Kei Yoneki

Relationship Between Lower Extremity Muscle Strength and All-Cause Mortality in Japanese Patients Undergoing Dialysis

Background Skeletal muscle wasting is common and insidious in patients who are undergoing hemodialysis. However, the association between lower extremity muscle strength and all-cause mortality remains unclear in this population. Objective The purpose of this study was to investigate the prognostic significance of lower extremity muscle strength on 7-year survival in a cohort of patients who were clinically stable and undergoing hemodialysis. Design A prospective cohort study was conducted. Methods A total of 190 Japanese outpatients who were undergoing maintenance hemodialysis 3 times per week at a hemodialysis center were followed for up to 7 years. Lower extremity muscle strength was evaluated using a handheld dynamometer at the time of patient enrollment in the study. Muscle strength data were divided by dry weight and expressed as a percentage. A Cox proportional hazards regression model was used to assess the contribution of lower extremity muscle strength to all-cause mortality. Results The median age (25th and 75th percentiles) of this study population was 64 years (57 and 72 years), 53.2% of the patients were women, and the time on hemodialysis was 39.0 months (15.9 and 110.5 months) at baseline. During a median follow-up of 36.0 months, there were 30 deaths. With a multivariate Cox model, the hazard ratio in the group with a knee extensor strength of <40% was 2.73 (95% confidence interval=1.14–6.52) compared with that in the ≥40% group. Limitations This was a small-scale observational study, and the mechanisms underlying the higher mortality risk in patients with poor muscle strength undergoing hemodialysis than in other patients undergoing hemodialysis remain to be elucidated. Conclusions Decreased lower extremity muscle strength was strongly associated with increased mortality risk in patients undergoing hemodialysis.

Association of Habitual Physical Activity Measured by an Accelerometer with High-Density Lipoprotein Cholesterol Levels in Maintenance Hemodialysis Patients

After confirming the relationship between high-density lipoprotein cholesterol (HDL-C) levels and mortality in hemodialysis patients for study 1, we investigated the effect of physical activity on their HDL-C levels for study 2. In study 1, 266 hemodialysis patients were monitored prospectively for five years, and Cox proportional hazard regression confirmed the contribution of HDL-C to mortality. In study 2, 116 patients were recruited after excluding those with severe comorbidities or requiring assistance from another person to walk. Baseline characteristics, such as demographic factors, physical constitution, primary kidney disease, comorbid conditions, smoking habits, drug use, and laboratory parameters, were collected from patient hospital records. An accelerometer measured physical activity as the number of steps per day over five consecutive days, and multiple regression evaluated the association between physical activity and HDL-C levels. Seventy-seven patients died during the follow-up period. In study 1, we confirmed that HDL-C level was a significant predictor of mortality (P = 0.03). After adjusting for patient characteristics in study 2, physical activity was independently associated with HDL-C levels (adjusted R 2 = 0.255; P = 0.005). In conclusion, physical inactivity was strongly associated with decreased HDL-C levels in hemodialysis patients.

Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients.

Evaluating the effectiveness of exercise training on elderly patients who require haemodialysis: study protocol for a systematic review and meta-analysis

Introduction As the average age of haemodialysis patients rapidly increases around the world, the number of frail, elderly patients has increased. Frailty is well known to be an indicator of disability and a poor prognosis for haemodialysis patients. Exercise interventions have been safely and successfully implemented for middle-aged or younger patients undergoing haemodialysis. However, the benefits of exercise interventions on elderly patients undergoing haemodialysis remain controversial. The main objective of this study is to systematically review the effects of exercise training on the physical function, exercise capacity and quality of life of elderly patients undergoing haemodialysis, and to provide an update on the relevant evidence. Methods and analyses Published randomised controlled trials (RCTs) that assessed the effectiveness of exercise training on haemodialysis patients with respect to physical function, exercise tolerance and quality of life will be included. Bibliographic databases include MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, CINAHL, Web of Science, PsycINFO and PEDro. The risk of bias of the included RCTs will be assessed using the Cochrane Collaborations tool and TESTEX. The primary outcome will be physical function and exercise tolerance. This review protocol is reported according to the PRISMA-P 2015 checklist. Statistical analysis will be performed using review manager software (RevMan V.5.3, Cochrane Collaboration, Oxford, England). Ethics and dissemination Ethical approval is not required because this study does not include confidential personal data nor does it perform interventions on patients. This review is expected to inform readers on the effectiveness of exercise training in elderly patients undergoing haemodialysis. Findings will be presented at conferences and submitted to a peer-reviewed journal for publication. PROSPERO registration number CRD42015020701.

