Objective:To explore the predictive value of different critical values of slow gait speed on adverse outcomes in elderly maintenance hemodialysis (MHD) patients.Methods:The study was a prospective cohort study. The clinical data of elderly patients (≥ 60 years old) who received MHD treatment in the Third Affiliated Hospital of Guangzhou Medical University from March 1 to June 30, 2021 were collected, including demographic characteristics, diseases-related data and laboratory examination results. The follow-up period was one year. The six-meter walking test was used to measure the gait speed (m/s), and 0.6 m/s, 0.8 m/s and 1.0 m/s were used as the different critical values of the gait speed for grouping. The differences of clinical data between different groups were compared. Logistic regression analysis method was used to assess the association of slow gait speed with adverse outcomes (falls and hospitalization) in elderly MHD patients. The receiver operating characteristic (ROC) curve was performed to evaluate the best critical value of slow gait speed to predict the risk of falls and hospitalization.Results:A total of 108 elderly patients with MHD were included, with 57 males and 51 females. There were 43 patients (39.8%) of falls and 34 patients (31.5%) of hospitalization. There were statistically significant differences in age, Charlson's comorbidity index, and the proportions of hypertension, family support needed in daily life, walking aids needed, falls and hospitalization events among the four groups of the patients grouped according to gait speed (all P < 0.05). Multivariate logistic regression analysis results showed that the risk of falls predicted by gait speed of 0.6- < 0.8 m/s was higher than that by gait speed of > 1.0 m/s ( OR=3.973, 95% CI 1.116-14.136, P=0.033). The risk of hospitalization predicted by gait speed < 0.6 m/s was higher than that by gait speed > 1.0 m/s ( OR=9.147, 95% CI 1.658-50.453, P=0.011). The logistic regression analysis was performed with the critical values of 0.6 m/s, 0.8 m/s and 1.0 m/s as the classification variables, and the results showed that the gait speed of < 0.8 m/s was an influencing factor of the falls risk in elderly MHD patients (≥ 0.8 m/s as reference, OR=3.200, 95% CI 1.099-9.318, P=0.033). The gait speed < 0.8 m/s and < 0.6 m/s were influencing factors of hospitalization (≥ 0.8 m/s as reference, OR=3.899, 95% CI 1.355-11.216, P=0.012; ≥ 0.6 m/s as reference, OR=4.226, 95% CI 1.107-16.140, P=0.035). The area under the ROC curve for gait speed of < 0.6 m/s, < 0.8 m/s and < 1.0 m/s to predict the risk of falls were 0.605(95% CI 0.493-0.717, P=0.065), 0.668(95% CI 0.562-0.774, P=0.003), and 0.634 (95% CI 0.529-0.739, P=0.019), respectively. The best critical value of slow gait speed to predict the risk of fall was 0.73 m/s, and the area under the ROC curve was 0.720(95% CI 0.623-0.817, P < 0.001), with the sensitivity and specificity of 0.846 and 0.512, respectively. The area under the ROC curve for gait speed of < 0.6 m/s, < 0.8 m/s and < 1.0 m/s to predict the risk of hospitalization were 0.629(95% CI 0.509-0.749, P=0.032),0.683(95% CI 0.573-0.793, P=0.002), and 0.608(95% CI 0.497- 0.719, P=0.073). The best critical value of slow gait speed to predict the risk of hospitalization was 0.81 m/s, and the area under the ROC curve was 0.688(95% CI 0.576-0.800, P=0.002), with the sensitivity and specificity of 0.689 and 0.676, respectively. Conclusion:The critical value of gait speed 0.8 m/s can be used to predict the risk of falls and hospitalization in elderly MHD patients.

Objective:To explore the association between increasing ultrafiltration rate before a long interdialytic interval and hospitalization risk in maintenance hemodialysis (MHD) patients.Methods:A retrospective study was conducted to collect and analyze the demographic characteristics, disease-related, and laboratory indicators of MHD patients in the hemodialysis center of the Third Affiliated Hospital of Guangzhou Medical University from August to November 2020. The actual ultrafiltration rate higher than the planned ultrafiltration rate was defined as increased ultrafiltration rate. The patients were divided into increased ultrafiltration rate group and control group, and the differences of clinical data between the two groups were compared. The actual ultrafiltration rate >13 ml·kg -1·h -1 was defined as high filtration rate. Multivariate logistic regression analysis was used to assess the association between high ultrafiltration rate, increased ultrafiltration rate in MHD patients and occurrence of hospitalization (all cause, cardiovascular, and heart failure events). The receiver-operating characteristic curve was performed to evaluate the best cut point value of actual ultrafiltration rate and percentage of additional ultrafiltration rate for predicting intradialytic hypotension. Results:A total of 126 MHD patients were included in the study, with age of (57.48±13.81) years old, including 67 males (53.2%) and 59 females (46.8%). There were 69 patients (54.8%) in the increased ultrafiltration rate group, and 57 patients (45.2%) in the control group. During 2-year follow-up period, there were 69 patients (54.8%) of all cause hospitalization, 37 patients (29.4%) of cardiovascular hospitalization, 25 patients (19.8%) of heart failure hospitalization, and 43 patients (34.1%) of intradialytic hypotension. The body mass index ( t=4.343, P<0.001) and actual ultrafiltration rate ( t=4.694, P<0.001) in the increased ultrafiltration rate group were higher than those in the control group. Multivariate logistic regression analysis results showed that high ultrafiltration rate was an independent related factor of cardiovascular hospitalization after adjusting for age, gender and cardiovascular disease ( OR=2.871, 95% CI 1.202-6.854, P=0.018), and increasing ultrafiltration rate was an independent related factor of heart failure hospitalization after adjusting for age and serum albumin in the MHD patients ( OR=0.302, 95% CI 0.112-0.812, P=0.018). When the actual ultrafiltration rate was ≤13 ml·kg -1·h -1, increasing ultrafiltration rate was correlated with the reduced risk of heart failure hospitalization (after adjusting for serum albumin, OR=0.044, 95% CI 0.005-0.360, P=0.004) and cardiovascular hospitalization (after adjusting for age, OR=0.052, 95% CI 0.010-0.259, P<0.001) in the MHD patients. Receiver-operating characteristic curve analysis results showed that the area under the curve of actual ultrafiltration rate for predicting the risk of intradialytic hypotension in MHD patients was 0.734 (95% CI 0.633-0.835, P<0.001) with the best cut point of 13.8 ml·kg -1·h -1, and the sensitivity and specificity of 0.488 and 0.951, respectively. When the actual ultrafiltration rate was ≤13 ml·kg -1·h -1, the area under the curve of percentage of additional ultrafiltration rate for predicting the risk of intradialytic hypotension in MHD patients was 0.746 (95% CI 0.603-0.889, P=0.001), with the best cut point of 26.0%, and the sensitivity and specificity of 0.579 and 0.914, respectively. Conclusions:Increasing ultrafiltration rate before a long interdialytic interval and reduced risk of heart failure and cardiovascular hospitalization in MHD patients with the ultrafiltration rate ≤13 ml·kg -1·h -1 during 2-year follow-up period.