Association of serum copeptin and urinary uromodulin with kidney function, blood pressure and albuminuria at 6 weeks post-partum in pre-eclampsia.

Background: Preeclampsia (PE) is associated with subsequent higher risk of cardiovascular and kidney disease. Serum copeptin, as a proxy for vasopressin, and urinary uromodulin, were associated with PE physiopathology and kidney functional mass respectively. We describe concentrations of these proteins in the post-partum period and characterize their association with persistent hypertension (HTN) or albuminuria. Methods: Patients with PE and healthy controls with uncomplicated pregnancy were prospectively included at two teaching hospitals in Switzerland. Clinical parameters along with serum copeptin and urinary uromodulin were measured at 6 weeks post-partum. PE patients were further characterized based on presence of HTN (defined as either systolic BP (SBP) ≥140 mmHg or diastolic (BP) ≥90 mmHg) or albuminuria [defined as urinary albumin to creatinine ratio (ACR) ≥3 mg/mmol]. Results: We included 226 patients with 35 controls, 120 (62.8%) PE with persistent HTN/albuminuria and 71 (37.1%) PE without persistent HTN/albuminuria. Median serum copeptin concentration was 4.27 (2.9-6.2) pmol/L without differences between study groups (p > 0.05). Higher copeptin levels were associated with higher SBP in controls (p = 0.039), but not in PE (p > 0.05). Median urinary uromodulin concentration was 17.5 (7.8-28.7) mg/g with lower levels in PE patients as compared to healthy controls (p < 0.001), but comparable levels between PE patients with or without HTN/albuminuria (p > 0.05). Higher uromodulin levels were associated with lower albuminuria in PE as well as control patients (p = 0.040). Conclusion: Serum copeptin levels at 6 weeks post-partum are similar between PE patients and healthy controls and cannot distinguish between PE with or without residual kidney damage. This would argue against a significant pathophysiological role of the vasopressin pathway in mediating organ damage in the post-partum period. On the opposite, post-partum urinary uromodulin levels are markedly lower in PE patients as compared to healthy controls, potentially reflecting an increased susceptibility to vascular and kidney damage that could associate with adverse long-term cardiovascular and kidney outcomes.

[Preservation of residual kidney function in chronic haemodialysis]. / Préservation de la fonction rénale résiduelle et hémodialyse incrémentale.

Residual kidney function (RKF) is defined as the production of a clinically significant amount of urine in dialysis patients. Observational studies suggest that those with preserved RKF have a better prognosis than anuric patients. Preserved RKF allows the prescription of a lower dialysis dose compared to the traditional thrice weekly schedule. Such an "incremental" approach has also been associated with a better global prognosis. In view of the overall growth of incremental HD in the western world, we review the main studies supporting this approach, as well as the benefits and limitations related to RKF preservation.

Chez les patients hémodialysés, la fonction rénale résiduelle (FRR) est définie comme la production d'une quantité d'urine significative du point de vue clinique. Les données observationnelles suggèrent que les patients en hémodialyse (HD) ayant une FRR conservée ont un meilleur pronostic que les patients anuriques. Une FRR préservée permet également la prescription d'une dose d'HD inférieure au schéma traditionnel de 3 séances par semaine. Ce type d'approche «â€…incrémentale ¼ a elle aussi été associée à une amélioration du pronostic global. Au vu de l'essor de l'HD incrémentale dans les pays développés, nous revenons dans cet article sur les principales études qui soutiennent cette approche ainsi que sur les bénéfices et limitations liées à la préservation de la FRR.

Predicting solute transfer rate in patients initiating peritoneal dialysis.

