Three-year trajectories of social networks, face-to-face interactions, and non-face-to-face interactions among community-dwelling older adults in Japan during the COVID-19 pandemic: Otassha study

OBJECTIVES

To investigate the trajectories of social networks and interactions among older Japanese individuals during the COVID-19 pandemic.

STUDY DESIGN

We used data from a cohort of community-dwelling older individuals from the Otassha study's 2019-2022 survey. Participants comprised 606 older individuals who participated in the 2019 survey and were followed up at least once.

MAIN OUTCOME MEASURES

Social networks were assessed using the Lubben Social Network Scale-6 (LSNS-6), whereas social interactions were assessed by the frequency of face-to-face or non-face-to-face contact with non-resident family members and friends. Trajectories of the LSNS-6 and face-to-face and non-face-to-face interactions were identified using group-based semiparametric mixture modeling. The trajectories of change in the LSNS-6 from 2019 were also identified. The factors associated with the changes in trajectory patterns were examined using logistic regression analysis.

RESULTS

Three LSNS-6 trajectories were identified, with slightly decreasing patterns over time. Specifically, face-to-face interactions tended to decrease over time, whereas non-face-to-face interactions exhibited almost no change. The reduction in LSNS-6 in the decreased pattern failed to recover to its pre-pandemic level. The group of participants with the decreased pattern had a significantly higher proportion of people participating in group activities [odds ratio (95 % confidence interval): 2.27 (1.12-4.59)] and performing calisthenics twice a week than the group with the maintained pattern [2.08 (1.18-3.68)].

CONCLUSIONS

During the three years of the pandemic, no changes were observed in the social networks of community-dwelling older Japanese individuals.

Social isolation, regardless of living alone, is associated with mortality: the Otassha study

Introduction

Social isolation has been recognized as a contributing factor to negative health outcomes. Although living alone is associated with health-related outcomes, existing findings are inconsistent. It is not the act of living alone that may predict poor health, but rather social isolation that can lead to increased mortality risk. This study investigated the combined associations of social isolation and living alone with mortality among community-dwelling older adults.

Methods

We included older adults from Itabashi ward, Tokyo, who participated in comprehensive health checkups. Participants were categorized into four groups based on their social isolation status and living alone. The primary outcome was all-cause mortality, analyzed using Cox proportional hazards models.

Results

Of the 1,106 participants (mean age 73, 42% male), 4.5% experienced both social isolation and living alone. This combination was associated with a worse prognosis regarding all-cause mortality (hazard ratio (HR): 2.08 [95% confidence interval (CI), 1.08-4. 00]). Those who were socially isolated but not living alone also showed a trend towards higher mortality risk (HR: 1.41 [95% CI, 0.90-2.20]). Contrastingly, those who were not socially isolated and lived alone did not show an increased mortality risk (HR: 0.81 [95% CI, 0.44-1.49]).

Discussion and conclusion

Living alone is not inherently associated with a poor prognosis in older adults; however, social isolation was associated with a higher mortality risk. Healthcare providers should focus on enhancing social interactions and support for older adults because of their effects on health rather than solely addressing living arrangements to prevent adverse health events.

Demonstration of nuclear gamma-ray polarimetry based on a multi-layer CdTe Compton camera

To detect and track structural changes in atomic nuclei, the systematic study of nuclear levels with firm spin-parity assignments is important. While linear polarization measurements have been applied to determine the electromagnetic character of gamma-ray transitions, the applicable range is strongly limited due to the low efficiency of the detection system. The multi-layer Cadmium-Telluride (CdTe) Compton camera can be a state-of-the-art gamma-ray polarimeter for nuclear spectroscopy with the high position sensitivity and the detection efficiency. We demonstrated the capability to operate this detector as a reliable gamma-ray polarimeter by using polarized 847-keV gamma rays produced by the [Formula: see text]([Formula: see text]) reaction. By combining the experimental data and simulated calculations, the modulation curve for the gamma ray was successfully obtained. A remarkably high polarization sensitivity was achieved, compatible with a reasonable detection efficiency. Based on the obtained results, a possible future gamma-ray polarimetery is discussed.

Reserved gait capacity and mortality among patients undergoing hemodialysis

BACKGROUND

Patients undergoing hemodialysis (HD) have difficulty increasing their gait speed in daily life. The extent of the increase from the usual gait speed (UGS) to the maximum gait speed (MGS) is considered the reserved gait capacity (RGC). Little is known regarding the implications of RGC. This study aimed to investigate the association between RGC and all-cause mortality in patients undergoing HD.

METHODS

In this retrospective study, we assessed the usual and maximum 10-m walking speed of outpatients who underwent HD between October 2002 and August 2021. RGC was defined as the ratio of MGS to UGS. Patients were divided into three groups according to the tertiles of RGC (low, moderate and high). A Cox proportional hazards regression model was used to examine the association between RGC and all-cause mortality.

RESULTS

Of the 496 (median age 66.0 years; men 59%) participants, 186 patients died during the follow-up (incident ratio of 62.0 per 1000 person-years). The patients with moderate [hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.46-0.94] and high (HR 0.44, 95% CI 0.30-0.65) RGC had a lower risk of mortality than the low RGC group. Furthermore, even when restricted to a population with only UGS <1.0 m/s, the group with high RGC still had a lower risk of mortality than those with low RGC (HR 0.55, 95% CI 0.33-0.94).

CONCLUSIONS

Lower RGC was independently associated with an increased risk of all-cause mortality among patients on HD; high RGC had a survival advantage even with a slow UGS.

