasma cytokines/chemokines significantly decreased with high-dose SO, with consistent reductions in interleukin-6 (IL-6) and IL-8. Exposure of HASMC and HCAEC cultures to serum of SO-treated patients reduced calcification and markers of activation (IL-6, IL-8 and vascular cell adhesion protein 1) compared with washout. Serum-induced HASMC calcification and HCAEC activation was ameliorated by removal of the CPP-containing fraction from patient sera. Effects of CPP removal were confirmed in an independent cohort of chronic kidney disease patients. CONCLUSIONS: High-dose SO reduced endogenous CPP formation in dialysis patients and yielded serum with attenuated pro-calcific and inflammatory effects in vitro.

Effect of lanthanum carbonate on serum calciprotein particles in patients with stage 3-4 CKD-results from a placebo-controlled randomized trial.

BACKGROUND: Calciprotein particles (CPP) are colloidal aggregates of calcium phosphate and the mineral-binding protein fetuin-A, and are potential mediators of cardiovascular disease in chronic kidney disease (CKD). Emerging evidence suggests non-calcium-containing phosphate binders may reduce serum CPP in patients with kidney failure who require dialysis; however, it is unclear whether similar interventions are effective in patients with earlier stages of CKD. METHODS: The IMpact of Phosphate Reduction On Vascular End-points in CKD (IMPROVE-CKD) was a multi-centre, placebo-controlled, randomized trial of lanthanum carbonate on cardiovascular markers in 278 participants with stage 3b/4 CKD. In this pre-specified exploratory analysis, primary (CPP-I) and secondary CPP (CPP-II) were measured in a sub-cohort of participants over 96 weeks. Treatment groups were compared using linear mixed-effects models and the relationship between serum CPP and pulse wave velocity (PWV) and abdominal aortic calcification (AAC) was examined. RESULTS: A total of 253 participants had CPP data for baseline and at least one follow-up timepoint and were included in this analysis. The mean age was 62.4 ± 12.6 years, 32.0% were female and the mean estimated glomerular filtration rate (eGFR) was 26.6 ± 8.3 mL/min/1.73 m2. Baseline median serum CPP-I was 14.9 × 104 particles/mL [interquartile range (IQR) 4.6-49.3] and median CPP-II was 3.3 × 103 particles/mL (IQR 1.4-5.4). There was no significant difference between treatment groups at 96 weeks in CPP-I [22.8% (95% confidence interval -39.2, 36.4), P = 0.65] or CPP-II [-18.3% (95% confidence interval -40.0, 11.2), P = 0.20] compared with a placebo. Serum CPP were not correlated with baseline PWV or AAC, or with the progression of either marker. CONCLUSIONS: Lanthanum carbonate was not associated with a reduction of CPP at 96 weeks when compared with a placebo in a CKD cohort.

Tunnelled central venous catheters for incident haemodialysis patients: a Victorian survey exploring reasons for use.

BACKGROUND: Tunnelled central venous catheters (T-CVCs) are used globally as vascular access for patients on haemodialysis (HD) but are associated with increased sepsis, mortality, cost and length of hospitalisation compared with more permanent HD vascular access. The reasons for using T-CVC are varied and poorly understood. A significant and increasing proportion of incident HD patients in Victoria, Australia, have required T-CVC over the last decade. AIM: To explore reasons for a significant and increasing proportion of incident HD patients in Victoria, Australia, having required T-CVC over the last decade. METHODS: With rates of starting HD with definitive vascular access consistently below a Victorian quality indicator target of 70%, an online survey was developed to explore reasons why the rate remained lower than desired and to help inform future decisions about this quality indicator. The survey was completed by dialysis access coordinators over an 8-month period and involved all public nephrology services in Victoria. RESULTS: Of the 125 surveys completed, 101 incident HD patients had no attempt at permanent vascular access prior to T-CVC insertion. For almost half of these (48 patients), there was no active medical decision not to create permanent vascular access prior to commencing dialysis. Reasons for insertion of the T-CVC included deterioration of kidney function faster than anticipated, surgical referral being overlooked, complications related to peritoneal dialysis requiring a change in dialysis modality and changes to initial decisions regarding dialysis modality for kidney failure. CONCLUSIONS: These survey results provide an opportunity for quality improvement initiatives with respect to dialysis access planning and care.

Community-acquired versus hospital-acquired acute kidney injury at a large Australian metropolitan quaternary referral centre: incidence, associations and outcomes.

