Abnormal increase in urinary aquaporin-2 excretion in response to hypertonic saline in essential hypertension

<p>Abstract</p> <p>Background</p> <p>Dysregulation of the expression/shuttling of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in renal collecting duct principal cells has been found in animal models of hypertension. We tested whether a similar dysregulation exists in essential hypertension.</p> <p>Methods</p> <p>We measured urinary excretion of AQP2 and ENaC β-subunit corrected for creatinine (u-AQP2_CR, u-ENaC_β-CR), prostaglandin E2 (u-PGE₂) and cyclic AMP (u-cAMP), fractional sodium excretion (FE_Na), free water clearance (C_H2O), as well as plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), and atrial and brain natriuretic peptide (ANP, BNP) in 21 patients with essential hypertension and 20 normotensive controls during 24-h urine collection (baseline), and after hypertonic saline infusion on a 4-day high sodium (HS) diet (300 mmol sodium/day) and a 4-day low sodium (LS) diet (30 mmol sodium/day).</p> <p>Results</p> <p>At baseline, no differences in u-AQP2_CRor u-ENaC_β-CRwere measured between patients and controls. U-AQP2_CRincreased significantly more after saline in patients than controls, whereas u-ENaC_β-CRincreased similarly. The saline caused exaggerated natriuretic increases in patients during HS intake. Neither baseline levels of u-PGE₂, u-cAMP, AVP, PRC, Ang II, Aldo, ANP, and BNP nor changes after saline could explain the abnormal u-AQP2_CRresponse.</p> <p>Conclusions</p> <p>No differences were found in u-AQP2_CRand u-ENaC_β-CRbetween patients and controls at baseline. However, in response to saline, u-AQP2_CRwas abnormally increased in patients, whereas the u-ENaC_β-CRresponse was normal. The mechanism behind the abnormal AQP2 regulation is not clarified, but it does not seem to be AVP-dependent.</p> <p>Clinicaltrial.gov identifier</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=00345124">NCT00345124</a>.</p

Does conservative kidney management offer a quantity or quality of life benefit compared to dialysis? A systematic review

Abstract Background Patients with stage 5 chronic kidney disease (CKD5) collaborate with their clinicians when choosing their future treatment modality. Most elderly patients with CKD5 may only have two treatment options: dialysis or conservative kidney management (CKM). The objective of this systematic review was to investigate whether CKM offers a quantity or quality of life benefit compared to dialysis for some patients with CKD5. Methods The databases MEDLINE, EMBASE, the Cochrane Library, and CINAHL were systematically searched for studies comparing patients with CKD5 who had chosen or were treated with either CKM or dialysis. The primary outcomes were mortality and quality of life (QoL). Hospitalization, symptom burden, and place of death were secondary outcomes. For studies reporting hazard ratios, pooled values were calculated, and forest plots conducted. Results Twenty-five primary studies, all observational, were identified. All studies reported an increased mortality in patients treated with CKM (pooled hazard ratio 0.47, 95 % confidence interval 0.34–0.65). For patients aged ≥ 80 years and for elderly individuals with comorbidities, results were ambiguous. In most studies, CKM seemed advantageous for QoL and secondary outcomes. Findings were limited by the heterogeneity of studies and biased outcomes favouring dialysis. Conclusions In general, patients with CKD5 who have chosen or are on CKM live for a shorter time than patients who have chosen or are on dialysis. In patients aged ≥ 80 years old, and in elderly individuals with comorbidities, the survival benefits of dialysis seem to be lost. Regarding QoL, symptom burden, hospitalization, and place of death, CKM may have advantages. Higher quality studies are needed to guide patients and clinicians in the decision-making process

No difference between alfacalcidol and paricalcitol in the treatment of secondary hyperparathyroidism in hemodialysis patients: a randomized crossover trial