BACKGROUND: While assessment of membrane characteristics is fundamental to peritoneal dialysis (PD) prescription in patients initiating therapy, peritoneal equilibration test has theoretical and practical drawbacks. We wished to determine whether an equation using simple clinical variables could predict fast (above population mean) peritoneal solute transfer rate without dialysate sampling. METHODS: We measured peritoneal solute transfer rate, as determined by peritoneal equilibration test using the 4-h dialysate to plasma creatinine ratio, in consecutive PD outpatients attending a single tertiary hospital for their first clinical follow-up within 3 months of dialysis initiation. An equation estimating peritoneal solute transfer rate based on readily available clinical variables was generated in a randomly selected modeling group and tested in a distinct validation group. RESULTS: We included 712 patients, with 562 in the modeling group and 150 in the validation group. Mean age was 58.4 ± 15.9 with 431 (60.5%) men. Mean peritoneal solute transfer rate value was 0.73 ± 0.13. An equation based on gender, race, serum sodium and albumin yielded a receiving operator characteristics (ROC) area under the curve (AUC) to detect fast peritoneal solute transfer rate (> 0.73) of 0.74 (0.67-0.82). Estimated peritoneal solute transfer rate values based on percentiles 15th (> 0.66), 20th (> 0.68), 25th (> 0.69) and 30th (> 0.70) could rule out fast peritoneal solute transfer rate with negative predictive values of 100%, 93.5%, 84.2% and 80.0%, respectively. CONCLUSIONS: An equation based on simple clinical variables allows ruling out fast transport in a significant proportion of patients initiating PD with a high degree of confidence without requiring dialysate sampling. This could prove useful in guiding dialysis prescription of PD patients in daily clinical practice, particularly in low-resource settings.

[Nephrology: what's new in 2023]. / Néphrologie: ce qui a changé en 2023.

Molecules such as sparsentan and budesonide look promising to treat proteinuric IGA nephropathy. SLGT2 inhibitors have a prominent place in nephroprotection and could be used in the treatment of acute kidney injury due to heart failure as well. High volume hemodiafiltration compared to hemodialysis improves survival in dialysis patients. Lessening dialysate temperature does not improve hemodynamic stability during the dialysis session. Sodium bicarbonate does not seem to protect renal function in renal transplant patients. SGLT2 inhibitors may have a beneficial effect in these patients in terms of nephroprotection.

Dans les formes protéinuriques de néphropathie à IgA, le sparsentan et le budésonide semblent être des molécules prometteuses. Les inhibiteurs du SGLT2 (iSGLT2) confirment leur place primordiale dans la néphroprotection et pourraient être utilisés dans le traitement de l'insuffisance rénale aiguë (IRA) liée à l'insuffisance cardiaque. En hémodialyse, l'hémodiafiltration à haut-débit comparée à l'hémodialyse diminue la mortalité d'environ 22 %. Abaisser la température du dialysat n'améliore pas la stabilité cardiovasculaire durant la séance d'hémodialyse. Le bicarbonate de sodium ne semble pas avoir d'effet néphroprotecteur sur la fonction rénale des greffés rénaux alors que les iSGLT2 pourraient avoir un effet bénéfique.

Multitargeted Internal Calibration for the Quantification of Chronic Kidney Disease-Related Endogenous Metabolites Using Liquid Chromatography-Mass Spectrometry.

Accurate quantitative analysis in liquid chromatography-mass spectrometry (LC-MS) benefits from calibration curves generated in the same matrix as the study sample. In the case of endogenous compound quantification, as no blank matrix exists, the multitargeted internal calibration (MTIC) is an attractive and straightforward approach to avoid the need for extensive matrix similarity evaluation. Its principle is to take advantage of stable isotope labeled (SIL) standards as internal calibrants to simultaneously quantify authentic analytes using a within sample calibration. An MTIC workflow was developed for the simultaneous quantification of metabolites related to chronic kidney disease (CKD) using a volumetric microsampling device to collect 20 µL of serum or plasma, followed by a single-step extraction with acetonitrile/water and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Since a single concentration of internal calibrant is necessary to calculate the study sample concentration, the instrument response function was investigated to determine the best SIL concentration. After validation, the trueness of 16 endogenous analytes in authentic human serum ranged from 72.2 to 116.0%, the repeatability from 1.9 to 11.3%, and the intermediate precision ranged overall from 2.1 to 15.4%. The proposed approach was applied to plasma samples collected from healthy control participants and two patient groups diagnosed with CKD. Results confirmed substantial concentration differences between groups for several analytes, including indoxyl sulfate and cortisone, as well as metabolite enrichment in the kynurenine and indole pathways. Multitargeted methodologies represent a major step toward rapid and straightforward LC-MS/MS absolute quantification of endogenous biomarkers, which could change the paradigm of MS use in clinical laboratories.

