Empagliflozin Changes Urine Supersaturation by Decreasing pH and Increasing Citrate.

Clinical Trial registry name and registration number: Empagliflozin and Renal Oxygenation in Healthy Volunteers (EMPA-REIN), NCT03093103.

Twenty-Four Hour Blood Pressure Response to Empagliflozin and Its Determinants in Normotensive Non-diabetic Subjects.

Background: Sodium-glucose co-transport 2 inhibitors (SGLT2i) lower blood pressure (BP) in normotensive subjects and in hypertensive and normotensive diabetic and non-diabetic patients. However, the mechanisms of these BP changes are not fully understood. Therefore, we examined the clinical and biochemical determinants of the BP response to empagliflozin based on 24-h ambulatory BP monitoring. Methods: In this post-hoc analysis of a double-blind, randomized, placebo-controlled study examining the renal effects of empagliflozin 10 mg vs. placebo in untreated normotensive non-diabetic subjects, the 1-month changes in 24 h ambulatory BP were analyzed in 39 subjects (13 placebo/26 empagliflozin) in regard to changes in biochemical and hormonal parameters. Results: At 1 month, empagliflozin 10 mg decreased 24-h systolic (SBP) and diastolic (DBP) BP significantly by -5 ± 7 mmHg (p < 0.001) and -2 ± 6 mmHg (p = 0.03). The effect on SBP and DBP was more pronounced during nighttime (resp. -6 ± 11 mmHg, p = 0.004; -4 ± 7 mmHg, p = 0.007). The main determinants of daytime and nighttime SBP and DBP responses were baseline BP levels (for daytime SBP: coefficient -0.5; adj. R2: 0.36; p = 0.0007; for night-time SBP: coefficient -0.6; adj. R2: 0.33; p = 0.001). Although empaglifozin induced significant biochemical changes, none correlated with blood pressure changes including urinary sodium, lithium, glucose and urate excretion and free water clearance. Plasma renin activity and plasma aldosterone levels increased significantly at 1 month suggesting plasma volume contraction, while plasma metanephrine and copeptin levels remained the same. Renal resistive indexes did not change with empagliflozin. Conclusion: SGLT2 inhibition lowers daytime and nighttime ambulatory systolic and diastolic BP in normotensive non-diabetic subjects. Twenty-four jour changes are pronounced and comparable to those described in diabetic or hypertensive subjects. Baseline ambulatory BP was the only identified determinant of systolic and diastolic BP response. This suggests that still other factors than sustained glycosuria or proximal sodium excretion may contribute to the resetting to lower blood pressure levels with SGLT2 inhibition. Clinical Trial Registration: [https://www.clinicaltrials.gov], identifier [NCT03093103].

Smartphone based blood pressure measurement: accuracy of the OptiBP mobile application according to the AAMI/ESH/ISO universal validation protocol.

OBJECTIVE: The aim of this study was to assess the accuracy of the OptiBP mobile application based on an optical signal recorded by placing the patient's fingertip on a smartphone's camera to estimate blood pressure (BP). Measurements were carried out in a general population according to existing standards of the Association for the Advancement of Medical Instrumentation (AAMI), the European Society of Hypertension (ESH) and the International Organization for Standardization (ISO). METHODS: Participants were recruited during a scheduled appointment at the hypertension clinic of Lausanne University Hospital in Switzerland. Age, gender and BP distribution were collected to fulfill AAMI/ESH/ISO universal standards. Both auscultatory BP references and OptiBP were measured and compared using the opposite arm simultaneous method as described in the 81060-2:2018 ISO norm. RESULTS: A total of 353 paired recordings from 91 subjects were analyzed. For validation criterion 1, the mean ± SD between OptiBP and reference BP recordings was respectively 0.5 ± 7.7 mmHg and 0.4 ± 4.6 mmHg for SBP and DBP. For validation criterion 2, the SD of the averaged BP differences between OptiBP and reference BP per subject was 6.3 mmHg and 3.5 mmHg for SBP and DBP. OptiBP acceptance rate was 85%. CONCLUSION: The smartphone embedded OptiBP cuffless mobile application fulfills the validation requirements of AAMI/ESH/ISO universal standards in a general population for the measurement of SBP and DBP.

