Short daily hemodialysis is associated with lower plasma FGF23 levels when compared with conventional hemodialysis

Plasma FGF23 is associated with left atrial remodeling in children on hemodialysis

BACKGROUND

FGF23 mediates cardiac fibrosis through the activation of pro-fibrotic factors in in vitro models and is markedly elevated in kidney disease. Left atrial global longitudinal strain (LA GLS) derived by echocardiographic speckle-tracking measures longitudinal shortening of the LA walls, quantifies atrial performance and may enable detection of early LA remodeling in the setting of normal ventricular function. We hypothesized that LA GLS is abnormal in children on hemodialysis (HD) compared to healthy controls of comparable age/sex distribution and that, among HD patients, greater FGF23 levels are associated with abnormal LA GLS.

METHODS

Clinical and echocardiographic data from 29 children receiving HD and 13 healthy controls were collected in a cross-sectional single-center study. Plasma FGF23 concentrations were measured using ELISA. The primary outcome was LA GLS measured using 2D speckle-tracking strain analysis. Linear regression analysis was used to investigate predictors of LA GLS in HD.

RESULTS

Median dialysis vintage was 1.5 (IQR 0.5-4.3) years. Median intact FGF23 levels were substantially higher in the HD vs. control group (1206 [215, 4707] vs. 51 [43, 66.5] pg/ml; P = 0.0001), and LA GLS was 39.9% SD 11.6 vs. 32.8% SD 5.7 (P = 0.04). Among HD patients, higher FGF23 was associated with lower LA GLS (β per unit Ln-FGF23: - 2.7; 95% CI slope - 5.4, - 0.1; P = 0.04 after adjustment for age, body size, and HD vintage. FGF23 was not associated with LA phasic reservoir, conduit, or contractile strain.

CONCLUSIONS

In children on HD and preserved left ventricular ejection fraction, greater FGF23 is associated with lower LA GLS (indicative of impaired atrial performance). A higher resolution version of the Graphical abstract is available as Supplementary information.

Low-Volume Home Haemodialysis and In-Centre Haemodialysis: Comparison of Dialysis Adequacy in Obese Individuals

Background Although frequent low-flow, low-volume haemodialysis using the NxStage System One is now well-established as an option for home therapy of end-stage chronic kidney disease, its ability to deliver adequate dialysis in people with high BMI remains questionable. This doubt may lead to obese individuals being denied the potential benefits of this modality. To establish if this doubt is justified, we compared dialysis adequacy in two groups of obese individuals; one receiving standard thrice-weekly in-centre haemodialysis and the other receiving frequent haemodialysis at home using the NxStage System One. Methods This is a retrospective observational cohort study of 105 adult dialysis patients with obesity (BMI ≥ 30 kg/m2). All had been on dialysis for at least six months. Fifty-five patients receiving in-centre haemodialysis were compared with 50 patients receiving home haemodialysis using NxStage System One. Dialysis adequacy (standard Kt/V calculated by the Daugirdas equation) was compared between the two groups. The clinical characteristics, laboratory test results, and treatment regimens of each group were also compared. Results The in-centre haemodialysis group was older (63.6 ± 12.8 years vs. 58.5 ± 10.9 years, p=0.033) and had a higher Charlson comorbidity score (5.9 ± 2.1 vs. 4.5 ± 2.5, p=0.003). Standard Kt/V was significantly higher in the home haemodialysis group (2.4 ± 0.5) than in the in-centre haemodialysis group (2.2 ± 0.2) (p = 0.006). The mean serum inorganic phosphate was significantly lower in the home haemodialysis group than in the in-centre haemodialysis group (1.6 ± 0.4 mmol/l vs. 1.8 ± 0.5 mmol/l, p = 0.010). There were no statistically significant differences in the usage of antihypertensives, phosphate binders, or erythropoiesis-stimulating agents between the two groups. Conclusions In this study, dialysis adequacy (expressed as standard Kt/V) was superior to that of standard thrice-weekly in-center haemodialysis delivered by frequent low-volume home haemodialysis using the NxStage System One. Hesitancy about recommending frequent low-volume home haemodialysis to obese individuals is therefore unjustified.

