[Can salt substitution or reduction replace pharmaceuticals for arterial hypertension?] / Kann eine Salzsubstitution oder -reduktion bei arterieller Hypertonie Arzneimittel ersetzen?

Nonpharmacological treatment is still an important supplement to the pharmacological treatment of hypertension. Thereby, either an elevated blood pressure can be lowered further or, alternatively, the use of antihypertensive drugs can be reduced. In the context of nonpharmacological treatment of hypertension, sodium restriction plays an important role. Sodium intake can either be reduced by lowering excessive dietary salt consumption or by the use of table salts with reduced sodium content. Lower dietary sodium consumption lowers blood pressure. This was controversial for a long time; however, now more and more observational and interventional studies have confirmed this fact. Nevertheless, some studies have shown an association of low salt consumption with increased mortality. This observation is explained by the so-called reverse epidemiology. This means that diseases with increased mortality, such as consuming diseases or severe heart diseases are associated with lowered food intake and as a consequence, with lower sodium intake. In addition to sodium restriction, the use of so-called salt substitutes with lower sodium content is also effective in lowering blood pressure. In most of the salt substitutes examined so far sodium chloride is partly replaced by potassium chloride. Numerous investigations show that these salt substitutes lower blood pressure. From a statistical point of view side effects such as hyperkalemia are very rare; however, hyperkalemia is potentially life-threatening. Therefore, the broader use of these salt substitutes is principally helpful but these salts should only be used after medical consultation. Especially renal insufficiency and the use of certain drugs, such as potassium-sparing diuretics and blockers of the renin-angiotensin system increase the risk of hyperkalemia.

Reduction of protein-bound uraemic toxins in plasma of chronic renal failure patients: A systematic review.

BACKGROUND: Protein-bound uraemic toxins (PBUTs) accumulate in patients with chronic kidney disease and impose detrimental effects on the vascular system. However, a unanimous consensus on the most optimum approach for the reduction of plasma PBUTs is still lacking. METHODS: In this systematic review, we aimed to identify the most efficient clinically available plasma PBUT reduction method reported in the literature between 1980 and 2020. The literature was screened for clinical studies describing approaches to reduce the plasma concentration of known uraemic toxins. There were no limits on the number of patients studied or on the duration or design of the studies. RESULTS: Out of 1274 identified publications, 101 studies describing therapeutic options aiming at the reduction of PBUTs in CKD patients were included in this review. We stratified the studies by the PBUTs and the duration of the analysis into acute (data from a single procedure) and longitudinal (several treatment interventions) trials. Reduction ratio (RR) was used as the measure of plasma PBUTs lowering efficiency. For indoxyl sulphate and p-cresyl sulphate, the highest RR in the acute studies was demonstrated for fractionated plasma separation, adsorption and dialysis system. In the longitudinal trials, supplementation of haemodialysis patients with AST-120 (Kremezin®) adsorbent showed the highest RR. However, no superior method for the reduction of all types of PBUTs was identified based on the published studies. CONCLUSIONS: Our study shows that there is presently no technique universally suitable for optimum reduction of all PBUTs. There is a clear need for further research in this field.

Regulation of endothelial nitric oxide synthase activation in endothelial cells by S1P1 and S1P3.

Endothelial nitric oxide synthase (eNOS) plays a crucial role in vascular homeostasis. Lysophospholipid interaction with sphingosine 1-phosphat (S1P) receptors results in eNOS activation in different cells. In endothelial cells, eNOS activation via S1P1 or S1P3 was shown controversially. The aim of this study is to investigate the meaning of both S1P receptors for eNOS activation in human endothelial cells. Therefore, several S1P1 and S1P3 agonists in combination with antagonists and specific RNAi approach were used. eNOS activation was measured in human umbilical vein endothelial cells (HUVEC) via DAF2-DA-based fluorescence microscopy. For investigation of the signaling pathway, agonists/antagonist studies, RNAi approach, Luminex™ multiplex, and Western Blot were used. In HUVEC, both the S1P1 agonist AUY954 as well as the S1P1,3 agonist FTY720P induced eNOS activation in a time- and dose-dependent manner. Other S1P1 agonists activated eNOS to a lesser extent. The AUY954-induced eNOS activation was blocked by the S1P1 antagonist W146, the combination of W146 and the S1P3 antagonist CAY10444 and the S1P1,3 antagonist VPC23019, but not by CAY10444 indicating the meaning of S1P1 for the AUY954-induced eNOS activation. The FTY720P-induced eNOS activation was blocked only by the combination of W146 and CAY10444 and the combined S1P1,3 antagonist VPC23019, but not by W146 or CAY10444 indicating the importance of both S1P1 and S1P3 for FTY720-induced eNOS activation. These results were confirmed using specific siRNA against S1P1 and S1P3. The S1P1,3 activation results in Akt phosphorylation and subsequent activation of eNOS via phosphorylation at serine(1177) and dephosphorylation at threonine(495). Beside former investigations with rather unspecific S1P receptor activation these data show potent selective S1P1 activation by using AUY954 and with selective S1P receptor inhibition evidence was provided that both S1P1 and S1P3 lead to downstream activation of eNOS in HUVEC in the same experimental setting. Inhibition or knockdown of one of these receptor subtypes did not abolish the eNOS activation and subsequent NO production.

Central blood pressure assessment using oscillometry is feasible for everyday clinical practice.

The benefit of the central systolic blood pressure (cSBP) has already been recognized, but its general measurement in the everyday routine is still limited mainly because available established non-invasive assessment devices are not suitable for everyday use. In this study, we investigated the performance of an oscillometric device Tel-O-GRAPH for cSBP assessment in terms of suitability for everyday clinical use. One hundred and three patients were prospectively included. cSBP was computed by Tel-O-GRAPH compared with Sphygmocor using applanation tonometry. There was a good agreement between Tel-O-GRAPH and Sphygmocor for cSBP (mean difference±s.d.: -0.3±6.7 mm Hg; Pearson's R=0.95; P<0.0001). Recorded cSBP values in the supine vs seated position and for the experienced vs non-experienced user did not significantly differ (mean cSBPsupine 122.1±13.9 mm Hg vs cSBPseated 120.7±15.7 mmHg; cSBPnon-experienced 120.6±20.5 mm Hg and cSBPexperienced 119.2±19.9 mm Hg). The mean difference of cSBP between supine and seated positions was 1.5±6.8 and -1.4±5.0 mm Hg between experienced and non-experienced users. This study showed good accuracy in assessing cSBP with an oscillometric BP measurement device Tel-O-GRAPH compared with a Sphygmocor. Furthermore, the calculation of cSBP by Tel-O-GRAPH appears to be easy and can be done during the routine brachial BP measurement. Computed cSBP values seem to remain reliable independently of the patient body position and experience of the operator. Consequently, the easiness of utilization and reliability of the device may open the opportunity for its extended use in everyday clinical practice, as well as reliable alternative for clinical studies, making complex applanation tonometry dispensable.