Hemodynamic effects of low versus high dialysate bicarbonate concentration in hemodialysis patients.

INTRODUCTION: Hemodialysis treatment using standard dialysate bicarbonate concentrations cause transient metabolic alkalosis possibly associated with hemodynamic instability. The aim of this study was to perform a detailed comparison of high and low dialysate bicarbonate in terms of blood pressure, intradialytic hemodynamic parameters, orthostatic blood pressure, and electrolytes. METHODS: Fifteen hemodialysis patients were examined in a single-blind, randomized, controlled, crossover study. Participants underwent a 4-h hemodialysis session with dialysate bicarbonate concentration of 30 or 38 mmol/L with 1 week between interventions. Blood pressure was monitored throughout hemodialysis, while cardiac output, total peripheral resistance, stroke volume, and central blood volume were assessed with ultrasound dilution technique (Transonic). Orthostatic blood pressure was measured pre- and post-hemodialysis. FINDINGS: With similar ultrafiltration (UF) volume (2.6 L), systolic blood pressure (SBP) tended to decrease more during high dialysate bicarbonate compared to low dialysate bicarbonate; the mean (95% confidence interval) between treatment differences in SBP were: 8 (-4; 20) mmHg (end of hemodialysis) and 7 (0; 15) mmHg (post-hemodialysis). Stroke volume decreased whereas total peripheral resistance increased significantly more during high dialysate bicarbonate compared to low dialysate bicarbonate with mean between treatment differences: Stroke volume: 12 (1; 23) mL; Total peripheral resistance: -2.9 (-5.3; -0.5) mmHg/(L/min). Cardiac output tended to decrease more with high dialysate bicarbonate compared to low dialysate bicarbonate with mean between treatment difference 0.7 (0.0; 1.4) L/min. High dialysate bicarbonate caused alkalosis, hypocalcemia, and lower plasma potassium, whereas patients remained normocalcemic with normal pH during low dialysate bicarbonate. Orthostatic blood pressure response after dialysis did not differ significantly. DISCUSSION: The use of high dialysate bicarbonate compared to low dialysate bicarbonate was associated with hypocalcemia, alkalosis, and a more pronounced hypokalemia. During hemodialysis with UF, a better preservation of blood pressure, stroke volume, and cardiac output may be achieved with low dialysate bicarbonate compared to high dialysate bicarbonate.

Effects of Empagliflozin in Type 2 Diabetes With and Without Chronic Kidney Disease and Nondiabetic Chronic Kidney Disease: Protocol for 3 Crossover Randomized Controlled Trials (SiRENA Project).

BACKGROUND: Sodium-glucose-cotransporter 2 inhibitors (SGLT2is) have revolutionized the treatment of type 2 diabetes mellitus (DM2) and chronic kidney disease (CKD), reducing the risk of cardiovascular and renal end points by up to 40%. The underlying mechanisms are not fully understood. OBJECTIVE: The study aims to examine the effects of empagliflozin versus placebo on renal hemodynamics, sodium balance, vascular function, and markers of the innate immune system in patients with DM2, DM2 and CKD, and nondiabetic CKD. METHODS: We conducted 3 double-blind, crossover, randomized controlled trials, each with identical study protocols but different study populations. We included patients with DM2 and preserved kidney function (estimated glomerular filtration rate >60 mL/min/1.73 m2), DM2 and CKD, and nondiabetic CKD (both with estimated glomerular filtration rate 20-60 mL/min/1.73 m2). Each participant was randomly assigned to 4 weeks of treatment with either 10 mg of empagliflozin once daily or a matching placebo. After a wash-out period of at least 2 weeks, participants were crossed over to the opposite treatment. End points were measured at the end of each treatment period. The primary end point was renal blood flow measured with 82Rubidium positron emission tomography-computed tomography (82Rb-PET/CT). Secondary end points include glomerular filtration rate measured with 99mTechnetium-diethylene-triamine-pentaacetate (99mTc-DTPA) clearance, vascular function assessed by forearm venous occlusion strain gauge plethysmography, measurements of the nitric oxide (NO) system, water and sodium excretion, body composition measurements, and markers of the complement immune system. RESULTS: Recruitment began in April 2021 and was completed in September 2022. Examinations were completed by December 2022. In total, 49 participants completed the project: 16 participants in the DM2 and preserved kidney function study, 17 participants in the DM2 and CKD study, and 16 participants in the nondiabetic CKD study. Data analysis is ongoing. Results are yet to be published. CONCLUSIONS: This paper describes the rationale, design, and methods used in a project consisting of 3 double-blind, crossover, randomized controlled trials examining the effects of empagliflozin versus placebo in patients with DM2 with and without CKD and patients with nondiabetic CKD, respectively. TRIAL REGISTRATION: EU Clinical Trials Register 2019-004303-12; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2019-004303-12, EU Clinical Trials Register 2019-004447-80; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2019-004447-80, EU Clinical Trials Register 2019-004467-50; https://www.clinicaltrialsregister.eu/ctr-search/search?query=and+2019-004467-50. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/56067.

