Amino acid removal during hemodialysis can be compensated for by protein ingestion and is not compromised by intradialytic exercise: a randomized controlled crossover trial.

BACKGROUND: Patients with end-stage renal disease (ESRD) undergoing hemodialysis experience a rapid decline in skeletal muscle mass and strength. Hemodialysis removes amino acids (AAs) from the circulation, thereby lowering plasma AA concentrations and stimulating proteolysis. OBJECTIVES: In the present study, we evaluate the impact of intradialytic protein ingestion at rest and following exercise on AA removal and plasma AA availability in patients with ESRD. METHODS: Ten patients (age: 65 ± 16 y, male/female: 8/2, BMI: 24.2 ± 4.8 kg/m2, serum albumin: 3.4 ± 0.3 g/dL) with ESRD undergoing hemodialysis participated in this randomized controlled crossover trial. During 4 hemodialysis sessions, patients were assigned to ingest 40 g protein or a placebo 60 min after initiation, both at rest (PRO and PLA, respectively) and following exercise (PRO + EX and PLA + EX, respectively). Spent dialysate and blood samples were collected every 30 min throughout hemodialysis to assess AA removal and plasma AA availability. RESULTS: Plasma AA concentrations declined by 26.1 ± 4.5% within 30 min after hemodialysis initiation during all interventions (P < 0.001, η2p > 0.79). Protein ingestion, but not intradialytic exercise, increased AA removal throughout hemodialysis (9.8 ± 2.0, 10.2 ± 1.6, 16.7 ± 2.2, and 17.3 ± 2.3 g during PLA, PLA + EX, PRO, and PRO + EX interventions, respectively; protein effect P < 0.001, η2p = 0.97; exercise effect P = 0.32, η2p = 0.11). Protein ingestion increased plasma AA concentrations until the end of hemodialysis, whereas placebo ingestion resulted in decreased plasma AA concentrations (time effect P < 0.001, η2p > 0.84). Plasma AA availability (incremental AUC) was greater during PRO and PRO + EX interventions (49 ± 87 and 70 ± 34 mmol/L/240 min, respectively) compared with PLA and PLA + EX interventions (-227 ± 54 and -208 ± 68 mmol/L/240 min, respectively; protein effect P < 0.001, η2p = 0.98; exercise effect P = 0.21, η2p = 0.16). CONCLUSIONS: Protein ingestion during hemodialysis compensates for AA removal and increases plasma AA availability both at rest and during recovery from intradialytic exercise. Intradialytic exercise does not compromise AA removal or reduce plasma AA availability during hemodialysis in a postabsorptive or postprandial state.

Three compartment bioimpedance spectroscopy in the nutritional assessment and the outcome of patients with advanced or end stage kidney disease: What have we learned so far?

Bioimpedance spectroscopy (BIS) is an easily applicable tool to assess body composition. The three compartment model BIS (3C BIS) conventionally expresses body composition as lean tissue index (LTI) (lean tissue mass [LTM]/height in meters squared) and fat tissue index (FTI) (adipose tissue mass/height in meters squared), and a virtual compartment reflecting fluid overload (FO). It has been studied extensively in relation to diagnosis and treatment guidance of fluid status disorders in patients with advanced-stage or end-stage renal disease. It is the aim of this article to provide a narrative review on the relevance of 3C BIS in the nutritional assessment in this population. At a population level, LTI decreases after the start of hemodialysis, whereas FTI increases. LTI below the 10th percentile is a consistent predictor of outcome whereas a low FTI is predominantly associated with outcome when combined with a low LTI. Recent research also showed the connection between low LTI, inflammation, and FO, which are cumulatively associated with an increased mortality risk. However, studies toward nutritional interventions based on BIS data are still lacking in this population. In conclusion, 3C BIS, by disentangling the components of body mass index, has contributed to our understanding of the relevance of abnormalities in different body compartments in chronic kidney disease patients, and appears to be a valuable prognostic tool, at least at a population level. Studies assessing the effect of BIS guided nutritional intervention could further support its use in the daily clinical care for renal patients.

Intensive hemodialysis in the (nursing) home: the bright side of geriatric ESRD care?

Elderly ESRD patients often lose functionality when they start dialysis, which may be due to a variety of clinical problems. We recently postulated that intensive (longer and/or more frequent) hemodialysis (HD) may be the ideal strategy to try to prevent these ESRD- and dialysis-related complications, including dialysis-induced hypotension, cardiac and cerebral events, malnutrition, infections, sleep problems, and psychological issues. The feasibility of home dialysis therapies has been demonstrated in observational studies. As self-care dialysis is often a challenge in the elderly patient, assisted intensive home HD may facilitate the long-term continuation of this modality. Intensive nursing home HD seems to be an attractive goal for the future because many elderly ESRD patients reside in an extended care facility. Combination with rehabilitation and support by social worker and psychologist remains crucial in the holistic approach toward the elderly ESRD patient. Further studies are required to test the potential protective effects of intensive HD on functionality and quality of life in elderly ESRD patients, and to elucidate the mechanisms underlying frailty and other geriatric syndromes in this highly vulnerable patient population.

Blood volume control by biofeedback and dialysis-induced symptomatology. A short-term clinical study.

In earlier studies, a reduction in intradialytic procedures was observed in patients with severe intradialytic hypotension symptomatology by the use of blood volume controlled biofeedback systems. However, few data are present on the use of biofeedback-controlled treatments in patients experiencing minor intradialytic symptoms. In the present study, 157 standard and 158 biofeedback-controlled treatments were compared during a 2-month period in 16 hemodialysis patients. Both the percentage of hypotensive episodes (6.3 +/- 11.3 vs. 15.8 +/- 18.3%; p < 0.05) as well as other intradialytic symptoms (cramps, nausea, headache, abdominal pain) (11.0 +/- 12.8 vs. 18.1 +/- 16.9%; p < 0.05) were significantly less during biofeedback-controlled treatments compared to standard dialysis treatments, despite a similar decline in relative blood volume (8.8 +/- 3.5 vs. 8.3 +/- 3.1%; p = n.s.). Interdialytic weight gain and intradialytic rise in plasma sodium levels were comparable. Concluding, in this short-term preliminary study, blood volume controlled biofeedback improved dialysis tolerance also in patients with minor intradialytic symptomatology.