Physical Exercise Improves Cognitive Function in Older Adults with Stage 3-4 Chronic Kidney Disease: A Randomized Controlled Trial.

INTRODUCTION: Patients with chronic kidney disease (CKD) exhibit a higher probability of having cognitive impairment or dementia than those without CKD. The beneficial effects of physical exercise on cognitive function are known in the general older population, but more research is required in older adults with CKD. METHODS: Eighty-one outpatients (aged ≥65 years) with CKD stage G3-G4 were assessed for eligibility. Among them, 60 were randomized (single-center, unblinded, and stratified) and 53 received the allocated intervention (exercise n = 27, control n = 26). Patients in the exercise group undertook group-exercise training at our facility once weekly and independent exercises at home twice weekly or more, for 24 weeks. Patients in the control group received general care. General and specific cognitive functions (memory, attention, executive, and verbal) were measured, and differences in their scores at baseline and at the 24-week follow-up visit were assessed between the 2 groups. RESULTS: Forty-four patients completed the follow-up at 24 weeks (exercise n = 23, control n = 21). Patients in the exercise group showed significantly greater changes in Wechsler Memory Scale-Revised Logical Memory delayed recall (exercise effect: 2.82, 95% CI: 0.46-5.19, p = 0.03), and immediate and delayed recall (exercise effect: 5.97, 95% CI: 1.13-10.81, p = 0.02) scores than those in the control group. CONCLUSIONS: The 24-week exercise intervention significantly improved the memory function in older adults with pre-dialysis CKD. This randomized controlled trial suggests that physical exercise is a useful nonpharmacological strategy for preventing cognitive decline in these patients.

Bone responsiveness to parathyroid hormone is negatively associated with parathyroid hormone-lowering drug use in patients undergoing hemodialysis: a cross-sectional study.

BACKGROUND: Parathyroid hormone (PTH) acts on bone to indirectly increase the number and activity of osteoclasts. Thus, PTH has a stimulatory effect on bone resorption and upregulates bone turnover. However, the responsiveness of bone to PTH varies widely among patients receiving dialysis. In fact, relative to the serum PTH level, the level of serum tartrate-resistant acid phosphatase-5b (TRACP-5b), a bone resorption marker derived from osteoclasts, varies as well. This study aimed to examine factors related to bone responsiveness to PTH in patients undergoing chronic hemodialysis (HD). METHODS: This study included patients receiving chronic HD in Kawasaki Municipal Tama Hospital (Kanagawa, Japan) and Yonaha Medical Clinic (Okinawa, Japan) and excluded patients who received HD for less than 6 months, those who received a combination of HD and peritoneal dialysis, and those who had cancer bone metastases or myeloma. The TRACP-5b/intact PTH (iPTH) ratio was created as an index of bone responsiveness to PTH, categorized into tertiles (low, medium, and high), and a cross-sectional study was conducted. P < 0.05 indicated statistically significant differences. RESULTS: One hundred and six patients were analyzed. Age (P = 0.010), body mass index (BMI) (P = 0.003), use of calcium-sensing receptor (CaSR) agonists (P = 0.008), use of vitamin D receptor activators (VDRAs) (P = 0.012), plasma iPTH level (P < 0.001), serum 1,25(OH)2D level (P = 0.003), and serum TRACP-5b level (P < 0.001) were significantly different among the three categories. In the single linear regression analysis, age (P = 0.016), corrected serum calcium level (P = 0.007), and ln [1,25(OH)2D] (P = 0.044) showed a significant positive correlation with ln [TRACP-5b/iPTH], whereas BMI (P = 0.026), use of CaSR agonists (P = 0.001), use of VDRAs (P = 0.009), and serum phosphorus level (P = 0.018) showed a significant negative correlation. Upon conducting multiple linear regression analysis incorporating significant variables in the single linear regression analysis, a significant negative correlation was observed between the TRACP-5b/iPTH ratio and intravenous administration of a CaSR agonist (etelcalcetide) and/or a VDRA (calcitriol or maxacalcitol) in all the adjusted models. CONCLUSIONS: Bone responsiveness to PTH is negatively correlated with the intravenous administration of a CaSR agonist and/or a VDRA in patients undergoing chronic HD.