Managing Transition between dialysis modalities: a call for Integrated care In Dialysis Units

Summary Patients with chronic kidney disease have three main possible groups of dialysis techniques: in-center hemodialysis, peritoneal dialysis, and home hemodialysis. Home dialysis techniques have been associated with clinical outcomes that are equivalent and sometimes superior to those of in-center hemodialysisTransitions between treatment modalities are crucial moments. Transition periods are known as periods of disruption in the patient’s life associated with major complications, greater vulnerability, greater mortality, and direct implications for quality of life. Currently, it is imperative to offer a personalized treatment adapted to the patient and adjusted over time.An integrated treatment unit with all dialysis treatments and a multidisciplinary team can improve results by establishing a life plan, promoting health education, medical and psychosocial stabilization, and the reinforcement of health self-care. These units will result in gains for the patient’s journey and will encourage home treatments and better transitions.Peritoneal dialysis as the initial treatment modality seems appropriate for many reasons and the limitations of the technique are largely overcome by the advantages (namely autonomy, preservation of veins, and preservation of residual renal function).The transition after peritoneal dialysis can (and should) be carried out with the primacy of home treatments. Assisted dialysis must be considered and countries must organize themselves to provide an assisted dialysis program with paid caregivers.The anticipation of the transition is essential to improve outcomes, although there are no predictive models that have high accuracy; this is particularly important in the transition to hemodialysis (at home or in-center) in order to plan autologous access that allows a smooth transition.

Hemodiafiltration Is Associated With Reduced Inflammation and Increased Bone Formation Compared With Conventional Hemodialysis in Children: The HDF, Hearts and Heights (3H) Study

Background

Patients on dialysis have a high burden of bone-related comorbidities, including fractures. We report a post hoc analysis of the prospective cohort study HDF, Hearts and Heights (3H) to determine the prevalence and risk factors for chronic kidney disease-related bone disease in children on hemodiafiltration (HDF) and conventional hemodialysis (HD).

Methods

The baseline cross-sectional analysis included 144 children, of which 103 (61 HD, 42 HDF) completed 12-month follow-up. Circulating biomarkers of bone formation and resorption, inflammatory markers, fibroblast growth factor-23, and klotho were measured.

Results

Inflammatory markers interleukin-6, tumor necrosis factor-α, and high-sensitivity C-reactive protein were lower in HDF than in HD cohorts at baseline and at 12 months (P < .001). Concentrations of bone formation (bone-specific alkaline phosphatase) and resorption (tartrate-resistant acid phosphatase 5b) markers were comparable between cohorts at baseline, but after 12-months the bone-specific alkaline phosphatase/tartrate-resistant acid phosphatase 5b ratio increased in HDF (P = .004) and was unchanged in HD (P = .44). On adjusted analysis, the bone-specific alkaline phosphatase/tartrate-resistant acid phosphatase 5b ratio was 2.66-fold lower (95% confidence interval, −3.91 to −1.41; P < .0001) in HD compared with HDF. Fibroblast growth factor-23 was comparable between groups at baseline (P = .52) but increased in HD (P < .0001) and remained unchanged in HDF (P = .34) at 12 months. Klotho levels were similar between groups and unchanged during follow-up. The fibroblast growth factor-23/klotho ratio was 3.86-fold higher (95% confidence interval, 2.15–6.93; P < .0001) after 12 months of HD compared with HDF.

Conclusion

Children on HDF have an attenuated inflammatory profile, increased bone formation, and lower fibroblast growth factor-23/klotho ratios compared with those on HD. Long-term studies are required to determine the effects of an improved bone biomarker profile on fracture risk and cardiovascular health.