The effect of nano hydroxyapatite coating implant surfaces on gene expression and osseointegration

BACKGROUND

Hierarchical micro-nano structured topography along with surface chemistry modifications of dental implants have been suggested to positively contribute to the osseointegration process. However, the effect of such surface modifications on the molecular response as well as bone formation rate and quality are still unclear, especially in the early healing period. This study aimed to evaluate the effect of coating a double acid etched (DAE) implant surface with nano-sized (20 nm) hydroxyapatite (Nano) with respect to gene expression, histologic parameters, and nanomechanical properties when compared to DAE control at 1 and 2 weeks after implant placement in a rodent femur model.

MATERIAL AND METHODS

Expression of bone-related genes was determined by qRT-PCR (Col-I, Runx-2, Osx, Opn, Ocn, Alp). Histomorphometric evaluation of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within implant threads was performed using photomicrographs after histologic processing. Mechanical properties, reduced elastic modulus and hardness, were determined through nanoindentation.

RESULTS

At 1 week, the Nano group demonstrated significantly higher expression of Col-I and Ocn compared to the DAE group, indicating upregulation of osteoprogenitor and osteoblast differentiation genes. At 2 weeks, Nano surface further exhibited enhanced gene expression of Col-I and Osx in comparison to the DAE surface, suggesting an increased mineralization of the newly formed bone. Nanoindentation analysis revealed that the Nano group presented no significant difference on the ranks of reduced elastic modulus and hardness compared to DAE for both timepoints. Histomorphometric analysis yielded no significant difference in the percentage of BIC and BAFO between the Nano and DAE surfaces at 1 and 2 weeks. However, Nano implants did present a higher mean value, ~50%, of BIC compared to DAE, ~30%, after 2 weeks in vivo.

CONCLUSIONS

While no significant differences were observed in the amount and mechanical properties of newly formed bone, Nano surface positively and significantly increased the expression osteogenic genes compared to DAE surface at early healing periods.

The Association of Short Physical Performance Battery With Mortality and Hospitalization in Patients Receiving Hemodialysis

OBJECTIVE

The Short Physical Performance Battery (SPPB) is recommended for evaluating physical performance in patients on hemodialysis (HD). However, the association between SPPB score and long-term health outcomes in these patients remains unclear. We examined the association of SPPB score with all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization in patients on HD.

DESIGN AND METHODS

This retrospective cohort study included 326 patients (median age, 68 years; 62% men) who received outpatient HD therapy. These patients were divided into 2 SPPB groups: low (SPPB ≤9) and high (SPPB >9). We investigated the association of SPPB score and their change over time with health outcomes using Cox regression analysis.

RESULTS

Low SPPB score was associated with a higher risk for all-cause mortality (hazard ratio [HR]: 3.19, 95% confidence interval [95% CI]: 1.89-5.38), all-cause hospitalization (HR: 2.01, 95% CI: 1.44-2.82), and cardiovascular hospitalization (HR: 2.20, 95% CI: 1.45-3.35). Additionally, change in SPPB score over 1 year was associated with health outcomes.

CONCLUSIONS

Lower SPPB score was significantly associated with a higher risk for all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization. The SPPB may be a valuable indicator for risk stratification in patients on HD. Additionally, preventive treatments may be an effective management strategy in limiting the high mortality and hospitalization rates in patients with decreased SPPB score.

Prevalence, overlap, and prognostic impact of multiple frailty domains in older patients on hemodialysis

BACKGROUND

Frailty is a state of increased vulnerability owing to adverse health outcomes and is recognized as a multidimensional construct. There is limited evidence on the association between multiple domains of frailty and the risk of adverse events in patients undergoing hemodialysis. We aimed to report on the prevalence, degree of overlap, and prognostic impact of multiple frailty domains in older patients undergoing hemodialysis.

METHODS

We retrospectively enrolled outpatients (aged ≥60 years) undergoing hemodialysis at two dialysis centers in Japan. The physical domain of frailty was defined as slow gait speed and low handgrip strength. The psychological and social domains of frailty were defined using a questionnaire to assess depressive symptoms and define social frailty status. The outcomes were all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization. Cox proportional hazard and negative binomial models were used to examine these associations.

RESULTS

Among the 344 older patients (mean age, 72 years; male, 61%), 15.4% had an overlap in all three domains. Patients with a higher number of frailty domains had a higher risk of all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization (P for trend = 0.001, 0.001, and 0.08, respectively).

CONCLUSIONS

These results suggest that multiple-domain assessment of frailty is an important strategy to prevent adverse events in patients requiring hemodialysis.

Impact of combinations of subscale declines in higher-level functional capacity on 8-year all-cause mortality among community-dwelling older Japanese adults

BACKGROUND

The frequency of combined declines in domains of multi-faceted frailty and their impact on adverse health outcomes have not been adequately investigated. We aimed to examine the association between combined subscale declines in higher-level functional capacity and 8-year all-cause mortality among community-dwelling older Japanese individuals and the impact of multi-faceted frailty on mortality.

MATERIALS AND METHODS

We administered a questionnaire to 7015 community-dwelling older adults aged 65-85 years. The higher-level functional capacity of the 3381 respondents was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence. Subscale decline was defined as (1) none, (2) only social role (SR), (3) only intellectual activity (IA), (4) SR and IA, (5) only instrumental activities of daily living (IADL), (6) IADL and SR, (7) IADL and IA, and (8) all. Associations between combined subscale declines and mortality were examined using adjusted Cox proportional hazards models. Follow-up was conducted from October 1, 2012, to death or November 1, 2020.

