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European Journal of Medical Research Jul 2023Dotinurad is a newer urate-lowering agent that selectively inhibits urate transporter 1 in the renal proximal tubule and increases urinary urate excretion. Currently,...
Clinical effects of a selective urate reabsorption inhibitor dotinurad in patients with hyperuricemia and treated hypertension: a multicenter, prospective, exploratory study (DIANA).
INTRODUCTION
Dotinurad is a newer urate-lowering agent that selectively inhibits urate transporter 1 in the renal proximal tubule and increases urinary urate excretion. Currently, little is known about the clinical efficacies of dotinurad in patients with hyperuricemia and hypertension. The aim of this study was to assess the clinical effects of a selective urate reabsorption inhibitor dotinurad on serum uric acid (SUA) levels and relevant vascular markers in patients with hyperuricemia and treated hypertension.
METHODS
This investigator-initiated, multicenter, prospective, single-arm, open-label, exploratory clinical trial in Japan enrolled patients with hyperuricemia and treated hypertension who received a 24-week dotinurad therapy (a starting dose at 0.5 mg once daily and up-titrated to 2 mg once daily). The primary endpoint was a percentage change in the SUA level from baseline to week 24. The secondary endpoints were cardiovascular and metabolic measurements, including changes in the cardio-ankle vascular index (CAVI) and derivatives of reactive oxygen metabolites (d-ROMs) concentration at week 24.
RESULTS
Fifty patients (mean age 70.5 ± 11.0 years, with 76.0% being men, and mean SUA level 8.5 ± 1.2 mg/dL) were included in the analysis. The percentage change from baseline in the SUA level at week 24 was - 35.8% (95% confidence interval [CI] - 39.7% to - 32.0%, P < 0.001), with approximately three quarters of patients achieving an SUA level of ≤ 6.0 mg/dL at week 24. The proportional changes from baseline in the geometric mean of CAVI and d-ROMs at week 24 were 0.96 (95% CI 0.92 to 1.00, P = 0.044) and 0.96 (95% CI 0.92 to 1.00, P = 0.044), respectively.
CONCLUSION
In addition to meaningful SUA-lowering effects, 24 weeks of dotinurad therapy may favorably affect arterial stiffness and oxidative stress markers, suggesting off-target vascular protection of dotinurad. Further research is expected to verify our findings and elucidate the entire off-target effects of dotinurad. Trial registration jRCTs021210013, registration date June 24, 2021.
Topics: Male; Humans; Middle Aged; Aged; Aged, 80 and over; Female; Hyperuricemia; Uric Acid; Prospective Studies; Uricosuric Agents; Hypertension
PubMed: 37461063
DOI: 10.1186/s40001-023-01208-1 -
International Urology and Nephrology Oct 2023Lithium intoxication is still an undefined and underestimated disease, especially those cases requiring extracorporeal treatment. Lithium is a monovalent cation with... (Review)
Review
Lithium intoxication is still an undefined and underestimated disease, especially those cases requiring extracorporeal treatment. Lithium is a monovalent cation with small molecular mass of 7 Da that has been regularly and successfully used since 1950 in the treatment of mania and bipolar disorders. However, its careless assumption can lead to a wide spectrum of cardiovascular, central nervous system and kidney diseases in case of acute, acute on chronic and chronic intoxications. In fact, lithium serum range is strict between 0.6 and 1.3 mmol/L, with a mild lithium toxicity observed at the steady-state of 1.5-2.5 mEq/L, moderate toxicity when lithium reaches 2.5-3.5 mEq/L, and severe intoxication with observed serum levels > 3.5 mEq/L. Its favorable biochemical profile allows the complete filtration and partial reabsorption in the kidney due to the similarity to sodium and also the complete removal by renal replacement therapy, that should be considered in specific poisoning conditions. In this narrative and updated review we discussed a clinical case of lithium intoxication, the different pattern of diseases attributable to excessive lithium load and the current indications for extracorporeal treatment.
Topics: Humans; Lithium; Bipolar Disorder; Kidney Diseases; Renal Replacement Therapy; Heart
PubMed: 36940005
DOI: 10.1007/s11255-023-03558-5 -
Kidney International Oct 2023Proteinuria is a prominent feature of chronic kidney disease. Interventions that reduce proteinuria slow the progression of chronic kidney disease and the associated...
