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Chronic kidney disease (CKD) is commonly associated with vitamin K deficiency. Some of the serious complications of CKD are represented by cardiovascular disease (CVD) and skeletal fragility with an increased risk of morbidity and mortality. A complex pathogenetic link between hormonal and ionic disturbances, bone tissue and metabolism alterations, and vascular calcification (VC) exists and has been defined as chronic kidney disease–mineral and bone disorder (CKD-MBD). Poor vitamin K status seems to have a key role in the progression of CKD, but also in the onset and advance of both bone and cardiovascular complications. Three forms of vitamin K are currently known: vitamin K1 (phylloquinone), vitamin K2 (menaquinone), and vitamin K3 (menadione). Vitamin K plays different roles, including in activating vitamin K-dependent proteins (VKDPs) and in modulating bone metabolism and contributing to the inhibition of VC. This review focuses on the biochemical and functional characteristics of vitamin K vitamers, suggesting this nutrient as a possible marker of kidney, CV, and bone damage in the CKD population and exploring its potential use for promoting health in this clinical setting. Treatment strategies for CKD-associated osteoporosis and CV disease should include vitamin K supplementation. However, further randomized clinical studies are needed to assess the safety and the adequate dosage to prevent these CKD complications. [ABSTRACT FROM AUTHOR]

Autosomal dominant polycystic kidney disease (ADPKD) is the most common congenital kidney disorder, generally caused by mutations in the PKD1 and PKD2 genes, coding for polycystins 1 and 2. Its pathogenesis is accompanied by alterations of the cAMP, mTOR, MAPK/ERK, and JAK/STAT pathways. ADPKD is clinically characterized by the formation of many growing cysts with kidney enlargement and a progressive damage to the parenchyma, up to its complete loss of function, and the onset of end‐stage renal disease (ESRD). The current aim of ADPKD therapy is the inhibition of cyst development and retardation of chronic kidney disease progression. Several drugs have been recently included as potential therapies for ADPKD including metformin, the drug of choice for the treatment of type 2 diabetes mellitus, according to its potential inhibitory effects on cystogenesis. In this review, we summarize preclinical and clinical evidence endorsing or rejecting metformin administration in ADPKD evolution and pathological mechanisms. We explored the biology of APDKD and the role of metformin in slowing down cystogenesis searching PubMed and Clinical Trials to identify relevant data from the database inception to December 2020. From our research analysis, evidence for metformin as emerging cure for ADPKD mainly arise from preclinical studies. In fact, clinical studies are still scanty and stronger evidence is awaited. Its effects are likely mediated by inhibition of the ERK pathway and increase of AMPK levels, which are both linked to ADPKD pathogenesis. [ABSTRACT FROM AUTHOR]

The mechanism of action of fibroblast growth factor‐23 (FGF23) is becoming increasingly clearer as a result of studies that have defined its structure and pleiotropic effects. Furthermore, data are emerging on the effects exerted on this hormone by iron administration. Ten main iron formulations are recognized (with clear differences in composition and possible reactions of intolerance and anaphylaxis), which are indicated for iron deficiency anemia, including nephropathic subjects, as suggested by medical guidelines. With some types of iron formulation (especially iron carboxymaltose) a particular side effect has been observed: hypophosphatemia, mediated by FGF23. This review aims to draw attention to this correlation and the contradiction represented by the presence of both positive and negative modulation by FGF23, with the effects induced by its increase even after long‐term treatment with iron formulation. However, more evidence is needed to understand the reasons for this differential stimulation. [ABSTRACT FROM AUTHOR]

Diabetes Mellitus (DM) is a chronic and severe metabolic disease, characterized by chronic hyperglycemia due to insulin resistance and/or reduced insulin secretion. Concerning the non-insulin glucose-lowering therapy for diabetes, Dipeptidyl-peptidase-4 (DPP-4) inhibitors, members of the incretin family, represent new agents, capable of a glycemic control improvement with an advantageous safety profile, given the absence of weight gain, the low incidence of hypoglycemia and the good renal tolerance in patients suffering from chronic renal failure. In addition to demonstrating efficacy in glycemic control through inhibition of GLP-1 degradation, DPP-4 inhibitors (DPP-4is) seem to demonstrate pleiotropic effects, which also make them interesting in both diabetic and non-diabetic nephropathies, especially for their capacity of reducing proteinuria. Several studies about diabetic nephropathy on patients' cohorts and murine models have demonstrated a solid direct relationship between DPP-4 activity and urinary albumin excretion (UAE), thus confirming the capacity of DPP-4is to reduce proteinuria; the mechanism responsible for that effect was studied to assess if it was the result of a direct action on renal impairment or a secondary consequence of the better glycemic control related to these agents. As a result of these more in-depth studies, DPP-4is have demonstrated an improvement of renal inflammation markers and consequent proteinuria reduction, regardless of glucose concentrations. Considering the nephroprotective effects of DPP-4is might be glycemic independent, several studies were conducted to prove the validity of the same effects in non-diabetic nephropathies. Among these studies, DPP-4is demonstrated an improvement of various renal inflammatory markers on several models of non-diabetes dependent renal impairment, confirming their capacity to reduce proteinuria, independently from the action on glucose metabolism. The objective of this review is to present and discuss the so far demonstrated antiproteinuric effect of DPP-4is and their effects on diabetic and non-diabetic nephropathies. [ABSTRACT FROM AUTHOR]

Introduction: The early suspension of Altitude trial in recent years has induced most nephrologists and cardiologists to abandon Aliskiren use. Consequently, the potential usefulness of the direct renin inhibition in IgA glomerulonephritis remained an under-investigated therapeutic option., Case Report: We report the case of a 53 years old IgA GMN patient unresponsive to all conventional anti-angiotensin-2 agents, steroids and immunosuppressants, in which the administration of Aliskiren permitted to achieve and maintain a complete proteinuria remission in the absence of any adverse event., Conclusion: Aliskiren might represent a valid and safe therapeutic option in IgA GMN, although further investigations would be needed to confirm this conclusion., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)