RESULTS

The mortality rate was 16.7/1000 person-years. Moreover, 44% of respondents had declined SR, and half of them had multiple declines. Compared with no decline, SR (adjusted hazard ratio [HR]: 1.49, 95% confidence interval [CI]: 1.14-1.93), SR and IA (HR: 1.59, 95% CI: 1.16-2.17), IADL and SR (HR: 1.97, 95% CI: 1.31-2.99), and all-domain (HR: 2.72, 95% CI: 1.98-3.74) declines were significantly associated with higher mortality risks.

CONCLUSIONS

Overlapping SR and IADL declines increased mortality risk, suggesting the importance of measuring social frailty and overlapping physical and social frailty.

Effects of anthropometric changes on hospitalization and mortality among patients on hemodialysis

BACKGROUND

Low values for anthropometric indicators are risk factors for adverse clinical outcomes among patients on hemodialysis. Nonetheless, little is known about the association between the trajectory of anthropometric indicators and prognosis. We examined the association between a one-year change in anthropometric indicators and hospitalization and mortality in patients undergoing hemodialysis.

METHODS

This retrospective cohort study collected data on five anthropometric indicators from patients undergoing maintenance hemodialysis: body mass index, mid-upper arm circumference, triceps skinfold, mid-arm muscle circumference, and calf circumference. We calculated their trajectories over one year. The outcomes were all-cause death and the number of all-cause hospitalizations. Negative binomial regressions were used to examine these associations.

RESULTS

We included 283 patients (mean age, 67.3 years; 60.4% males). During the follow-up period (median, 2.7 years), 30 deaths and 200 hospitalizations occurred. Body mass index (incident rate ratio [IRR]: 0.87; 95% confidence interval [CI] 0.85-0.90), mid-upper arm circumference (IRR: 0.94; 95% CI 0.88-0.99), triceps skinfold (IRR: 0.92; 95% CI 0.84-0.99), and mid-arm muscle circumference (IRR: 0.99; 95% CI 0.98-0.99) increases over one year were associated with a lower risk of all-cause hospitalizations and death regardless of their value at any one point in time. However, the calf circumference trajectory was not associated with clinical events (IRR: 0.94; 95% CI 0.83-1.07).

CONCLUSIONS

Body mass index, mid-upper arm circumference, triceps skinfold, and mid-arm muscle circumference trajectories were independently associated with clinical events. Routinely assessing these simple measures in clinical practice may provide additional prognostic information for managing patients undergoing hemodialysis.

Association between Physical Frailty and Sleep Disturbances among Patients on Hemodialysis: A Cross-Sectional Study

INTRODUCTION

Among patients on hemodialysis (HD), physical frailty and sleep disturbances are not only common but also associated with adverse outcomes. The aim of this study was to evaluate the association between physical frailty and sleep disturbances in patients on HD.

METHODS

This cross-sectional study was conducted from June 2017 to March 2021, with outpatients receiving HD 3 times a week at two dialysis facilities in Japan. Sleep disturbances were identified with the Athens Insomnia Scale (AIS). Physical frailty was defined using the Fried Frailty Phenotype. Patients were classified as "non-frailty (number of frailty components: 0-2)" or "frailty (3-5)." We examined the association of sleep disturbances with physical frailty and its components by performing a logistic regression analysis.

RESULTS

We analyzed 360 patients (mean age 65.6 years; 62% men). Eighty-one patients (23%) were classified into the group with frailty, and the mean AIS score was 5.2 ± 4.2 points. After adjusting for clinical characteristics, increasing the AIS score per 1 point was associated with higher odds of physical frailty (odds ratio, 1.12; 95% confidence interval, 1.05-1.20; p < 0.01). As for the frailty components, exhaustion, low physical activity, and weak grip strength showed an association with sleep disturbances (all p < 0.05).

CONCLUSIONS

Sleep disturbances were independently associated with physical frailty in patients on HD. Future studies are warranted to investigate the causality between physical frailty and sleep disturbances in this population.

Trajectory of Serum Albumin Prior to Death in Patients Receiving Hemodialysis

OBJECTIVE

Although some clinical expert guidelines recommend regular monitoring of serum albumin levels in patients undergoing maintenance hemodialysis, little is known about the serum albumin trajectory patterns over time, and it is unclear how the trajectory change before death.

METHODS

We performed this retrospective study using data from 421 patients receiving hemodialysis in a dialysis facility. We divided patients into died and survived groups according to whether they died during the observation period. To compare the albumin trajectories during the observation period between the died and survived groups, linear mixed-effect models and a backward timescale from the year of death or study end were used.

RESULTS

During the observation period (median, 5.1 years; maximum, 8.4 years), 115 patients receiving dialysis died. The serum albumin level showed steeper decline 3 years before death in the died group than in the survived group. The difference in albumin between the died and survived groups became apparent 3 years before death (difference, 0.08 g/dL; 95% confidence interval, 0.00-0.15 g/dL; P = .04), and the difference widened over time (difference at 1 year before death, 0.24 g/dL; 95% confidence interval, 0.14-0.33 g/dL; P < .001). Furthermore, in an analysis of albumin trajectories according to cause of death, the albumin level showed a downward trend regardless of the cause of death.

CONCLUSION

The serum albumin trajectory differed between patients undergoing hemodialysis who died and who survived, supporting the importance of monitoring the albumin trajectory in clinical practice.

Comparison of the association between six different frailty scales and clinical events in patients on hemodialysis

BACKGROUND

Frailty is associated with adverse outcomes in patients undergoing hemodialysis (HD). However, no study has used various frailty assessments in patients on HD to examine their association with clinical events. In this study, we investigated the association between clinical events and six frailty scales.