Aortic Calcification is Associated With the Difference Between Invasive Central and Cuff-Measured Brachial Blood Pressure in Chronic Kidney Disease.

BACKGROUND: Chronic kidney disease (CKD) is associated with accelerated vascular calcification and increased central systolic blood pressure when measured invasively (invCSBP) relative to cuff-based brachial systolic blood pressure (cuffSBP). The contribution of aortic wall calcification to this phenomenon has not been clarified. We, therefore, examined the effects of aortic calcification on cuffSBP and invCSBP in a cohort of patients representing all stages of CKD. METHODS: During elective coronary angiography, invCSBP was measured in the ascending aorta with a fluid-filled catheter with simultaneous recording of cuffSBP using an oscillometric device. Furthermore, participants underwent a non-contrast computed tomography scan of the entire aorta with observer-blinded calcification scoring of the aortic wall ad modum Agatston. RESULTS: We included 168 patients (mean age 67.0 ±â€…10.5, 38 females) of whom 38 had normal kidney function, while 30, 40, 28, and 32 had CKD stages 3a, 3b, 4, and 5, respectively. Agatston scores adjusted for body surface area ranged from 48 to 40,165. We found that invCSBP increased 3.6 (95% confidence interval 1.4-5.7) mm Hg relative to cuffSBP for every 10,000-increment in aortic Agatston score. This association remained significant after adjustment for age, diabetes, antihypertensive treatment, smoking, eGFR, and BP level. No such association was found for diastolic BP. CONCLUSIONS: Patients with advanced aortic calcification have relatively higher invCSBP for the same cuffSBP as compared to patients with less calcification. Advanced aortic calcification in CKD may therefore result in hidden central hypertension despite apparently well-controlled cuffSBP. ClinicalTrials.gov identifier: NCT04114695.

Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment in CKD.

Introduction: Central aortic blood pressure (BP) could be a better risk predictor than brachial BP. This study examined whether invasively measured aortic systolic BP improved outcome prediction beyond risk prediction by conventional cuff-based office systolic BP in patients with and without chronic kidney disease (CKD). Methods: In a prospective, longitudinal cohort study, aortic and office systolic BPs were registered in patients undergoing elective coronary angiography (CAG). CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2. Multivariable Cox models were used to determine the association with incident myocardial infarction (MI), stroke, and death. Results: Aortic and office systolic BPs were available in 39,866 patients (mean age: 64 years; 58% males; 64% with hypertension) out of which 6605 (17%) had CKD. During a median follow-up of 7.2 years (interquartile range: 4.6-10.1 years), 1367 strokes (CKD: 353), 1858 MIs (CKD: 446), and 7551 deaths (CKD: 2515) occurred. CKD increased the risk of stroke, MI, and death significantly. Office and aortic systolic BP were both associated with stroke in non-CKD patients (adjusted hazard ratios with 95% confidence interval per 10 mm Hg: 1.08 [1.05-1.12] and 1.06 [1.03-1.09], respectively) and with MI in patients with CKD (adjusted hazard ratios: 1.08 [1.03-1.13] and 1.08 [1.04-1.12], respectively). There was no significant difference between prediction of outcome with office or aortic systolic BP when adjusted models were compared with C-statistics. Conclusion: Regardless of CKD status, invasively measured central aortic systolic BP does not improve the ability to predict outcome compared with brachial office BP measurement.