Proteinuria is a prominent feature of chronic kidney disease. Interventions that reduce proteinuria slow the progression of chronic kidney disease and the associated risk of cardiovascular disease. Here, we propose a mechanistic coupling between proteinuria and proprotein convertase subtilisin/kexin type 9 (PCSK9), a regulator of cholesterol and a therapeutic target in cardiovascular disease. PCSK9 undergoes glomerular filtration and is captured by megalin, the receptor responsible for driving protein reabsorption in the proximal tubule. Accordingly, megalin-deficient mice and patients carrying megalin pathogenic variants (Donnai Barrow syndrome) were characterized by elevated urinary PCSK9 excretion. Interestingly, PCSK9 knockout mice displayed increased kidney megalin while PCSK9 overexpression resulted in its reduction. Furthermore, PCSK9 promoted trafficking of megalin to lysosomes in cultured proximal tubule cells, suggesting that PCSK9 is a negative regulator of megalin. This effect can be accelerated under disease conditions since either genetic destruction of the glomerular filtration barrier in podocin knockout mice or minimal change disease (a common cause of nephrotic syndrome) in patients resulted in enhanced tubular PCSK9 uptake and urinary PCSK9 excretion. Pharmacological PCSK9 inhibition increased kidney megalin while reducing urinary albumin excretion in nephrotic mice. Thus, glomerular damage increases filtration of PCSK9 and concomitantly megalin degradation, resulting in escalated proteinuria.
Topics: Humans; Mice; Animals; Nephrotic Syndrome; Proprotein Convertase 9; Low Density Lipoprotein Receptor-Related Protein-2; Cardiovascular Diseases; Proteinuria; Kidney Tubules, Proximal; Renal Insufficiency, Chronic; Mice, Knockout; Subtilisins
PubMed: 37406929
DOI: 10.1016/j.kint.2023.06.024 -
Nutrients Feb 2024Bone represents a metabolically active tissue subject to continuous remodeling orchestrated by the dynamic interplay between osteoblasts and osteoclasts. These cellular... (Review)
Review
Bone represents a metabolically active tissue subject to continuous remodeling orchestrated by the dynamic interplay between osteoblasts and osteoclasts. These cellular processes are modulated by a complex interplay of biochemical and mechanical factors, which are instrumental in assessing bone remodeling. This comprehensive evaluation aids in detecting disorders arising from imbalances between bone formation and reabsorption. Osteoporosis, characterized by a reduction in bone mass and strength leading to heightened bone fragility and susceptibility to fractures, is one of the more prevalent chronic diseases. Some epidemiological studies, especially in patients with chronic kidney disease (CKD), have identified an association between osteoporosis and vascular calcification. Notably, low bone mineral density has been linked to an increased incidence of aortic calcification, with shared molecules, mechanisms, and pathways between the two processes. Certain molecules emerging from these shared pathways can serve as biomarkers for bone and mineral metabolism. Detecting and evaluating these alterations early is crucial, requiring the identification of biomarkers that are reliable for early intervention. While traditional biomarkers for bone remodeling and vascular calcification exist, they suffer from limitations such as low specificity, low sensitivity, and conflicting results across studies. In response, efforts are underway to explore new, more specific biomarkers that can detect alterations at earlier stages. The aim of this review is to comprehensively examine some of the emerging biomarkers in mineral metabolism and their correlation with bone mineral density, fracture risk, and vascular calcification as well as their potential use in clinical practice.
Topics: Humans; Chronic Kidney Disease-Mineral and Bone Disorder; Osteoporosis; Bone Density; Renal Insufficiency, Chronic; Fractures, Bone; Vascular Calcification; Biomarkers; Minerals
PubMed: 38474734
DOI: 10.3390/nu16050605 -
Current Opinion in Nephrology and... Sep 2023Women experience unique life events, for example, pregnancy and lactation, that challenge renal regulation of electrolyte homeostasis. Recent analyses of nephron... (Review)
Review
PURPOSE OF REVIEW
Women experience unique life events, for example, pregnancy and lactation, that challenge renal regulation of electrolyte homeostasis. Recent analyses of nephron organization in female vs. male rodent kidneys, revealed distinct sexual dimorphisms in electrolyte transporter expression, abundance, and activity. This review aims to provide an overview of electrolyte transporters' organization and operation in female compared with the commonly studied male kidney, and the (patho)physiologic consequences of the differences.
RECENT FINDINGS
When electrolyte transporters are assessed in kidney protein homogenates from both sexes, relative transporter abundance ratios in females/males are less than one along proximal tubule and greater than one post macula densa, which is indicative of a 'downstream shift' in fractional reabsorption of electrolytes in females. This arrangement improves the excretion of a sodium load, challenges potassium homeostasis, and is consistent with the lower blood pressure and greater pressure natriuresis observed in premenopausal women.
SUMMARY
We summarize recently reported new knowledge about sex differences in renal transporters: abundance and expression along nephron, implications for regulation by Na + , K + and angiotensin II, and mathematical models of female nephron function.
