Step length and fall risk in adults with chronic kidney disease: a pilot study

Automatic Radar-Based Step Length Measurement in the Home for Older Adults Living with Frailty

With an aging population, numerous assistive and monitoring technologies are under development to enable older adults to age in place. To facilitate aging in place, predicting risk factors such as falls and hospitalization and providing early interventions are important. Much of the work on ambient monitoring for risk prediction has centered on gait speed analysis, utilizing privacy-preserving sensors like radar. Despite compelling evidence that monitoring step length in addition to gait speed is crucial for predicting risk, radar-based methods have not explored step length measurement in the home. Furthermore, laboratory experiments on step length measurement using radars are limited to proof-of-concept studies with few healthy subjects. To address this gap, a radar-based step length measurement system for the home is proposed based on detection and tracking using a radar point cloud followed by Doppler speed profiling of the torso to obtain step lengths in the home. The proposed method was evaluated in a clinical environment involving 35 frail older adults to establish its validity. Additionally, the method was assessed in people's homes, with 21 frail older adults who had participated in the clinical assessment. The proposed radar-based step length measurement method was compared to the gold-standard Zeno Walkway Gait Analysis System, revealing a 4.5 cm/8.3% error in a clinical setting. Furthermore, it exhibited excellent reliability (ICC(2,k) = 0.91, 95% CI 0.82 to 0.96) in uncontrolled home settings. The method also proved accurate in uncontrolled home settings, as indicated by a strong consistency (ICC(3,k) = 0.81 (95% CI 0.53 to 0.92)) between home measurements and in-clinic assessments.

Novel risk-factor analysis and risk-evaluation model of falls in patients receiving maintenance hemodialysis

This study investigated the prevalence of falls in maintenance hemodialysis (MHD) patients, and established a nomogram model for evaluating the fall risk of MHD patients. This study enrolled 303 MHD patients from the dialysis department of a tertiary hospital in July 2021. The general data of the participants, as well as the scores on the FRAIL scale, Sarcopenia Screening Questionnaire (SARC-F), Short Physical Performance Battery (SPPB) Scale, and of anxiety and depression, and the occurrence of falls were recorded. Using R language, data were assigned to the training set (n = 212) and test set (n = 91), and a logistic regression model was established. The regression model was verified by the receiver operating characteristic (ROC) curve, area under the curve (AUC), and the calibration curve. As a result, the prevalence of falls in MHD patients was 20.46%. Risk factors for falls in the optimal multivariate logistic regression model included hearing impairment, the depression score, and the SPPB score, of which a higher depression score (odds ratio (OR): 1.28, 95% confidence interval (CI): 1.09-1.49, p = 0.002) and SPPB ≤ 6 (OR_vsSPPB9-12: 3.69, 95% CI: 1.04-13.14, p = 0.043) conferred independent risk for falls. AUC of the nomogram in the training was 0.773, which in the test group was 0.663. The calibration and standard curves were fitted closely, indicated that the evaluation ability of the model was good. Thus, a higher depression score and SPPB ≤ 6 are independent risk factors for falls in MHD patients, and the nomogram with good accuracy and discrimination that was established in this study has clinical application value.

Game-based intradialytic non-weight-bearing exercise training on gait speed and balance in older adults with diabetes: a single-blind randomized controlled trial

Older adults with diabetes receiving hemodialysis have impaired gait speed and balance compared to the general population, which have been associated with increased risks of falls and mortality. This study evaluated the effectiveness of a game-based intradialytic exercise training program (iExergame) on improving gait speed and balance. This was a single-blind randomized controlled trial. The intervention group (IG) received iExergame training using real-time audiovisual feedback with wearable inertial sensors. The control group (CG) received conventional training without any technology. Both trainings were intradialytic, non-weight-bearing, and used ankle range of motion. Gait and balance parameters were collected at baseline and 4-week follow-up. Data from 70 adults (age 64.2 ± 9.0 years) were analyzed. Compared to the CG, the IG showed greater changes between baseline and 4-week follow-up in several parameters. Gait parameters included faster speeds and longer stride lengths, particularly during dual task walking (p < 0.050). Balance parameters included reductions in center of mass (p = 0.004), ankle (p < 0.001), and hip (p = 0.010) sways during semi-tandem stance, particularly in users of assistive devices. iExergame training could improve gait speed and balance in this population and might be an option to increase intradialytic exercise adherence while reducing burdens of exercise administration.