Dietary Sodium and Human Health.

Sodium, contained in dietary salt, is essential to human life [...].

[Plasma exchange in nephrology]. / Place des échanges plasmatiques en néphrologie.

Plasma exchange is often prescribed in nephrology and represents a technical as well as logistic challenge. It is thus important to master its most frequent indications. In this narrative review, we discuss main diseases requiring therapeutic plasma exchange in nephrology: anti-glomerular basement membrane disease, thrombotic microangiopathy as well as various clinical scenarios in kidney transplant. We also review plasma exchange in ANCA associated vasculitis, where indications have recently been restricted owing to recent scientific evidences.

Dans sa pratique clinique, le néphrologue est souvent confronté à la prescription d'échanges plasmatiques, qui représentent toujours un défi technique et logistique. Il est donc nécessaire d'avoir une bonne connaissance des indications fréquentes. Dans cet article narratif, nous rappelons les principales pathologies bénéficiant de ce type de prise en charge en néphrologie : maladie anti-membrane basale glomérulaire, microangiopathies thrombotiques, ainsi que divers scénarios en transplantation rénale. Finalement, nous revenons sur le cas des vasculites à ANCA, domaine dans lequel les indications aux échanges plasmatiques ont récemment été limitées suite à de nouvelles données scientifiques.

Variability of 24-Hour Sodium Urinary Excretion in Young Healthy Males Based on Consecutive Urine Collections: Impact on Categorization of Salt Intake.

OBJECTIVE: Several nonconsecutive 24-h urinary collections are considered the gold standard for estimating dietary salt intake. As those samples are logistically demanding, we aimed to describe the variability of 24-h sodium urinary excretion over consecutive days and report its adequacy with sodium intake. METHODS: We enrolled 16 healthy male volunteers in a prospective controlled study. All participants randomly received a low salt diet (LSD) (3 g/day of NaCl), a normal salt diet (NSD) (6 g/day of NaCl), and a high salt diet (HSD) (15 g/day of NaCl) for 7 days in a crossover design without wash-out period. RESULTS: On day 6, median sodium urinary excretion was 258 (216-338), 10 (8-18), and 87 (69-121) mmol/day for HSD, LSD, and NSD, respectively (P < .001). When considering days 4-6, sodium urinary excretion was in steady state as models with and without interaction term "diet type X sample day" were not significantly different (P = .163). On day 6, area under the curve (AUC) of receiver operating characteristic for urinary sodium excretion to detect HSD was 1.0 (1.0-1.0) and a cut-point of 175 mmol/day was 100% sensitive and specific to detect HSD. On day 6, receiver operating characteristic AUC to detect LSD was 0.993 (0.978-1.0) and a cut-point of 53 mmol/day was 96.4% sensitive and 100% specific to detect LSD. CONCLUSION: A steady state of sodium balance, where sodium intake is proportional to its excretion, is reached within a few days under a constant diet in the real-life setting. Categorization of salt consumption into low (3 g/day), normal (6 g/day), or high (15 g/day) based on a single 24-h urine collection is nearly perfect. Based on these results, repeated nonconsecutive urine collection might prove unnecessary to estimate sodium intake in daily clinical practice provided that diet is rather constant over time.

[Nephrology: what's new in 2022]. / Néphrologie : ce qui a changé en 2022.

