FGF23 induces left ventricular hypertrophy

Fibroblast growth factor 23 as a risk factor for incident diabetes

PURPOSE OF REVIEW

Diabetes is a major global health concern, affecting millions and increasing morbidity and mortality. Recent research highlights fibroblast growth factor 23 (FGF23) as a potential contributor to type 2 diabetes and its cardiovascular complications. This review explores the role of FGF23 in metabolic and cardiovascular dysfunction and discusses possible therapeutic interventions.

RECENT FINDINGS

Deregulated FGF23 is linked to insulin resistance, pancreatic β-cell dysfunction, and systemic inflammation. Studies suggest FGF23 influences glucose metabolism via insulin signaling, oxidative stress, and inflammation. Epidemiological data indicate that elevated FGF23 levels are associated with an increased risk of type 2 diabetes and posttransplant diabetes, independent of traditional risk factors. Higher FGF23 levels have also been linked with an increased cardiovascular risk in patients with diabetes, even without chronic kidney disease.

SUMMARY

FGF23 is emerging as a key factor in the cardiovascular-kidney-metabolic syndrome, connecting diabetes and cardiovascular disease. While studies suggest consistent associations, causal mechanisms remain unclear. No therapies specifically target FGF23 to lower diabetes risk, but fibroblast growth factor receptor 4 (FGFR4) inhibitors show promise. Future research should examine the role of FGF23 in individuals with normal kidney function and explore whether modifying its levels could reduce diabetes and cardiovascular risk.

Postoperative outcome and clinical management of tumor-induced osteomalacia: a single-center retrospective cohort study on 117 patients

We reported a single-center retrospective cohort study on 117 patients of Tumor-induced osteomalacia (TIO) to summarize our experience with TIO over the past decade. The clinical characteristics, diagnosis, treatment and postoperative outcomes were analyzed. Together, our data demonstrate the characteristics and prognosis of TIO and unveil a possible TIO management process.

INTRODUCTION

TIO is a rare paraneoplastic syndrome that ultimately results in debilitating musculoskeletal deficits and regressive activity obstacles due to hypophosphatemia. The diagnosis and treatment of TIO are challenging owing to nonspecific symptoms, occult tumors and the lack of awareness. We aimed to summarize our experience with TIO over the past decade and to optimize its clinical management.

METHODS

A retrospective analysis was conducted of all patients with TIO admitted to our department and underwent surgical treatment at our hospital between 2012 and 2023. Clinical characteristics and postoperative outcomes were evaluated.

RESULTS

A total of 117 patients with typical clinical characteristics were enrolled, manifesting diffuse bone pain, decreased serum phosphate and elevated serum intact fibroblast growth factor-23 (iFGF23). All the patients were managed using a stepwise pathway detailing diagnosis, identification of the causative tumors, operations and postoperative surveillance. The causative tumors were equally located in bone and soft tissues, and the main sites were the lower extremities and pelvis (63.2%). 117 cases were caused by phosphaturic mesenchymal tumors (PMTs), which were usually small and benign, with a median volume of 1.45cm3 (IQR 0.70-4.17 cm3) and low Ki67 labeling indices (< 10%, 91.7%). After surgery, the serum P became normal within 7 days in 82.7% of the cured patients; serum iFGF23 decreased rapidly in one day and then gradually increased to normal with other laboratory indices and bone mineral density. The median follow-up period was 12 months (range, 1-144), during which 19 patients remained uncured. Among them, 5 patients experienced local recurrence and 2 suffered distant metastases. Younger age, bone-derived tumors and malignant tumors were risk factors for adverse outcomes. Tumors located in the femoral head, acetabulum, and spine showed a higher risk of obstinacy among bone-derived tumors.

CONCLUSION

TIO patients were able to benefit from the management including early recognition and diagnosis of the disease, identification and complete removal of the causative tumors, followed by regular postoperative surveillance. Of particular concern were patients with bone-derived tumors, who had high non-remission and recurrence rates.

CLINICAL TRIAL REGISTRATION

This study was registered with CHICTR.ORG.CN (ChiCTR2100042796).

Evaluation of fibroblast growth factor 23 as a marker of severity in stable chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), a multi-component disease, is one of the leading causes of morbidity and mortality globally. Considering the drawbacks of current severity markers of COPD, there is a need to find newer alternatives that are easily accessible and provide insight into the underlying pathophysiology of the disease. This study evaluated fibroblast growth factor 23 (FGF23), a pro-inflammatory hormone, as a severity marker for COPD. A total of 54 stable COPD patients were recruited as per the inclusion and exclusion criteria. All participants were subjected to spirometry and body plethysmography with diffusion capacity of lungs for carbon monoxide (DLCO) evaluation. Plasma FGF23 levels were measured for all participants. This study aimed to evaluate FGF23 as a severity indicator of COPD, along with its association with serum phosphate levels, static lung volumes, and DLCO. The mean age of the study population (n=54) was 59±11 years. The majority of study participants had moderate COPD (50%), followed by severe (27.8%), mild (20.4%), and very severe (1.9%). The mean plasma FGF23 value observed was 115±169 pg/mL. A significant negative correlation was observed between FGF23 levels and forced expiratory volume in 1 second (FEV1) (% predicted), demonstrating the diagnostic role of FGF23. The phosphaturic action of FGF23 was validated by a strong negative correlation observed between serum phosphate and plasma FGF23 levels. Receiver-operating characteristic curve analysis of FGF23 showed that cut-off levels of 73.71 pg/mL can be used to distinguish mild to moderate COPD from severe to very severe, with a sensitivity and specificity of 62.5% and 68.4%, respectively. FGF23 levels were found to be significantly increased in individuals with poor lung function and compromised lung volumes. FGF23 levels were negatively correlated with FEV1 (% predicted) and can be used as a potential severity marker. Hence, plasma FGF23 levels showed a promising role as a severity marker of COPD.

Cardiorenal syndrome: clinical diagnosis, molecular mechanisms and therapeutic strategies

As the heart and kidneys are closely connected by the circulatory system, primary dysfunction of either organ usually leads to secondary dysfunction or damage to the other organ. These interactions play a major role in the pathogenesis of a clinical entity named cardiorenal syndrome (CRS). The pathophysiology of CRS is complicated and involves multiple body systems. In early studies, CRS was classified into five subtypes according to the organs associated with the vicious cycle and the acuteness and chronicity of CRS. Increasing evidence shows that CRS is associated with a variety of pathological mechanisms, such as haemodynamics, neurohormonal changes, hypervolemia, hypertension, hyperuraemia and hyperuricaemia. In this review, we summarize the classification and currently available diagnostic biomarkers of CRS. We highlight the recently revealed molecular pathogenesis of CRS, such as oxidative stress and inflammation, hyperactive renin‒angiotensin‒aldosterone system, maladaptive Wnt/β-catenin signalling pathway and profibrotic TGF‒β1/Smad signalling pathway, as well as other pathogeneses, such as dysbiosis of the gut microbiota and dysregulation of noncoding RNAs. Targeting these CRS-associated signalling pathways has new therapeutic potential for treating CRS. In addition, various chemical drugs, natural products, complementary therapies, blockers, and agonists that protect against CRS are summarized. Since the molecular mechanisms of CRS remain to be elucidated, no single intervention has been shown to be effective in treating CRS. Pharmacologic therapies designed to block CRS are urgently needed. This review presents a critical therapeutic avenue for targeting CRS and concurrently illuminates challenges and opportunities for discovering novel treatment strategies for CRS.

Renal-Cardiac Crosstalk in the Pathogenesis and Progression of Heart Failure

Chronic kidney disease (CKD) represents a global health issue with a high socioeconomic impact. Beyond a progressive decline of kidney function, patients with CKD are at increased risk of cardiovascular diseases, including heart failure (HF) and sudden cardiac death. HF in CKD can manifest both as HF with reduced ejection fraction and HF with preserved ejection fraction, with the latter further increasing in relative importance in the more advanced stages of CKD. Typical cardiac remodeling characteristics in uremic cardiomyopathy include left ventricular hypertrophy, myocardial fibrosis, cardiac electrical dysregulation, capillary rarefaction, and microvascular dysfunction, which are triggered by increased cardiac preload, cardiac afterload, and preload and afterload-independent factors. The pathophysiological mechanisms underlying cardiac remodeling in CKD are multifactorial and include neurohormonal activation (with increased activation of the renin-angiotensin-aldosterone system, the sympathetic nervous system, and mineralocorticoid receptor signaling), cardiac steroid activation, mitochondrial dysfunction, inflammation, innate immune activation, and oxidative stress. Furthermore, disturbances in cardiac metabolism and calcium homeostasis, macrovascular and microvascular dysfunction, increased cellular profibrotic responses, the accumulation of uremic retention solutes, and mineral and bone disorders also contribute to cardiovascular disease and HF in CKD. Here, we review the current knowledge of HF in CKD, including the clinical characteristics and pathophysiological mechanisms revealed in animal studies. We also elaborate on the detrimental impact of comorbidities of CKD on HF using hypertension as an example and discuss the clinical characteristics of hypertensive heart disease and the genetic predisposition. Overall, this review aims to increase the understanding of HF in CKD to support future research and clinical translational approaches for improved diagnosis and therapy of this vulnerable patient population.

Cardiovascular Biomarkers in Nocturnal Hemodialysis and Their Association With Physical Performance

INTRODUCTION

The cardiovascular biomarkers troponin T, N-terminal pro-B-type natriuretic peptide, and fibroblast growth factor 23 are elevated in hemodialysis patients and associated with an increased cardiovascular mortality risk. Nocturnal hemodialysis improves the fluid status in hemodialysis patients. Therefore, we investigated whether nocturnal hemodialysis (7-8 h sessions) was associated with lower levels of troponin T, N-terminal pro-B-type natriuretic peptide, and fibroblast growth factor 23 in comparison to conventional hemodialysis. Second, we investigated whether these biomarkers were independently associated with physical performance in hemodialysis patients.