High versus low measurement frequency during 24-h ambulatory blood pressure monitoring - a randomized crossover study.

Ambulatory blood pressure monitoring (ABPM) may be stressful and associated with discomfort, possibly influenced by the number of cuff inflations. We compared a low frequency (LF-ABPM) regimen with one cuff inflation per hour, with a high frequency (HF-ABPM) regimen performed according to current guidelines using three cuff-inflations per hour during daytime and two cuff-inflations during night time. In a crossover study, patients underwent ABPMs with both frequencies, in a randomized order, within an interval of a few days. Patients reported pain (visual analogue scale from 0 to 10) and sleep disturbances after each ABPM. The primary endpoint was the difference in mean 24 h systolic BP (SBP) between HF-ABPM and LF-ABPM. A total of 171 patients were randomized, and data from 131 (age 58 ± 14 years, 47% females, 24% normotensive, 53% mildly hypertensive, and 22% moderately-severely hypertensive) completing both ABPMs were included in the analysis. Mean SBP was 137.5 mmHg (95% CI, 134.8;140.2) for HF-ABPM and 138.2 mmHg (95%CI, 135.2;141.1) for LF-ABPM. The 95% limits of agreement were -15.3 mmHg and +14.0 mmHg. Mean 24 h SBP difference between HF-ABPM and LF-ABPM was -0.7 mmHg (95%CI, -2.0;0.6). Coefficients of variation were similar for LF-ABPM and HF-ABPM. Pain scores (median with interquartile range), for HF-ABPM and LF-ABPM were 1.5 (0.6;3.0) and 1.3 (0.6;2.9) during daytime, and 1.3 (0.4:3.4) and 0.9 (0.4;2.0) during nighttime (P < 0.05 for both differences). We conclude that LF-ABPM and HF-ABPM values are in good agreement without any clinically relevant differences in BP. Furthermore, LF-ABPM causes a relatively modest reduction in procedure-related pain.

Absence of Coronary Artery Disease is a Strong Negative Predictor of Major Adverse Cardiovascular Events in Patients with Chronic Kidney Disease.

Purpose: To investigate the interplay between chronic kidney disease (CKD) and coronary artery disease (CAD) on the incidence of cardiovascular events in patients with suspected chronic coronary syndrome (CCS). Patients and Methods: Patients with suspected CCS who underwent first-time coronary angiography in Western Denmark between 2003 and 2016 were included in this cohort study. Moreover, an age- and sex-matched general population cohort was established. Patients were stratified according to estimated glomerular filtration rate (eGFR). Presence of CAD was defined as ≥1 obstructive stenosis or non-obstructive diffuse disease. Major adverse cardiovascular events (MACE) were defined as a composite of myocardial infarction, ischemic stroke, and cardiac death. Results: A total of 42,611 patients were included with a median follow-up of 7.3 years. Patients without and with CAD had MACE rates per 100 person-years that were 0.52 and 1.67 for eGFR ≥90 mL/min/1.73 m2, 0.68 and 2.09 for eGFR 60-89 mL/min/1.73 m2, 1.27 and 3.85 for eGFR 30-59 mL/min/1.73 m2, and 2.27 and 6.92 for eGFR <30 mL/min/1.73 m2. Comparing to eGFR ≥90 mL/min/1.73 m2, the adjusted incidence rate ratios for MACE were 1.29 (1.10-1.51) for eGFR 60-89 mL/min/1.73 m2, 1.86 (1.49-2.33) for eGFR 30-59 mL/min/1.73 m2, and 3.57 (1.92-6.67) for eGFR <30 mL/min/1.73 m2 in patients without CAD, and 1.11 (1.03-1.20), 1.71 (1.55-1.90), and 2.46 (1.96-3.09) in patients with CAD. The inverse relationship between kidney function and risk of MACE was confirmed when comparing patients with and without CAD to matched individuals in the general population. Conclusion: Absence of CAD is a strong negative predictor of major adverse cardiovascular events in patients with CKD.

