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Background Several studies have examined the frequency of sleep apnoea (SA) in patients with chronic kidney disease (CKD), reporting different prevalence rates. Our systematic review and meta-analysis aimed to define the clinical penetrance of SA in CKD and end-stage kidney disease (ESKD) patients. Methods Ovid-MEDLINE and PubMed databases were explored up to 5 June 2023 to identify studies providing SA prevalence in CKD and ESKD patients assessed by different diagnostic methods, either sleep questionnaires or respiration monitoring equipment [such as polysomnography (PSG), type III portable monitors or other diagnostic tools]. Single-study data were pooled using the random-effects model. The Chi2 and Cochrane-I2 tests were used to assess the presence of heterogeneity, which was explored performing sensitivity and/or subgroup analyses. Results A cumulative analysis from 32 single-study data revealed a prevalence of SA of 57% [95% confidence interval (CI) 42%–71%] in the CKD population, whereas a prevalence of 49% (95% CI 47%–52%) was found pooling data from 91 studies in ESKD individuals. The prevalence of SA using instrumental sleep monitoring devices, including classical PSG and type III portable sleep monitors, was 62% (95% CI 52%–72%) and 56% (95% CI 42%–69%) in CKD and ESKD populations, respectively. Sleep questionnaires revealed a prevalence of 33% (95% CI 16%–49%) and 39% (95% CI 30%–49%). Conclusions SA is commonly seen in both non-dialysis CKD and ESKD patients. Sleep-related questionnaires underestimated the presence of SA in this population. This emphasizes the need to use objective diagnostic tools to identify such a syndrome in kidney disease. [ABSTRACT FROM AUTHOR]

Background Hypertension (HTN) is common following renal transplantation and it is associated with adverse effects on cardiovascular (CV) and graft health. Ambulatory blood pressure monitoring (ABPM) is the preferred method to characterize blood pressure (BP) status, since HTN misclassification by office BP (OBP) is quite common in this population. We performed a systematic review and meta-analysis aimed at determining the clinical utility of 24-h ABPM and its potential implications for the management of HTN in this population. Methods Ovid-MEDLINE and PubMed databases were searched for interventional or observational studies enrolling adult kidney transplant recipients (KTRs) undergoing 24-h ABP readings compared with OBP or home BP. The main outcome was the proportion of KTRs diagnosed with HTN by ABPM, home or OBP recordings. Additionally, day–night BP variability and dipper/non-dipper status were assessed. Results Forty-two eligible studies (4115 participants) were reviewed. A cumulative analysis including 27 studies (3481 participants) revealed a prevalence of uncontrolled HTN detected by ABPM of 56% [95% confidence interval (CI) 46–65%]. The pooled prevalence of uncontrolled HTN according to OBP was 47% (95% CI 36–58%) in 25 studies (3261 participants). Very few studies reported on home BP recordings. The average concordance rate between OBP and ABPM measurements in classifying patients as controlled or uncontrolled hypertensive was 66% (95% CI 59–73%). ABPM revealed HTN phenotypes among KTRs. Two pooled analyses of 11 and 10 studies, respectively, revealed an average prevalence of 26% (95% CI 19–33%) for masked HTN (MHT) and 10% (95% CI 6–17%) for white-coat HTN (WCH). The proportion of non-dippers was variable across the 28 studies that analysed dipping status, with an average prevalence of 54% (95% CI 45–63%). Conclusions In our systematic review, comparison of OBP versus ABP measurements disclosed a high proportion of MHT, uncontrolled HTN and, to a lesser extent, WCH in KTRs. These results suggest that HTN is not adequately diagnosed and controlled by OBP recordings in this population. Furthermore, the high prevalence of non-dippers confirmed that circadian rhythm is commonly disturbed in KTRs. [ABSTRACT FROM AUTHOR]