METHODS

A prospective cohort of 33 hemodialysis patients was compared to 32 patients who voluntarily switched from conventional hemodialysis to nocturnal hemodialysis. First, we studied the difference between the two cohorts in change over 12 months of troponin T, N-terminal pro-B-type natriuretic peptide, and fibroblast growth factor 23 with linear mixed models. Second, the associations between these biomarkers and physical-activity monitor, six minute walk test, and physical component summary score were assessed at baseline, 6 and 12 months.

FINDINGS

N-terminal pro-B-type natriuretic peptide increased 122% during conventional hemodialysis, whereas it decreased 31% during nocturnal hemodialysis (p = 0.001). In conventional hemodialysis, fibroblast growth factor 23 rose numerically by 19% (23%-66%) in 12 months, while a decline of 44% (21%-58%) was found in nocturnal hemodialysis patients (p = 0.17). Troponin T did not differ between groups. Regarding physical performance, a higher N-terminal pro-B-type natriuretic peptide (per 1000 ng/L) and fibroblast growth factor 23 (per 1000 RU/mL) were associated with lower physical component summary scores of -0.02 (p = 0.02) and -0.04 (p = 0.05), respectively. Troponin T was not associated with physical performance.

DISCUSSION

Our findings showed that nocturnal hemodialysis was associated with a decrease in N-terminal pro-B-type natriuretic peptide. This suggested that nocturnal hemodialysis diminished volume overload and thereby myocardial stretch. Additionally, lower levels of N-terminal pro-B-type natriuretic peptide and fibroblast growth factor 23 were found to be associated with better self-reported physical performance scores.

Klotho plasma levels are an independent predictorof mortality in women with acute coronary syndrome

Alterations in plasma levels of the components of the mineral metabolism (MM) system are related to cardiovascular diseases. However, gender differences of the whole MM system in patients with acute coronary syndrome (ACS) have not been reported. Our objective was to analyse the potential differences on the prognostic role of MM in women suffering an ACS as compared to men. We included 1,230 patients with ACS and collected clinical data and plasma levels of MM components. Primary outcome was a composite of acute ischaemic events, heart failure and all-cause mortality. Secondary outcomes included each component separately. 282 patients (22.9%) were female. After 5.44 years of follow-up, primary outcome occurred in 28.0% women and 23.5% men, and death in 10.6% and 9.4% respectively. FGF23 was associated with primary outcome in both sexes, and calcidiol only in men (HR 1.04, CI95%1.00-1.03). Klotho levels are inversely related to all-cause mortality only in women (HR 0.80, CI95% 0.67-0.96), while calcidiol (HR 0.84, CI95%0.72-0.98) and FGF23 levels (HR 1.02 CI95%1.00-1.03) were predictors in men, highlighting a possible gender-specific prognostic biomarker. These results underline the importance of considering MM biomarkers in risk stratification and management of patients with acute coronary syndromes, with attention to gender differences.

Hyperphosphatemia in Kidney Failure: Pathophysiology, Challenges, and Critical Role of Phosphorus Management

Phosphorus is one of the most abundant minerals in the body and plays a critical role in numerous cellular and metabolic processes. Most of the phosphate is deposited in bones, 14% is present in soft tissues as various organic phosphates, and only 1% is found in extracellular space, mainly as inorganic phosphate. The plasma inorganic phosphate concentration is closely maintained between 2.5 and 4.5 mg/dL by intertwined interactions between fibroblast growth factor 23 (FGF-23), parathyroid hormone (PTH), and vitamin D, which tightly regulate the phosphate trafficking across the gastrointestinal tract, kidneys, and bones. Disruption of the strict hemostatic control of phosphate balance can lead to altered cellular and organ functions that are associated with high morbidity and mortality. In the past three decades, there has been a steady increase in the prevalence of kidney failure (KF) among populations. Individuals with KF have unacceptably high mortality, and well over half of deaths are related to cardiovascular disease. Abnormal phosphate metabolism is one of the major factors that is independently associated with vascular calcification and cardiovascular mortality in KF. In early stages of CKD, adaptive processes involving FGF-23, PTH, and vitamin D occur in response to dietary phosphate load to maintain plasma phosphate level in the normal range. However, as the CKD progresses, these adaptive events are unable to overcome phosphate retention from continued dietary phosphate intake and overt hyperphosphatemia ensues. As these hormonal imbalances and the associated adverse consequences are driven by the underlying hyperphosphatemic state in KF, it appears logical to strictly control serum phosphate. Conventional dialysis is inadequate in removing phosphate and most patients require dietary restrictions and pharmacologic interventions to manage hyperphosphatemia. However, diet control comes with many challenges with adherence and may place patients at risk for inadequate protein intake and malnutrition. Phosphate binders help to reduce phosphate levels but come with a sizable pill burden and high financial costs and are associated with poor adherence and psychosocial issues. Additionally, long-term use of binders may increase the risk of calcium, lanthanum, or iron overload or promote gastrointestinal side effects that exacerbate malnutrition and affect quality of life. Given the aforesaid challenges with phosphorus binders, novel therapies targeting small intestinal phosphate absorption pathways have been investigated. Recently, tenapanor, an agent that blocks paracellular absorption of phosphate via inhibition of enteric sodium-hydrogen exchanger-3 (NHE3) was approved for the treatment of hyperphosphatemia in KF. While various clinical tools are now available to manage hyperphosphatemia, there is a lack of convincing clinical data to demonstrate improvement in outcomes in KF with the lowering of phosphorus level. Conceivably, deleterious effects associated with hyperphosphatemia could be attributable to disruptions in phosphorus-sensing mechanisms and hormonal imbalance thereof. Further exploration of mechanisms that precisely control phosphorus sensing and regulation may facilitate development of strategies to diminish the deleterious effects of phosphorus load and improve overall outcomes in KF.

MLO-Y4 fluid flow shear stress conditioned media enhances cardiac contractility and intracellular Ca2

The skeleton is in complex interplay with the other systems of the body and is highly responsive to input from the external environment. Bone mechanical loading results in interstitial fluid flow via the lacunar-canalicular system, generating fluid flow sheer stress (FFSS). FFSS variably stresses osteocytes, subsequently causing the release of metabolites and protein factors that function locally to increase bone formation and may play a role in cross talk between various organ systems, for instance between bone and skeletal muscle. Therefore, we hypothesized that this cross talk includes altering cardiac function. To test this hypothesis, media conditioned by MLO-Y4 osteocyte-like cell culture line under FFSS was used to model the endocrine effects of bone during mechanical loading on contraction of ex vivo Langendorf-perfused isolated hearts. When hearts were externally paced at a fixed rate, FFSS osteocyte conditioned media (CM) induced significant premature contractions compared with vehicle (control). FFSS osteocyte CM administration to self-paced hearts increased total contraction force by 31%. To determine whether the mechanism involved intracellular Ca2+, vehicle and FFSS bone CM were perfused over cultured H9C2 cardiomyocytes while undergoing Ca2+ imaging using Fluo-8. We observed an increase in intracellular Ca2+ with FFSS CM perfusion of cardiomyocytes compared with vehicle. These increases were only present with exogenous electrical pacing. Our findings demonstrate that FFSS bone CM enhances cardiac contractility by increasing intracellular cardiomyocyte Ca2+. The results obtained in this study suggest that the skeleton, responding to mechanical strain, has the potential to augment cardiac output and provide evidence for bone-heart cross talk.NEW & NOTEWORTHY The skeletal system operates as an endocrine organ, releasing factors that impact multi-tissue physiology. The results obtained in this study demonstrate that conditioned media collected from MLO-Y4 osteocytes exposed to fluid flow shear stress increases cardiomyocyte intracellular calcium and enhances cardiac contractility in vitro. These results support the concept of bone-heart cross talk that may have implications in exercise training, reduced-function settings such as bedrest, and the interplay between bone and heart health.

Fibroblast growth factor 23 and fibroblast growth factor receptor 4 promote cardiac metabolic remodeling in chronic kidney disease

Chronic kidney disease (CKD) is a global health epidemic that greatly increases mortality due to cardiovascular disease. Left ventricular hypertrophy (LVH) is an important mechanism of cardiac injury in CKD. High serum levels of fibroblast growth factor (FGF) 23 in patients with CKD may contribute mechanistically to the pathogenesis of LVH by activating FGF receptor (FGFR) 4 signaling in cardiac myocytes. Mitochondrial dysfunction and cardiac metabolic remodeling are early features of cardiac injury that predate development of hypertrophy, but these mechanisms have been insufficiently studied in models of CKD. We found in wild-type mice with CKD induced by adenine diet, that morphological changes occurred in mitochondrial structure and cardiac mitochondrial and that metabolic dysfunction preceded the development of LVH. In bioengineered cardio-bundles and neonatal rat ventricular myocytes grown in vitro, FGF23-mediated activation of FGFR4 caused mitochondrial pathology, characterized by increased bioenergetic stress and increased glycolysis that preceded the development of cellular hypertrophy. The cardiac metabolic changes and associated mitochondrial alterations in mice with CKD were prevented by global and cardiac-specific deletion of FGFR4. Our findings indicate that metabolic remodeling and mitochondrial dysfunction are early cardiac complications of CKD that precede structural remodeling of the heart. Mechanistically, FGF23-mediated activation of FGFR4 causes mitochondrial dysfunction, suggesting that early pharmacologic inhibition of FGFR4 might serve as novel therapeutic intervention to prevent development of LVH and heart failure in patients with CKD.

Klotho Is Cardioprotective in the mdx Mouse Model of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a lethal, progressive skeletal and cardiac myopathy. Cardiomyopathy is the leading cause of death in patients with DMD, but the molecular basis for heart failure is incompletely understood. As with humans, in the mdx mouse model of DMD, cardiac function is impaired after the onset of skeletal muscle pathology. Dysregulation of Klotho gene regulation in dystrophic skeletal muscles occurs at disease onset, affecting pathogenesis. Whether Klotho is protective against dystrophin-deficient cardiomyopathy is unknown. This study found that expression of a Klotho transgene prevented deficits in left ventricular ejection fraction and fractional shortening in mdx mice. Improvements in cardiac performance were associated with reductions in adverse cardiac remodeling, cardiac myocyte hypertrophy, and fibrosis. In addition, mdx mice expressed high concentrations of plasma fibroblast growth factor 23 (FGF23), and expression was increased locally in hearts. The cardioprotective effects of Klotho were not associated with differences in renal function or serum biochemistries, but transgene expression prevented increased expression of plasma FGF23 and cardiac Fgf23 mRNA expression. Cardiac reactive oxygen species, oxidative damage, mitochondrial damage, and apoptosis were reduced in transgenic hearts. FGF23 stimulated hypertrophic growth in dystrophic neonatal mouse ventricular myocytes in vitro, which was inhibited by co-stimulation with soluble Klotho. Taken together, these results show that Klotho prevented dystrophic cardiac remodeling and improved function.

