The impact of malnutrition on the effectiveness of intradialytic exercise in hemodialysis patients: amulticenter cohort study.

PURPOSE: Low physical function can be effectively improved via intradialytic exercise. However, the association between the effects of intradialytic exercise on physical function and malnutrition severity has not been studied extensively. This study aimed to investigate the impact of nutritional status severity on physical function in patients undergoing hemodialysis with low physical function to whom intradialytic exercise was prescribed. METHODS: The participants were patients with decreased mobility [walking speed < 1.0 m/s and/or Short Physical Performance Battery (SPPB) < 12] who had been undergoing hemodialysis thrice a week for 6 months and performing intradialytic exercise program. Patients were divided into groups based on the Geriatric Nutritional Risk Index (GNRI) [Non-malnutrition group (GNRI > 98), Gentle/slim malnutrition group (GNRI ≤ 98, GNRI ≥ 92), Mild malnutrition group (GNRI < 92, GNRI ≥ 82), Severe malnutrition group (GNRI < 82)]. The primary outcomes were Grip strength, isometric knee extension strength (IKES), SPPB, and 10-m walking speed measured at baseline and at 6 months. Statistical analyses were performed using a linear mixed-effects model with the intention-to-treat analysis, including within-group analysis and between-group comparison. RESULTS: A total of 805 participants were included in the study. Within-group comparisons showed significantly improved IKES, 10-m walking speed, and SPPB improved, except in the Severe malnutrition group. Grip strength significantly improved in the Gentle/slim and mild malnutrition groups. Between-group comparison with controls showed that the improvement in Grip strength was significantly bigger in the Gentle/slim malnutrition group [0.98 (0.15 to 1.82) kg] than in the non-malnutrition group. However, IKES in the Severe malnutrition group [- 5.14 (- 9.18 to - 1.10) %] less significantly improve than that in the non-malnutrition group. No significant differences were found in the other indices. CONCLUSION: In patients with severe malnutrition, the changes in IKES scores resulting from Intradialytic exercise were significantly smaller than those observed in non-malnourished patients. Therefore, it is necessary to initiate suitable nutritional and exercise therapy based on the severity of malnutrition.

Factors associated with improved health-related quality of life due to improvements in physical function and dialysis-related symptoms following intradialytic exercise in outpatients undergoing haemodialysis.

PURPOSE: Exercise therapy is a crucial intervention for improving health-related quality of life (HRQOL) in patients undergoing haemodialysis. However, factors that improve HRQOL by improving physical function and dialysis-related symptoms remain unknown. This study aimed to examine the physical function parameters and dialysis-related symptoms that improve HRQOL following intradialytic exercise. METHODS: This multicentre cohort study included 596 patients who participated in an intradialytic exercise program three times per week for a period of 6 months, which comprised of stretching and resistance training. EuroQol 5 dimensions 5-level (EQ5D-5L), grip strength, isometric knee extension strength, 10-m walking speed, Short Physical Performance Battery (SPPB), and improvement in dialysis-related symptoms were measured at the baseline and post-intervention. A linear mixed model was used to analyse the effects of improved physical function and dialysis-related symptoms on improvements in EQ5D-5L. RESULTS: As a physical function index affecting ΔEQ5D-5L, only SPPB showed a significant increase in ΔEQ5D-5L compared with the non-improved group [difference in ΔEQ5D-5L, 0.05 (0.004 to 0.092) point; p < 0.05]). In addition, dialysis-related symptoms with Improved physical conditions [difference in ΔEQ5D-5L, 0.07 (0.02 to 0.13) point] and an Extended walking distance [difference in ΔEQ5D-5L was 0.07 (0.01 to 0.12) point] significantly influenced ΔEQ5D-5L (p < 0.05, both). CONCLUSIONS: The improvements observed in the SPPB scores and self-percieved physical fitness and ambulation range, attributable to intradialytic exercise, may potentially improve HRQOL.