Fibroblast growth factor 23 (FGF23) level is associated with ultrafiltration rate in patients on hemodialysis

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. High circulating FGF23 levels are associated with increased mortality in patients with chronic kidney disease and those on dialysis. Current data also suggest higher circulating levels of FGF23 are associated with cardiovascular mortality, vascular calcification, and left ventricular hypertrophy; however, evidence on the role of FGF23 in patients on dialysis is incomplete, and some of the data, especially those on cardiovascular disease (CVD), are controversial. This study aimed to evaluate factors associated with FGF23 in hemodialysis patients with or without CVD. Randomly selected 76 patients on maintenance hemodialysis at a single hemodialysis center were enrolled. After the exclusion of eight patients with extremely outlying FGF23 levels, 68 patients, including 48 males and 46 patients with a CVD history, were included in the study. The mean age was 64.4 ± 12.1 years, and the mean dialysis duration was 12.7 ± 7.1 years. Dialysis duration, time-averaged concentration of urea (TAC-urea), ultrafiltration rate (UFR), blood pressure during hemodialysis session, laboratory data, and echocardiographic parameters including interventricular septum thickness (IVST), left ventricular mass indices (LVMI), and ejection fraction were included in univariate and multivariate analyses. The median lgFGF23 levels in the overall cohort and in those with and without CVD were 2.14 (interquartile range, IQR − 0.43 to − 4.23), 2.01 (− 0.52 to 4.12), and 2.59 (0.07 to 4.32), respectively, and there was no difference between the patients with and without CVD (p = 0.14). The univariate analysis revealed that FGF23 was significantly associated with age (r =  − 0.12, p < 0.01), duration of hemodialysis (r =  − 0.11, p < 0.01), TAC-urea (r = 0.29, p = 0.01), UFR (r = 0.26, p = 0.04), alkaline phosphatase (ALP; r =  − 0.27, p = 0.03), corrected serum calcium (cCa; r = 0.32, p < 0.01), serum phosphate (iP, r = 0.57, p < 0.01), intact parathyroid hormone (iPTH; r = 0.38, p < 0.01), IVST (r = 0.30, p = 0.01), and LVMI (r = 0.26, p = 0.04). In multivariate regression analysis, FGF23 was significantly associated with cCa (F = 25.6, p < 0.01), iP (F = 22.5, p < 0.01), iPTH (F = 19.2, p < 0.01), ALP (F = 5.34, p = 0.03), and UFR (F = 3.94, p = 0.05). In addition, the univariate analysis after the categorization of patients according to CVD indicated that FGF23 was significantly associated with cCa (r = 0.34, p = 0.02), iP (r = 0.41, p < 0.01), iPTH (r = 0.39, p = 0.01), and TAC-urea (r = 0.45, p < 0.01) in patients with CVD, whereas only IVST (r = 0.53, p = 0.04) was associated with FGF23 in those without CVD. FGF23 levels in hemodialysis patients were extremely high and associated not only with mineral bone disease-related factors but also with UFR. Additionally, dialysis efficacy might be associated with lower FGF23 levels in patients with CVD.

Clinical Potential of Targeting Fibroblast Growth Factor-23 and αKlotho in the Treatment of Uremic Cardiomyopathy

