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Older patients with chronic kidney disease (CKD) undergoing maintenance hemodialysis are at a higher risk of falling. However, there is no standard method to screen patients at higher risk. We have evaluated whether calf circumference (CC) measurement would be able to predict falls in this population.This is a prospective study that enrolled patients aged ≥65 years on conventional hemodialysis, followed for 6 months. The presence of falls was associated with demographical, clinical, and biochemical data. Reduced CC was set at34 cm for men and33 cm for women. We evaluated physical status using Duke activity status index (DASI) and hand grip strength (HGS).Ninety-one patients were included (age 73.7 ± 5.4 years, 69.2% men, 56% with diabetes). Mean CC was 32.6 ± 3.7 cm, with a high prevalence of reduced CC (61.5%). During the follow-up, 13 falls were identified (1 had a fracture and died). These patients were older and heavier (P = .017 and P = .025, respectively). Most falls occurred in patients with sarcopenic obesity (BMI27 kg/mCC measurement, an easy and nonexpensive tool, was able to predict falls in older patients on HD. Further studies should test the inclusion of CC in a fall risk assessment in older patients on hemodialysis.

Objective to explore the status of concentration of klotho and fibroblast growth factor 23 (FGF23) in cerebrospinal fluid (CSF) of patients with narcolepsy. Patients/methods 59 patients with narcolepsy and 17 control individuals were enrolled. We used radioimmunoassay, human klotho enzyme-linked immunosorbent assay (ELISA), human intact FGF23 ELISA and spectrophotometry to measure hypocretin-1, klotho, FGF-23 and phosphorus, respectively. T-Student Test was used to compare klotho and phosphate concentrations, Mann–Whitney U Test were used to compare FGF-23 levels between groups. ANOVA Test was used to compare klotho and phosphate CSF concentrations among narcolepsy patients with CSF hypocretin-1 110 pg/ml (HCRT+) versus control subjects. Results Klotho and phosphorus CSF levels were lower in narcoleptic patients than in control (908.18 ± 405.51 versus 1265.78 ± 523.26 pg/ml; p = 0.004 and 1.34 ± 0.25 versus 1.58 ± 0.23 mg/dl; p = 0.001, respectively). We found higher FGF-23 levels in narcoleptic patients (5.51 versus 4.00 pg/mL; p = 0.001). Klotho and phosphorus CSF levels were lower in both HCRT- and HCRT+ than controls. Moreover, there were higher FGF-23 levels in both HCRT-/HCRT+ groups versus controls. However, we did not find differences comparing HCRT- and HCRT+ groups, analyzing CSF klotho, FGF-23 or phosphorus levels. Conclusions Patients with narcolepsy have decreased CSF concentration of klotho and increased CSF levels of FGF-23. These findings may play a role in understanding the pathogenesis of narcolepsy.

Background Although a successful kidney transplant (KTx) improves most of the mineral and bone disorders (MBD) produced by chronic kidney disease (CKD), hyperparathyroidism may persist (pHPT). Current guidelines recommend parathyroidectomy if serum parathormone is persistently elevated 1 year after KTx, because pHPT has been recently associated with poor graft outcomes. However, whether patients with pHPT and adequate renal function are at risk for long-term graft failure is unknown. Methods Longitudinal follow-up of 911 adults submitted to KTx between January 2005 and December 2014, with estimated glomerular filtration rate (eGFR) ≥ 30 mL/min 1 year after surgery. Clinical and laboratory data were collected from electronic database. Graft failure was defined as return to dialysis. Results Overall, 62% of the patients were classified as having pHPT 1 year after KTx. After a mean follow-up time of 47 months, there were 59 graft failures (49 in pHPT and 10 in non-pHPT group, P = .003). At last follow-up, death-censored graft survival was lower in the pHPT group (P = .009), even after adjustment for age at KTx, donor age, donor type, acute rejection, parathyroidectomy, and eGFR at 1 year after transplantation (odds ratio [OR] 1.99; 1.004–3.971; P = .049). A PTH of 150 pg/mL at 6 months was the best cutoff to predict pHPT at 1 year (specificity = 92.1%). Conclusion Having pHPT after a successful KTx increases the long-term risk of death-censored graft failure. This result highlights the need for better recognition and management of CKD-MBD before and during the first year after KTx, and opens a discussion on the more appropriate timing to perform parathyroidectomy.

Chronic Kidney Disease (CKD)-Mineral and Bone Disorder (CKD-MBD) is a complex disease that is not completely understood. However, some factors secreted by the osteocytes might play an important role in its pathophysiology. Therefore, we evaluated the bone expression of proteins in a group of patients with CKD 2-3, CKD 4, and CKD 5 on dialysis and healthy individuals. We also tested several bone remodeling markers, and correlated these levels with bone biopsy findings. As expected, as serum calcium decreased, serum phosphate, alkaline phosphatase, fibroblast growth factor-23 (FGF-23), parathyroid hormone, and osteoprotegerin increased, as CKD progressed. Additionally, there was a gradual increase in bone resorption associated with a decrease in bone formation and impairment in bone mineralization. Bone expression of sclerostin and parathyroid hormone receptor-1 seemed to be increased in earlier stages of CKD, whereas FGF-23 and phosphorylated β-catenin had increased expression in the late stages of CKD, although all these proteins were elevated relative to healthy individuals. Immunohistochemical studies showed that FGF-23 and sclerostin did not co-localize, suggesting that distinct osteocytes produce these proteins. Moreover, there was a good correlation between serum levels and bone expression of FGF-23. Thus, our studies help define the complex mechanism of bone and mineral metabolism in patients with CKD. Linkage of serum markers to bone expression of specific proteins may facilitate our understanding and management of this disease.

Although it is recognized that cortical bone contributes significantly to the mechanical strength of the skeleton, little is known about this compartment from bone biopsy studies, particularly in CKD patients. In addition, there is no prospective data on the effects of CKD-MBD therapy on cortical porosity (Ct.Po). This is a post hoc analysis on data from a randomized controlled trial on the effects of different phosphate binders on bone remodelling. Therapy was adjusted according to the first biopsy, and included sevelamer or calcium acetate, calcitriol and changes in calcium dialysate concentration. We measured Ct.Po at baseline and one year after. Fifty-two patients (46±13years old, 67% women and 60% white) were enrolled. Ct.Po was already high at baseline in 85% of patients [30% (17, 46)] and correlated with PTH (p=0.001). Low bone turnover was seen in 28 patients (54.9%). After one-year treatment, PTH increased in patients with low turnover, as intended. However, increased Ct.Po was seen in 49 patients (94%). This increase correlated with the delta of phosphate (p=0.015) and the delta of PTH (p=0.03); it was also higher among non-white patients than in white patients (p=0.039). The risk of increase in Ct.Po was 4.5 higher among non-white patients. Adjusted multiple regression analysis showed that the delta of Ct.Po was dependent on delta PTH and race (r(2)=0.193). We concluded that in an attempt to increase bone turnover, the increase in PTH levels might be associated with higher cortical porosity, particularly in non-white patients. Whether this finding leads to a high risk of fracture deserves further investigation.