Age-associated effects of intradialytic exercise on physical function and nutritional status in patients receiving ambulatory hemodialysis: A multicenter cohort study.

INTRODUCTION: Intradialytic exercise is essential for improving physical function for older patients. This study aimed to examine the relationship between the effects of exercise therapy and aging. METHODS: This multicenter cohort study included 1176 patients aged 40-89 years, who participated in an intradialytic exercise program, comprising stretching and resistance training, three times per week for 12 months. Isometric knee extension strength (IKES), 10-m walking speed, Short Physical Performance Battery (SPPB), and Geriatric Nutritional Risk Index (GNRI) were measured at baseline and after 12 months. The patients were divided according to age as follows: 40-59, 60-69, 70-79, and 80-89 years. A linear mixed-effects model examined the improvement within-group and between-control differences, as the 40-59 age group was the control group. FINDINGS: The 40-59, 60-69, 70-79, and 80-89 age groups comprised 180, 317, 466, and 213 participants, respectively. Within-group differences, all the age groups significantly improved IKES and SPPB. The 10-m walking speed [0.02 (0.02) m/s] and GNRI [0.38 (0.33)] did not improved only in the 80-89 age group despite other age groups significantly improved. Between-control differences, IKES of the 70-79 age group [-0.24 (-0.42 to -0.06) %] was significantly lower improvement than control. GNRI of all the older groups were significantly smaller improvement than control (p < 0.05). DISCUSSION: The older group demonstrated difficulty in improving walking ability and nutritional status compared with the younger groups. Clinicians need to consider the difference in effectiveness due to age and prescribe intradialytic exercises accordingly.

Differences in the purpose of exercise between hemodialysis patients who continued or dropped out of exercise programs: a multicenter cohort study.

BACKGROUND: Selecting suitable exercise goals is crucial for fostering adherence to, and maintenance of, exercise therapy. We aimed to evaluate the variance in exercise objectives between individuals who continued and those who dropped out of a 6-month intradialytic exercise program by analyzing an open-ended questionnaire administered to patients undergoing hemodialysis. METHODS: The study consisted of outpatients (n = 541; mean age, 70 years) undergoing maintenance hemodialysis, who had been informed of an intradialytic exercise program and voluntarily agreed to participate. The primary outcome was the exercise purpose. The difference in exercise purpose was quantitatively analyzed between the exercise continuation and dropout groups. A co-occurrence network was created and concepts were constructed. The basic attributes were compared using chi-squared and independent t-tests. RESULTS: Over 6 months, 154 patients (28.5%) dropped out of the intradialytic exercise program. Concepts related to the goals of the program were: (1) physical function and condition, (2) addressing limitations, (3) maintaining daily life activities, and (4) physical condition recognition. Co-occurrence network analysis showed that the exercise continuation group established their objectives based on the health benefits of exercise, and proactively set goals rooted in comprehending their current issues and problems. The dropout group tended to perceive treatment passively as an extension of daily clinical practice, rather than actively formulating exercise objectives. CONCLUSION: The exercise objectives of those who continued the exercise program differed from those who dropped out. Patients in the exercise continuation group set more affirmative and specific exercise objectives, whereas those in the dropout group set more passive and abstract exercise objectives.

Factors associated with dropout from an intradialytic exercise program among patients undergoing maintenance hemodialysis.