Chronic kidney disease is highly prevalent, affecting 10% to 15% of the adult population worldwide and is associated with increased cardiovascular morbidity and mortality. As chronic kidney disease worsens, a unique cardiovascular phenotype develops characterized by heart muscle disease, increased arterial stiffness, atherosclerosis, and hypertension. Cardiovascular risk is multifaceted, but most cardiovascular deaths in patients with advanced chronic kidney disease are caused by heart failure and sudden cardiac death. While the exact drivers of these deaths are unknown, they are believed to be caused by uremic cardiomyopathy: a specific pattern of myocardial hypertrophy, fibrosis, with both diastolic and systolic dysfunction. Although the pathogenesis of uremic cardiomyopathy is likely to be multifactorial, accumulating evidence suggests increased production of fibroblast growth factor-23 and αKlotho deficiency as potential major drivers of cardiac remodeling in patients with uremic cardiomyopathy. In this article we review the increasing understanding of the physiology and clinical aspects of uremic cardiomyopathy and the rapidly increasing knowledge of the biology of both fibroblast growth factor-23 and αKlotho. Finally, we discuss how dissection of these pathological processes is aiding the development of therapeutic options, including small molecules and antibodies, directly aimed at improving the cardiovascular outcomes of patients with chronic kidney disease and end-stage renal disease.

The stability and variability of serum and plasma fibroblast growth factor-23 levels in a haemodialysis cohort

Background

Serum fibroblast growth factor 23 (FGF-23) levels are markedly elevated in haemodialysis patients and have been linked to mortality outcomes. Small studies in health and chronic kidney disease, have demonstrated marked intra- and inter-individual variability in measured FGF-23 levels, and variable degradation in serum as compared to plasma samples. In end-stage kidney disease (ESKD), the intra- and inter-individual variability of FGF-23 levels, and the optimal collection methods remain poorly characterized. In this study we assessed the variability of FGF-23 levels in a cohort of stable haemodialysis patients. Secondly, in a subset of patients, we assessed the effects of different collection methods on measured FGF-23 levels.

Methods

To assess the variability of FGF-23, pre-dialysis blood samples were collected over 3 consecutive weeks from 75 haemodialysis patients. The effects of different specimen collection methods were examined in a subset of patients (n = 23), with pre-dialysis blood collected into different tubes: plain (serum), EDTA (plasma) and EDTA with the addition of a protease inhibitor (EDTA-PI). All analyses were performed in the main cohort and repeated in each subgroup. Variability over a 3-week period was assessed using repeated measures ANOVA and random effects linear regression models. Intra-class correlation coefficients were calculated to assess agreement, and coefficients of variation were calculated to assess intra- and inter-individual variability.

Results

Over the 3-week study period the mean FGF-23 levels were not significantly different in the serum (p = 0.26), EDTA (p = 0.62) and EDTA-PI (p = 0.55) groups. FGF-23 levels demonstrated marked intra- and inter-individual variability with a CV of 36 and 203.2%, respectively. In the subgroup analysis, the mean serum FGF-23 levels were significantly lower than the EDTA (p < 0.001) or EDTA-PI (p < 0.001) groups, however there was no difference in mean FGF-23 levels between EDTA and EDTA-PI (p = 0.54).

Conclusions

The measured FGF-23 levels were significantly lower in serum as compared to plasma, and the addition of a protease inhibitor did not confer an additional benefit. Importantly in this cohort of ESKD patients, FGF-23 levels showed marked intra- and inter-individual variability. The routine measurement of FGF-23 in ESKD remains challenging, however this study suggests the plasma is the optimal collection method for FGF-23 analysis.