Severe cases of IGA nephropathy might benefit from corticosteroid therapy. Inflimidase may be a promising treatment of Goodpasture disease. SGLT2 inhibitors and acetazolamide act synergistically with loop diuretics in the treatment of acute cardiac failure. In hemodialysis, use of lung ultrasound to determine the ultrafiltration seems to decrease hospitalizations due to acute heart failure but does not reduce patient-centered outcomes. Icodextrin may mitigate the loss of ultrafiltration in PD patients who are carriers of the Aquaporin I promotor TT genotype. MICA-antibodies have an impact on the risk of graft rejection. Xenotransplantation may become a reality.

Une corticothérapie peut être proposée dans les formes sévères de néphropathie à IgA. L'inflimidase est une molécule prometteuse dans le traitement de la maladie de Goodpasture. Les inhibiteurs du SGLT2 et l'acétazolamide sont des diurétiques d'appoint aux diurétiques de l'anse dans le traitement de l'insuffisance cardiaque aiguë. En hémodialyse, l'ultrason pulmonaire pour déterminer le volume d'ultrafiltration diminue les hospitalisations pour insuffisance cardiaque mais pas la morbimortalité globale. L'hémodialyse incrémentale gagne en popularité. L'icodextrine permet de pallier la baisse de l'ultrafiltration chez les patients en dialyse péritonéale porteurs du génotype TT du promoteur de l'aquaporine-1. Les anticorps anti-MICA dirigés spécifiquement contre le greffon rénal ont un impact sur le risque de rejet du greffon. La xénotransplantation devient une réalité.

Aging and hypertension in kidney function decline: A 10 year population-based study.

Background: Aging is associated with a physiological decline in kidney function (KFD). In this study, we aimed to describe the impact of age on the rate of KFD and its interplay with risk factors for chronic kidney disease (CKD), considering mainly hypertension (HT), in the general population. Materials and methods: Participants of European descent, aged 35-75, were recruited from a populational cohort in Lausanne, Switzerland. Participants with a 10 year follow-up were selected. KFD was defined as the difference in estimated glomerular filtration rate (eGFR) between baseline and follow-up, divided by the observation period. Multivariate linear regressions were used with KFD as the outcome and age as the main predictor. HT was tested as a modifying factor. Results: We included 4,163 participants with mean age 52.2 ± 10.4, 44.7% men, 31.9% HT, and 5.0% diabetics. Mean baseline eGFR was 85.9 ± 14.6 ml/min/1.73 m2. Mean KFD was -0.49 ± 1.08 ml/min/1.73 m2 per year with 70% of participants decreasing their eGFR during follow-up. The relationship between age and KFD was non-linear and age was divided in tertiles. Old participants had faster rates of KFD as compared to young and middle-age participants (p < 0.001). A significant interaction was found between age and HT on KFD prediction (p < 0.001). In HT participants, KFD was significantly different across tertiles of age (p < 0.001). On contrary, KFD was not different across tertiles of age in non-HT participants. Conclusion: A physiological KFD is present over time in the general population. Age contributes non-linearly to the rate of this decline with older subjects declining the fastest. The presence of HT is a major contributing factor in this setting as KFD worsened with age only in hypertensive participants. Thus, HT represents an important pathological factor aggravating the age-related physiological decline in eGFR in the general population.

Comparative efficacy of patiromer and sodium polystyrene sulfonate on potassium levels in chronic haemodialysis patients: a randomized crossover trial.

