Prevalence of Carnitine Deficiency and Decreased Carnitine Levels in Patients on Hemodialysis.

BACKGROUND: Patients on hemodialysis (HD) are known to be at risk of carnitine deficiency. The aims of this study were to investigate the prevalence of carnitine deficiency in patients on dialysis and to compare the likelihood of a reduction in the serum carnitine level on HD with that on hemodiafiltration (HDF). METHODS: The prevalence of carnitine deficiency, defined as a serum free carnitine level < 20 µmol/L, and that of carnitine insufficiency, defined as an acyl/free carnitine ratio > 0.4, was investigated in 150 patients on dialysis. The reduction rate of serum carnitine was then compared between HD and HDF. RESULTS: The prevalence of carnitine deficiency and that of carnitine insufficiency was 25.3 and 86.7%, respectively. Patients at high risk of carnitine deficiency accounted for 64.7%. Multivariate regression identified an association of duration of dialysis with the free serum carnitine level. The reduction rates of serum free carnitine in HD and HDF were 64 ± 4 and 75 ± 7%, respectively (p < 0.0001). CONCLUSION: The prevalence rates of carnitine deficiency and carnitine insufficiency were high in patients on dialysis. The serum carnitine reduction rate was greater with HDF than with HD.

Ferric Citrate Decreases Fibroblast Growth Factor 23 and Improves Erythropoietin Responsiveness in Hemodialysis Patients.

BACKGROUND: Serum phosphate and vitamin D receptor activator regulate fibroblast growth factor 23 (FGF23), and iron may modulate FGF23 metabolism. The aim of the present study was to elucidate the effects of ferric citrate hydrate and lanthanum carbohydrate on serum FGF23 levels in hemodialysis patients. METHODS: This prospective, open-label, multicenter study enrolled 60 patients on hemodialysis treated with lanthanum carbonate. Patients were randomly assigned to 2 groups: those switching from lanthanum carbonate to ferric citrate hydrate (ferric citrate group, n = 30) or those continuing lanthanum carbonate (control group, n = 30). Patients were monitored for 24 weeks. Endpoints included changes in FGF23, phosphate, and the dose of erythropoiesis stimulating agent (ESA), erythropoietin responsiveness index (ERI), and adverse events. RESULTS: FGF-23 levels were significantly lower in the ferric citrate group compared with the levels in the control group (change from baseline -6,160 vs. -1,118 pg/mL; p = 0.026). There were no significant changes in serum calcium, phosphate, and intact parathyroid hormone levels in either group. The ferric citrate group had significantly increased serum iron, ferritin, and transferrin saturation. Hemoglobin levels were significantly elevated, and the dose of ESA was significantly decreased in the ferric citrate group but not in the control group. ERI and the dose of intravenous saccharated ferric oxide were significantly lower in the ferric citrate group compared with those of the control group (p = 0.015 and p = 0.002). CONCLUSION: In patients on hemodialysis, 24-week treatment with ferric citrate hydrate resulted in significant reduction in FGF23 and ERI independently of serum phosphate level.

Testing the Feasibility and Usability of a Novel Smartphone-Based Self-Management Support System for Dialysis Patients: A Pilot Study.

BACKGROUND: Diet and fluid restrictions that need continuous self-management are among the most difficult aspects of dialysis treatment. Smartphone applications may be useful for supporting self-management. OBJECTIVE: Our objective is to investigate the feasibility and usability of a novel smartphone-based self-management support system for dialysis patients. METHODS: We developed the Self-Management and Recording System for Dialysis (SMART-D), which supports self-monitoring of three mortality-related factors that can be modified by lifestyle: interdialytic weight gain and predialysis serum potassium and phosphorus concentrations. Data is displayed graphically, with all data evaluated automatically to determine whether they achieve the values suggested by the Japanese Society for Dialysis Therapy guidelines. In a pilot study, 9 dialysis patients used SMART-D system for 2 weeks. A total of 7 of them completed questionnaires rating their assessment of SMART-D's usability and their satisfaction with the system. In addition, the Kidney Disease Quality of Life scale was compared before and after the study period. RESULTS: All 9 participants were able to use SMART-D with no major problems. Completion rates for body weight, pre- and postdialysis weight, and serum potassium and phosphorus concentrations were, respectively, 89% (SD 23), 95% (SD 7), and 78% (SD 44). Of the 7 participants who completed the usability survey, all were motivated by the sense of security derived from using the system, and 6 of the 7 (86%) reported that using SMART-D helped improve their lifestyle and self-management. CONCLUSIONS: Using SMART-D was feasible, and the system was well regarded by patients. Further study with larger scale cohorts and longer study and follow-up periods is needed to evaluate the effects of SMART-D on clinical outcomes and quality of life.

Efficacy and safety of saxagliptin, a dipeptidyl peptidase-4 inhibitor, in hemodialysis patients with diabetic nephropathy: A randomized open-label prospective trial.

AIMS: Saxagliptin is a dipeptidyl peptidase-4 inhibitor that was approved in Japan for the treatment of type 2 diabetes in 2013. We examined its efficacy and safety in Japanese hemodialysis patients with diabetic nephropathy. METHODS: In this prospective, open-label, parallel-group study, Japanese hemodialysis patients were randomized to receive either oral saxagliptin (2.5mg/day) or usual care (control group) for 24weeks. Before randomization, patients received fixed doses of conventional antidiabetic drugs (oral drugs and/or insulin) for 8weeks; these drugs were continued during the study. Endpoints included changes in glycated albumin (GA), hemoglobin A1c (HbA1c), postprandial plasma glucose (PPG), and adverse events. RESULTS: Both groups included 41 patients. Mean GA, HbA1c, and PPG decreased significantly in the saxagliptin group (-3.4%, -0.6% [-7mmol/mol], and -38.3mg/dL, respectively; all P<0.0001) but not in the control group (0%, -0.1% [-1mmol/mol], and -3.7mg/dL, respectively) (P<0.0001, P<0.001, and P<0.0001, respectively). In saxagliptin-treated patients, the reduction in GA was significantly greater when saxagliptin was administered as monotherapy than in combination therapy (-4.2% vs. -3.0%, P=0.012) despite similar baseline values (24.5% vs. 23.3%). Reductions in GA, HbA1c, and PPG were greater in patients whose baseline values exceeded the median (23.8% for GA, 6.6% for HbA1c, and 180mg/dL for PPG). There were no adverse events associated with saxagliptin. CONCLUSIONS: Saxagliptin (2.5mg/day) was effective and well tolerated when used as monotherapy or combined with other antidiabetic drugs in Japanese hemodialysis patients with type 2 diabetes. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000018445.