Pharmacokinetic Study of Cefazolin in Short Daily Hemodialysis

Background: A number of centers across the world offer short daily hemodialysis (SDHD) treatments. To date, cefazolin pharmacokinetics have not been described in patients undergoing SDHD. Objective: The purpose of this study was to investigate the effect of SDHD on the pharmacokinetics of cefazolin. Methods: This was a prospective, open-label, pharmacokinetic study of cefazolin during SDHD in 10 noninfected patients. Participants received a 1-g intravenous (IV) infusion of cefazolin after SDHD on study day 1 and a second dose after SDHD on study day 2. To determine the concentration of cefazolin, 6 blood samples were drawn at 0, 1, 2, 2.3, 4, and 24 hours after initiation of dialysis on day 2, and 2 dialysate samples were drawn at 1 and 2 hours after initiation of dialysis on day 2. Samples were analyzed using high-performance liquid chromatography, and pharmacokinetic parameters were determined. Results: Median interdialysis clearance was 0.16 L/h (interquartile range [IQR]: 0.11-0.21 L/h), and median intradialysis clearance was 1.95 L/h (IQR: 1.66-2.45 L/h). Median interdialysis half-life was 28.2 hours (IQR: 23.5-59.3 hours) as compared with a median intradialysis half-life of 2.3 hours (IQR: 1.7-2.7 hours). The median percentage removal of cefazolin during dialysis was 41% (IQR: 35%-53%). Conclusion and Relevance: Estimated cefazolin dialysis clearance is similar to previous estimates with conventional thrice-weekly regimens. Current dosing recommendations of 1 g IV post-SDHD achieve total serum drug concentrations greater than 40 mg/L in all patients, which is the total drug concentration required for bactericidal activity against Staphylococcus species.

Fractures and Osteomalacia in a Patient Treated With Frequent Home Hemodialysis

Bone deformities and fractures are common consequences of renal osteodystrophy in the dialysis population. Persistent hypophosphatemia may be observed with more frequent home hemodialysis regimens, but the specific effects on the skeleton are unknown. We present a patient with end-stage renal disease treated with frequent home hemodialysis who developed severe bone pain and multiple fractures, including a hip fracture and a tibia-fibula fracture complicated by nonunion, rendering her nonambulatory and wheelchair bound for more than a year. A bone biopsy revealed severe osteomalacia, likely secondary to chronic hypophosphatemia and hypocalcemia. Treatment changes included the addition of phosphate to the dialysate, a higher dialysate calcium concentration, and increased calcitriol dose. Several months later, the patient no longer required a wheelchair and was able to ambulate without pain. Repeat bone biopsy revealed marked improvements in bone mineralization and turnover parameters. Also, with increased dialysate phosphate and calcium concentrations, as well as increased calcitriol, circulating fibroblast growth factor 23 levels increased.

Extrarenal effects of FGF23

Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular mortality, infections, and impaired cognitive function. It is characterized by excessively increased levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23) and a deficiency of its co-receptor Klotho. Despite the important physiological effect of FGF23 in maintaining phosphate homeostasis, there is increasing evidence that higher FGF23 levels are a risk factor for mortality and cardiovascular disease. FGF23 directly induces left ventricular hypertrophy via activation of the FGF receptor 4/calcineurin/nuclear factor of activated T cells signaling pathway. By contrast, the impact of FGF23 on endothelial function and the development of atherosclerosis are poorly understood. The results of recent experimental studies indicate that FGF23 directly impacts on hippocampal neurons and may thereby impair learning and memory function in CKD patients. Finally, it has been shown that FGF23 interferes with the immune system by directly acting on polymorphonuclear leukocytes and macrophages. In this review, we discuss recent data from clinical and experimental studies on the extrarenal effects of FGF23 with respect to the cardiovascular, central nervous, and immune systems.

Acetate-free biofiltration to remove fibroblast growth factor 23 in hemodialysis patients: a pilot study

AIM

Serum levels of 32 kDa-phosphaturic hormone fibroblast growth factor 23 (FGF23) rise early in renal failure in order to keep phosphatemia within the normal range; however, this compensatory mechanism itself contributes to chronic kidney disease-mineral bone disorder. High FGF23 is also associated to left ventricular hypertrophy, vascular calcifications and thus increased cardiovascular risk. The aim of this pilot pre-post study was to evaluate the effects of a single hemodiafiltration session with acetate-free biofiltration (AFB) on FGF23 serum levels.

METHODS

Nine hemodialysis patients were enrolled; sessions were performed using the Integra^® monitor (Hospal, Bologna, Italy) and a polyacrylonitrile membrane. Peripheral venous blood samples were taken before (pre-HD), at mid- and after treatment (post-HD); dialysate samples were collected by the Quantiscan™ monitoring system. FGF23 was measured by a human FGF-23 ELISA kit. Mid- and post-HD values were corrected for hemoconcentration.