FGF-based drug discovery: advances and challenges

The fibroblast growth factor (FGF) family comprises 15 paracrine-acting and 3 endocrine-acting polypeptides, which govern a multitude of processes in human development, metabolism and tissue homeostasis. Therapeutic endocrine FGFs have recently advanced in clinical trials, with FGF19 and FGF21-based therapies on the cusp of approval for the treatment of primary sclerosing cholangitis and metabolic syndrome-associated steatohepatitis, respectively. By contrast, while paracrine FGFs were once thought to be promising drug candidates for wound healing, burns, tissue repair and ischaemic ailments based on their potent mitogenic and angiogenic properties, repeated failures in clinical trials have led to the widespread perception that the development of paracrine FGF-based drugs is not feasible. However, the observation that paracrine FGFs can exert FGF hormone-like metabolic activities has restored interest in these FGFs. The recent structural elucidation of the FGF cell surface signalling machinery and the formulation of a new threshold model for FGF signalling specificity have paved the way for therapeutically harnessing paracrine FGFs for the treatment of a range of metabolic diseases.

Cardiorenal Syndrome in Right Heart Failure Due to Pulmonary Arterial Hypertension-The Right Ventricle as a Therapeutic Target to Improve Renal Function

Cardiorenal syndrome (CRS) due to right ventricular (RV) failure is a disease entity emerging as a key indicator of morbidity and mortality. The multifactorial aspects of CRS and the left-right ventricular interdependence complicate the link between RV failure and renal function. RV failure has a direct pathophysiological link to renal dysfunction by leading to systemic venous congestion in certain circumstances and low cardiac output in other situations, both leading to impaired renal perfusion. Indeed, renal dysfunction is known to be an independent predictor of mortality in patients with pulmonary arterial hypertension (PAH) and RV failure. Thus, it is important to further understand the interaction between the RV and renal function. RV adaptation is critical to long-term survival in patients with PAH. The RV is also known for its remarkable capacity to recover once the aggravating factor is addressed or mitigated. However, less is known about the renal potential for recovery following the resolution of chronic RV failure. In this review, we provide an overview of the intricate relationship between RV dysfunction and the subsequent development of CRS, with a particular emphasis on PAH. Additionally, we summarize potential RV-targeted therapies and their potential beneficial impact on renal function.

Fgf23 expression increases atherosclerotic plaque burden in male ApoE deficient mice

INTRODUCTION

Components of both the innate and adaptive immune system impact on arterial walls in atherosclerosis. Fibroblast growth factor-23 (FGF23) is a phosphate regulating hormone linked to cardiovascular disease (CVD) in patients with and without chronic renal disease. However, it remains controversial whether FGF23 is merely a biomarker or contributes to CVD. Here, we overexpressed Fgf23 in ApoE-/-mice to delineate the role of FGF23 in atherogenesis.

METHODS AND RESULTS

10-week old ApoE-/- mice received a hydrodynamic tail vein with a plasmid encoding for Fgf23, and were sacrificed 10 weeks later. FGF23 concentrations increased more than 400-fold in the Fgf23 treated group, remaining high throughout the experiment. Mice in the Fgf23 group developed hypophosphatemia, secondary hyperparathyroidism and a moderate increase in plasma creatinine concentrations. Male ApoE-/- mice exposed to high Fgf23 developed larger atherosclerotic lesions compared to controls, in two different locations of aorta, whereas no differences in plaque burden were seen between female ApoE-/- mice and controls. Serum IL-6 concentrations were increased in the Fgf23 group, associated with a vascular inflammatory response of recruited macrophages and neutrophils, and with a shift of CD4+ T effector cells from Th1 to Th17 and migration of lymphocytes to the spleen.

CONCLUSION

Fgf23 overexpression increases the atherosclerotic burden in male ApoE-/- mice and alters both the innate immune system and T cell subpopulations, generating an inflammatory environment that may promote adverse clinical outcomes associated with FGF23 excess.

Molecular mechanism for transcriptional regulation of the parathyroid hormone gene by Epiprofin

Epiprofin (Epfn), an Sp/KLF family transcription factor that regulates cell proliferation and determines cell fates, is essential for normal skin, hair follicle, and tooth development. We found that Epfn was expressed in parathyroid glands, and Epfn-knockout mice displayed elevated serum parathyroid hormone (PTH) concentrations, decreased bone volume, and intracranial ectopic calcification. To investigate the role of Epfn in the regulation of PTH expression, parathyroid gland explant and parathyroid cell line culture methods were used. Epfn expression was found to be upregulated in response to an increase in extracellular calcium concentration, whereas PTH expression was downregulated, thus demonstrating an inverse correlation. Forced expression of Epfn inhibited PTH gene expression and PTH promoter reporter activity in parathyroid cells. In addition, with a high extracellular calcium concentration, Epfn silencing in cultured parathyroid glands failed to block PTH gene expression. ChIP-qPCR analysis also revealed Epfn binding in the proximal region of the PTH promoter, which was accelerated in the presence of a high concentration of calcium ions. The results from our in vitro and ex vivo analyses suggest that Epfn is a newly identified negative regulator of PTH transcription by regulating the proximal PTH promoter. Furthermore, the expression of Epfn was significantly reduced in parathyroid adenomas of primary hyperparathyroidism patients. The identification of Epfn as a potential therapeutic target for the control of PTH production in hyperparathyroidism patients opens new avenues for targeted treatment approaches.

Office Blood Pressure and Obesity in Children with X-Linked Hypophosphatemia

X-linked hypophosphatemia (XLH) is the most common inherited form of hypophosphatemic rickets. Children with XLH have an increased risk of obesity, which may promote high blood pressure, but data on blood pressure in XLH are inconclusive. We aimed to assess blood pressure and its determinants in pediatric XLH patients. We conduct a prospective, multicenter observational study of children with XLH in Germany and Switzerland. Office blood pressure and body mass index (BMI) were annually measured in 128 pediatric XLH patients with a median follow-up of 2 years (range 1-6). Potential predictors of blood pressure were investigated by Spearman correlation. Seventeen percent of patients were treated with phosphate supplements and active vitamin D for a median of 8 years, 83% of patients received burosumab for 2.3 years with 3.1 years of prior treatment with phosphate supplements and active vitamin D. Median systolic (0.75 z-score) and diastolic (0.32 z-score) blood pressure and BMI (0.72 z-score) were increased compared to healthy children (each p < 0.01). The prevalence of obesity (9.8% vs. 3%), arterial hypertension (26.2% vs. 5%), and high-normal blood pressure (22.9% vs. 5%) was higher in the XLH cohort compared to the general pediatric population (each p < 0.001). Spearman rank correlation analysis revealed significant associations between both systolic (r = 0.24; p < 0.01) and diastolic (r = 0.20; p < 0.05) blood pressure with BMI, while the mode of treatment, i.e. burosumab versus phosphate supplements and active vitamin D, was no significant correlate. Children with XLH present with elevated office blood pressure values, associated with elevated BMI.

Dietary Phosphorus and Metabolic Health in CKD and ESKD

The contribution of dietary phosphate (P) in the pathogenesis of CKD-associated mineral bone disease and the management of P intake in patients with CKD are essential to slow down disease progression and improve patient outcomes. In patients with CKD, and most likely in the general population, P retention and overload can affect four critical aspects of the cardiovascular system: increased arterial BP, vascular and valvular calcification, and left ventricular hypertrophy. All of these factors contribute to increased cardiovascular risk and mortality. Intestinal absorption of P from a mixed diet is approximately 60%-70% of the dietary P content, with lower rates for organic P from plant sources and higher rates for inorganic P from processed foods containing additives. The widespread use of phosphate additives in processed foods and the high consumption of animal protein in the Western diet have led to a steady increase in phosphate consumption in recent decades. Although it is unclear whether this high P intake has adverse effects in people with normal kidney function, several studies have found that increased dietary P contributes to the progression of CKD and cardiovascular damage. High P intake may be detrimental, but there is no clear evidence that it should be avoided in the general population. On the contrary, kidney function impairment is the setting in which modulation of P intake is justified and easy to implement by restricting/reducing protein intake. However, it is quite difficult to implement P restriction in patients on dialysis because of the conflicting recommendation of high protein intake. Educational approaches, together with solid motivation and adherence by patients and caregivers, are needed to achieve the goal of successful dietary phosphate management in patients with CKD.

Role of kidney transplantation in long-term cardiac reverse remodeling and interconnecting mechanisms in type 4 cardiorenal syndrome

Background

Type 4 cardiorenal syndrome (CRS) involves cardiovascular alterations caused by chronic kidney disease (CKD). Fibroblast growth factor-23 (FGF23), carboxy-terminal propeptide of procollagen type I (PIP), and parathyroid hormone (PTH) have been proposed as biomarkers of pathological cardiac remodeling in CKD. In contrast, it has been suggested that MicroRNA 221 has a cardioprotective role. Available evidence shows that, 12 months after kidney transplantation (KT), type 4 CRS reverts in only half of the patients.

Objective

To assess long-term cardiac reverse remodeling after KT and its association with FGF23, PIP, and PTH levels.

Methods

Patients with end-stage renal disease were assessed before and 28 months after KT using FGF23, PIP, and PTH serum concentrations and transthoracic echocardiography.