BACKGROUND: There is increasing global incidence of acute kidney injury (AKI) and significant short- and long-term impacts on patients. AIMS: To determine incidence and outcomes of community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI) among inpatients in the Australian healthcare setting using modern health information systems. METHODS: A retrospective cohort study of adult patients admitted to a quaternary hospital in Melbourne, Australia, between 1 January 2018 and 31 December 2019 utilising an electronic data warehouse. Participants included adult patients admitted for >24 h who had more than one serum creatinine level recorded during admission. Kidney transplant and maintenance dialysis patients were excluded. Main outcomes measured included AKI, as classified by the Kidney Disease Improving Global Outcomes (KDIGO) criteria, hospital length of stay and 30-day mortality. RESULTS: A total of 6477 AKI episodes was identified across 43 791 admissions. Of all AKI episodes, 77% (n = 5011), 15% (n = 947) and 8% (n = 519) were KDIGO stage 1, 2 and 3 respectively. HA-AKI accounted for 55.9% episodes. Patients required intensive care unit admission in 22.7% (n = 1100) of CA-AKI and 19.3% (n = 935) of HA-AKI, compared with 7.5% (n = 2815) of patients with no AKI (P = 0.001). Patients with AKI were older with more co-morbidities, particularly chronic kidney disease (CKD). Length of stay was longer in CA-AKI (8.8 days) and HA-AKI (11.8 days) compared with admissions without AKI (4.9 days; P < 0.001). Thirty-day mortality was increased with CA-AKI (10.2%) and HA-AKI (12.8%) compared with no AKI (3.7%; P < 0.001). CONCLUSION: The incidence of AKI detected by the electronic data warehouse was higher than previously reported. Patients who experienced AKI had greater morbidity and mortality. CKD was an important risk factor for AKI in hospitalised patients.

Impact of haemodialysis hours on outcomes in older patients.

AIM: Previous studies report an association between longer haemodialysis treatment sessions and improved survival. Worldwide, there is a trend to increasing age among prevalent patients receiving haemodialysis. This analysis aimed to determine whether the mortality benefit of longer haemodialysis treatment sessions diminishes with increasing age. METHODS: This was a retrospective cohort study of people who first commenced thrice-weekly haemodialysis aged ≥65 years, reported to the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry from 2005 to 2015, included from 90 days after dialysis start. The primary outcome was all-cause mortality. Cox regression analysis was performed with haemodialysis session duration the exposure of interest. RESULTS: Of 8224 people who commenced haemodialysis as their first treatment for kidney failure aged ≥65 years during this period, 4727 patients died. Longer dialysis hours per session was associated with a decreased risk of death in unadjusted analyses [hazard ratio, HR, for ≥5 h versus 4 to <4.5 h: 0.81 (0.75-0.88, p < .001)]. Patients having longer dialysis sessions were younger but had greater co-morbidity. In an adjusted model including age and other variables, the survival benefit of longer hours was only partially attenuated [HR for previous comparison: 0.75 (0.69-0.82, p < .001)], and no interaction between age and hours was demonstrated (p = .89). CONCLUSION: The apparent survival benefit associated with longer haemodialysis session length appears to be preserved in patients 65 years or older. In practice, the benefit of longer dialysis hours should be carefully weighed against other factors in this patient group.

Interventions To Attenuate Vascular Calcification Progression in Chronic Kidney Disease: A Systematic Review of Clinical Trials.

BACKGROUND: Vascular calcification is associated with cardiovascular morbidity and mortality in people with CKD. Evidence-based interventions that may attenuate its progression in CKD remain uncertain. METHODS: We conducted a systematic review of prospective clinical trials of interventions to attenuate vascular calcification in people with CKD, compared with placebo, another comparator, or standard of care. We included prospective clinical trials (randomized and nonrandomized) involving participants with stage 3-5D CKD or kidney transplant recipients; the outcome was vascular calcification measured using radiologic methods. Quality of evidence was determined by the Cochrane risk of bias assessment tool and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method. RESULTS: There were 77 trials (63 randomized) involving 6898 participants eligible for inclusion (median sample size, 50; median duration, 12 months); 58 involved participants on dialysis, 15 involved individuals with nondialysis CKD, and 4 involved kidney transplant recipients. Risk of bias was moderate over all. Trials involving magnesium and sodium thiosulfate consistently showed attenuation of vascular calcification. Trials involving intestinal phosphate binders, alterations in dialysate calcium concentration, vitamin K therapy, calcimimetics, and antiresorptive agents had conflicting or inconclusive outcomes. Trials involving vitamin D therapy and HMG-CoA reductase inhibitors did not demonstrate attenuation of vascular calcification. Mixed results were reported for single studies of exercise, vitamin E-coated or high-flux hemodialysis membranes, interdialytic sodium bicarbonate, SNF472, spironolactone, sotatercept, nicotinamide, and oral activated charcoal. CONCLUSIONS: Currently, there are insufficient or conflicting data regarding interventions evaluated in clinical trials for mitigation of vascular calcification in people with CKD. Therapy involving magnesium or sodium thiosulfate appears most promising, but evaluable studies were small and of short duration.