METHODS

Outpatients who underwent HD between 2018 and 2020 were retrospectively enrolled. Frailty was defined using the Fried Frailty Phenotype, Study of Osteoporotic Fractures (SOF) Index, Short Physical Performance Battery (SPPB), Frail Screening Index, FRAIL scale and Clinical Frailty Scale. Outcomes were clinical events, including a composite of multiple (i.e. recurrent) all-cause hospitalizations, fractures and/or all-cause mortality. The association of clinical events and the frailty scales were investigated using negative binomial regression analysis.

RESULTS

Fried Frailty Phenotype [incident rate ratio (IRR), 1.62; 95% confidence interval (CI), 1.49-1.76], SOF Index (IRR, 1.42; 95% CI, 1.10-1.83), SPPB (IRR, 1.79; 95% CI, 1.11-2.88) and Clinical Frailty Scale (IRR, 1.65; 95% CI, 1.04-2.61) were significantly associated with clinical events. However, Frail Screening Index (IRR, 1.38; 95% CI, 0.60-3.18) and FRAIL scale (IRR, 1.30; 95% CI, 0.88-1.92) showed no significant association with clinical events.

CONCLUSIONS

Objective frailty assessments (SPPB) and medical staff impression-based frailty (Clinical Frailty Scale) may be useful prognostic predictors for patients on HD. Questionnaire-based frailty assessment should be carefully considered when used as a measurement of frailty.

Changes in body composition of patients undergoing hemodialysis during the coronavirus disease 2019 pandemic: a retrospective longitudinal study

Background

The spread of coronavirus disease 2019 (COVID-19) has dramatically altered the lifestyles of many people worldwide. Several studies reported that body weight of young adults increased during the COVID-19 pandemic; however, weight loss has been observed in the elderly population. Therefore, trends in body composition due to the COVID-19 pandemic may vary depending on the characteristics of the population. This study aimed to investigate the changes in body mass index (BMI), muscle mass, and fat mass before and during the COVID-19 pandemic among patients undergoing hemodialysis.

Methods

In this retrospective longitudinal study, we enrolled 115 clinically stable outpatients (mean age: 65.7 ± 11.2 years, 62.6% men) who underwent hemodialysis thrice a week. Baseline data were collected between April 2019 and March 2020, before the declaration of the COVID-19 emergency by the Japanese government. The follow-up measurements were performed between July 2020 and March 2021 during the COVID-19 pandemic. Patient characteristics, laboratory data, and BMI measurements were collected from the medical records. Muscle mass and fat mass were measured using bioelectrical impedance analysis.

Results

BMI and fat mass among the study participants were significantly higher during the COVID-19 pandemic than before the pandemic (p < 0.01), but no significant change in muscle mass was observed. A restricted cubic spline function showed that the increase in BMI appeared to correlate well with fat mass, but not with muscle mass.

Conclusions

BMI and fat mass of patients on hemodialysis significantly increased due to preventive measures against the COVID-19 pandemic in Japan. These findings may provide useful information in making nutritional management decisions for patients undergoing hemodialysis during and after the COVID-19 pandemic.

Physical function and physical activity in hemodialysis patients with peripheral artery disease

INTRODUCTION

Peripheral artery disease (PAD) is commonly observed in patients undergoing hemodialysis. PAD impairs the vasculature and leads to pathophysiologic changes in the skeletal muscles, causing physical function impairment and physical inactivity in general. However, it is unclear whether PAD adversely affects physical function and physical activity in patients on hemodialysis.

METHODS

We performed a cross-sectional study with a retrospective review of the data to determine whether PAD is associated with impaired physical function and physical activity in patients undergoing hemodialysis. The study population comprised 310 patients and 88 healthy subjects. PAD was diagnosed based on an ankle-brachial index of <1.00 in patients on hemodialysis. Measurements of physical function included maximum walking speed, muscle strength in the lower extremities, and balance while standing.

FINDINGS

Of the 310 patients, 84 (27.1%) had PAD. When patients undergoing hemodialysis were divided into those without PAD and those with PAD, both groups had poorer physical function and physical activity than the healthy control subjects. After adjustments for potential confounders, it was found that patients on hemodialysis with PAD had slower walking speed, poorer standing balance, and less physical activity than those without PAD. However, there was no significant difference in lower extremity muscle strength between the two groups.

DISCUSSION

PAD diagnosed based on an ankle-brachial index of <1.00 was independently associated with impaired physical function and reduced physical activity in patients undergoing hemodialysis.

Motor training promotes both synaptic and intrinsic plasticity of layer V pyramidal neurons in the primary motor cortex

Layer V neurons in the primary motor cortex (M1) are important for motor skill learning. Since pretreatment of either CNQX or APV in rat M1 layer V impaired rotor rod learning, we analysed training-induced synaptic plasticity by whole-cell patch-clamp technique in acute brain slices. Rats trained for 1 day showed a decrease in small inhibitory postsynaptic current (mIPSC) frequency and an increase in the paired-pulse ratio of evoked IPSCs, suggesting a transient decrease in presynaptic GABA release in the early phase. Rats trained for 2 days showed an increase in miniature excitatory postsynaptic current (mEPSC) amplitudes/frequency and elevated AMPA/NMDA ratios, suggesting a long-term strengthening of AMPA receptor-mediated excitatory synapses. Importantly, rotor rod performance in trained rats was correlated with the mean mEPSC amplitude and the frequency obtained from that animal. In current-clamp analysis, 1-day-trained rats transiently decreased the current-induced firing rate, while 2-day-trained rats returned to pre-training levels, suggesting dynamic changes in intrinsic properties. Furthermore, western blot analysis of layer V detected decreased phosphorylation of Ser^408-409 in GABA_A receptor β₃ subunits in 1-day-trained rats, and increased phosphorylation of Ser⁸³¹ in AMPA receptor GluA1 subunits in 2-day-trained rats. Finally, live-imaging analysis of Thy1-YFP transgenic mice showed that the training rapidly recruited a substantial number of spines for long-term plasticity in M1 layer V neurons. Taken together, these results indicate that motor training induces complex and diverse plasticity in M1 layer V pyramidal neurons. KEY POINTS: Here we examined motor training-induced synaptic and intrinsic plasticity of layer V pyramidal neurons in the primary motor cortex. The training reduced presynaptic GABA release in the early phase, but strengthened AMPA receptor-mediated excitatory synapses in the later phase: acquired motor performance after training correlated with the strength of excitatory synapses rather than inhibitory synapses. As to the intrinsic property, the training transiently decreased the firing rate in the early phase, but returned to pre-training levels in the later phase. Western blot analysis detected decreased phosphorylation of Ser^408-409 in GABA_A receptor β₃ subunits in the acute phase, and increased phosphorylation of Ser⁸³¹ in AMPA receptor GluA1 subunits in the later phase. Live-imaging analysis of Thy1-YFP transgenic mice showed rapid and long-term spine plasticity in M1 layer V neurons, suggesting training-induced increases in self-entropy per spine.