Results

Fifty-three patients were followed for 28 months after KT. All the patients showed cardiac abnormalities upon inclusion. A follow-up assessment showed a reduction in left ventricle (LV) mass (121 ± 48 vs. 65 ± 14 gr/m2) and left atrial volume (46 vs. 30 ml/m2). The LV ejection fraction (53 vs. 63%), LV global longitudinal strain (-15.9 vs.-19.4%), and LV diastolic function improved. miR-221 expression increased after KT (8.73 RIQ= 3.7-25 vs. 40.16 RIQ= 24-223, p=0.001) and was correlated with the Ee´ratio (r= -0.32, p= 0.02). Multivariate analysis showed that post-KT LV mass was determined by pre-KT LV mass, serum Cr level, post-KT PIP, and hypertension (R2 = 0.65, F=12.1, p=0.001).

Conclusions

Contrary to other evidence, this study demonstrated that type 4 CRS is reversible over the long term. This is a paramount finding because KT normalizes cardiac structure and function independently of the severity of basal cardiac abnormalities.

Association between sex steroid hormones and α-klotho: Results from the NHANES 2013-2016 and Mendelian randomization study

PURPOSE

This study aimed to explore the association and causal links between sex steroid hormones and the anti-aging protein α-Klotho, extending to investigate the mediation effects of potential mediators.

METHODS

Based on data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016, this study performed weighted multivariable-adjusted logistic regression to evaluate the association between sex steroid hormones and α-Klotho. Then, utilizing summary data from genome-wide association studies (GWAS), a bidirectional two-sample Mendelian randomization (MR) was conducted to assess the causal relationship between sex steroid hormones and α-Klotho. Finally, mediation analysis was conducted to delineate the influence of five identified potential mediators on the sex steroid hormones-α-Klotho association.

RESULTS

In men, significant positive correlations with α-Klotho were consistent across both unadjusted and fully adjusted models for total testosterone (TT), bio-available testosterone (Bio-T), estradiol (E2) and sex hormone-binding globulin (SHBG) (Model 3: TT: β = 3.54, 95 % CI: 1.63-5.44, P = 0.0003; Bio-T: β = 1.74, 95 % CI: 0.73-2.74, P = 0.0007; E2: β = 0.25, 95 % CI: 0.11-0.38, P = 0.0003; SHBG: β = 0.95, 95 % CI: 0.63-1.27, P < 0.0001); In premenopausal women, we detected a potential nonlinear relationship between TT levels and α-Klotho, with α-Klotho levels rising to a peak at a TT level of 72.2 ng/mL, after which they declined. Furthermore, results from MR analyses reaffirmed positive associations of TT and Bio-T with α-Klotho in men (TT: β = 3.54, 95 % CI: 1.63-5.44, P = 0.0003; Bio-T: β = 1.74, 95 % CI: 0.73-2.74, P = 0.0007). Finally, significant mediation effects were observed for uric acid (β = 0.27, 95 % CI: 0.15-0.67, P < 0.0001) and creatinine (β = 0.05, 95 % CI: 0.01-0.16, P = 0.0060), accounting for 26.7 % and 5.23 % of the total mediation effect, respectively.

CONCLUSION

In conclusion, our results demonstrate that both TT and Bio-T enhance the expression of α-Klotho in men. The positive association observed may be partly mediated by uric acid and creatinine.

The true cost of phosphate control in chronic kidney disease

The loss of kidney function entails the development of a positive phosphate balance. The burden of addressing elevated phosphate levels is high. Both parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) are increased to promote phosphaturia, thereby preventing the rise in serum phosphate. However, if the phosphate load is excessive, the corresponding phosphaturia is maximal, kidney function deteriorates and hyperphosphataemia becomes clinically evident in advanced stages of chronic kidney disease (CKD). In addition to its role in CKD progression, hyperphosphataemia has been linked to a multitude of adverse outcomes, including overt inflammation, vascular calcifications, endothelial dysfunction, cardiovascular disease, renal osteodystrophy and secondary hyperparathyroidism. Collectively, these factors contribute to the markedly elevated mortality rates observed among individuals with CKD. Furthermore, hyperphosphataemia has been identified as a significant contributor to the development of inflammatory processes, oxidative stress and fibrosis, which underlie the aetiology of numerous comorbidities. Additionally, elevated levels of PTH and FGF23 have been demonstrated to independently induce organ and tissue injury, which is associated with poor outcomes in CKD. This article provides a concise overview of the current understanding of phosphate handling by the kidney in the context of CKD. It outlines the detrimental effects of phosphate on various organs and the mechanisms through which it contributes to CKD progression. Additionally, we discuss the tools available for clinicians to identify patients at risk of an excessive phosphate load.

Uric acid mediates the association between testosterone and α-Klotho among males: results from the NHANES 2013-2016

PURPOSE

This study initially conducted a cross-sectional analysis to examine the association between total testosterone (TT), uric acid, and Klotho. The investigation examined whether uric acid mediates the association between TT and Klotho in males.

METHODS

Based on data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016, this study performed weighted multivariable-adjusted linear regression to evaluate the association between TT, uric acid, and α-Klotho. Then, mediation analysis was conducted to delineate the potential mediating role of uric acid in the TT-Klotho association.

RESULTS

Multivariable linear regression analyses revealed inverse relationships between TT and uric acid (β = - 2.75, 95% CI: - 4.21, 1.28, p < 0.001) and between uric acid and α-Klotho (β = - 4.80, 95% CI: - 6.47, - 3.13, p < 0.001). Conversely, a positive correlation existed between TT and α-Klotho (β = 5.38, 95% CI: 2.23, 8.53, p < 0.001). Updated subgroup analyses show that the association strength between α-Klotho, TT, and uric acid levels was consistent across various population settings without significant variations. Restricted cubic spline analysis identified a non-linear association between TT and uric acid with an inflection point at 201 ng/mL. Mediation analysis confirmed uric acid-mediated 18.59% of the association between TT and α-Klotho (p < 0.001), highlighting its significant intermediary role.

CONCLUSION

This study elucidates the complex interrelationship between TT, uric acid, and α-Klotho, highlighting uric acid's significant mediating role. These findings provide novel insights into the hormonal and metabolic mechanisms underlying age-related processes and longevity.

Association of Fibroblast Growth Factor 23 and Cardiac Mechanics in the Cardiovascular Health Study

Key Points

Evaluation of cardiac mechanics through two-dimensional speckle tracking echocardiography can identify early alterations in cardiac function. In a subset of the Cardiovascular Health Study, c-terminal and intact fibroblast growth factor 23 were not independently associated with cardiac mechanic indices.

Background

Elevated levels of fibroblast growth factor 23 (FGF23) are associated with left ventricular hypertrophy and heart failure in individuals with and without kidney disease. Prior studies investigated the association of FGF23 and structural cardiac changes using conventional echocardiography, which is limited in its ability to detect early cardiac dysfunction. We investigated the relationship between FGF23 levels and cardiac dynamics using two-dimensional speckle tracking echocardiography (2D-STE), a novel imaging modality.

Methods

This was a cross-sectional analysis of data from the Cardiovascular Health Study (CHS), an ongoing prospective, population-based cohort study. The study population included 506 participants from CHS with available c-terminal FGF23 (cFGF23) and intact FGF23 (iFGF23) measurements from 1996 to 1997 and 2D-STE images from 1994 to 1995. Forty-two percent of the study population had CKD, defined as an eGFR <60 ml/min per 1.73 m2, and the mean eGFR was 63 ml/min per 1.73 m2. The primary exposures were cFGF23 and iFGF23. The primary outcomes were six 2D-STE parameters performed at the 1994–1995 study visit. Linear regression models were used to examine the independent associations of FGF23 with six cardiac 2D-STE indices adjusting for demographics, cardiovascular risk factors, markers of kidney disease severity, and inflammation.

Results

cFGF23 levels were moderately correlated with iFGF23 levels in the CHS population. In fully adjusted models, cFGF23 was associated with left atrial dysfunction, but no other cardiac imaging parameter (β estimate, −2.47; 95% confidence interval, −4.68 to −0.25; Table 2 ). iFGF23 was not associated with any of the six 2D-STE indices. Limitations include small sample size and noncurrent FGF23 measurements and 2D-STE imaging.

Conclusions

In a limited sample of individuals enrolled in the CHS with cFGF23 and iFGF23 measurements, we did not find consistent associations between FGF23 levels and 2D-STE parameters. Further investigations in a larger population with concurrent 2D-STE are needed to better understand the associations of FGF23 with early changes in cardiac mechanics.

The bone-heart axis in the pathogenesis of cardiovascular diseases: A narrative review

Cardiovascular diseases (CVDs) cause about 30% of deaths worldwide, increasing social and economic burden in our societies. Although the treatment of the canonical cardiovascular risk factors has reduced the impact of CVDs on morbidity and mortality in the past few years, they continue to represent a major health problem. The definition of the biological properties of the bone-heart axis has led to new insights in the pathogenesis of CVDs; hence, the aim of this review is to try to elucidate the role of this axis on the susceptibility to CVDs. There is evidence that the bone interacts with extra-skeletal organs, including the cardiovascular system, through its endocrine functions. Clinical and experimental data strongly indicate that the interplay between the bone and the cardiovascular system represents a future tool for the prevention, diagnosis and treatment of CVDs. The identification of these non-canonical cardiovascular risk factors could prompt pharmacological research towards new target therapy aimed at precision medicine.

Controlled dietary phosphate loading in healthy young men elevates plasma phosphate and FGF23 levels

Increased dietary inorganic phosphate (Pi) intake stimulates renal Pi excretion, in part, by parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23) or dopamine. High dietary Pi may also stimulate sympathetic outflow. Rodent studies provided evidence for these regulatory loops, while controlled experiments in healthy humans examined periods of either a few hours or several weeks, and often varied dietary calcium intake. The effects of controlled, isolated changes in dietary Pi intake over shorter periods are unknown. We studied the effects of a low or high Pi diet on parameters of mineral metabolism in 10 healthy young men. Participants received a standardized diet (1000 mg phosphorus equivalent/day) supplemented with either a phosphate binder (low Pi diet) or phosphate capsules (750 mg phosphorus, high Pi diet) in a randomized cross-over trial for 5 days with a 7-day washout between diets. High Pi intake increased plasma Pi levels and 24-h excretion and decreased urinary calcium excretion. High Pi intake increased intact FGF23 (iFGF23) and suppressed plasma Klotho without affecting cFGF23, PTH, calcidiol, calcitriol, Fetuin-A, dopamine, epinephrine, norepinephrine, metanephrine, or aldosterone. Higher iFGF23 correlated with lower calcitriol and higher PTH. These data support a role for iFGF23 in increasing renal Pi excretion and reducing calcitriol in healthy young men during steady-state high dietary Pi intake. High dietary Pi intake elevated blood Pi levels in healthy young subjects with normal renal function and may therefore be a health risk, as higher serum Pi levels are associated with cardiovascular risk in the general population.