Validation of Gait Measurements on Short-Distance Walkways Using Azure Kinect DK in Patients Receiving Chronic Hemodialysis

Muscle dysfunction, skeletal muscle fibrosis, and disability are associated with weakness in patients with end-stage renal disease. The main purpose of this study was to validate the effectiveness of a proposed system for gait monitoring on short-distance 1.5 m walkways in a dialysis center. Gaits with reduced speed and stride length, long sit-to-stand time (SST), two forward angles, and two unbalanced gait regions are defined in the proposed Kinect v3 gait measurement and analysis system (K3S) and have been considered clinical features in end-stage renal disease (ESRD) associated with poor dialysis outcomes. The stride and pace calibrations of the Kinect v3 system are based on the Zeno Walkway. Its single rating intraclass correlation (ICC) for the stride is 0.990, and its single rating ICC for the pace is 0.920. The SST calibration of Kinect v3 is based on a pressure insole; its single rating ICC for the SST is 0.871. A total of 75 patients on chronic dialysis underwent gait measurement and analysis during walking and weighing actions. After dialysis, patients demonstrated a smaller stride (p < 0.001) and longer SST (p < 0.001). The results demonstrate that patients' physical fitness was greatly reduced after dialysis. This study ensures patients' adequate physical gait strength to cope with the dialysis-associated physical exhaustion risk by tracing gait outliers. As decreased stride and pace are associated with an increased risk of falls, further studies are warranted to evaluate the clinical benefits of monitoring gait with the proposed reliable and valid system in order to reduce fall risk in hemodialysis patients.

Impact of the Nutrition-Inflammation Status on the Functionality of Patients with Chronic Kidney Disease

Functional capacity of chronic kidney disease (CKD) patients is compromised by their nutrition-inflammation status. We evaluated the functional capacity of advanced chronic kidney disease (ACKD) patients and the influence of the nutrition-inflammation status. In a cross-sectional study, which included ACKD patients from the nephrology department of the Hospital Universitario de la Princesa in Madrid, Spain, we assessed: functional capacity with the Short Physical Performance Battery (SPPB) test, interpreting a result <7 in the test as low functionality; body composition with monofrequency bioimpedance; muscular strength with hand grip strength; nutritional and inflammatory status using biochemical parameters and the Malnutrition Inflammation Scale (MIS). A total of 255 patients with ACKD were evaluated, 65.8% were men, their mean age was 70.65 ± 11.97 years and 70.2% of the patients had an age >65 years. The mean score of SPPB was 8.50 ± 2.81 and 76.4% of the patients presented a score ≥7, with a higher percentage in the group of men. The percentage of patients with limitations increased with age. The patients with SPPB values higher than 7 showed high values of albumin and low soluble C-reactive protein (s-CRP) and MIS. We found better functionality in well-nourished patients. A multivariate logistic regression model established an association of high albumin values with a better functional capacity (OR: 0.245 CI: 0.084−0.714 p < 0.010), while another model showed an association between CRP values and decreased functionality (OR: 1.267 CI: 1.007−1.594 p = 0.044). Conclusion: nutritional status and body composition influence on the functional capacity of patients with ACKD.

Continuous Long-Term Physical Activity Monitoring in Hemodialysis Patients

Background

Physical inactivity is common in patients receiving hemodialysis, but activity patterns throughout the day and in relation to dialysis are largely unknown. This knowledge gap can be addressed by long-term continuous activity monitoring, but this has not been attempted and may not be acceptable to patients receiving dialysis.

Methods

Ambulatory patients with end-stage kidney disease receiving thrice-weekly hemodialysis wore commercially available wrist-worn activity monitors for 6 months. Step counts were collected every 15 minutes and were linked to dialysis treatments. Physical function was assessed using the Short Physical Performance Battery (SPPB). Fast time to recovery from dialysis was defined as ≤2 hours. Mixed effects models were created to estimate step counts over time.

Results

Of 52 patients enrolled, 48 were included in the final cohort. The mean age was 60 years, and 75% were Black or Hispanic. Comorbidity burden was high, 38% were transported to and from dialysis by paratransit, and 79% had SPPB <10. Median accelerometer use (199 days) and adherence (95%) were high. Forty-two patients (of 43 responders) reported wearing the accelerometer every day, and few barriers to adherence were noted. Step counts were lower on dialysis days (3991 [95% CI, 3187 to 4796] versus 4561 [95% CI, 3757 to 5365]), but step-count intensity was significantly higher during the hour immediately after dialysis than during the corresponding time on nondialysis days (188 steps per hour increase [95% CI, 171 to 205]); these levels were the highest noted at any time. Postdialysis increases were more pronounced among patients with fast recovery time (225 [95% CI, 203 to 248] versus 134 [95% CI, 107 to 161] steps per hour) or those with SPPB ≥7. Estimates were unchanged after adjustment for demographics, diabetes status, and ultrafiltration rate.

Conclusions

Long-term continuous monitoring of physical activity is feasible in patients receiving hemodialysis. Highly granular data collection and analysis yielded new insights into patterns of activity after dialysis treatments.