Background: Hyperkalaemia is frequent in haemodialysis (HD) patients and associated with increased cardiovascular mortality. Despite routine clinical use, evidence regarding the efficacy of potassium (K+) binders in HD is scant. We wished to compare the efficacy of patiromer (PAT) and sodium polystyrene sulfonate (SPS) on K+ levels in this setting. Methods: We screened patients in three HD centres with pre-HD K+ value between 5.0 and 6.4 mmol/L, after an initial 2-week washout period for those previously on K+ binders. We included patients in an unblinded two-arm crossover trial comparing SPS 15 g before each meal on non-dialysis days with PAT 16.8 g once daily on non-dialysis days with randomized attribution order and a 2-week intermediate washout period. The primary outcome was the mean weekly K+ value. Results: We included 51 patients and analysed 48 with mean age of 66.4 ± 19.4 years, 72.9% men and 43.4% diabetics. Mean weekly K+ values were 5.00 ± 0.54 mmol/L, 4.55 ± 0.75 mmol/L and 5.17 ± 0.64 mmol/L under PAT (P = .003), SPS (P < .001) and washout, respectively. In direct comparison, K+ values and prevalence of hyperkalaemia were lower under SPS as compared with PAT (P < .001). While the incidence of gastrointestinal side effects was similar between treatments, SPS showed lower subjective tolerability score (6.0 ± 2.4 and 6.9 ± 1.9) and compliance (10.8 ± 20.4% and 2.4 ± 7.3% missed doses) as compared with PAT (P < .001 for both). Conclusion: Both PAT and SPS are effective in decreasing K+ levels in chronic HD patients. However, at the tested doses, SPS was significantly more effective in doing so as compared with PAT, despite lower tolerability and compliance. Larger randomized controlled trials should be conducted in order to confirm our findings and determine whether they would impact clinical outcomes.

Association between bone mineral density at different anatomical sites and both mortality and fracture risk in patients receiving renal replacement therapy: a longitudinal study.

Background: The clinical utility of bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry (DXA) is debated in end-stage kidney disease (ESKD). We assessed the ability of BMD measured at different anatomical sites to predict mortality and fracture risk in patients requiring renal replacement therapy (RRT). Methods: We reviewed all-cause mortality as well as incident hip and overall fracture risk in RRT patients who had BMD measured at the femoral neck, lumbar spine, arm, head, pelvis and total body as part of their routine follow-up between January 2004 and June 2012 at a single university centre. Results: A total of 588 patients were included. The median follow-up was 6.5 years, the mean age was 59.6 years and 57.9% were males. Femoral neck BMD (FNBMD) (normal/high versus low) was negatively associated with mortality in univariate and multivariate analyses (P < .001 and P = .048, respectively). Other sites of BMD measurements were not associated with mortality. In multivariate analysis, FNBMD was negatively associated with hip and any fracture risk (P = .004 and P = .013, respectively). No significant interaction was found between FNBMD and gender or parathyroid hormone (PTH) (P = .112 and P = .794, respectively). Conclusions: BMD measured at the femoral neck is predictive of mortality in patients requiring RRT, regardless of modality. Low BMD might be a marker of global patient frailty rather than a direct causal factor in this setting. FNBMD is also a strong predictor of hip and any fracture risk in this population, regardless of bone turnover as assessed by PTH levels. FNBMD is thus an overall prognostic marker in patients requiring RRT.

Outcomes of incident patients treated with incremental haemodialysis as compared with standard haemodialysis and peritoneal dialysis.

BACKGROUND: Residual kidney function is considered better preserved with incremental haemodialysis (I-HD) or peritoneal dialysis (PD) as compared with conventional thrice-weekly HD (TW-HD) and is associated with improved survival. We aimed to describe outcomes of patients initiating dialysis with I-HD, TW-HD or PD. METHODS: We conducted a retrospective analysis of a prospectively assembled cohort in a single university centre including all adults initiating dialysis from January 2013 to December 2020. Primary and secondary endpoints were overall survival and hospitalization days at 1 year, respectively. RESULTS: We included 313 patients with 234 starting on HD (166 TW-HD and 68 I-HD) and 79 on PD. At the end of the study, 10 were still on I-HD while 45 transitioned to TW-HD after a mean duration of 9.8 ± 9.1 months. Patients who stayed on I-HD were less frequently diabetics (P = .007). Mean follow-up was 33.1 ± 30.8 months during which 124 (39.6%) patients died. Compared with patients on TW-HD, those on I-HD had improved survival (hazard ratio 0.49, 95% confidence interval 0.26-0.93, P = .029), while those on PD had similar survival. Initial kidney replacement therapy modality was not significantly associated with hospitalization days at 1 year. CONCLUSIONS: I-HD is suitable for selected patients starting dialysis and can be maintained for a significant amount of time before transition to TW-HD, with diabetes being a risk factor. Although hospitalization days at 1 year are similar, initiation with I-HD is associated with improved survival as compared with TW-HD or PD. Results of randomized controlled trials are awaited prior to large-scale implementation of I-HD programmes.