Iron in Chronic Kidney Disease and End-Stage Kidney Disease-Current Trends and Future Direction

Anaemia is a frequent and serious complication in chronic kidney disease (CKD), affecting both non-dialysis-dependent (NDD) and dialysis-dependent (DD) patients. While erythropoietin (EPO) deficiency is the primary cause, iron deficiency (ID) also plays a crucial role. ID in CKD can be classified as either absolute, resulting from blood loss, or functional, driven by inflammation and elevated hepcidin levels, which trap iron in macrophages and hepatocytes, preventing its use in erythropoiesis. Elevated hepcidin also reduces dietary iron absorption in the gut, making oral iron supplements ineffective, particularly in advanced CKD. This review summarises the available intravenous (IV) iron formulations, discusses diagnostic definitions and treatment thresholds for ID in NDD and DD CKD, and explores potential future therapeutic directions.

C-terminal FGF-23 production coupling with aldosterone via FAM20C and predicting cardiovascular events in primary aldosteronism

This study examined the involvement of fibroblast growth factor-23 (FGF-23) in primary aldosteronism (PA), a condition characterized by elevated aldosterone levels and hypertension. We recruited patients with unilateral PA (uPA) and observed increased levels of C-terminal FGF-23 (cFGF-23) and C-terminal to intact FGF-23 (iFGF-23) in patients with uPA compared with essential hypertension control participants. Elevated preoperative cFGF-23 levels were associated with adverse outcomes, including mortality and cardiovascular or kidney events. Plasma cFGF-23 levels demonstrated a nonlinear rise with aldosterone, but iFGF-23 levels were not correlated with plasma aldosterone concentration. Higher cFGF-23 levels independently predicted hypertension remission after adrenalectomy for patients with uPA. Patients with uPA, who exhibited elevated cFGF-23 levels, had decreased levels after adrenalectomy. In cell cultures, aldosterone enhanced cleavage of iFGF-23, leading to increased levels of cFGF-23 fragments, an effect mitigated by silencing of family with sequence similarity 20, member C (FAM20C). However, the enhancement of cFGF-23 levels remained unaffected by the furin inhibitor. The study suggests that aldosterone influences FGF-23 phosphorylation by interacting with FAM20C, with docking experiments indicating aldosterone's binding to FAM20C. This work highlights that patients with uPA with elevated cFGF-23 levels are associated with cardiovascular risks, and adrenalectomy reduces cFGF-23. Aldosterone likely promotes cFGF-23 production through FAM20C-mediated phosphorylation of iFGF-23.

Fibroblast Growth Factor 23, Endogenous Erythropoietin, Erythropoiesis-Stimulating Agents, and Erythropoietin Resistance in Hemodialysis Patients

INTRODUCTION

Recent experimental studies have reported that fibroblast growth factor 23 (FGF23) inhibits erythropoiesis by suppressing erythropoietin (EPO) production and downregulating the EPO receptor. Conversely, either endogenous or exogenous EPO has been shown to stimulate FGF23 production. However, little is known about the relationships between FGF23, erythropoiesis-stimulating agent (ESA) treatment, ESA resistance, and endogenous EPO in hemodialysis patients.

METHODS

We analyzed cross-sectional data from a cohort of 654 maintenance hemodialysis patients. We examined the associations of intact or C-terminal FGF23 with ESA treatment, ESA resistance index (ERI), hemoglobin, C-reactive protein, and endogenous EPO levels using linear regression models. EPO was measured only in patients not receiving ESAs.

RESULTS

A total of 458 patients (70%) were treated with ESAs. The median EPO concentration in non-ESA users was 7.8 (interquartile range, 5.3-14.4) mIU/mL. The median levels of intact and C-terminal FGF23 were 1,598 (interquartile range, 548-4,586) pg/mL and 38.7 (interquartile range, 14.0-127.6) pmol/L, respectively, in non-ESA users and 1,955 (interquartile range, 573-5,264) pg/mL and 41.4 (interquartile range, 13.9-116.8) pmol/L, respectively, in ESA users. After adjustment for potential confounders, higher ESA dose was associated with higher FGF23 levels measured by both intact and C-terminal assays. Higher C-terminal FGF23 was also associated with higher ERI, lower hemoglobin, and higher endogenous EPO, but no such associations were observed for intact FGF23 levels.

CONCLUSIONS

Both intact and C-terminal FGF23 showed similar associations with ESA dose, but they showed different patterns of association with other parameters related to anemia. Further research is needed to elucidate the mechanisms underlying these different associations.

Heart Failure and Osteoporosis: Shared Challenges in the Aging Population

In clinical practice, heart failure (HF) and osteoporosis (OP) are commonly paired conditions. This association is particularly relevant in patients over the age of 50, among whom its prevalence increases dramatically with every decade of life. This can be especially impactful since patient prognosis when facing both conditions is poorer than that of each disease alone. Clinical studies suggest that prior fractures increase the risk for heart failure hospitalization and, conversely, an episode of heart failure increases the risk of subsequent fractures. In other words, the relationship between osteoporosis and heart failure seems to be two-way, meaning that each condition may influence or contribute to the development of the other. However, the details of the pathophysiological relationship between HF and OP have yet to be revealed. The two conditions share multiple pathological mechanisms that seem to be intertwined. Patients affected by OP are more prone to develop HF because of vitamin D deficiency, elevation of parathyroid hormone (PTH) plasma levels, and increased Fibroblast Growth Factor 23 (FGF-23) activity. On the other hand, HF patients are more prone to develop OP and pathological fractures because of low vitamin D level, high PTH, chronic renal failure, alteration of renin-angiotensin-aldosterone system, reduced testosterone level, and metabolic effects derived from commonly used medications. Considering the increasingly aging worldwide population, clinicians can expect to see more often an overlap between these two conditions. Thus, it becomes crucial to recognize how HF and OP mutually influence the patient's clinical condition. Clinicians attending these patients should utilize an integrated approach and, in order to improve prognosis, aim for early diagnosis and treatment initiation. The aim of this paper is to perform a review of the common pathophysiological mechanisms of OP and HF and identify potentially new treatment targets.

Fibroblast growth factor 23 - A review with particular reference to the physiology and pathophysiology of phosphate homeostasis in the cat

Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone, discovery of which has transformed our understanding of mineral regulation in healthy mammals, including the cat. It is produced by osteoblasts and osteocytes and its prime role is to regulate phosphate entry into extracellular fluid (from bone and via the gut) and its excretion via the kidney. It interacts with other hormones (calcitriol and parathyroid hormone), inhibiting their activation and secretion respectively and so impacts on calcium as well as phosphate homeostasis. Physiological factors regulating its secretion are not well understood, although phosphate ion sensing is likely to be important. Calcium and magnesium ions are also involved and unravelling the control points and integration of the system regulating bone turnover and mineral balance whilst preventing soft tissue (non-osseous) mineralisation is a future research goal. Calciprotein particle size and number likely play an important role in this system but precisely how remains to be determined. Elevated serum FGF23 is the earliest indicator of mineral bone disorder associated with chronic kidney disease in human patients and in cats, enabling reference-range serum phosphorus to be maintained despite reduction in glomerular filtration rate which limits phosphate excretion. FGF23 also predicts CKD progression and survival in cats. The many factors influencing its secretion at different stages of CKD, including relative iron deficiency, anaemia and chronic systemic inflammation, hypomagnesaemia and α-klotho deficiency are discussed in this review, where the data available in cats with naturally occurring CKD is presented alongside that from rodent models and human CKD patients.

Interaction Effect of Estimated Pulse Wave Velocity and Serum Klotho Level on Chronic Kidney Disease

Objectives

Older individuals usually have greater arterial stiffness, lower serum Klotho levels and a greater incidence of chronic kidney disease (CKD). The current study aimed to evaluate the interaction effect of estimated pulse wave velocity (ePWV) and serum Klotho levels on CKD in Americans.

Methods

Data from the National Health and Nutrition Examination Survey database from 2007 to 2016 were used. Participants with data for the assessment of ePWV and serum Klotho and for the assessment of CKD were enrolled. The associations between ePWV and serum Klotho levels were analyzed via restricted cubic spline analysis and a linear regression model. The associations between exposure factors and CKD prevalence were assessed via a logistic regression model. Subgroup analysis was performed for each confounding factor to assess the robustness of the results.

Results

This study enrolled 13,273 participants, 3859 of whom were CKD patients. CKD patients had higher ePWV (9.66 ± 1.75 m/s vs. 8.48 ± 1.64 m/s, p < 0.001) and lower levels of serum Klotho (816.35 ± 290.47 pg/mL vs. 869.87 ± 315.87 pg/mL, p < 0.001). A significant negative linear association was found between ePWV and serum Klotho. According to the fully adjusted model, a significant interaction effect between ePWV and serum Klotho was observed on the risk of CKD (p < 0.001). Compared with individuals with a lower ePWV and higher serum Klotho, individuals with an increased ePWV and lower serum Klotho had a significantly elevated risk of CKD (OR: 1.847, 95% confidence interval: 1.467-2.325; p < 0.001). The subgroup analysis revealed that the results were robust.

Conclusions

The study demonstrated significant interaction effect of ePWV and serum Klotho on the prevalence of CKD. Individuals with increased ePWV and decreased serum Klotho levels had the highest risk of CKD. The assessment of the combination of ePWV and serum Klotho for CKD management should be considered routine in clinical practice.

Baseline fibroblast growth factor 23 predicts incident heart failure and cardiovascular mortality in patients with chronic kidney disease: A 3-year follow-up study

Background

Heart failure (HF) is a significant cause of death among patients with chronic kidney disease (CKD). Emerging data suggest a crucial role of fibroblast growth factor 23 (FGF23) in the pathogenesis of HF in CKD patients. The present study aimed to investigate whether the serum intact FGF23 (iFGF23) level is elevated when ejection fraction (EF) is preserved and to evaluate its predictive value for incident HF and cardiac mortality in CKD patients with preserved EF.