Obstructive sleep apnea, coronary calcification and arterial stiffness in patients with diabetic kidney disease.

BACKGROUND AND AIMS: Obstructive sleep apnea (OSA) may accelerate arterial calcification, but the relation remains unexplored in diabetic kidney disease (DKD). We examined the associations between OSA, coronary calcification and large artery stiffness in patients with DKD and reduced renal function. METHODS: Patients with type 2 diabetes, estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 and urine albumin-creatinine ratio (UACR) > 30 mg/g were tested for OSA quantified by the apnea-hypopnea index (AHI, events/hour). Patients without OSA (AHI< 5) were compared to patients with moderate (AHI 15-29) or severe (AHI ≥30) OSA and underwent computed tomography angiography with coronary Agatston scoring (CAS) to quantify coronary calcification. Arterial stiffness was determined as carotid-femoral pulse wave velocity (PWV). RESULTS: Among 114 patients with acceptable AHI recordings had 43 no OSA, 33 mild OSA and 38 moderate-severe OSA. Mean age of the 74 patients completing the study was 71.5 ± 9.4 years (73% males), eGFR 32.2 ± 12.3 ml/min/1.73 m2 and UACR 533 (192-1707) mg/g. CAS (ln-transformed) was significantly higher in patients with OSA compared to patients without (6.6 ± 1.7 vs. 5.6 ± 2.4, p = 0.04), and the same was observed for PWV (11.9 ± 2.7 vs. 10.5 ± 2.2 m/s, p = 0.02). In multivariable linear regression analyses adjusted for sex, age, body mass index, UACR, and mean arterial pressure, moderate-severe OSA remained significantly associated with PWV but not with CAS. Dominance analysis revealed OSA as the third and second most important factor relative to CAS and PWV respectively. CONCLUSIONS: In DKD patients, moderate-severe OSA is a significant predictor of arterial stiffness but is not independently associated with coronary calcification.

Prediction of CKD Progression and Cardiovascular Events Using Albuminuria and Pulse Wave Velocity.

INTRODUCTION: Chronic kidney disease (CKD) is associated with cardiovascular disease (CVD) and death. Albuminuria is an established risk factor, but additional biomarkers predicting CKD progression or CVD are needed. Arterial stiffness is an easily measurable parameter that has been associated with CVD and mortality. We evaluated the ability of carotid-femoral pulse wave velocity (PWV) and urine albumin-creatinine (UAC) ratio to predict CKD progression, cardiovascular events, and mortality in a cohort of CKD patients. METHODS: In CKD stage 3-5 patients, PWV and UAC were measured at baseline. CKD progression was defined as 50% decline in estimated glomerular filtration rate (eGFR), initiation of dialysis, or renal transplantation. A composite endpoint was defined as CKD progression, myocardial infarction, stroke, or death. Endpoints were analyzed using Cox regression analysis adjusted for possible confounders. RESULTS: We included 181 patients (median age 69 [interquartile range 60-75] years, 67% males) with a mean eGFR of 37 ± 12 mL/min/1.73 m2 and UAC 52 (5-472) mg/g. Mean PWV was 10.6 m/s. Median follow-up until first event was 4 (3-6) years with 44 and 89 patients reaching a CKD progression or composite endpoint, respectively. UAC (g/g) significantly predicted both CKD progression (HR 1.5 [1.2; 1.8]) and composite endpoints (HR 1.4 [1.1; 1.7]) in adjusted Cox regression. In contrast, PWV (m/s) was not associated with neither CKD progression (HR 0.99 [0.84; 1.18]) nor the composite endpoint (HR 1.03 [0.92; 1.15]). CONCLUSION: In an aging CKD population, UAC predicted both CKD progression and a composite endpoint of CKD progression, cardiovascular events, or death, while PWV did not.

Prediction of Renal Function in Living Kidney Donors and Recipients of Living Donor Kidneys Using Quantitative Histology.