BACKGROUND: Continuation of an intradialytic exercise program is necessary to improve and maintain physical function in patients undergoing hemodialysis. Factors associated with dropout must be identified to ensure program continuation. This study aimed to investigate the dropout rates from an intradialytic exercise program at 6 and 12 months in patients undergoing hemodialysis and to identify dropout predictors. METHODS: This was a multicenter, retrospective observational study. Overall, 980 patients were enrolled in this study. Grip strength, 10-m walking speed, physical function, demographics and blood sampling data were measured at baseline, and dropouts were observed. Patients were classified as either continued or dropped out of the program at 6 and 12 months. The dropout rate was calculated for each time point. Multivariate logistic regression analysis was performed to identify the predictors of dropout. RESULTS: The dropout rate was 26.4% (n = 259) after 6 months, 24.1% (n = 172) between 6 and 12 months, and 44.3% (n = 424) overall at 1 year. Significant predictors of dropout after 6 months were slower 10-m walking speed, older age and high C-reactive protein level. Predictors of dropout after 12 months were slower 10-m walking speed and lower standardized dialysis volume. CONCLUSIONS: Walking capacity, age, inflammation and hemodialysis volume were determinants of dropout from the exercise program. Our findings provide new and important insights into the potential risk factors for dropout from long-term intradialytic exercise programs in patients undergoing hemodialysis.

Influence of Malnutrition on the Improvement of Physical Function by Intradialytic Resistance Exercise in Patients Undergoing Hemodialysis.

OBJECTIVE: Intradialytic exercise improves physical function. However, malnutrition may be an essential factor affecting the effectiveness of exercise to improve physical function. Few studies of the relationship between malnutrition and the effectiveness of intradialytic exercise to improve physical function exist. Therefore, this study investigated malnutrition at the beginning of intradialytic exercise and how it affects the subsequent improvement in physical function. METHODS: Patients who performed intradialytic exercise for 12 months were enrolled in this study. A Geriatric Nutritional Risk Index of 91.2 was defined as malnutrition. Patients were assigned to 2 groups using propensity score matching to adjust for confounding factors. Physical function outcomes were handgrip strength, isometric knee extension strength, short physical performance battery, and 10-m walking speed; these were compared at baseline, 3 months, 6 months, and 12 months. The 2 groups were further divided into another 2 groups as per whether the nutritional status had improved after 12 months; therefore, a total of 4 groups were analyzed. RESULTS: After matching, the data of 154 patients in each group were analyzed. During the intragroup comparison, isometric knee extension strength, short physical performance battery, and 10-m walking speed improved significantly in both groups after intradialytic exercise was started compared with before intradialytic exercise was started. However, there was no significant improvement in handgrip strength in the malnutrition group. There were no significant differences in any of the physical function measurements or changes from the baseline values among the 4 groups divided as per subsequent recovery of the nutritional status. CONCLUSION: Malnutrition may not impact the effectiveness of intradialytic exercise to improve lower-leg physical function. Its effect on the improvement of handgrip strength requires further investigation.

Exercise intolerance and malnutrition associated with all-cause mortality in elderly patients undergoing peritoneal dialysis: a single-center prospective cohort study.

BACKGROUND: Low physical function and malnutrition in elderly patients undergoing peritoneal dialysis (PD) are important issues that may be associated with prognosis. We aimed to determine the association between physical function and nutritional status and survival in elderly patients undergoing PD. METHODS: This single-center, prospective cohort study included 45 stable, ambulatory patients undergoing PD. Physical function was measured using the 6-min walk distance (6MWD) test, 10-m walk speed, handgrip strength, lower extremity muscle strength, and short physical performance battery. Nutritional status was assessed using albumin levels and the Geriatric Nutritional Risk Index (GNRI). Patients were divided into two groups according to adverse events. Receiver operating characteristic curve analysis was used to predict mortality. The relationships between all-cause mortality and physical function and nutritional status were studied using Kaplan-Meier analysis and the log-rank test. RESULTS: The mean patient age was 75.3 ± 6.5 years. The median follow-up time was 32 (interquartile range 18-51) months, during which 11 deaths occurred. Death during follow-up was significantly associated with lower 6MWD (237.4 ± 120.2 vs. 355.2 ± 105.9 m), lower GNRI (77.3 ± 16.3 vs. 89.3 ± 8.1), and lower albumin levels (2.8 ± 0.6 vs. 3.3 ± 0.4 mg/dL) at baseline (p < 0.05). The cut-off values were 338 m, 83.3, and 2.95 g/dL for the 6MWD, GNRI, and albumin levels, respectively. The 6MWD test, GNRI, and albumin levels were significantly associated with all-cause mortality (p < 0.05). Additionally, the group with combined exercise intolerance and malnutrition had a lower survival rate (p < 0.05). CONCLUSION: Lower 6MWD and malnutrition are predictors of mortality in elderly patients undergoing PD.