Methods and results

We prospectively recruited 209 patients (mean age 52.7 ± 11.9 years, 37.3 % male) with CKD stages 3-5 and preserved EF, including those on peritoneal dialysis (PD) from a nephropathy center from November 2020 until July 2024.

Results

Over a median follow-up of 29 (IQR 24-35) months, 60 (28.7 %) patients met the primary composite endpoints, including 53 (25.4 %) incident HF events and 7 (3.3 %) cardiac deaths. The cumulative incidence of composite endpoints was approximately 2-fold higher in patients with the highest quartile (Q4) level of lgiFGF23, compared with the lower quartiles (Q1-3). Baseline iFGF23 concentration was significantly associated with an increased risk of composite endpoint in the multivariable-adjusted Cox model, independent of kidney function, traditional cardiovascular risk factors, echocardiographic parameters, and α-Klotho. In a competing risk analysis, the Q4 level of lgiFGF23 (HR 2.43, 95 %CI 1.44-4.11; P = 0.001) was independently associated with HF and cardiac death.

Conclusion

In CKD patients with preserved EF, serum iFGF23 was elevated before LVEF declined. A higher baseline serum iFGF23 level is significantly associated with the incidence of HF and cardiovascular mortality over a 3-year follow-up, demonstrating independent and incremental predictive value beyond traditional risk factors.

Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) in Pediatric Kidney Transplant Recipients

Kidney transplantation remains the gold standard treatment for end-stage kidney disease (ESKD), effectively alleviating numerous comorbidities and offering a substantial survival advantage over long-term dialysis. Despite advancements in immunosuppressive regimens and improvements in graft and patient survival rates, extended patient longevity brings an accumulating burden and complexity of bone disease in this population, which often goes underrecognized. The present study reviews the pathophysiology of CKD-MBD in pediatric KTR, focusing on the progression of bone disease before and after transplantation. We aim to enhance understanding of available screening options, highlighting their advantages and limitations, to support more informed decision-making in CKD-MBD management.

Current and novel biomarkers in cardiogenic shock

Cardiogenic shock (CS) carries a 30-50% in-hospital mortality rate, with little improvement in outcomes in the last decade. Challenges in improving outcomes are closely linked to the frequent late presentation or diagnosis of CS where the 'point of no return' has often passed, leading to haemodynamic dysregulation, progressive myocardial depression, hypotension, and a downward spiral of hypoperfusion, organ dysfunction and decreasing myocardial function, driven by inflammation and metabolic derangements. Novel therapeutic interventions may have varying efficacy depending on the type and stage of shock in which they are applied. Biomarkers that aid prediction and early detection of CS, provide early signs of organ dysfunction and define prognosis could help optimize management. Temporal change in such biomarkers, particularly in response to pharmacological interventions and/or mechanical circulatory support, can guide management and predict outcome. Several novel biomarkers enhance the prediction of mortality in CS, compared to conventional parameters such as lactate, with some, such as adrenomedullin and circulating dipeptidyl peptidase 3, also able to predict the development of CS. Some biomarkers reflect systemic inflammation (e.g. interleukin-6, angiopoietin 2, fibroblast growth factor 23 and suppressor of tumorigenicity 2) and are not specific to CS, yet inform on the activation of important pathways involved in the downward shock spiral. Other biomarkers signal end-organ hypoperfusion and could guide targeted interventions, while some may serve as novel therapeutic targets. We critically review current and novel biomarkers that guide prediction, detection, and prognostication in CS. Future use of biomarkers may help improve management in these high-risk patients.

Emerging concepts on the FGF23 regulation and activity

Fibroblast growth factor 23 (FGF23) discovery has provided new insights into the regulation of Pi and Ca homeostasis. It is secreted by osteoblasts and osteocytes, and acts mainly in the kidney, parathyroid, heart, and bone. The aim of this review is to highlight the current knowledge on the factors modulating the synthesis of FGF23, the canonical and non-canonical signaling pathways of the hormone, the role of FGF23 in different pathophysiological conditions, and the anti-FGF23 therapy. This is a narrative review based on the search of PubMed database in the range of years 2000-2023 using the keywords local and systemic regulators of FGF23 synthesis, FGF23 receptors, canonical and non-canonical pathways, pathophysiological conditions and FGF23, and anti-FGF23 therapy, focusing the data on the molecular mechanisms. The regulation of FGF23 synthesis is complex and multifactorial. It is regulated by local factors and systemic regulators mainly involved in bone mineralization. The excessive FGF23 production is associated with different congenital diseases and with diseases occurring with a secondary high FGF23 production such as in chronic disease kidney and tumor-induced osteomalacia (TIO). The anti-FGF23 therapy appears to be useful to treat chromosome X-linked hypophosphatemia and TIO, but there are doubts about the handle of excessive FGF23 production in CKD. FGF23 biochemistry and pathophysiology are generating a plethora of knowledge to reduce FGF23 bioactivity at many levels that might be useful for future therapeutics of diseases associated with high-serum FGF23 levels.

Vitamin D-Parathyroid Hormone-Fibroblast Growth Factor 23 Axis and Cardiac Remodeling

Cardiac remodeling is a compensatory adaptive response to chronic heart failure (HF) altering the structure, function, and metabolism of the heart. Many nutritional and metabolic diseases can aggravate the pathophysiological development of cardiac remodeling. Vitamin D deficiency leads to cardiac remodeling by activating the renin-angiotensin-aldosterone system (RAAS), resulting in enhanced inflammation and directly promoting cardiac fibrosis and extracellular matrix deposition. Hyperparathyroidism upregulates protein kinase A or protein kinase C, enhances intracellular calcium influx, promotes oxidative stress, activates RAAS, and increases aldosterone levels, thereby aggravating cardiac remodeling. Besides, fibroblast growth factor 23 (FGF23) plays a direct role in the heart, resulting in ventricular hypertrophy and myocardial fibrosis. Vitamin D deficiency leads to hyperparathyroidism, which in turn increases the level of FGF23. Elevated levels of FGF23 further inhibit vitamin D synthesis. Evidence exists that vitamin D deficiency, hyperparathyroidism, and marked elevations in FGF23 concentration form a vicious cycle and are believed to contribute directly to cardiac remodeling. Therefore, the purpose of this article is to introduce the specific effects of the above substances on the heart and to explain the significance of understanding the vitamin D-parathyroid hormone-FGF23 axis in improving or even reversing cardiac remodeling, thus contributing to the treatment of patients with HF.

α-Klotho is associated with cardiovascular and all-cause mortality in patients with stage 3b and 4 chronic kidney disease (CKD): a long-term prospective cohort study

BACKGROUND

α-Klotho deficiency may increase cardiovascular risks and worsen survival. We evaluated the association of α-Klotho with cardiovascular and all-cause mortality in pre-dialysis chronic kidney disease (CKD) patients.

METHODS

In this prospective study, 75 non-diabetic CKD stage 3b-4 patients were followed-up for a median of 8 years. Primary and secondary outcomes were all-cause and cardiovascular mortality, respectively. Human soluble α-Klotho ELISA Assay (IBL-Takara 27,998-96Well), Human Fibroblast Growth Factor-23 ELISA Assay (intact FGF23, Merck Millipore MILLENZ FGF23-32 K), and Human Sclerostin ELISA kits (Biomedica, Vienna, BI-20492) were used to measure serum α-Klotho, FGF23 and sclerostin levels in the certified laboratory at the Sechenov University according to the manufacturers' protocols. All patients underwent echocardiography to evaluate left ventricular mass index (LVMI), left ventricular ejection fraction by Simpson method, and cardiac (valve) calcification score by a semi-quantitative point scale. Lateral abdominal radiography by Kauppila method was used to estimate calcification of the abdominal aorta. Cox multivariate regression and receiver-operating characteristic curve (ROC)-analysis were used to evaluate risk factors for death and their cut-off values.

RESULTS

Primary and secondary endpoints were reached in 15 (20%) and 9 (12%) patients, respectively. Median α-Klotho levels in deceased and surviving patients were 344 and 484 pg/ml, respectively (p = 0.002). In a multivariate Cox regression model, baseline α-Klotho levels (HR 0.99, 95% CI 0.98-1.00, p = 0.023), aortic calcification (HR 1.18, 95% CI 1.02-1.36, p = 0.029) and left ventricular mass index (LVMI) (HR 1.04, 95% CI 1.00-1.08, p = 0.033) were associated with the primary endpoint, whereas α-Klotho (HR 0.99, 95% CI 0.98-1.00, p = 0.029), aortic calcification (HR 1.23, 95% CI 1.07-1.42, p = 0.003) and LVMI (HR 1.04, 95% CI 1.00-1.08, p = 0.021) were associated with the secondary endpoint. α-Klotho levels had the highest area under the curve (AUC) by ROC analysis, that is, 0.766 (95% CI 0.70-0.82) for the primary endpoint and 0.842 (95% CI 0.79-0.90) for the secondary endpoint with cut-off values of 412 pg/ml (HR 3.06, 95% CI 1.36-6.89, p = 0.007) and 368 pg/ml (HR 4.84, 95% CI 1.59-14.73, p = 0.005), respectively.

CONCLUSION

In pre-dialysis CKD patients, α-Klotho levels are associated with all-cause and cardiovascular mortality and may be considered an early prognostic marker.

Pemigatinib suppresses liver fibrosis and subsequent osteodystrophy in mice

BACKGROUND

Liver fibrosis could lead to serious secondary diseases, including osteodystrophy. The interaction between liver and bone has not been fully elucidated, thus existing therapies for osteodystrophy secondary to liver fibrosis are often ineffective. FGF23 was initially found as an endocrine regulator of phosphate homeostasis, but recently, its involvement in fibrosis has been suggested. In this study, we hypothesized that the FGF23 level increases with liver injury, which in turn induces liver fibrosis and osteodystrophy.