BACKGROUND: Living kidney donors (LKDs) are at increased risk of chronic kidney disease, whereas transplant recipients experience progressive reduction of graft function. We examined the predictive value of quantitative stereology on renal function in LKDs and recipients of living donor kidneys, based on perioperative biopsies from the donated kidney. METHODS: Cortex volume of both donor kidneys was determined by contrast-enhanced computed tomography and single-kidney glomerular filtration rate (GFR) by 51 chrome-EDTA clearance together with renography. Glomerular density was used to estimate total glomeruli number in addition to glomerular volume, glomerular sclerosis, kidney fibrosis, and arteriole dimensions. GFR measurements were repeated 1 y after transplantation in both LKDs and recipients. Associations between GFR at follow-up and cortex volume and histomorphometric parameters after adjustment of age, gender, body mass index, smoking status, 24-h blood pressure, and single-kidney GFR were examined. RESULTS: We included 49 LKDs (age, 51 ± 12 y) and 51 recipients (age, 44 ± 13 y). At follow-up, GFR was 71 ± 16 mL/min in LKDs and 61 ± 18 mL/min in recipients with hyperfiltration being more prominent in LKDs (30.4%) as compared to recipients (16.4%; P < 0.05). One-year GFR in donors correlated to cortex volume ( P < 0.001) but not to any histological parameters, whereas GFR in recipients correlated to the amount of interstitial fibrosis ( P < 0.01) but not to other histological parameters or cortex volume. CONCLUSIONS: Kidney cortex volume, but not renal histology parameters, predicts 1-y renal outcome in LKDs. In contrast, the amount of interstitial fibrosis, but not cortex volume, predicts 1-y graft function in recipients.

Dosing Limitation for Intra-Renal Arterial Infusion of Mesenchymal Stromal Cells.

The immunomodulatory and regenerative properties of mesenchymal stromal cells (MSCs) make MSC therapy a promising therapeutic strategy in kidney disease. A targeted MSC administration via the renal artery offers an efficient delivery method with limited spillover to other organs. Although local administration alleviates safety issues with MSCs in systemic circulation, it introduces new safety concerns in the kidneys. In a porcine model, we employed intra-renal arterial infusion of ten million allogenic adipose tissue-derived MSCs. In order to trigger any potential adverse events, a higher dose (hundred million MSCs) was also included. The kidney function was studied by magnetic resonance imaging after the MSC infusion and again at two weeks post-treatment. The kidneys were assessed by single kidney glomerular filtration rate (skGFR) measurements, histology and inflammation, and fibrosis-related gene expression. None of the measured parameters were affected immediately after the administration of ten million MSCs, but the administration of one hundred million MSCs induced severe adverse events. Renal perfusion was reduced immediately after MSC administration which coincided with the presence of microthrombi in the glomeruli and signs of an instant blood-mediated inflammatory reaction. At two weeks post-treatment, the kidneys that were treated with one hundred million MSCs showed reduced skGFR, signs of tissue inflammation, and glomerular and tubular damage. In conclusions, the intra-renal administration of ten million MSCs is well-tolerated by the porcine kidney. However, higher concentrations (one hundred million MSCs) caused severe kidney damage, implying that very high doses of intra-renally administered MSCs should be undertaken with caution.

Estimated Pulse Wave Velocity Is Associated With All-Cause Mortality During 8.5 Years Follow-up in Patients Undergoing Elective Coronary Angiography.