The trajectory of psychological well-being during the COVID-19 pandemic and its association with health-promoting coping behavior among Japanese community-dwelling older adults: The Otassha Study

This study aims to identify the trajectory of psychological well-being during the COVID-19 pandemic among community-dwelling older adults and to clarify the association between coping behavior in the early stage of the pandemic and the trajectory of psychological well-being. The study was based on a cohort study, known as "the Otassha Study." We administered three follow-up surveys to 720 older adults who participated in the survey in October 2019 (T0): T1: June 2020, T2: October 2020, and T3: October 2021. Furthermore, we assessed coping behavior in T1 via a self-developed questionnaire comprising 10 items. Psychological well-being was assessed by the WHO-5 Well-Being Index (score range: 0 to 25) in all surveys. The trajectories of psychological well-being were identified by group-based trajectory modeling. The association between coping behaviors and trajectory patterns was assessed using multinomial logistic regression analysis. Furthermore, among the 508 participants who participated in the follow-up survey two times or more, three patterns of the trajectory of psychological well-being were identified: heavily decreased group (n = 39), decreased group (n = 352), and increased group (n = 39). "Walking" as a coping behavior had a significantly higher odds ratio (OR) to be in the increased group (OR = 2.32, 95 % confidence interval (CI) 1.06-5.05, p = 0.035) compared to the heavily decreased group. "Conversations with family living together" had a slightly higher OR to become an increased group (OR = 1.96, 95 % CI: 0.87-4.41, p = 0.106), and "actively gathering information on COVID-19" had a slightly lower OR to become the decreased group (OR = 0.53, 95 % CI: 0.26-1.06, p = 0.072) compared to the heavily decreased group. The results of this study suggest how maintaining health in the early stage of the pandemic had a great influence on the long-term health status.

Simplified discriminant parameters for sarcopenia among patients undergoing haemodialysis

BACKGROUND

Patients with end-stage renal disease (ESRD) are at an increased risk of developing sarcopenia, which can lead to various adverse health outcomes. Although the diagnosis of sarcopenia is essential for clinical management, it is not feasible in routine clinical practice for populations undergoing haemodialysis because it is time-consuming and resources are limited. Serum creatinine levels in patients with ESRD have been gaining attention as a screening parameter for sarcopenia because serum creatinine is a routinely measured byproduct of skeletal muscle metabolism. This study aimed to evaluate the discriminative ability of the creatinine-derived index for sarcopenia in patients undergoing haemodialysis.

METHODS

We diagnosed sarcopenia according to the Asian Working Group for Sarcopenia (AWGS) 2 criteria in 356 clinically stable outpatients with ESRD enrolled from three dialysis facilities. We adopted the modified creatinine index as a simplified discriminant parameter for sarcopenia in addition to the calf circumference, SARC-F score, and combination of both (i.e. SARC-CalF score), which are recommended by the AWGS. Receiver operating characteristic analysis and logistic regression analysis were conducted to evaluate the discriminative ability of the modified creatinine index for sarcopenia.

RESULTS

Of the study participants, 142 (39.9%) were diagnosed with sarcopenia. The areas under the curve of the modified creatinine index against sarcopenia in the male and female participants were 0.77 (95% confidence interval [CI]: 0.71 to 0.83) and 0.77 (95% CI: 0.69 to 0.85), respectively. All simplified discriminant parameters were significantly associated with sarcopenia, even after adjusting for patient characteristics and centre. In the comparison of the odds ratios for sarcopenia for 1-standard deviation change in the simplified discriminant parameters, the odds ratio of the modified creatinine index was 1.92 (95% CI: 1.15 to 3.19), which was lower than that of the calf circumference (odds ratio: 6.58, 95% CI: 3.32 to 13.0) and similar to that of the SARC-F (odds ratio: 1.57, 95% CI: 1.14 to 2.16) and SARC-CalF scores (odds ratio: 2.36, 95% CI: 1.60 to 3.47).

CONCLUSIONS

This study revealed a strong association between the creatinine-derived index and sarcopenia in patients undergoing haemodialysis. The modified creatinine index was equal or superior to those of SARC-F and SARC-CalF score in discriminability for sarcopenia. However, the ability of the calf circumference to discriminate sarcopenia is extremely high, and further study is needed to determine whether it can be used to detect deterioration of muscle mass and function over time.