Mild cognitive impairment in older adults with pre-dialysis patients with chronic kidney disease: Prevalence and association with physical function.

AIM: Chronic kidney disease (CKD) is a risk factor for declining cognitive and physical function. However, the prevalence of mild cognitive impairment (MCI) and its relationship with physical function is not clear. Therefore, our aim was to evaluate the prevalence of MCI and the relationship between MCI and physical function among older adults with pre-dialysis CKD. METHODS: We conducted a cross-sectional study of 120 patients, aged ≥65 years (mean age, 77.3 years), with pre-dialysis CKD but without probable dementia (Mini Mental State Examination <24). MCI was evaluated using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). For analysis, patients were classified into two cognitive function groups: normal (MoCA-J ≥ 26) and MCI (MoCA-J < 26). Physical, clinical, and biochemical parameters were compared between the groups. Logistic and linear regression analyses were used to evaluate the specific association between cognitive and physical function. RESULTS: Seventy-five (62.5%) patients belonged to the MCI group. Significant differences between the two groups were identified for gait speed, balance, age, and haemoglobin concentration. After adjustment for covariates, only gait speed was significantly associated with MCI (odds ratio, 0.06; 95% confidence interval, 0.009-0,411). CONCLUSION: The prevalence of MCI among older adults with pre-dialysis CKD was as high as 62.5%. The association between MCI and reduced gait speed supports the possible interaction between physical and cognitive functions and the need for early screening.

Predictive Factors for Withdrawal from Peritoneal Dialysis: A Retrospective Cohort Study at Two Centers in Japan.

Peritoneal dialysis (PD) is recognized as an excellent method of dialysis because the therapy is gentle, continuous, and cost-effective. However, a large number of patients must unfortunately transfer from PD to hemodialysis because of peritonitis or fluid overload in the early phase after PD initiation. In the present study, we reviewed clinical indicators before PD initiation to try to identify predictive factors for early withdrawal from PD.For this retrospective cohort study at two hospitals between March 2003 and October 2016, we defined withdrawal from PD as the induction of combination therapy, transfer to hemodialysis, or death. Data about clinical indicators before PD induction-namely age, sex, presence of diabetes mellitus, past history of cardiovascular disease (CVD), body mass index, primary kidney disease, and blood biochemistry-were collected from medical records. The primary outcome was duration of PD until withdrawal.We analyzed 151 PD patients (median age: 62.5 years; 94 men; 74 with diabetes mellitus; median duration of PD: 30.2 months). Univariate Cox regression analysis showed that the hazard ratio (HR) for withdrawal was 1.08 [95% confidence interval (CI): 1.04 to 1.12; p < 0.001] per 1 mg/L increase in ß2-microglobulin (ß2MG), 0.65 (95% CI: 0.46 to 0.93; p = 0.02) per 1 g/dL decrease in serum albumin, and 1.07 (95% CI: 1.02 to 1.11; p = 0.01) per 1 g per gram creatinine increase in daily urinary protein excretion. Using multivariate Cox regression analysis, ß2MG (HR: 1.08; 95% CI: 1.04 to 1.12; p < 0.001) and past history of CVD (HR: 1.47; 95% CI: 1.02 to 2.13; p = 0.04) were factors predictive for withdrawal from PD. Kaplan-Meier analysis showed that the technique survival rate was significantly different in the two groups defined as having a serum ß2MG level above or below the measured median (p = 0.047).Serum ß2MG at PD initiation and past history of CVD are high-risk factors for withdrawal from PD. Special focus should be placed on the care and management of patients found to have a high risk of withdrawal at the time of PD induction.

Long-Term Prognosis of Peritoneal Dialysis Patients with a Re-embedded Catheter.