[Age-related decline in renal function Physiological aging or chronic kidney disease ?] / Déclin de la fonction rénale liée à l'âge - Sénescence physiologique ou insuffisance rénale chronique ?

Kidneys undergo structural as well as functional aging. Imaging and microscopic exams show alterations that manifest as a decline in glo merular filtration rate (GFR) over time. As a GFR < 60 ml/min/1,73m2 during more than three months is sufficient to diagnose chronic kidney disease (CKD), a large proportion of elderly fall into this category. However, morphological, clinical and epidemiological data show that the decline in GFR with age is not per se associated with adverse consequences. An age-adapted definition of CKD would allow managing patients on an individual prognostic basis rather than on an arbitrary biological construct.

Les reins subissent un processus de vieillissement entraînant des répercussions de structure et de fonction. Les examens d'imagerie et de microscopie mettent ainsi en évidence des altérations qui sont reflétées par une diminution du débit de filtration glomérulaire (DFG) avec le temps. La présence d'un DFG < 60 ml/min/1,73 m2 durant plus de trois mois étant suffisant pour poser le diagnostic d'insuffisance rénale chronique (IRC), une proportion importante de personnes âgées entre dans cette catégorie. Les données morphologiques, cliniques et épidémiologiques montrent toutefois que le déclin physiologique du DFG avec l'âge n'est pas en soi associé à des conséquences néfastes. Une définition de l'IRC tenant compte de l'âge permettrait une prise en charge basée sur le pronostic individuel plutôt que sur une norme biologique arbitraire.

[Hemodynamic and cardiovascular implications of arteriovenous fistulas in hemodialysis]. / Répercussions hémodynamiques et cardiovasculaires des fistules artérioveineuses en hémodialyse.

Arteriovenous fistula (AVF) remains the vascular access of choice in hemodialysis but generates cardiovascular constraints. Its creation immediately induces an increase in cardiac output. Increased venous return and subsequent volume overload lead to biventricular remodeling, and eventually to dysfunction. High-output heart failure (HOHF) caused by high-flow AVF is a recognized but not strictly defined clinical entity, based on the combination of hypervolemia with an elevated cardiac output. A Qa greater than 2 L/min is a risk factor for HOHF, particularly in susceptible patients. The most used flow reduction procedure is post-anastomotic vein caliber reduction by a banding technique, relieving symptoms and partially reversing previously induced structural abnormalities, but the benefit often remains limited in time.

La fistule artérioveineuse (FAV) demeure l'accès vasculaire de choix en hémodialyse mais engendre des contraintes cardiovasculaires. Sa création génère une élévation du débit cardiaque. L'augmentation du retour veineux puis la surcharge en volume induisent un remodelage biventriculaire pouvant mener à une dysfonction. L'insuffisance cardiaque à haut débit (ICHD) causée par un hyperdébit de la FAV est une entité clinique connue mais pas strictement définie, reposant sur une hypervolémie et une élévation du débit cardiaque. Un débit d'accès supérieur à 2 l/min est un facteur de risque d'ICHD, en particulier chez des patients susceptibles. Une intervention possible de réduction de débit est la réduction du calibre de la veine post-anastomotique par cerclage, soulageant les symptômes et inversant partiellement les anomalies structurelles induites mais a souvent un effet transitoire.

[Nephrology: what's new in 2021?] / Néphrologie.