Associations between dynapenia, cardiovascular hospitalizations, and all-cause mortality among patients on haemodialysis

BACKGROUND

Low muscle strength is associated with adverse clinical outcomes in patients undergoing haemodialysis (HD). No studies have reported the association between dynapenia, defined by both low handgrip strength (HGS) and quadriceps isometric strength (QIS), and long-term clinical outcomes in patients on HD. We examined the associations between dynapenia, cardiovascular (CV) hospitalizations, and all-cause mortality in the HD population.

METHODS

This retrospective study used data from outpatients undergoing HD at two dialysis facilities between October 2002 and March 2020. We defined low muscle strength as an HGS of <28 kg for men and <18 kg for women and a QIS of <40% dry weight. Furthermore, we categorized dynapenia into three groups: robust ('high HGS and high QIS'), either low HGS or low QIS ('low HGS only' or 'low QIS only'), and dynapenia ('low HGS and low QIS'). The outcomes were all-cause mortality and a composite of CV hospitalizations and mortality. Cox proportional hazards and negative binomial models were used to examine these associations.

RESULTS

A total of 616 patients (mean age, 65.4 ± 12.2 years; men, 61%) were included in the analyses. During the follow-up (median, 3.0 years), a total of 163 deaths and 288 CV hospitalizations occurred. Patients with the either low HGS or low QIS [hazard ratio (HR), 1.75; 95% confidence intervals (CIs), 1.46-2.10] and dynapenia (HR, 2.80; 95% CIs, 2.49-3.14) had a higher risk of mortality than those in the robust group. When compared with the robust group, the either low HGS or low QIS [incidence rate ratio (IRR): 1.41, 95% CI: 1.00-1.99] and dynapenia (IRR: 2.04, 95% CI: 1.44-2.89) groups were associated with a significantly higher incident risk of CV hospitalizations.

CONCLUSIONS

Dynapenia (muscle weakness in both upper and lower extremities) was associated with increased risks of all-cause mortality and CV hospitalizations among patients on HD. Screening for dynapenia using both HGS and QIS may be useful for prognostic stratification in the HD population.

Relationship between psychiatric symptoms and activities of daily living in patients undergoing hemodialysis

Background

Accurately identifying the factors contributing to decline in activities of daily living (ADL) is important for preventing such decline in patients undergoing hemodialysis (HD). We studied the prevalence and number of overlapping psychiatric symptoms (depressive symptoms, apathy, and sleep disturbance) in patients undergoing HD and examined the relationship between psychiatric symptoms and ADL.

Methods

The study utilized a cross-sectional research design. The sample included 203 outpatients (median age: 69 years) undergoing stable HD treatment three times a week. Patient characteristics, including age, sex, body composition, dialysis vintage, primary kidney disease, comorbidity, and nutritional status, were collected from patients’ medical records. Functional status was assessed based on the self-reported questionnaire that combined five basic and eight instrumental ADL items. Usual walking speed was used as an index of physical function. Additionally, the short version of the Center for Epidemiologic Studies Depression Scale was used to assess depressive symptoms. Further, apathy and sleep disturbance were assessed using the Motivation Score and the Athens Insomnia Scale, respectively.

Results

Overall, 59 (29.1%) patients demonstrated depressive symptoms, 100 (49.3%) reported apathy, 83 (40.9%) had sleep disturbance, 31 (15.3%) had three overlapping psychiatric symptoms, 43 (21.2%) had two overlapping psychiatric symptoms, 63 (31.0%) had only one symptom, and 66 (32.5%) had no psychiatric symptoms. Multiple logistic regression analysis showed that having two or three overlapping psychiatric symptoms was independently and significantly associated with ADL (functional status of 13 points for the ADL maintenance group, and of < 13 points for the ADL decline group, respectively), even after adjusting for patient characteristics and walking speed (odds ratio: 2.74, 95% confidence interval: 1.12–6.69, reference; no psychiatric symptoms).

Conclusion

The present study clarified that the overlapping symptoms, including depressive symptoms, apathy, and sleep disturbance, were independently associated with ADL decline in patients undergoing HD. It is useful to examine not only depressive symptoms but also other symptoms such as apathy and sleep disturbance to elucidate factors associated with deteriorated ADL in chronic patients. Our findings provide a strong basis for targeted interventions to prevent functional dependence in the HD population.

Social isolation is associated with future decline of physical performance in community-dwelling older adults: a 1-year longitudinal study

BACKGROUND

Social isolation and decline of physical function, such as muscle strength and physical performance, are known to be associated with deterioration of functional capacity. However, the relationship between social isolation and physical function has not been sufficiently clarified by a longitudinal observational study.

AIMS

The aim of this study was to examine whether social isolation is associated with a future decline in physical function in older people.

METHODS

The participants were 166 community-dwelling older people (aged ≥ 65 years). Social isolation and physical function were assessed using the 6-item Lubben Social Network Scale and handgrip strength, knee extensor strength, usual walking time, and the Timed Up and Go (TUG) test in both the baseline and follow-up surveys. To define the presence or absence of physical function decline over time, we used the minimal detectable change. The associations between social isolation and physical function were analyzed using logistic regression analysis adjusted for confounding factors. Further, to examine the possibility of drop-out bias, inverse probability weighting (IPW) was performed.

RESULTS

The results of the logistic regression analysis adjusted for confounding factors showed social isolation at baseline was significantly associated with future TUG decline (OR 2.88, 95% CI 1.15-7.22). Social isolation was not associated with a decline in other physical functions. Similar results were found in an analysis using IPW.

CONCLUSIONS

Social isolation was an independent risk factor for future TUG decline in community-dwelling older people. Our results indicated that assessment of social isolation may be necessary to assess the risk of physical performance decline.

