Cluster Randomized Controlled Trial on the Effects of 12 Months of Combined Exercise Training during Hemodialysis in Patients with Chronic Kidney Disease-Study Protocol of the Dialysis Training Therapy (DiaTT) Trial

Exercise and nutrition interventions for renal cachexia

PURPOSE OF REVIEW

Renal cachexia is a deleterious condition characterized by weight loss, muscle wasting and loss of physical function, quality of life, and increased mortality. Multimodal treatment strategies utilizing exercise and nutrition interventions have been recently suggested although the evidence base is still in its infancy. This paper aimed to review the current literature surrounding the use of exercise and nutrition for renal cachexia.

MAIN FINDINGS

Evidence from systematic reviews and narrative reviews indicates that resistance training (RT) is proven to have beneficial effects on improving muscle strength and in some cases physical function, although effects on muscle mass are mixed and inconclusive. Further, combined RT and aerobic training (AT) may have also beneficial effects on overall functional capacity and there appears to be no superior mode of protocol (inter/intra-dialysis vs. home-based). For nutrition, there is new data from systematic review of studies indicating that oral nutritional supplementation (ONS) may have beneficial effects on nutritional status (e.g. body mass index, plasma albumin and handgrip strength). Omega-3 fatty acids have been shown to have anti-inflammatory effects in haemodialysis patients from two recent systematic reviews, and evidence from other populations groups indicate they may be beneficial for improving muscle mass and strength.

SUMMARY

Evidence is accumulating for individual exercise and nutrition components but specific multimodal treatment studies in renal cachexia need to be urgently undertaken.

Exercise during Hemodialysis in Patients with Chronic Kidney Failure

BACKGROUND: Patients with kidney failure undergoing hemodialysis experience physical deconditioning and multimorbidity. Exercise interventions may mitigate this outcome, but their clinical role is unclear. METHODS: This multicenter, cluster randomized controlled trial evaluated combined endurance and resistance exercise training during hemodialysis versus usual care in chronic kidney failure. It assessed physical functioning, quality of life, hospitalizations, and overall survival. The primary outcome was the change in the 60-second sit-to-stand test (STS60) between baseline and 12 months. RESULTS: A total of 1211 patients underwent randomization, 917 (65.9±14.4 years; 38.9% female) of whom were included in the full analysis (exercise intervention, n=446; usual care, n=471). At 12 months, the STS60 repetitions improved from 16.2±7.6 to 19.2±9.1 in the exercise group but declined from 16.2±7.1 to 14.7±7.9 in the usual care group (group difference, 3.85 repetitions; 95% confidence interval [CI], 2.22 to 5.48; P<0.0001). The timed up-and-go test (−1.1 seconds; 95% CI, −1.9 to −0.3) and the 6-minute walk test (37.5 m; 95% CI, 14.7 to 60.4) also differed in the exercise group versus usual care group. The physical summary score and vitality subscale of the quality of life questionnaire (i.e., the 36-item Short Form Health Survey) differed in the exercise group versus usual care group, but the other subscales did not change. Adverse events during dialysis sessions were similar in both groups. Median days spent in the hospital annually were 2 in the exercise group and 5 in the usual care group. Mortality and dialysis-specific adverse events were not affected. CONCLUSIONS: Twelve months of intradialytic exercise in patients with kidney failure significantly improved the STS60 compared with usual care. (Funded by the Innovation Fund, Federal Joint Committee; ClinicalTrials.gov number, NCT03885102.)

Frailty and Clinical Outcomes in Patients Treated With Hemodialysis: A Prospective Cohort Study

Rationale and Objective

Frailty is common among people with kidney failure treated with hemodialysis (HD). The objective was to describe how frailty evolves over time in people treated by HD, how improvements in frailty and frailty markers are associate with clinical outcomes, and the characteristics that are associated with improvement in frailty.

Study Design

Prospective cohort study.

Setting and Participants

Adults initiating thrice weekly in-center HD in Canada.

Exposure

We classified frailty using a 5-point score (3 or more indicates frailty) based on physical inactivity, slowness or weakness, poor endurance or exhaustion, and malnutrition. We categorized the frailty trajectory as never present, improving, deteriorating, and always present.

Outcomes

All-cause death, hospitalizations, and placement into long-term care.

Analytical Approach

We examined the association between time-varying frailty measures and these outcomes using Cox and negative binomial models, after adjustment for potential confounders.

Results

985 participants were included and followed up for a median of 33 months; 507 (51%) died, 761 (77%) experienced ≥1 hospitalization and 115 (12%) entered long-term care. Overall, 760 (77%) reported frailty during follow-up. Three-quarters (78%) of those with frailty at baseline remained frail throughout the follow-up, 46% without baseline frailty became frail, and 23% with baseline frailty became nonfrail. Higher frailty scores were associated with an increased risk of mortality (fully adjusted HR, 1.58 per unit; 95% CI, 1.39-1.80) and an increased rate of hospitalization (RR, 1.16 per unit; 95% CI, 1.09-1.23). Compared with those who were frail throughout the follow-up, participants with frailty at baseline but improving during follow-up showed a lower mortality (HR, 0.59; 95% CI, 0.42-0.81), and a lower rate of hospitalization (RR, 0.70; 95% CI, 0.56-0.87).

Limitations

There was missing data on frailty at baseline and during follow-up.

Conclusions

Frailty was associated with a higher risk of poor outcomes compared with those without frailty, and participants whose status improved from frail to nonfrail showed better clinical outcomes than those who remained frail. These findings emphasize the importance of identifying and implementing effective treatments for frailty in patients receiving maintenance HD.

Prognostic Signature of Chronic Kidney Disease in Advanced Age: Secondary Analysis from the InGAH Study with One-Year Follow-Up

The negative impact of chronic kidney disease (CKD) on health status and quality of life in older patients has been well documented. However, data on frailty trajectories and long-term outcomes of older CKD patients undergoing structured Comprehensive Geriatric Assessment (CGA) with multidimensional frailty evaluation are sparse. Here, we analysed records from 375 CKD patients admitted to our university hospital (mean age 77.5 (SD 6.1) years, 36% female) who had undergone a CGA-based calculation of the frailty score with the multidimensional prognostic index (MPI) as well as follow-up evaluations at 3, 6 and 12 months after discharge. Based on the MPI score at admission, 21% of the patients were frail and 56% were prefrail. MPI values were significantly associated with KDIGO CKD stages (p = 0.003) and rehospitalisation after 6 months (p = 0.027) and mortality at 3, 6 and 12 months (p = 0.001), independent of chronological age. Kidney transplant recipients (KTR) showed a significantly lower frailty compared to patients with renal replacement therapy (RRT, p = 0.028). The association between frailty and mortality after 12 months appeared particularly strong for KTR (mean MPI 0.43 KTR vs. 0.52 RRT, p < 0.001) and for patients with hypoalbuminemia (p < 0.001). Interestingly, RRT was per se not significantly associated with mortality during follow up. However, compared to patients on RRT those with KTR had a significantly lower grade of care (p = 0.031) and lower rehospitalisation rates at 12 months (p = 0.010). The present analysis shows that the large majority of older CKD inpatients are prefrail or frail and that the risk for CKD-related adverse outcomes on the long term can be accurately stratified by CGA-based instruments. Further studies are needed to explore the prognostic and frailty-related signature of laboratory biomarkers in CKD.