Major advances in the treatment of nondiabetic chronic nephropathy and ANCA associated-renal vasculitis were published within the past two years. A new formula for assessing GFR was developed that does not take ethnicity into account. For hemodialysis patients, hemodiafiltration does not diminish uremic neuropathy. In hemodialysis patients, DOACs induce less bleeding than K vitamin antagonists. Weaning of steroids should be more rapid in some transplant patients. COVID-19 vaccination is less effective in dialysis and transplant patients and will necessitate a third dose.

De grandes avancées thérapeutiques ont été publiées récemment dans le chapitre de la néphropathie chronique non diabétique et des vascularites rénales. Une nouvelle formule d'estimation du débit de filtration glomérulaire estimé a été développée sans facteur de correction ethnique. En hémodialyse, l'hémodiafiltration ne diminue pas la neuropathie urémique et les anticoagulants oraux directs occasionnent moins de complications hémorragiques que les antivitamines K. Un sevrage plus rapide des corticostéroïdes chez certains greffés rénaux est possible. La vaccination contre le Covid a une efficacité moindre chez les dialysés et les transplantés rénaux, et nécessite une troisième dose.

Relationship between renal function and blood pressure dipping status in renal transplant recipients: a longitudinal study.

BACKGROUND: Hypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown. METHODS: We retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable. RESULTS: A total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m2 respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m2 higher eGFR. HT was negatively associated with eGFR (p = 0.003). CONCLUSIONS: We confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.

Sodium Intake as a Cardiovascular Risk Factor: A Narrative Review.

While sodium is essential for human homeostasis, current salt consumption far exceeds physiological needs. Strong evidence suggests a direct causal relationship between sodium intake and blood pressure (BP) and a modest reduction in salt consumption is associated with a meaningful reduction in BP in hypertensive as well as normotensive individuals. Moreover, while long-term randomized controlled trials are still lacking, it is reasonable to assume a direct relationship between sodium intake and cardiovascular outcomes. However, a consensus has yet to be reached on the effectiveness, safety and feasibility of sodium intake reduction on an individual level. Beyond indirect BP-mediated effects, detrimental consequences of high sodium intake are manifold and pathways involving vascular damage, oxidative stress, hormonal alterations, the immune system and the gut microbiome have been described. Globally, while individual response to salt intake is variable, sodium should be perceived as a cardiovascular risk factor when consumed in excess. Reduction of sodium intake on a population level thus presents a potential strategy to reduce the burden of cardiovascular disease worldwide. In this review, we provide an update on the consequences of salt intake on human health, focusing on BP and cardiovascular outcomes as well as underlying pathophysiological hypotheses.

Serum sodium variation is a major determinant of peridialytic blood pressure trends in haemodialysis outpatients.

Intradialytic hypotension (IDH) and peridialytic blood pressure (BP) trends are associated with morbidity and mortality in haemodialysis (HD) patients. We aimed to characterise the respective influence of volume status and small solutes variation on peridialytic systolic BP (SBP) trends during HD. We retrospectively analysed the relative peridialytic SBP decrease in 647 prevalent outpatients attending for their mid-week session with corresponding pre- and post-HD bioelectrical impedance analysis. Mean SBP decreased by 10.5 ± 23.6 mmHg. Factors positively associated with the relative decrease in SBP were: serum sodium (Na) decrease, body mass index, serum albumin, dialysis vintage, ultrafiltration rate and urea Kt/V (p < 0.05 for all). Antihypertensive medications and higher dialysate calcium were negatively associated with the relative decrease in SBP (p < 0.05 for both). Age had a quadratic relationship with SBP trends (p < 0.05). Pre-HD volume status measured by extracellular to total body water ratio was not associated with SBP variation (p = 0.216). Peridialytic SBP trends represent a continuum with serum Na variation being a major determinant while volume status has negligible influence. Middle-aged and overweight patients are particularly prone to SBP decline. Tailoring Na and calcium dialysate concentrations could influence haemodynamic stability during HD and improve patient experience and outcomes.