Background We conducted a systematic review and meta-analysis to compare benefits and harms of different antihypertensive drug classes in kidney transplant recipients, as post-transplant hypertension (HTN) associates with increased cardiovascular (CV) morbidity and mortality. Methods The Ovid-MEDLINE, PubMed and CENTRAL databases were searched for randomized controlled trials (RCTs) comparing all main antihypertensive agents versus placebo/no treatment, routine treatment. Results The search identified 71 RCTs. Calcium channel blockers (CCBs) (26 trials) reduced the risk for graft loss {risk ratio [RR] 0.58 [95% confidence interval (CI) 0.38–0.89]}, increased glomerular filtration rate (GFR) [mean difference (MD) 3.08 mL/min (95% CI 0.38–5.78)] and reduced blood pressure (BP). Angiotensin-converting enzyme inhibitors (ACEIs) (13 trials) reduced the risk for graft loss [RR 0.62 (95% CI 0.40–0.96)] but decreased renal function and increased the risk for hyperkalaemia. Angiotensin receptor blockers (ARBs) (10 trials) did not modify the risk of death, graft loss and non-fatal CV events and increased the risk for hyperkalaemia. When pooling ACEI and ARB data, the risk for graft failure was lower in renin–angiotensin system (RAS) blockade as compared with control treatments. In direct comparison with ACEIs or ARBs (11 trials), CCBs increased GFR [MD 11.07 mL/min (95% CI 6.04–16.09)] and reduced potassium levels but were not more effective in reducing BP. There are few available data on mortality, graft loss and rejection. Very few studies performed comparisons with other active drugs. Conclusions CCBs could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss. No definite patient or graft survival benefits were associated with RAS inhibitor use over conventional treatment. [ABSTRACT FROM AUTHOR]

In the general population and in heart disease, pulmonary hypertension (PH) is a strong and independent risk factor for mortality and adverse cardiovascular outcomes. We performed a systematic review and meta‐analysis of longitudinal cohort studies of individuals with chronic kidney disease (CKD) of any‐stage (also including end‐stage kidney disease and kidney transplantation) stratified according to presence/absence of PH. Eighteen eligible studies (10 740 participants) were retrieved. PH had an overall pooled prevalence of 33% (95% CI 28–42) and portended a higher risk of all‐cause mortality (RR 2.08; 1.06–4.08), cardiovascular mortality (RR 3.77; 2.46–5.78) and non‐fatal cardiovascular events (RR 1.60; 1.28–1.99). PH is highly prevalent in CKD and end‐stage kidney disease and may represent a novel factor for mortality and cardiovascular risk stratification, particularly in selected sub‐categories. Future high‐quality research is required to confirm the need for clinical attention on PH in the CKD setting. [ABSTRACT FROM AUTHOR]

Muscle sympathetic nerve activity (MSNA) has shown that sympathetic activation may occur in essential hypertension (EHT). However, the small sample size of the studies, the heterogeneity of the patients examined, and the presence of confounders represented major weaknesses not allowing to draw definite conclusions. Among the 432 studies identified providing information in EHT on MSNA, 63 were eligible (1216 patients) and meta-analyzed grouping them on the basis of clinically relevant questions: (1) Is MSNA increased in hypertension of mild/moderate-to-severe degree? (2) Does sympathetic activation occur in borderline, white-coat, and masked EHT? (3) Is MSNA related to clinic and ambulatory blood pressure and target organ damage? (4) Are heart rate and venous plasma norepinephrine valuable surrogate markers of MSNA in clinical practice? The results show that MSNA was significantly greater (1.5×; P<0.001) in mild-to-moderate and severe EHT as compared with normotensive controls and that this was the case also in borderline, white-coat, and masked hypertension as well. Interestingly, MSNA was significantly greater in both untreated and treated hypertension (P<0.001 for both), related to clinic and ambulatory blood pressure (r=0.67 and r=0.83; P<0.001 for both), inversely related to heart rate (r=-0.38; P<0.001) and directly to venous plasma norepinephrine (r=0.28; P<0.001) and left ventricular mass index (r=0.27; P<0.001). Thus, EHT is a condition characterized by a sustained sympathetic overdrive, whose magnitude is proportional to its clinical severity. This is more clearly manifest when MSNA rather than indirect markers of adrenergic drive, such as heart rate and plasma norepinephrine, are used. [ABSTRACT FROM AUTHOR]