Background Estimated pulse wave velocity (ePWV) calculated by equations using age and blood pressure has been suggested as a new marker of mortality and cardiovascular risk. However, the prognostic potential of ePWV during long-term follow-up in patients with symptoms of stable angina remains unknown. Methods and Results In this study, ePWV was calculated in 25 066 patients without diabetes, previous myocardial infarction (MI), stroke, heart failure, or valvular disease (mean age 63.7±10.5 years, 58% male) with stable angina pectoris undergoing elective coronary angiography during 2003 to 2016. Multivariable Cox models were used to assess the association with incident all-cause mortality, MI, and stroke. Discrimination was assessed using Harrell´s C-index. During a median follow-up period of 8.5 years (interquartile range 5.5-11.3 years), 779 strokes, 1233 MIs, and 4112 deaths were recorded. ePWV was associated with all-cause mortality (hazard ratio [HR] per 1 m/s, 1.13; 95% CI, 1.05-1.21) and MI (HR per 1 m/s 1.23, 95% CI, 1.09-1.39) after adjusting for age, systolic blood pressure, body mass index, smoking, estimated glomerular filtration rate, Charlson Comorbidity Index score, antihypertensive treatment, statins, aspirin, and number of diseased coronary arteries. Compared with traditional risk factors, the adjusted model with ePWV was associated with a minor but likely not clinically relevant increase in discrimination for mortality, 76.63% with ePWV versus 76.56% without ePWV, P<0.05. Conclusions In patients with stable angina pectoris, ePWV was associated with all-cause mortality and MI beyond traditional risk factors. However, the added prediction of mortality was not improved to a clinically relevant extent.

Renal Artery Stenting in Consecutive High-Risk Patients With Atherosclerotic Renovascular Disease: A Prospective 2-Center Cohort Study.

Background The aim of this study was to prospectively evaluate the effects of renal artery stenting in consecutive patients with severe atherosclerotic renal artery stenosis and high-risk clinical presentations as defined in a national protocol developed in 2015. Methods and Results Since the protocol was initiated, 102 patients have been referred for revascularization according to the following high-risk criteria: severe renal artery stenosis (≥70%) with true resistant hypertension, rapidly declining kidney function, or recurrent heart failure/sudden pulmonary edema. At baseline, the mean 24-hour ambulatory systolic blood pressure was 166.2 mm Hg (95% CI, 162.0-170.4), the defined daily dose of antihypertensive medication was 6.5 (95% CI, 5.8-7.3), and the estimated glomerular filtration rate was 41.1 mL/min per 1.73m2 (95% CI, 36.6-45.6). In 96 patients with available 3-month follow-up data, mean 24-hour ambulatory systolic blood pressure decreased by 19.6 mm Hg (95% CI, 15.4-23.8; P<0.001), the defined daily dose of antihypertensive medication was reduced by 52% (95% CI, 41%-62%; P<0.001), and estimated glomerular filtration rate increased by 7.8 mL/min per 1.73m2 (95% CI, 4.5-11.1; P<0.001). All changes persisted after 24 month follow-up. Among 17 patients with a history of hospitalization for acute decompensated heart failure, 14 patients had no new episodes after successful revascularization. Conclusions In this prospective cohort study, we observed a reduction in blood pressure and antihypertensive medication, an increase in estimated glomerular filtration rate, and a decrease in new hospital admissions attributable to heart failure/sudden pulmonary edema after renal artery stenting. Registration URL: https://clinicaltrials.gov. Identifier: NCT02770066.

The role of potassium in muscle membrane dysfunction in end-stage renal disease.

OBJECTIVE: Uremic myopathy is a condition seen in end-stage renal disease (ESRD), characterized by muscle weakness and muscle fatigue, in which the pathophysiology is uncertain. The aim of this study was to assess the role of abnormal serum constituents in ESRD patients by relating them to the excitability properties of the tibialis anterior muscle, at rest and during electrically induced muscle activation, by recording muscle velocity recovery cycles (MVRC) and frequency ramp responses. METHODS: Eighteen ESRD patients undergoing hemodialysis were evaluated by blood sample, MVRC, and frequency ramp (before and near the end of dialysis treatment), quantitative electromyography, and nerve conduction studies. Patients were compared to 24 control subjects. RESULTS: In patients, muscle relative refractory period, early supernormality, late supernormality after 5 conditioning stimuli, and latency of the last of 15 and 30 frequency ramp pulses were strongly associated with potassium levels (p < 0.01), showing depolarization before and normalization in the end of hemodialysis. CONCLUSIONS: In ESRD patients, the muscle membrane is depolarized, mainly due to hyperkalemia. SIGNIFICANCE: Since normal muscle fatigue has been attributed to potassium-induced depolarization, it seems likely that this mechanism is also a major cause of the exaggerated muscle fatigue and weakness in ESRD patients.

Unattended automated office blood pressure in living donor kidney transplant recipients.