Influence of sex differences in maintenance-hemodialysis participants on motivation of exercise therapy implementation: a multicenter cross-sectional study.

BACKGROUND: Exercising requires continuing training and maintenance of motivation. Support for exercise continuation by setting sex-appropriate goals is needed. However, this has not been investigated in patients undergoing hemodialysis. This study aimed to investigate sex differences in exercise motivation by analyzing an open-ended questionnaire of patients undergoing hemodialysis. METHODS: This multicenter, cross-sectional study was conducted among participants undergoing outpatient hemodialysis at 21 dialysis clinics. Before the intradialytic exercise program, a self-reported questionnaire was used to assess exercise purpose using open-label questions. Exercise purpose was analyzed between sexes by quantitative analysis of text, extracting frequently occurring words, creating a co-occurrence network, and constructing concepts. The basic attributes of the two groups were compared using the chi-squared and independent t tests. RESULTS: The analysis of 669 participants who attended an exercise program showed that the common words for exercise purpose in both sexes were strength, maintenance, walking, exercise, and muscle strength. Significant differences were observed in exercise purpose. Concepts related to the purpose of exercise were categorized into (1) physical function and condition, (2) addressing limitations, and (3) maintaining daily life activities. Physical appearance was important in both sexes. The main purpose of exercise for men was to increase physical fitness and muscle strength, while that for women was to maintain or improve their current functional status and prevent limb weakness. Women had significantly weaker muscle strength and poorer exercise habits than men and had more difficulty in daily life, suggesting that their purpose for exercise was to reduce difficulties in daily life and the burden on family. Women had significantly weaker muscle strength and poorer exercise habits than men and had more difficulty in daily life, suggesting that their purpose for exercise was to reduce difficulties in daily life and the burden on family. Furthermore, fear of falls was higher in women and prevention of falls may be a key for motivation. CONCLUSION: Exercise purpose in patients undergoing hemodialysis was summarized into the categories of physical function and condition, exercise, and daily life. Men aimed to maintain and increase their current physical status, and women aimed to reduce anxiety regarding their lower limbs and lack of exercise. It is necessary to consider sex differences in exercise purpose when designing exercise regimens and motivating participants.

Effects of cognitive impairment and assisted peritoneal dialysis on exit-site infection in older patients.

BACKGROUND: Elderly peritoneal dialysis (PD) patients required assistance for a variety of PD-related tasks. The usefulness of assisted PD in reducing the peritonitis risk has been reported; however, there is little evidence on the effectiveness of assisted PD in preventing exit-site infections in older patients. METHODS: This was a single-center, prospective cohort study. Thirty-three patients (mean age: 74.8 ± 5.9 years) on PD were evaluated for cognitive impairment (CI) using the Japanese version of the Montreal Cognitive Assessment. They were also evaluated to determine whether they performed the exit-site care procedure alone or with assistance. Patients were categorized into four groups based on the presence or absence of CI and the presence or absence of exit-site care assistance. They were followed up until the occurrence of peritonitis and exit-site infection at the end of the follow-up. RESULTS: Altogether, 8, 8, and 17 patients were assigned to the "without CI and without assistance", "without CI and with assistance", and "with CI and with assistance groups", respectively; no patients were assigned to the "with CI and without assistance group". Six and 16 patients experienced peritonitis and exit-site infection during follow-up, respectively. Kaplan-Meier analysis and log-rank tests revealed that the "without CI and without assistance group" was significantly associated with exit-site infection (log-rank < 0.05). CONCLUSION: Patients who did not receive assistance for exit-site care were at a higher risk of exit-site infections, even in the absence of CI. Caregiver assistance is important for preventing exit-site infections in older patients on PD.