Background: Catheter-based renal denervation (RDN) is a possible treatment to lower blood pressure. The invasive nature of RDN and the use of contrast agents raise concerns about potential consequent kidney damage. Our objective was to determine the change in renal function after RDN by performing a systematic review on hypertensive patients treated with RDN. Methods: A systematic search was performed in the Embase and MEDLINE databases to identify studies reporting on the effects of catheter-based RDN on renal outcome. Studies published between January 2009 and May 2016, irrespective of study design, device used or indication for treatment were included. We performed random effects meta-analyses on the change in estimated glomerular filtration rate (eGFR), serum creatinine, serum cystatin C and albumin:creatinine ratio after RDN. We only extracted and meta-analysed data from patients treated with RDN. Results: From 1034 citations, 52 studies (38 cohort studies, 4 non-randomized comparative studies and 10 randomized controlled trials) reporting on 56 RDN cohorts were included in meta-analyses and another 14 studies in a qualitative review. Of these 56 cohorts, 48 were specifically eligible for determining the change in eGFR after RDN, totaling 2381 patients. There was no statistically significant change in eGFR after a mean follow-up time of 9.1±7.0months [0.64mL/min/1.73 m2 (95% confidence interval --0.47 to 1.76), P=0.26]. The pooled mean change in serum creatinine and the results of the qualitative review further supported these findings. Conclusions: Based on meta-analyses of 52 studies and a qualitative review of an additional 14 studies, reporting on 2898 patients in total, we conclude that renal function does not significantly change up to at least 9months after RDN. [ABSTRACT FROM AUTHOR]

Introduction: Accruing evidence suggests that vitamin Ecoated membranes (ViE-m) might improve the clinical management of chronic hemodialysis (HD) patients. Methods: We conducted a systematic review and meta-analysis of RCTs comparing ViE-m to conventional HD. Endpoints of interest were a series of biomarkers pertaining to anemia status, inflammation, oxidative stress and dialysis efficacy/status. Results: Sixty studies were included. ViE-m significantly improved the Erythropoietin Resistance Index but had no impact on other anemia parameters. As for oxidative stress and inflammation, ViE-m produced a significant decrease in interleukin-6 levels, thiobarbituric acid reactive substances, plasma and red blood cell (RBC) malonylaldehyde and a significant increase in blood and RBC vitamin E. Conversely, ViE-m use had no impact on lipid profile, dialysis adequacy, blood pressure, albumin and uric acid. Conclusions: ViE-m might ameliorate anemia management by reducing oxidative stress and inflammation. Benefits of these bio-membranes on harder clinical outcomes are uncertain and need to be investigated by future, targeted trials. [ABSTRACT FROM AUTHOR]

Background. The utility of renal biopsy in patients with diabetes is highly debated. Diabetics with rapidly worsening renal disease are often 'clinically' labelled as having diabetic nephropathy (DN), whereas, inmany cases, they are rather developing a nondiabetic renal disease (NDRD) or mixed forms (DN+ NDRD). Methods. We performed a systematic search for studies on patients with diabetes with data on the frequency of DN, NDRD and mixed forms, and assessed the positive predictive values (PPVs) and odds ratios (ORs) for such diagnoses by metaanalysing single-study prevalence. Possible factors explaining heterogeneity among the different diagnoses were explored by meta-regression. Results. In the 48 included studies (n = 4876), the prevalence of DN, NDRD and mixed forms ranged from 6.5 to 94%, 3 to 82.9% and 4 to 45.5% of the overall diagnoses, respectively. IgA nephropathy was the most common NDRD (3-59%). PPVs for DN, NDRD and mixed forms were 50.1% [95% confidence interval (CI): 44.7-55.2], 36.9% (95% CI: 32.3-41.8) and 19.7% (95% CI: 16.3-23.6), respectively. The PPV when combining NDRD and mixed forms was 49.2% (95% CI: 43.8-54.5). Metaregression identified systolic pressure, HbA1c, diabetes duration and retinopathy as factors explaining heterogeneity for NDRD, creatinine and glomerular filtration rate for mixed forms and only serum creatinine for DN. ORs of DN versus NDRD and mixed forms were 1.71 (95% CI: 1.54-1.91) and 4.1 (95% CI: 3.43-4.80), respectively. Conclusions. NDRD are highly prevalent in patients with diabetes. Clinical judgment alone can lead to wrong diagnoses and delay the establishment of adequate therapies. Risk stratification according to individual factors is needed for selecting patients whomight benefit from biopsy. [ABSTRACT FROM AUTHOR]