METHODS

Liver fibrosis model mice were generated via carbon tetrachloride administration and bile duct ligation. Fibrosis was assessed using Masson trichrome staining and hydroxyproline assay. The bone structure was evaluated using dual-energy x-ray absorptiometry and microcomputed tomography. Human HSC lines LX-2 and primary rat HSCs were used for in vitro analyses.

RESULTS

Carbon tetrachloride-induced and bile duct ligation-induced liver injury increased the serum FGF23 level compared with that in control mice. RNA sequencing analysis of FGF23-treated LX-2 showed that FGF23 promotes the production of matrisome, which helps in forming the extracellular matrix. The FGF receptor antagonist pemigatinib alleviated carbon tetrachloride-induced and bile duct ligation-induced liver fibrosis and the deleterious alterations in bone density and microstructure in mice.

CONCLUSIONS

The serum FGF23 level increased with liver injury, and FGF23 promoted liver fibrosis. Moreover, pemigatinib alleviated liver fibrosis and hepatic osteodystrophy. These findings suggest that FGF23 mediates the communication between the liver and bone and that FGF23 may be a new therapeutic target for liver fibrosis and subsequent osteodystrophy.

Novel therapeutic targets for cardiorenal syndrome

Cardiorenal syndrome (CRS) is an interdependent dysfunction of the heart and kidneys, where failure in one organ precipitates failure in the other. The pathophysiology involves sustained renin-angiotensin-aldosterone-system (RAAS) activation, mitochondrial dysfunction, inflammation, fibrosis, oxidative stress and tissue remodeling, culminating in organ dysfunction. Existing therapies targeting the RAAS, diuretics and other agents have limitations, including diuretic resistance and compensatory sodium reabsorption. Therefore, there is a pressing need for novel druggable targets involved in CRS pathogenesis. This review addresses the challenges of existing treatments and emphasizes the importance of discovering new therapeutic targets. It highlights emerging targets such as Klotho, sex-determining region Y box 9 (SOX9), receptor-interacting protein kinase 3 (RIPK3), β-amino-isobutyric acid (BAIBA), thrombospondin-1 (TSP-1), among others, with their potential roles in CRS.

Transgenic augmentation of erythroferrone in mice ameliorates anemia in adenine-induced chronic kidney disease

Anemia is a common and disabling complication of chronic kidney disease (CKD). Current therapies can be burdensome, and full correction of anemia is limited by cardiovascular side effects. New approaches that may offer additional therapeutic options are needed. We explored the anti-anemic effects of erythroferrone, an erythroid hormone that induces iron mobilization by suppressing the master iron-regulatory hormone hepcidin. In a preclinical murine model of adenine-induced CKD, transgenic augmentation of erythroferrone mobilized iron, increased hemoglobin concentrations by approximately 2 g/dl, and modestly improved renal function without affecting systemic or renal inflammation, fibrosis, or markers of mineral metabolism. This study supports the concept that therapeutic augmentation of erythroferrone is a promising approach for alleviating CKD-associated anemia.

Phosphorous metabolism and manipulation in chronic kidney disease

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a syndrome commonly observed in subjects with impaired renal function. Phosphate metabolism has been implicated in the pathogenesis of CKD-MBD and according to the phosphorocentric hypothesis may be the key player in the pathogenesis of these abnormalities. As phosphorous is an essential component for life, absorption from the bowel, accumulation and release from the bones, and elimination through the kidneys are all homeostatic mechanisms that maintain phosphate balance through very sophisticated feedback mechanisms, which comprise as main actors: vitamin D (VD), parathyroid hormone (PTH), calciproteins particles (CPPs), fibroblast growth factor-23 (FGF-23) and other phosphatonins and klotho. Indeed, as the renal function declines, factors such as FGF-23 and PTH prevent phosphate accumulation and hyperphosphatemia. However, these factors per se may be responsible for the organ damages associated with CKD-MBD, such as bone osteodystrophy and vascular calcification. We herein review the current understanding of the CKD-MBD focusing on phosphorous metabolism and the impact of phosphate manipulation on surrogate and hard outcomes.

Protein Biomarkers of Adverse Clinical Features and Events in Sarcomeric Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a heterogeneous condition that can lead to atrial fibrillation, heart failure, and sudden cardiac death in many individuals but mild clinical impact in others. The mechanisms underlying this phenotypic heterogeneity are not well defined. The aim of this study was to use plasma proteomic profiling to help illuminate biomarkers that reflect or inform the heterogeneity observed in HCM.

METHODS

The Olink antibody-based proteomic platform was used to measure plasma proteins in patients with genotype positive (sarcomeric) HCM participating in the HCM Registry. We assessed associations between plasma protein levels with clinical features, cardiac magnetic resonance imaging metrics, and the development of atrial fibrillation.

RESULTS

We measured 275 proteins in 701 patients with sarcomeric HCM. There were associations between late gadolinium enhancement with proteins reflecting neurohormonal activation (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and ACE2 [angiotensin-converting enzyme 2]). Metrics of left ventricular remodeling had novel associations with proteins involved in vascular development and homeostasis (vascular endothelial growth factor-D and TM [thrombomodulin]). Assessing clinical features, the European Society of Cardiology sudden cardiac death risk score was inversely associated with SCF (stem cell factor). Incident atrial fibrillation was associated with mediators of inflammation and fibrosis (MMP2 [matrix metalloproteinase 2] and SPON1 [spondin 1]).

CONCLUSIONS

Proteomic profiling of sarcomeric HCM identified biomarkers associated with adverse imaging and clinical phenotypes. These circulating proteins are part of both established pathways, including neurohormonal activation and fibrosis, and less familiar pathways, including endothelial function and inflammatory proteins less well characterized in HCM. These findings highlight the value of plasma profiling to identify biomarkers of risk and to gain further insights into the pathophysiology of HCM.

Left ventricular remodeling and its association with mineral and bone disorder in kidney transplant recipients

BACKGROUND

The assessment of left ventricular (LV) remodeling and its association with mineral and bone disorder (MBD) in kidney transplant recipients (KTRs) have not been systematically studied. We aimed to evaluate LV remodeling changes one year after kidney transplantation (KT) and identify their influencing factors.

METHODS

Ninety-five KTRs (68 males; ages 40.2 ± 10.8 years) were followed before and one year after KT. Traditional risk factors and bone metabolism indicators were assessed. Left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF) and left ventricular diastolic dysfunction (LVDD) were measured using two-dimensional transthoracic echocardiography. The relationship between MBD and LV remodeling and the factors influencing LV remodeling were analyzed.

RESULTS

One year after KT, MBD was partially improved, mainly characterized by hypercalcemia, hypophosphatemia, hyperparathyroidism, 25-(OH) vitamin D deficiency, elevated bone turnover markers, and bone loss. LVMI, the prevalence of left ventricular hypertrophy (LVH), and the prevalence of LVDD decreased, while LVEF increased. LVH was positively associated with postoperative intact parathyroid hormone (iPTH) and iPTH nonnormalization. △LVMI was positively associated with preoperative type-I collagen N-terminal peptide and postoperative iPTH. LVEF was negatively associated with postoperative phosphorous. △LVEF was negatively associated with postoperative iPTH. LVDD was positively associated with postoperative lumbar spine osteoporosis. Preoperative LVMI was negatively associated with △LVMI and positively associated with △LVEF. Advanced age, increased BMI, diabetes, longer dialysis time, lower albumin level, and higher total cholesterol and low-density lipoprotein levels were associated with LV remodeling.

CONCLUSIONS

LV remodeling partially improved after KT, showing a close relationship with MBD.

Impact of successful secondary hyperparathyroidism treatment on cardiovascular morbidity in patients with chronic kidney disease KDIGO stages G3b-5

INTRODUCTION

Chronic kidney disease is common, with a projected increase to 5.4 million people in need of kidney replacement therapy by 2030. As many as 61.7% of patients on hemodialysis have secondary hyperparathyroidism (SHPT). This has been associated with high cardiovascular morbidity. The present study investigates the effect of SHPT treatment success on cardiovascular morbidity in patients with CKD KDIGO stages G3b, 4, and 5.

METHODS

A retrospective single center analysis of 211 chronic kidney disease stages G3b-5 patients undergoing computed tomography for coronary artery calcium (CAC) scoring at the University Hospital of Zurich between 2015 and 2019 was performed. The presence of and control of SHPT was assessed at the timepoint of CAC scoring and 6-12 months prior. Information on left ventricular ejection fraction (LVEF), left ventricular hypertrophy (LVH), and left ventricular myocardial mass index (LVMMI) were calculated from echocardiography values obtained at the timepoint of CAC scoring. Occurrence of major acute cardiovascular events, including acute coronary syndrome (ACS), within 1 year of CAC scoring was drawn from the charts. Independent predictive factors for ACS and LVH were assessed by multivariable analysis.

RESULTS

Thirty-four percent (n=72) of the patients had uncontrolled SHPT, whereas 66% (n=139) had either no (n=18%, n=39) or a controlled SHPT (n=48%, n=100). The CKD stage G3b-5 patients with uncontrolled SHPT had a significantly lower LVEF (p=0.028) and significantly more pronounced LVH (p=0.003) and a higher LVMMI (p=0.002) than the group with either no SHPT or well-controlled SHPT. Uncontrolled SHPT in the observed CKD cohort had a significantly higher risk for developing ACS (p=0.011, HR 2.76, 95%CI 1.26-6.05) compared to no or controlled SHPT patients (41.7% vs 31.7%). While patients with uncontrolled SHPT showed a median CAC score of 290 (IQR 18-866), those with no or controlled SHPT had a lower median CAC score of 194 (IQR 14-869), although not significant (p=0.490). Patients with CAC scores >400 displayed a significantly higher incidence of ACS (56.8% vs 33.1%, p=0.010).

CONCLUSIONS

SHPT is common (82%) in advanced CKD (≥G3b) patients and insufficiently controlled in one-third of patients. Insufficient control of SHPT is associated with higher cardiovascular morbidity, lower LVEF, increased LVH, and a higher incidence of ACS. Thus, increased focus on SHPT control in CKD patients may have a beneficial impact on cardiovascular outcomes.