Topics: Female; Male; Humans; Sex Characteristics; Kidney; Nephrons; Membrane Transport Proteins; Sodium; Electrolytes
PubMed: 37382185
DOI: 10.1097/MNH.0000000000000909 -
Nature Reviews. Nephrology Sep 2023Aquaporin (AQP) water channels are pivotal to renal water handling and therefore in the regulation of body water homeostasis. However, beyond the kidney, AQPs facilitate... (Review)
Review
Aquaporin (AQP) water channels are pivotal to renal water handling and therefore in the regulation of body water homeostasis. However, beyond the kidney, AQPs facilitate water reabsorption and secretion in other cells and tissues, including sweat and salivary glands and the gastrointestinal tract. A growing body of evidence has also revealed that AQPs not only facilitate the transport of water but also the transport of several small molecules and gases such as glycerol, HO, ions and CO. Moreover, AQPs are increasingly understood to contribute to various cellular processes, including cellular migration, adhesion and polarity, and to act upstream of several intracellular and intercellular signalling pathways to regulate processes such as cell proliferation, apoptosis and cell invasiveness. Of note, several AQPs are highly expressed in multiple cancers, where their expression can correlate with the spread of cancerous cells to lymph nodes and alter the response of cancers to conventional chemotherapeutics. These data suggest that AQPs have diverse roles in various homeostatic and physiological systems and may be exploited for prognostics and therapeutic interventions.
Topics: Humans; Water; Hydrogen Peroxide; Aquaporins; Body Water; Homeostasis
PubMed: 37460759
DOI: 10.1038/s41581-023-00734-9 -
Cardiology in Review Apr 2024Dapagliflozin (trade name FARXIGA) is a sodium-glucose cotransporter-2 (SGLT-2) inhibitor that has transcended its initial antidiabetic application to demonstrate...
Dapagliflozin (trade name FARXIGA) is a sodium-glucose cotransporter-2 (SGLT-2) inhibitor that has transcended its initial antidiabetic application to demonstrate benefits in cardiac and renal diseases. It was first approved by the food and department administration for type 2 diabetes in 2014. Since then, it has gained food and department administration approval for chronic kidney disease in 2021, heart failure with reduced ejection fraction in 2020, and heart failure with preserved ejection fraction in 2023. Thus, dapagliflozin plays a pivotal role in improving patient outcomes. By competitive binding to renal SGLT-2 cotransporters, dapagliflozin effectively prevents glucose and sodium reabsorption, leading to glucosuria. Its pharmacokinetic profile involves minimal cytochrome P450-induced metabolism, rapid absorption with an 18-hour duration of action, and stable effects. Clinical trials have revealed dapagliflozin's efficacy in glycemic control without the risk of hypoglycemia, making it an advantageous choice for patients insufficiently managed on other antidiabetic drugs. Comparative analysis with other SGLT-2 inhibitors suggests dapagliflozin's potential superiority in preventing heart failure. Compared to empagliflozin, it has more extended effects, contributing to stable sodium diuresis, reduced blood pressure fluctuations, and potentially lower cardiovascular disease risks. However, it leads to less urinary glucose excretion compared with canagliflozin. Dapagliflozin has specific contraindications, such as type 1 diabetes and end-stage chronic kidney disease. Adverse effects include an increased risk of genital infections, urinary tract infections, and Fournier's gangrene. A nuanced understanding of dapagliflozin's benefits and limitations is imperative for informed clinical decision-making in the management of diabetes and its complications.
PubMed: 38666776
DOI: 10.1097/CRD.0000000000000694 -
Journal of Magnetic Resonance Imaging :... Nov 2023Diffusion measurements in the kidney are affected not only by renal microstructure but also by physiological processes (i.e., glomerular filtration, water reabsorption,... (Review)
Review
Diffusion measurements in the kidney are affected not only by renal microstructure but also by physiological processes (i.e., glomerular filtration, water reabsorption, and urine formation). Because of the superposition of passive tissue diffusion, blood perfusion, and tubular pre-urine flow, the limitations of the monoexponential apparent diffusion coefficient (ADC) model in assessing pathophysiological changes in renal tissue are becoming apparent and motivate the development of more advanced diffusion-weighted imaging (DWI) variants. These approaches take advantage of the fact that the length scale probed in DWI measurements can be adjusted by experimental parameters, including diffusion-weighting, diffusion gradient directions and diffusion time. This forms the basis by which advanced DWI models can be used to capture not only passive diffusion effects, but also microcirculation, compartmentalization, tissue anisotropy. In this review, we provide a comprehensive overview of the recent advancements in the field of renal DWI. Following a short introduction on renal structure and physiology, we present the key methodological approaches for the acquisition and analysis of renal DWI data, including intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), non-Gaussian diffusion, and hybrid IVIM-DTI. We then briefly summarize the applications of these methods in chronic kidney disease and renal allograft dysfunction. Finally, we discuss the challenges and potential avenues for further development of renal DWI. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.
PubMed: 37991093
DOI: 10.1002/jmri.29127