Background: Pentoxifylline (PTX) is a promising therapeutic approach for reducing inflammation and improving anemia associated to various systemic disorders. However, whether this agent may be helpful for anemia management also in CKD patients is still object of debate. Study Design: Systematic review and meta-analysis. Population: Adults with CKD (any KDOQI stage, including ESKD patients on regular dialysis) and anemia (Hb<13 g/dL in men or < 12 g/dL in women). Search Strategy and Sources: Cochrane CENTRAL, EMBASE, Ovid-MEDLINE and PubMed were searched for studies providing data on the effects of PTX on anemia parameters in CKD patients without design or follow-up restriction. Intervention: PTX derivatives at any dose regimen. Outcomes: Hemoglobin, hematocrit, ESAs dosage and resistance (ERI), iron indexes (ferritin, serum iron, TIBC, transferrin and serum hepcidin) and adverse events. Results: We retrieved 11 studies (377 patients) including seven randomized controlled trials (all comparing PTX to placebo or standard therapy) one retrospective case-control study and three prospective uncontrolled studies. Overall, PTX increased hemoglobin in three uncontrolled studies but such improvement was not confirmed in a meta-analysis of seven studies (299 patients) (MD 0.12 g/dL, 95% CI -0.22 to 0.47). Similarly, there were no conclusive effects of PTX on hematocrit, ESAs dose, ferritin and TSAT in pooled analyses. Data on serum iron, ERI, TIBC and hepcidin were based on single studies. No evidence of increased rate of adverse events was also noticed. Limitations: Small sample size and limited number of studies. High heterogeneity among studies with respect to CKD and anemia severity, duration of intervention and responsiveness/current therapy with iron or ESAs. Conclusions: There is currently no conclusive evidence supporting the utility of pentoxifylline for improving anemia control in CKD patients. Future trials designed on hard, patient-centered outcomes with larger sample size and longer follow-up are advocated. [ABSTRACT FROM AUTHOR]

Background: The effect of anemia correction on kidney function in chronic kidney disease (CKD) patients remains unclear. As 19-40% of patients with CKD receive an erythropoiesis-stimulating agent (ESA), this is a potentially important consideration. Summary: We conducted a systematic review and meta-analysis of randomized trials to January 1, 2014 in adult patients with CKD stages 1 to 4. Selection criteria for studies: randomized controlled trials of at least 2 months duration. Patients were allocated to ESA versus placebo, no treatment, or different ESA doses with the purpose of achieving a higher versus a lower hemoglobin target. The analyzed outcomes were the need for renal replacement therapy, doubling of serum creatinine, change in GFR (ml/min), mortality and withdrawal of treatment due to adverse events. A total of 19 trials (n = 8,129 participants with CKD stage 1-4) were reviewed. There was no difference in the risk of end-stage kidney disease (RR, 0.97 [CI 0.83-1.20], 17 trials, 8,104 participants), change in GFR (Mean Difference [MD] -0.45 [-2.21, 1.31], 9 trials, 1,848 participants) or withdrawal of treatment due to adverse events (RR, 1.18 [CI 0.77-1.81], 10 trials, n = 1,958 participants) for patients at higher hemoglobin (Hb) targets. Furthermore, no statistically significant differences in mortality (Risk Ratio [RR] 1.10 [CI 0.90-1.35], 16 trials, n = 8,082 participants) were observed. Key Messages: There is no evidence that ESA treatment affects renal function in patients with CKD. Use of these agents should not therefore be influenced by considerations about influencing CKD progression. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]