RESULTS

Pre-HD FGF23 levels positively correlated with dialysis vintage (r = 0.7192; p = 0.0443). They were significantly reduced by the hemodialysis session (from 2.38 ± 1.80 to 1.15 ± 1.21 ng/ml, p = 0.0171) with a reduction ratio of 52.55 ± 28.76%. FGF23 was detected in the dialysate samples.

CONCLUSION

FGF23 underwent a significant reduction during AFB. Such removal was greater than that induced by conventional hemodialysis as reported in the literature (19%-decrease using modified cellulosic membranes). This difference may be attributed to the ability of AFB hemodiafiltration to efficiently remove middle molecules by convection. Whether a better clearance of FGF23 during hemodialysis may result in improved cardiovascular outcomes in the long term needs to be confirmed by randomized controlled trials.

[Low flux dialysate daily home hemodialysis: A result for the 62 first French and Belgian patients]

Since 2011, a new device is available for low flux dialysate quotidian home hemodialysis in France and Belgium. This study aims to evaluate the characteristics and dialysis prescriptions for Nx Stage System One™ users. We retrospectively included patients trained between 2011 and 2013 in France and Belgium. We collected data concerning their clinical features, their dialysis prescriptions, their laboratory parameters until 6 months of dialysis and, reason for dropping in case of cessation. Sixty-two patients from 31 centers, aged 48±18 years old, with a sex ratio 46/16 (M/F) are included with a median Charlson comorbidity index of 1 [0-3]. Of these patients, 71% are anuric and have been on dialysis for a mean time of 136.6±125 months. Previously, most of them had been taken care of in satellite units of dialysis (45%) and 14% are incident patients. In total, A total of 60% have an arterio-veinous fistula (AVF), with 18 patients using the Buttonhole system and 2 patients have a tunneled catheter. Median time for training was 26.5 days (17-45). Among the patients, 69% are dialyzed 6 days a week, during a mean time of 142.5±20 minutes with a volume of 20.9±3 liters of dialysate and without anticoagulant (63%). Predialytic levels of hemoglobin, creatinin, urea, phosphorus and β2microglobulin remain stable. On the contrary, there is a significant improvement of albumin and bicarbonate levels. Technique survival was 75% at 1 year, and major reason for cessation was kidney transplant. It seems that this device fits for young patients, with few comorbidities and a long past in renal chronic failure. These results suggest that dialysis adequacy is acceptable despite low dialysate volumes but need confirmation with a longer follow up and a larger cohort.

Fibroblast growth factor 23 correlates with volume status in haemodialysis patients and is not reduced by haemodialysis

BACKGROUND

Recent data suggest a role for fibroblast growth factor 23 (FGF-23) in volume regulation. In haemodialysis patients, a large ultrafiltration volume (UFV) reflects poor volume control, and both FGF-23 and a large UFV are risk factors for mortality in this population. We studied the association between FGF-23 and markers of volume status including UFV, as well as the intradialytic course of FGF-23, in a cohort of haemodialysis patients.

METHODS

We carried out observational, post hoc analysis of 109 prevalent haemodialysis patients who underwent a standardized, low-flux, haemodialysis session with constant ultrafiltration rate. We measured UFV, plasma copeptin and echocardiographic parameters including cardiac output, end-diastolic volume and left ventricular mass index at the onset of the haemodialysis session. We measured the intradialytic course of plasma C-terminal FGF-23 (corrected for haemoconcentration) and serum phosphate levels at 0, 1, 3 and 4 h after onset of haemodialysis and analysed changes with linear mixed effect model.