Relationship between malnutrition and possible sarcopenia in the AWGS 2019 consensus affecting mortality in hemodialysis patients: a prospective cohort study.

BACKGROUND: The first objective of this study was to determine the relationship between muscle strength or physical performance and mortality, and the second objective was to show the relationship of Geriatric Nutritional Risk Index (GNRI) to muscle strength and physical performance decline. METHODS: We examined handgrip, the 5-times chair stand test, and GNRI in 635 maintenance hemodialysis patients and followed up for 72 months. Predictors for all-cause death were examined using Kaplan-Meier analysis and Cox proportional analysis. The relationship between possible sarcopenia and nutritional disorder (GNRI) was constructed receiver operating characteristic (ROC) curve. We used the Youden index to determine the optimal cutoff points for GNRI. RESULTS: The multivariate Cox proportional hazard analysis revealed that the GNRI did not show any significance, although handgrip (HR 3.61, 95% CI 1.70-7.68, p < 0.001) and the 5-times chair stand test (HR 1.71 95% CI 1.01-2.90, p = 0.045) were significant predictors for mortality. On the evaluation of possible sarcopenia by handgrip strength, the area under curve (AUC) on ROC curve analysis were 0.68 (95% CI 0.64-0.72), and 5-chair stand, the AUC on ROC were 0.55 (95% CI 0.51-0.60). The cut-off value for the GNRI discriminating those at possible sarcopenia by handgrip strength based on the Youden index was 91.5. CONCLUSIONS: Our study suggests that the handgrip strength test of the AWGS 2019 sarcopenia consensus was a simple and useful tool to predict mortality in chronic hemodialysis patients. Furthermore, GNRI assessment can be a useful tool for screening before assessing possible sarcopenia when it is difficult to perform SARC-F to all patients.

Predicting a target exercise heart rate that reflects the anaerobic threshold in nonbeta-blocked hemodialysis patients: The Karvonen and heart rate reserve formulas.

The aim of this study was to evaluate constants of the Karvonen (k) and heart rate reserve (HRR) (α) formulas that correspond to the anaerobic threshold (AT) to conveniently estimate the intensity of exercise therapy in nonbeta-blocked patients undergoing hemodialysis. Twenty-three patients undergoing hemodialysis performed cardiopulmonary exercise testing (CPX) and their HR at AT was measured. The predictor coefficients for a target HR corresponding to AT were calculated for each patient based on CPX. Interclass correlation coefficients (ICC) and Bland-Altman analysis were used to evaluate the reliability of the formulas. Mean values of coefficient k of the Karvonen formula and α of the HRR formula were 0.24 ± 0.11 and 17.4 ± 8, respectively. The target HR calculated with k = 0.24 and α = 17 had significant ICC between HR at AT (0.74 and 0.77, respectively; P < 0.05). Using the Karvonen and HRR formulas to determine a target HR corresponding to AT is a simple and easy method that can be used to develop exercise programs for hemodialysis patients.

The association between six month intra-dialytic resistance training and muscle strength or physical performance in patients with maintenance hemodialysis: a multicenter retrospective observational study.