Utility of Regular Management of Physical Activity and Physical Function in Hemodialysis Patients

Background/Aims: Several clinical practice guidelines recommend regular assessment of physical activity and physical function as part of routine care in hemodialysis patients. However, there is no clear evidence to support these recommendations. We investigated whether the proportion of attendance at a regular program for management of physical activity and physical function can predict all-cause mortality and cardiovascular events in hemodialysis patients. Methods: This retrospective cohort study consisted of 266 hemodialysis patients participating in the management program at least once. Participants were tracked for 3 years after their first attendance at the management program to determine their attendance proportion. The main study outcomes included all-cause mortality and a composite of fatal and nonfatal cardiovascular events. Results: Median patient age was 64.5 (interquartile range, 56.8 – 72.0) years, 45% were women, and the median time on hemodialysis was 35.5 (interquartile range, 12.0 – 114.3) months at baseline. Sixty-five patients died over a median follow-up of 79 months. The incidence of cardiovascular events was 60 over a median follow-up of 68 months. Even after adjusting for any of the prognostic models, participants who attended ≤ 75% of sessions (n = 140) had higher risks of mortality (hazard ratio (HR), 1.79; 95% confidence interval (CI): 1.00 – 3.36; P = 0.049) and cardiovascular events (HR, 1.84; 95% CI: 1.07 – 3.48; P = 0.03) than those attending > 75% of sessions (n = 126). Conclusion: Hemodialysis patients in whom physical activity and physical function could be assessed more regularly had better prognosis than those with only intermittent assessment.

Exercise Training in Elderly People Undergoing Hemodialysis: A Systematic Review and Meta-analysis

Introduction Previous reviews have indicated the effectiveness of exercise in people undergoing hemodialysis. However, these analyses did not take into account whether the subjects were elderly. We performed a systematic review of the effects of exercise training in elderly people undergoing hemodialysis and updated the evidence of exercise for people undergoing hemodialysis by adding recent research data. Methods We searched 8 electronic databases up to June 2016. Inclusion criteria were as follows: randomized controlled trial, English publication, subjects aged 18 and older undergoing hemodialysis, evaluation of physical function as an outcome of exercise intervention. We defined elderly as age 60 years and older. The main outcomes were exercise tolerance (peak/maximum oxygen consumption) and walking ability (6-minute walk distance). Secondary outcomes were lower extremity muscle strength and quality of life. Results After screening of 10,923 references, 30 comparisons were entered into the analysis. However, because we found only 1 study in which elderly subjects were treated, we could not perform a meta-analysis for these people. For the general population undergoing hemodialysis, supervised exercise training was shown to significantly increase peak/maximum oxygen consumption (standard mean difference, 0.62; 95% confidence interval 0.38–0.87; P < 0.001), 6-minute walk distance (standard mean difference, 0.58; 95% confidence interval 0.24–0.93; P < 0.001), lower extremity muscle strength (standard mean difference, 0.94; 95% confidence interval 0.67–1.21; P < 0.001), and quality of life (standard mean difference, 0.53; 95% confidence interval 0.52–0.82; P < 0.001). Discussion Our analysis on the effectiveness of exercise training in elderly people undergoing hemodialysis as compared with nonelderly people was somewhat inconclusive. Future studies should be carried out for elderly people to identify the most favorable exercise program for this population.