RESULTS

Median age was 66 (interquartile range: 51-75) years, 65% were male with a weekly Kt/V 4.3 ± 0.7 and dialysis vintage of 25.4 (8.5-52.5) months. In univariable analysis, pre-dialysis plasma FGF-23 was associated with UFV, end-diastolic volume, cardiac output, early diastolic velocity e' and plasma copeptin. In multivariable regression analysis, UFV correlated with FGF-23 (standardized β: 0.373, P < 0.001, model R(2): 57%), independent of serum calcium and phosphate. The association between FGF-23 and echocardiographic volume markers was lost for all but cardiac output upon adjustment for UFV. Overall, FGF-23 levels did not change during dialysis [7627 (3300-13 514) to 7503 (3109-14 433) RU/mL; P = 0.98], whereas phosphate decreased (1.71 ± 0.50 to 0.88 ± 0.26 mmol/L; P < 0.001).

CONCLUSIONS

FGF-23 was associated with volume status in haemodialysis patients. The strong association with UFV suggests that optimization of volume status, for example by more intensive haemodialysis regimens, may also benefit mineral homeostasis. A single dialysis session did not lower FGF-23 levels.

Prognostic value and link to atrial fibrillation of soluble Klotho and FGF23 in hemodialysis patients

Deranged calcium-phosphate metabolism contributes to the burden of morbidity and mortality in dialysis patients. This study aimed to assess the association of the phosphaturic hormone fibroblast growth factor 23 (FGF23) and soluble Klotho with all-cause mortality. We measured soluble Klotho and FGF23 levels at enrolment and two weeks later in 239 prevalent hemodialysis patients. The primary hypothesis was that low Klotho and high FGF23 are associated with increased mortality. The association between Klotho and atrial fibrillation (AF) at baseline was explored as secondary outcome. AF was defined as presence of paroxysmal, persistent or permanent AF. During a median follow-up of 924 days, 59 (25%) patients died from any cause. Lower Klotho levels were not associated with mortality in a multivariable adjusted analysis when examined either on a continuous scale (HR 1.25 per SD increase, 95% CI 0.84–1.86) or in tertiles, with tertile 1 as the reference category (HR for tertile two 0.65, 95% CI 0.26–1.64; HR for tertile three 2.18, 95% CI 0.91–2.23). Higher Klotho levels were associated with the absence of AF in a muItivariable logistic regression analysis (OR 0.66 per SD increase, 95% CI 0.41–1.00). Higher FGF23 levels were associated with mortality risk in a multivariable adjusted analysis when examined either on a continuous scale (HR 1.45 per SD increase, 95% CI 1.05–1.99) or in tertiles, with the tertile 1 as the reference category (HR for tertile two 1.63, 95% CI 0.64–4.14; HR for tertile three 3.91, 95% CI 1.28–12.20). FGF23 but not Klotho levels are associated with mortality in hemodialysis patients. Klotho may be protective against AF.

Coronary artery calcification and cardiovascular disease in children with chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death in children and young adults with end-stage renal disease (ESRD). As adults, children with advanced chronic kidney disease (CKD) have extremely high prevalence of traditional and uremia-related cardiovascular risk factors. Coronary artery calcification is one of the earliest cardiovascular markers detected in children with ESRD. The purpose of this review is to examine the new developments in pathogenesis of coronary artery calcification and to describe recently published studies on this topic in children with CKD.

RECENT FINDINGS

There is growing evidence that fibroblast growth factor 23 (FGF23) and Klotho factor play a key role in the development of coronary artery calcification in ESRD. Recent studies have shown that induction of vascular calcification begins in early normophosphatemic CKD by the reduction of vascular Klotho and increased FGF23 secretion. Pediatric studies confirmed the presence of abnormal FGF23 and Klotho metabolism and the association of increased circulating FGF23 with coronary artery calcification in children with CKD.

SUMMARY

New developments in our understanding of the mechanisms of vascular calcification in patients with early CKD require further investigation of whether control of FGF23/Klotho metabolism will prevent or delay the development of coronary artery calcification and other cardiovascular outcomes.