BACKGROUND: Reduced muscle strength and physical performance are prevalent in patients of maintenance hemodialysis (MHD), and deleterious changes in these parameters are associated with increased mortality. METHODS: This retrospective observational study included 306 patients, who received a 6-month resistance exercise program during hemodialysis, three times per week on an outpatient basis. The training protocol consisted of two sets of 10 repetitions of knee extension, hip abduction, and hip flexion, using an elastic band in a sitting or supine position. Primary outcome measures included muscle strength, measured by percent knee extension muscle power to dry body weight (pKEMP-dBW), and physical performance, measured by short physical performance battery (SPPB). The adjusted mean differences in these variables during the 6 months were estimated using a multivariate linear regression model. RESULTS: The mean age with standard deviation was 70 ± 11 years. One hundred and sixty patients (52.3%) were men and the dry weight was 55.6 ± 11.3 kg. Sarcopenia, defined as SPPB ≤8, was present in 21.4% patients. Their hemodialysis adequacy was acceptable, with a Kt/V of 1.65 ± 0.29, and their nutritional status was good, with a normalized protein catabolism rate of 0.89 ± 0.18 g/kg/day. During the 6 months, both pKEMP-dBW and SPPB showed a slight but significant increase with an adjusted mean difference of 2.8 (95% confidence interval 1.3-4.3, p <  0.001) and 0.6 (0.4-0.9, p <  0.001), respectively. CONCLUSIONS: Six-month resistance training was associated with improved muscle strength and physical performance in patients with MHD.

Chronic Kidney Disease is Associated with Physical Impairment.

BACKGROUND: Physical impairment or frailty due to sarcopaenia is common in patients with chronic kidney disease and those receiving dialysis. This study examined the association between muscle weakness and kidney function in Japanese patients with chronic kidney disease. METHODS: A total of 23 stable outpatients were enrolled in the study. Several indices were used to assess muscle function; hand grip strength, isometric knee extension strength, Timed Up and Go test (TUG), and the short physical performance battery. The relationships between these indices and estimated glomerular filtration rate (eGFR) as a measure of kidney function were analysed statistically. RESULTS: Patients' characteristics were as follows: mean age 73.9 years (standard deviation (SD) 13); 12 males, 11 females; body mass index (BMI) 22.5 kg/m2 (SD 3.2); serum creatinine (sCr) 4.6 mg/ dl (SD 3.7); estimated glomerular filtration rate (eGFR) 19.1 ml/min (SD 16). Their physical performance indices were: hand grip strength 20.8 kg (SD 7.9); isometric knee extension strength 19.1 kgf/kg (SD 10.6); TUG 14.9 s (SD 6.0); and short physical performance battery score 7.0 (SD 4.3). Multiple regression analysis adjusted for age revealed significant associations between isometric knee extension strength/body weight and eGFR (F [2,19] = 8.38, p = 0.002) and TUG and eGFR (F=4.98 [2,18], p = 0.02). CONCLUSION: Deterioration in muscle function or maintenance of posture is associated with chronic kidney disease.

Acute effects of endurance exercise on nocturnal autonomic functions in sedentary subjects: a pilot study.

Nocturnal heart rate variability (HRV) is thought to reflect healthy recovery function of the autonomic nervous system. Although exercise is recommended for health promotion, exercise itself decreases HRV. We studied acute effect of daytime exercise on nocturnal HRV in 5 healthy adults (age, 22-40 years; 2 female subjects) without regular exercise habit. Using a treadmill, they performed 30-min walking at 4 km/hr and 30-min running at 9 km/hr from 11 a.m. on different days at an interval of 2 weeks. On these days and a day without exercise (control), Holter electrocardiograms were recorded from 9 a.m. for 24 hr. The amplitudes of low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0.45 Hz) components of HRV were measured continuously by complex demodulation and were averaged over periods of 11:00-11:30 a.m., 3 hr after going to bed, and time in bed at night. Exercise intensities of the walking and running were at 10% to 44% and 55% to 67% of heart rate reserve, respectively. During exercise, heart rate increased and LF and HF amplitudes decreased with exercise intensity. Nocturnal heart rate and LF and HF amplitude, however, showed no consistent changes with exercise intensity and their averages on the days of walking and running did not differ significantly from those of the control day. In conclusion, 30-min walking and running exercises performed in the morning had no significant acute effects on nocturnal heart rate or HRV.