Upon peritoneal dialysis (PD) discontinuation in frail patients, we have re-embedded the catheter and left it subcutaneously buried. However, we have not evaluated the long-term prognosis of those patients after the procedure or the complications associated with buried catheters. We therefore aimed to clarify the long-term prognosis of patients with a re-embedded catheter and to identify any associated complications.The outcomes of 10 patients having a catheter that was re-embedded between February 2010 and May 2016 were assessed by interviewing the patients or their families (when possible), and by reviewing medical records.Catheter re-embedding to reduce the surgical burden was elected by 7 patients, and 3 patients underwent re-embedding because they wanted to resume PD in the future. By the time of the interviews, 6 patients had already died of causes that were unrelated either to the buried catheter or infection. No abnormality was found in any buried catheter. A re-embedded catheter was later externalized to resume PD in 1 of the 4 patients who survived.Catheter re-embedding is safe and allows for PD resumption at the terminal stage of dialysis.

Using a Peritoneal Dialysis Access Simulator in Surgical Training for Nephrologists.

In Japan, peritoneal dialysis (PD) catheter insertion has been performed by both nephrologists and surgeons. However, nephrologists have fewer opportunities to train in the insertion procedure. We therefore used a PD access simulator to provide training in this operative technique for nephrologists. A PD access simulator developed by Terumo Medical Corporation was used for the training. The simulator uses a mannequin made of acrylic resin. The abdominal wall of a pig is attached to the abdominal area, and a plastic bag represents the abdominal cavity. The simulator enables the surgical procedure to be performed from skin incision to PD catheter insertion. Between October 2011 and December 2013, 3 supervising doctors used the simulator to guide 17 nephrologists with no experience through a PD catheter insertion. One-on-one training was provided in a single 2- or 3-hour session. In a questionnaire survey after the training, trainees gave high marks to the handling of surgical instruments, the environment of the operating room, and the surgical guidance during training. However, the supervising doctors required the ability to respond flexibly, because trainees had individual differences in skills. The PD access simulator might be useful for providing guided training in operative technique for PD catheter insertion.

A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan.

BACKGROUND: This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications. METHODS: Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest. RESULTS: Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines. CONCLUSION: PD catheter placement in Japan was proven to be safe and appropriate.

Welfare receipt and the risk of vitamin D deficiency in Japanese patients on maintenance hemodialysis: a cross-sectional, retrospective study.

BACKGROUND: Vitamin D deficiency is often observed in patients undergoing maintenance hemodialysis and is associated with significantly increased risk of overall mortality. Despite reports of poor nutrition/intake, vitamin D status among patients on maintenance hemodialysis receiving welfare remains unknown. This study investigated the vitamin D status in welfare recipients undergoing maintenance hemodialysis. METHODS: This cross-sectional study investigated vitamin D status among 106 outpatients undergoing maintenance hemodialysis at two medical facilities in Japan. Patients were divided into welfare and non-welfare groups based on their status as of September 2018. Patients were divided into two categories: serum vitamin D deficiency, defined as serum 25(OH)D concentrations < 12 ng/mL, or non-deficiency. Vitamin D deficiency was used as a dependent variable, while welfare receipt was used as the main predictor variable. RESULTS: Mean [± standard deviation] patient age, median [interquartile range] body mass index, and hemodialysis duration were 66.9 [± 10.8] years, 21.5 [19.6, 24.3] kg/m2, and 7.9 [2.9, 12.3] years, respectively. Among 106 patients, 45 were women (42.5%) and 16 (15.1%) were receiving welfare. The welfare group had a higher diabetes prevalence (P = 0.003) and significantly lower median serum 25-hydroxyvitamin D concentrations (11.5 [8.7, 14.0] vs. 14.8 [11.2, 19.9] ng/mL, P = 0.005). Multiple logistic regression analysis revealed that welfare receipt was a significant risk factor for vitamin D deficiency (odds ratio [95% confidence interval], 4.41 [1.08, 18.07]). CONCLUSIONS: Welfare recipients undergoing maintenance hemodialysis are at significantly increased risks of vitamin D deficiency compared with patients not receiving welfare.