Anemia and Mineral Bone Disorder in Kidney Disease Patients: The Role of FGF-23 and Other Related Factors

Anemia and mineral and bone disorder (MBD) are significant complications of chronic kidney disease (CKD). The erythropoietin (Epo) pathway plays a key role in both of these processes in CKD. Another molecule that plays an important role in CKD-MBD is fibroblast growth factor (FGF)-23, whose main role is to maintain serum phosphate levels in the normal range, acting via its co-receptor Klotho; however, its activity may also be related to anemia and inflammation. In this review, the regulation of Epo and FGF-23 and the molecular mechanisms of their action are outlined. Furthermore, the complex interaction between EPO and FGF-23 is discussed, as well as their association with other anemia-related factors and processes such as Klotho, vitamin D, and iron deficiency. Together, these may be part of a "kidney-bone marrow-bone axis" that promotes CKD-MBD.

Severe Coronary Artery Calcifications in Chronic Kidney Disease Patients, Coupled with Inflammation and Bone Mineral Disease Derangement, Promote Major Adverse Cardiovascular Events through Vascular Remodeling

INTRODUCTION

Cardiovascular (CV) diseases persist as the foremost cause of morbidity/mortality among chronic kidney disease (CKD) patients. This paper examines the values of coronary artery calcification (CAC) and biomarkers of CV on major adverse CV events (MACE)/CV death in a sample of 425 non-dialysis CKD patients.

METHODS

At inclusion, patients underwent chest multidetector computed tomography for CAC scoring and biomarkers of CV risk including CRP, mineral metabolism markers, fibroblast growth factor-23 (FGF-23), α-Klotho, osteoprotegerin, tartrate-resistant acid phosphatase 5b (TRAP5b), sclerostin, matrix gla protein (both dephosphorylated uncarboxylated [dp-ucMGP] and total uncarboxylated), and growth differentiation factor-15 (GDF-15) were measured. Patients were followed for a median of 3.61 years (25th-75th percentiles = 1.92-6.70).

RESULTS

Our results reported that CAC was a major independent factor of MACE/CV mortality showing a hazard ratio of 1.71 95% (confidence interval = 1.00-2.93) after adjustment for age, gender, diabetes, and history of CV events for patients with CAC >300. Interestingly, CAC effect was further enhanced in the presence of low levels of 25(OH) vitamin D3 or α-Klotho and high levels of intact parathyroid hormone (PTH), high-sensitive C reactive protein, FGF-23, osteoprotegerin, sclerostin, dp-ucMGP, or GDF-15.

CONCLUSION

CAC constitutes a significant CV risk, further exacerbated by inflammation, hyperparathyroidism, and regulation of bone molecules implicated in calcification progression. This finding aligns with the original concept of multiple hits. Consequently, addressing the detrimental environment that fosters plaque vulnerability, reducing chronic low-grade inflammation, and normalizing mineral metabolism markers (such as vitamin D and PTH) and bone-regulating molecules may emerge as a viable therapeutic strategy.

Global Trends and Hotspots in the Association between Chronic Kidney Disease and Cardiovascular Diseases: A Bibliometric Analysis from 2010 to 2023

INTRODUCTION

This study endeavors to evaluate the distribution patterns and research frontiers within the international literature on the association between chronic kidney disease and cardiovascular diseases in the medical field, through bibliometric analysis and visualized information.

METHODS

The Web of Science Core Collection database was selected as the data source from 2010 to 2023, and articles related to the association between chronic kidney disease and cardiovascular diseases were retrieved. The article data were analyzed through CiteSpace for bibliometric mapping, involving the examination of keywords, references, country/region distributions, and institutional contributions to identify and understand the evolving research dynamics and frontiers in this interdisciplinary field.

RESULTS

A total of 2,936 publications on the association between chronic kidney disease and cardiovascular diseases were included. The country with the most publications was USA (n = 904), and the institution with the most publications was University of Pennsylvania (n = 116). The most frequent keywords were chronic kidney disease (n = 2,194), cardiovascular disease (n = 1,188), and mortality (n = 604). The top 20 keywords and top 10 references that burst during 2010 to 2023 were listed.

CONCLUSION

The association between chronic kidney disease and cardiovascular diseases has sparked extensive research, particularly in high-prevalence areas. From 2010 to 2023, publications on the association between chronic kidney disease and cardiovascular diseases show a linear increase. Current research hotspots and frontiers are mainly in cardiovascular-kidney-metabolic syndrome; innovative therapies and drug impact; gut microbiome; Mendelian randomization analysis. Overall, our study offers a comprehensive scientometric analysis of the association between chronic kidney disease and cardiovascular diseases, providing valuable insights for both researchers and healthcare professionals in the field.

[Non-classical hormones from the fibroblast growth factor family]

Fibroblast growth factors (FGFs) are a group of signaling molecules named for their ability to promote the growth and proliferation of fibroblasts and various other cell types. Typically, FGFs exert their effects locally by binding to receptors within the tissues where they are synthesized. However, certain members of this family, such as FGF 19, FGF 21, and FGF 23, diverge from this pattern. Following synthesis, these FGFs enter the bloodstream and act on distant organs and tissues by binding to their receptors and associated cofactors, thereby classified as non-classical hormones within the FGF family.The biological functions of FGFs are diverse and contingent upon the specific receptors and cofactors involved in their signaling pathways. For instance, FGF 19 and FGF 21 play crucial roles in regulating glucose and lipid metabolism, whereas FGF 23 primarily influences phosphorus metabolism. Given their varied roles, FGFs present promising targets for therapeutic interventions and drug development.This review aims to consolidate current understanding of FGF family hormones, elucidating their biological impacts and exploring their potential applications as therapeutic targets.

Fibroblast Growth Factors in Cardiovascular Disease

Despite advancements in managing traditional cardiovascular risk factors, many cardiovascular diseases (CVDs) persist. Fibroblast growth factors (FGFs) have emerged as potential diagnostic markers and therapeutic targets for CVDs. FGF1, FGF2, and FGF4 are primarily used for therapeutic angiogenesis. Clinical applications are being explored based on animal studies using approaches such as recombinant protein administration and adenovirus-mediated gene delivery, targeting patients with coronary artery disease and lower extremity arterial disease. Although promising results have been observed in animal models and early-stage clinical trials, further studies are required to assess their therapeutic potential. The FGF19 subfamily, consisting of FGF19, FGF21, and FGF23, act via endocrine signaling in various organs. FGF19, primarily expressed in the small intestine, plays important roles in glucose, lipid, and bile acid metabolism and has therapeutic potential for metabolic disorders. FGF21, found in various tissues, improves glucose metabolism and insulin sensitivity, suggesting potential for treating obesity and diabetes. FGF23, primarily secreted by osteocytes, regulates vitamin D and phosphate metabolism and serves as an important biomarker for chronic kidney disease and CVDs. Thus, FGFs holds promise for both therapeutic and diagnostic applications in metabolic and cardiovascular diseases. Understanding the mechanisms of FGF may pave the way for novel strategies to prevent and manage CVDs, potentially addressing the limitations of current treatments. This review explores the roles of FGF1, FGF2, FGF4, and the FGF19 subfamily in maintaining cardiovascular health. Further research and clinical trials are crucial to fully understand the therapeutic potential of FGFs in managing cardiovascular health.

Lupus nephritis-related chronic kidney disease

Lupus nephritis is a common complication of systemic lupus erythematosus (SLE) and a determinant of overall morbidity and mortality, as lupus nephritis-related chronic kidney disease (CKD) drives cardiovascular disease and secondary immunodeficiency. Two lines of action are required to prevent the progression of lupus nephritis-related CKD: suppression of autoimmune SLE activity, which is a risk factor for immunopathology-related irreversible kidney injury, and management of non-immune risk factors that contribute to CKD progression. As each episode or relapse of active lupus nephritis implicates CKD progression, preventing flares of lupus nephritis is a key treatment target. Non-immune risk factors of CKD mostly include causes of nephron hyperfiltration, such as obesity, hypertension, sodium- or protein-rich diets and type 2 diabetes mellitus, as well as pregnancy. Nephrotoxic agents and smoking also drive kidney cell loss. Intrinsic risk factors for CKD progression include poor nephron endowment because of prematurity at birth, nephropathic genetic variants, ageing, male sex and previous or concomitant kidney diseases. Care for lupus nephritis involves the control of all modifiable risk factors of CKD progression. In addition, remnant nephron overload can be reduced using early dual therapy with inhibitors of the renin-angiotensin system and sodium-glucose transporter-2, whereas further renoprotective drug interventions are underway. As patients with lupus nephritis are at risk of CKD progression, they would all benefit from interdisciplinary care to minimize the risk of kidney failure, cardiovascular disease and infections.

Targeted Deletion of Fibroblast Growth Factor 23 Rescues Metabolic Dysregulation of Diet-induced Obesity in Female Mice

Fibroblast growth factor 23 (FGF23) is a bone-secreted protein widely recognized as a critical regulator of skeletal and mineral metabolism. However, little is known about the nonskeletal production of FGF23 and its role in tissues other than bone. Growing evidence indicates that circulating FGF23 levels rise with a high-fat diet (HFD) and they are positively correlated with body mass index (BMI) in humans. In the present study, we show for the first time that increased circulating FGF23 levels in obese humans correlate with increased expression of adipose Fgf23 and both positively correlate with BMI. To understand the role of adipose-derived Fgf23, we generated adipocyte-specific Fgf23 knockout mice (AdipoqFgf23Δfl/Δfl) using the adiponectin-Cre driver, which targets mature white, beige, and brown adipocytes. Our data show that targeted ablation of Fgf23 in adipocytes prevents HFD-fed female mice from gaining body weight and fat mass while preserving lean mass but has no effect on male mice, indicating the presence of sexual dimorphism. These effects are observed in the absence of changes in food and energy intake. Adipose Fgf23 inactivation also prevents dyslipidemia, hyperglycemia, and hepatic steatosis in female mice. Moreover, these changes are associated with decreased respiratory exchange ratio and increased brown fat Ucp1 expression in knockout mice compared to HFD-fed control mice (Fgf23fl/fl). In conclusion, this is the first study highlighting that targeted inactivation of Fgf23 is a promising therapeutic strategy for weight loss and lean mass preservation in humans.