PURPOSE: Hypertension is common in kidney transplant recipients (KTRs). For the evaluation of blood pressure (BP), 24-h ambulatory BP measurements (ABPM) are considered superior to usual office measurements but are also resource demanding and troublesome to many patients. We therefore evaluated the use of unattended automated office BP (AOBP) during the first year following living donor kidney transplantation and compared AOBP with ABPM as obtained 12 months after transplantation. MATERIALS AND METHODS: Data were retrieved from a cohort of 57 KTRs (mean age 45 ± 14 years, 75% males) who all received kidneys from living donors and had a good graft function (estimated glomerular filtration rate (eGFR) 52 ± 16 ml/min/1.73 m2 at 12 months). Unattended AOBP was measured at each visit to the outpatient clinic using the BpTru® device, while ABPM was obtained by Spacelabs® equipment before and 12 months after transplantation. RESULTS: AOBP remained stable from month 2 (130.2 ± 10.8/82.2 ± 7.8 mmHg) to month 12 (129.0 ± 12.8/83.1 ± 9.6 mmHg) post-transplantation. At 12 months follow-up, ambulatory daytime systolic BP was slightly higher than AOBP (132.7 ± 10.7 vs. 129.4 ± 12.2 mmHg, p = 0.04), while diastolic BP was similar (82.7 ± 7.7 vs. 82.0 ± 10.2 mmHg). Using Bland-Altman plots, 95% limits of agreements were -17.9 to 24.5 mmHg for systolic and -16.5 to 15.1 mmHg for diastolic BP. When considering a target BP of ≤130/<80 mmHg, 62% had sustained hypertension, 9% white coat hypertension and 11% masked hypertension. Using multiple linear regression analysis, only urine albumin-creatinine ratio tended to predict a higher systolic AOBP (p = 0.07). CONCLUSION: In a cohort of stable living donor KTRs, mean values of unattended AOBP using BpTru® are comparable to daytime ABPM with a misclassification rate of approximately 20%.

Employment of patients with kidney failure treated with dialysis or kidney transplantation-a systematic review and meta-analysis.

BACKGROUND: Patients with kidney failure treated with dialysis or kidney transplantation experience difficulties maintaining employment due to the condition itself and the treatment. We aimed to establish the rate of employment before and after initiation of dialysis and kidney transplantation and to identify predictors of employment during dialysis and posttransplant. METHODS: This systematic review and meta-analysis were carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines for studies that included employment rate in adults receiving dialysis or a kidney transplant. The literature search included cross-sectional or cohort studies published in English between January 1966 and August 2020 in the PubMed, Embase, and Cochrane Library databases. Data on employment rate, study population, age, gender, educational level, dialysis duration, kidney donor, ethnicity, dialysis modality, waiting time for transplantation, diabetes, and depression were extracted. Quality assessment was performed using the Newcastle-Ottawa Scale. Meta-analysis for predictors for employment, with odds ratios and confidence intervals, and tests for heterogeneity, using chi-square and I2 statistics, were calculated. PROSPERO registration number: CRD42020188853. RESULTS: Thirty-three studies included 162,059 participants receiving dialysis, and 31 studies included 137,742 participants who received kidney transplantation. Dialysis patients were on average 52.6 years old (range: 16-79; 60.3% male), and kidney transplant patients were 46.7 years old (range: 18-78; 59.8% male). The employment rate (weighted mean) for dialysis patients was 26.3% (range: 10.5-59.7%); the employment rate was 36.9% pretransplant (range: 25-86%) and 38.2% posttransplant (range: 14.2-85%). Predictors for employment during dialysis and posttransplant were male, gender, age, being without diabetes, peritoneal dialysis, and higher educational level, and predictors of posttransplant: pretransplant employment included transplantation with a living donor kidney, and being without depression. CONCLUSIONS: Patients with kidney failure had a low employment rate during dialysis and pre- and posttransplant. Kidney failure patients should be supported through a combination of clinical and social measures to ensure that they remain working.

Effects of Corticosteroid Treatment on Mycophenolic Acid Exposure in Renal Transplant Patients-Results From the SAILOR Study.