MO924: Association Between Dynapenia, Cardiovascular Hospitalizations and All-Cause Mortality Among Patients on Hemodialysis

BACKGROUND AND AIMS

Low muscle strength is associated with adverse clinical outcomes in patients on hemodialysis (HD). However, the association between dynapenia, characterized by both low handgrip strength (HGS) and leg strength (LS) and long-term clinical outcomes in patients on HD has not yet been reported. Therefore, this study investigated whether dynapenia was associated with higher cardiovascular (CV) hospitalization risk and all-cause mortality in patients on HD.

METHOD

This retrospective study used the data of outpatients on HD from two dialysis facilities between October 2002 and March 2020. This study was approved by the Institutional Review Board/Ethics Committee of Kitasato University of Allied Health Sciences and was conducted in accordance with the principles of the Declaration of Helsinki. All participants provided written informed consent before inclusion in the study. Low muscle strength was defined as an HGS of &lt; 28 kg for men and &lt; 18 kg for women and an LS of &lt; 40% dry weight. Furthermore, dynapenia was categorized into three groups: robust (‘high HGS and high LS’), either low HGS or low LS (‘low HGS only’ or ‘low LS only’) and dynapenia (‘low HGS and low LS’). The outcomes were all-cause mortality and a composite of CV hospitalizations and mortality. These associations were examined using Cox proportional hazards and negative binomial models.

RESULTS

Data from 616 patients (mean age, 65.4 ± 12.2 years; men, 61%) were analyzed. During the follow-up (median, 3.0 years), 163 deaths and 288 CV hospitalizations occurred. Figure 1 shows the results of the Kaplan–Meier survival analyses of the robust, either low HGS or low LS, and dynapenia groups. The log-rank test showed significantly worse survival in the either low HGS or low LS and dynapenia groups than in the robust group (P &lt; 0.001). After adjusting for age, sex, body mass index, HD vintage, comorbidity index, serum albumin, serum hemoglobin, serum creatinine and C-reactive protein levels, patients with either low HGS or low LS [hazard ratio (HR), 1.81; 95% confidence intervals (95% CIs), 1.51–2.17] and dynapenia (HR 2.77, 95% CI 2.48–3.08) were found to have a higher mortality risk than those in the robust group. Similarly, compared with the robust group, either the low HGS or low LS [incidence rate ratio (IRR) 1.45, 95% CI 1.04–2.03] and dynapenia (IRR 2.06, 95% CI 1.48–2.89) groups had higher multiple CV hospitalization and all-cause mortality risks.

CONCLUSION

Dynapenia, characterized by both low HGS and LS, was significantly associated with increased CV hospitalization and mortality risk in patients on HD. Clinical assessments of muscle strength and screening patients with low muscle strength are crucial for disease management in this population. Measuring the muscle strength of the entire extremity, and not only the upper or lower extremities, may be necessary for accurate prognostic stratification.

Physical activity and its trajectory over time and clinical outcomes in hemodialysis patients

PURPOSE

We examined whether physical activity measured at starting point and its trajectory over time were simultaneously associated with vital prognosis.

METHODS

This retrospective cohort study included 295 ambulatory maintenance hemodialysis patients (mean age 63.9 years; 54.6% male). We measured physical activity at index date (starting point) and its change over 1 year as predictors, and all-cause death and cardiovascular events were assessed as the outcomes. Two groups each of high versus low physical activity at starting point (based on 4000 steps per day) and no decline versus decline (based on a predicted mean slope) were created. Cox proportional-hazards regression and Fine-Gray proportional sub-distribution hazards model were used to examine associations between physical activity and its trajectory and clinical outcomes.

RESULTS

Decline in physical activity over 1 year was associated with a higher risk of all-cause death and cardiovascular events, irrespective of the physical activity at starting point. Furthermore, both lower physical activity at starting point and decrease in physical activity over time were independently associated with a higher risk of all-cause death and cardiovascular events in models in which each exposure was mutually adjusted. Compared to other groups that worsened in either exposure, the lowest risk for death/cardiovascular events was observed in the high at starting point/no decline over time group.

CONCLUSIONS

Both physical activity at starting point and its change over time were independently associated with vital prognosis. The assessment of both exposures provides additional prognostic information for the assessment of each exposure.

Comparative Analysis of Simplified, Objective Nutrition-Associated Markers in Patients Undergoing Hemodialysis

OBJECTIVE

Protein-energy wasting is prevalent among patients undergoing dialysis. Hence, identifying an optimal index is necessary for the comprehensive measurement of nutritional status. This study evaluated and compared the prognostic significance of the modified creatinine index (mCI) and geriatric nutritional risk index (GNRI), with the principal aim to identify markers that are more closely associated with clinical events in patients undergoing hemodialysis.

METHODS

We performed a retrospective cohort study of 472 patients undergoing maintenance hemodialysis (mean age, 66.4 years; 62.9% males). We evaluated the mCI, GNRI, and their respective rates of change over a 1-year period. The outcome analysis included all-cause death, number and duration of all-cause hospitalizations, and number and duration of hospitalizations due to cardiovascular disease. In addition, we analyzed the associations of the mCI, GNRI, and their trajectories with clinical outcomes using Cox proportional hazard regression and negative binomial regression.

RESULTS

Over a median 3.6-year follow-up, both the lower mCI (hazard ratio 3.00; 95% confidence interval 2.19, 4.09) and lower GNRI (hazard ratio 1.76; 95% confidence interval 1.45, 2.13) per 1 standard deviation decrease were associated with a higher risk of all-cause death. However, a lower mCI was consistently associated with a higher risk of hospitalization, whereas the GNRI was poorly associated with the risk of hospitalization after adjusting for covariates. Furthermore, although a decline in the mCI over time was associated with a higher risk of each adverse event, a significant association between the change in GNRI and clinical events was not detected.