Acute and Chronic Effects of SGLT2 Inhibitor Empagliflozin on Renal Oxygenation and Blood Pressure Control in Nondiabetic Normotensive Subjects: A Randomized, Placebo-Controlled Trial.

Background The sodium/glucose cotransporter 2 inhibitor empagliflozin has cardiorenal protective properties through mechanisms beyond glucose control. In this study we assessed whether empagliflozin modifies renal oxygenation as a possible mechanism of renal protection, and determined the metabolic, renal, and hemodynamic effects of empagliflozin in nondiabetic subjects. Methods and Results In this double-blind, randomized, placebo-controlled study, 45 healthy volunteers underwent blood and urine sampling, renal ultrasound, and blood-oxygenation-level-dependent magnetic resonance imaging before and 180 minutes after administration of 10 mg empagliflozin (n=30) or placebo (n=15). These examinations were repeated after 1 month of daily intake. Cortical and medullary renal oxygenation were not affected by the acute or chronic administration of empagliflozin, as determined by 148 renal blood-oxygenation-level-dependent magnetic resonance imaging examinations. Empagliflozin increased glucosuria (24-hour glucosuria at 1 month: +50.1±16.3 g). The acute decrease in proximal sodium reabsorption, as determined by endogenous fractional excretion of lithium (-34.6% versus placebo), was compensated at 1 month by a rise in plasma renin activity (+28.6%) and aldosterone (+55.7%). The 24-hour systolic and diastolic ambulatory blood pressures decreased significantly after 1 month of empagliflozin administration (-5.1 and -2.0 mm Hg, respectively). Serum uric acid levels decreased (-28.4%), hemoglobin increased (+1.7%), and erythropoietin remained the same. Conclusions Empagliflozin has a rapid and significant effect on tubular function, with sustained glucosuria and transient natriuresis in nondiabetic normotensive subjects. These effects favor blood pressure reduction. No acute or sustained changes were found in renal cortical or medullary tissue oxygenation. It remains to be determined whether this is the case in nondiabetic or diabetic patients with congestive heart failure or kidney disease. REGISTRATION: URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT03093103.

[Gut microbiota and kidney diseases : dangerous liaisons?] / Microbiote et maladies rénales : liaison dangereuse ?

Recent studies have found a relationship between the kidney and the intestinal microbiome, called the colo-renal axis. Mounting evidence suggests that patients suffering from chronic kidney disease (CKD) have an altered composition of gut microbiota. This leads to 1) the increased fermentation of intestinal proteins to uremic toxins such as p-cresyl sulphate and indoxyl sulphate, 2) an altered, more 'leaky' intestinal barrier, and 3) translocation of bacteria and toxins from the gut lumen to the circulation, inducing systemic inflammation. This may contribute to the increased morbidity and mortality in this population. Future studies are needed to confirm this hypothesis, and to assess whether manipulating the intestinal microbiota with pre-, pro-, or symbiotics may alter the development and course of CKD.

Des études récentes démontrent l'existence d'une relation entre le rein et le microbiote intestinal, parfois appelée « axe intestin-rein ¼. Les patients souffrant de maladie rénale chronique (MRC) ont une composition altérée du microbiote intestinal. Ces modifications conduisent à : 1) une augmentation de la fermentation de protéines intestinales en toxines urémiques comme par exemple le p-crésyl sulfate et l'indoxyl sulfate ; 2) une augmentation de la perméabilité de la barrière intestinale et 3) une translocation de bactéries et de toxines de la lumière intestinale vers la circulation sanguine, responsables d'une inflammation systémique. Ces mécanismes pourraient contribuer à l'augmentation de la morbi-mortalité dans cette population. Des études ultérieures sont nécessaires pour confirmer cette hypothèse, mais également pour évaluer si des modifications dans la composition du microbiote par des agents pré, pro ou symbiotiques pourraient avoir un effet bénéfique sur l'évolution de la MRC.