Background: Mycophenolic acid (MPA) is a potent immunosuppressive agent used in solid organ transplantation. MPA exhibits large interindividual variation in dose-normalized plasma concentrations but is nevertheless usually prescribed as a fixed dose without use of therapeutic drug monitoring (TDM). Data on the effect of corticosteroid (CS) treatment on MPA concentrations during concomitant tacrolimus treatment remains sparse. Methods: Data is based on TDM of MPA area under the concentration curve (AUC) in 210 renal transplant recipients participating in the prospective, randomized, controlled, multi-center trial (SAILOR) where a steroid-free immunosuppressive regimen with mycophenolate mofetil (MMF) and low-dose tacrolimus was compared with a conventional prednisolone-based treatment regimen. Multilevel mixed-effects linear regression post-hoc analyses of MPA AUC was performed. Results: Median MPA AUC at baseline (within the first 2 weeks post-transplant) in patients taking 2 g MMF daily was 53 mg*h/L (interquartile range: 43-69 mg*h/L, min: 24-max: 117 mg*h/L). Between-patient variation in MPA AUC was up to 5-fold on the same MMF dose. Patients in the steroid-free group had 12.5% lower (95% CI; 3.2-20.9%, p = 0.01) MPA AUC levels at baseline compared to the steroid treated group. During follow-up (14 days-2 years post-transplant) there were no significant differences in MPA AUC between the groups with MPA AUC being 4.2% lower (95% CI: -4.8%-12,5%, p = 0.35) in the steroid-free vs standard treatment group in restricted analysis after multivariate adjustment for tacrolimus trough level, body weight, time after transplantation and MMF dose. MMF dose was positively correlated with MPA AUC (p < 0.001) whereas body weight was negatively correlated with MPA AUC (p < 0.001). MPA AUC was 0.4% (95% CI: 0.2-0.6%, p < 0.001) lower per 1 kg increase in weight. Tacrolimus trough levels had no significant effect on MPA AUC. Conclusion: Immunosuppression with CS during concomitant tacrolimus treatment was shortly after transplantation associated with a significantly higher MPA exposure but the effect was small and not maintained during follow-up. Low body weight was associated with higher MPA exposure, which suggests a potential for weight adjusted MMF dosing.

Effects of enhanced versus reduced vasodilating treatment on brachial and central blood pressure in patients with chronic kidney disease: a randomized controlled trial.

BACKGROUND: Blood pressure (BP) control is important in chronic kidney disease (CKD), but a reduction in brachial BP may not mirror changes in central aortic BP (cBP) during antihypertensive medication. We hypothesize that a fall in cBP is better reflected during enhanced vasodilation treatment (EVT) compared with reduced vasodilation treatment (RVT) because of different hemodynamic actions of these interventions. METHODS: Eighty-one hypertensive CKD stage 3-4 patients (mean measured glomerular filtration rate 36 ml/min per 1.73 m2) were randomized to either EVT based on renin--angiotensin blockade and/or amlodipine or RVT based on nonvasodilating ß-blockade (metoprolol). Before randomization and following 18 months of treatment, we performed 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis for estimation of cBP and augmentation index (AIx). Forearm resistance (Rrest) was determined by venous occlusion plethysmography and arterial stiffness by carotid--femoral pulse wave velocity (PWV). Matched healthy controls were studied once for comparison. RESULTS: Compared with controls, CKD patients had elevated ABPM, cBP and PWV. Although ABPM remained unchanged from baseline to follow-up in both treatment groups, cBP decreased 4.7/2.9 mmHg (systolic/diastolic) during EVT and increased 5.1/1.5 mmHg during RVT (Δ=9.8/4.4 mmHg, P=0.02 for SBP, P = 0.05 for DBP). At follow-up, the difference between systolic cBP and 24-h ABPM (ΔBPsyst) was negatively associated with heart rate and positively associated with AIx and Rrest (all P < 0.01) but not PWV (P = 0.32). CONCLUSION: In CKD patients, EVT and RVT have opposite effects on cBP and the difference between cBP and ambulatory BP is larger for EVT than RVT.