Alfacalcidol and paricalcitol are vitamin D analogs used for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease, but have known dose-dependent side effects that cause hypercalcemia and hyperphosphatemia. In this investigator-initiated multicenter randomized clinical trial, we originally intended two crossover study periods with a washout interval in 86 chronic hemodialysis patients. These patients received increasing intravenous doses of either alfacalcidol or paricalcitol for 16 weeks, until parathyroid hormone was adequately suppressed or calcium or phosphate levels reached an upper threshold. Unfortunately, due to a period effect, only the initial 16-week intervention period for 80 patients was statistically analyzed. The proportion of patients achieving a 30% decrease in parathyroid hormone levels over the last four weeks of study was statistically indistinguishable between the two groups. Paricalcitol was more efficient at correcting low than high baseline parathyroid hormone levels, whereas alfacalcidol was equally effective at all levels. There were no differences in the incidence of hypercalcemia and hyperphosphatemia. Thus, alfacalcidol and paricalcitol were equally effective in the suppression of secondary hyperparathyroidism in hemodialysis patients while calcium and phosphorus were kept in the desired range

Dual endothelin antagonist aprocitentan for resistant hypertension (PRECISION): a multicentre, blinded, randomised, parallel-group, phase 3 trial

Auteurs : the PRECISION investigatorsInternational audienceBackground Resistant hypertension is associated with increased cardiovascular risk. The endothelin pathway has been implicated in the pathogenesis of hypertension, but it is currently not targeted therapeutically, thereby leaving this relevant pathophysiological pathway unopposed with currently available drugs. The aim of the study was to assess the blood pressure lowering efficacy of the dual endothelin antagonist aprocitentan in patients with resistant hypertension. Methods PRECISION was a multicentre, blinded, randomised, parallel-group, phase 3 study, which was done in hospitals or research centres in Europe, North America, Asia, and Australia. Patients were eligible for randomisation if their sitting systolic blood pressure was 140 mm Hg or higher despite taking standardised background therapy consisting of three antihypertensive drugs, including a diuretic. The study consisted of three sequential parts: part 1 was the 4-week double-blind, randomised, and placebo-controlled part, in which patients received aprocitentan 12•5 mg, aprocitentan 25 mg, or placebo in a 1:1:1 ratio; part 2 was a 32-week single (patient)-blind part, in which all patients received aprocitentan 25 mg; and part 3 was a 12-week double-blind, randomised, and placebo-controlled withdrawal part, in which patients were re-randomised to aprocitentan 25 mg or placebo in a 1:1 ratio. The primary and key secondary endpoints were changes in unattended office systolic blood pressure from baseline to week 4 and from withdrawal baseline to week 40, respectively. Secondary endpoints included 24-h ambulatory blood pressure changes. The study is registered on ClinicalTrials.gov, NCT03541174. Findings The PRECISION study was done from June 18, 2018, to April 25, 2022. 1965 individuals were screened and 730 were randomly assigned. Of these 730 patients, 704 (96%) completed part 1 of the study; of these, 613 (87%) completed part 2 and, of these, 577 (94%) completed part 3 of the study. The least square mean (SE) change in office systolic blood pressure at 4 weeks was-15•3 (SE 0•9) mm Hg for aprocitentan 12•5 mg,-15•2 (0•9) mm Hg for aprocitentan 25 mg, and-11•5 (0•9) mm Hg for placebo, for a difference versus placebo of-3•8 (1•3) mm Hg (97•5% CI-6•8 to-0•8, p=0•0042) and-3•7 (1•3) mm Hg (-6•7 to-0•8; p=0•0046), respectively. The respective difference for 24 h ambulatory systolic blood pressure was-4•2 mm Hg (95% CI-6•2 to-2•1) and-5•9 mm Hg (-7•9 to-3•8). After 4 weeks of withdrawal, office systolic blood pressure significantly increased with placebo versus aprocitentan (5•8 mm Hg, 95% CI 3•7 to 7•9, p<0•0001). The most frequent adverse event was mild-to-moderate oedema or fluid retention, occurring in 9%, 18%, and 2% for patients receiving aprocitentan 12•5 mg, 25 mg, and placebo, during the 4-week double-blind part, respectively. This event led to discontinuation in seven patients treated with aprocitentan. During the trial, a total of 11 treatment-emergent deaths occurred, none of which were regarded by the investigators to be related to study treatment. Interpretation In patients with resistant hypertension, aprocitentan was well tolerated and superior to placebo in lowering blood pressure at week 4 with a sustained effect at week 40