CONCLUSION

The mCI at one timepoint and its trajectory had consistently stronger associations with clinical events than the GNRI in patients undergoing hemodialysis. This study further emphasizes the importance of risk screening using a marker of nutritional status in patients undergoing hemodialysis.

Limitations of SARC-F as a Screening Tool for Sarcopenia in Patients on Hemodialysis

INTRODUCTION

There are limited screening tools for sarcopenia in patients undergoing hemodialysis. This study aimed to investigate the reliability and validity of the SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) questionnaire as a screening tool for sarcopenia (defined by the Asian Working Group for Sarcopenia [AWGS2019]) in patients undergoing hemodialysis.

METHODS

This cross-sectional study enrolled 179 patients (mean age: 66.5 ± 12 years, 58% men) undergoing maintenance hemodialysis 3 times per week at a hemodialysis center in Japan. The SARC-F score, handgrip strength, usual gait speed, sit-to-stand test time, short physical performance battery (SPPB), and appendicular skeletal muscle mass were evaluated. The reliability and validity of the SARC-F were analyzed using receiver-operating characteristic curve, area under the curve (AUC), and sensitivity/specificity analyses.

RESULTS

There were 49 (27.4%) patients with sarcopenia. Patients with SARC-F ≥4 (59 patients, 33.0%) had poorer grip strength, lower SPPB score, and slower gait speed than those with SARC-F <4, while the skeletal muscle mass index did not differ significantly between the two groups. The sensitivity and specificity values of the SARC-F for identifying sarcopenia were 42.9% and 70.8%, respectively, while those for identifying severe sarcopenia were 66.7% and 72.3%, respectively. The AUCs of SARC-F were 0.57 for sarcopenia and 0.70 for severe sarcopenia.

DISCUSSION/CONCLUSION

The SARC-F alone is an inadequate screening tool for sarcopenia in patients undergoing hemodialysis. It should be used in combination with objective assessment measures, rather than as a first-step screening tool, to diagnose sarcopenia.

Changes in fears and worries related to COVID-19 during the pandemic among current employees in Japan: a 5-month longitudinal study

Objectives

This study investigates and describes the time course of fears and worries about COVID-19 among current employees during this outbreak.

Study design

This was a longitudinal study.

Methods

This study was a part of the Employee Cohort Study in Japan. The study comprised 4120 individuals from February 2019. A baseline survey in March 2020, a 2-month follow-up survey in May 2020, and a 5-month follow-up survey in August 2020 were conducted. Questions surveyed respondents’ global fear and worry and six items related to COVID-19. A mixed model for repeated measures of an analysis of variance was used.

Results

A total of 1421 respondents completed the baseline survey. At 2- and 5-month follow-ups, 1032 and 1181 respondents completed surveys, respectively. Of those, 64 and 33 individuals who were temporarily laid off or on leave were recorded as missing values. Global fear and worry about COVID-19 significantly increased from March to August 2020. Fears of personal or family infection, limiting one's activities and national and local government policies also significantly increased with time. In contrast, fears of lack of knowledge and difficulty of obtaining hygiene products significantly decreased.

Conclusion

To conduct efficient risk communication during a pandemic, knowing the concerns of the populace, providing correct information and a sufficient supply of products, and setting clear guidelines are essential.

MO884ASSOCIATION BETWEEN QUADRICEPS ISOMETRIC STRENGTH AND SLEEP DISTURBANCES AMONG PATIENTS ON HEMODIALYSIS

Background and Aims

The muscle strength of patients on hemodialysis (HD) is lower than that of community-dwelling older adults. Because decreased muscle strength, especially quadriceps isometric strength (QIS), has been reported to be a risk factor for increased mortality rate among patients undergoing HD, the prevention and correction of decreased QIS are very important in this population. Although some factors associated with decreased QIS among patients on HD have been reported, these factors remain unclear because patients on HD have many comorbidities with increasing age and prolonged HD vintage. In community-dwelling older adults, sleep disturbance is reported to be a factor associated with reduced muscle strength. In addition, the prevalence of sleep disturbance is higher in patients on HD. Therefore, it is necessary to investigate these associations in this population. We examined the association between QIS and sleep disturbances among patients receiving HD.

Method

This cross-sectional study included 211 outpatients undergoing HD three times a week. To evaluate QIS, a handheld dynamometer (μtas F-1; Anima, Tokyo, Japan) was used. Patients were asked to sit on a bench with their hip and knee flexed at an angle of 90°. They performed isometric voluntary contraction of the quadriceps for a maximum of 5 seconds, thrice, for both legs. The average of the right and left maximal QIS divided by the dry weight (%DW) was used in the analysis. Sleep disturbances were measured using the Athens Insomnia Scale (AIS), a self-administered questionnaire consisting of eight questions, each scored from 0 to 3. The total scores range from 0 to 24, with higher scores indicative of worse sleep quality. Clinical characteristics, including age, sex, body mass index, HD vintage, comorbidity score, serum albumin, C-reactive protein, and the Mini-Mental State Examination, were investigated. Multiple linear regression analysis and multivariable-adjusted restricted cubic splines with four knots were used to examine the association between QIS and sleep disturbances.

Results

The median age was 68 (interquartile range: 59–76) years, and 62% of the patients were men. In multiple linear regression analysis, the AIS score was extracted as a significant factor related to QIS after adjusting for clinical characteristics (regression coefficient: -0.45, 95% confidence interval: -0.84 to -0.05, p = 0.028). In the multivariable-adjusted restricted cubic splines, a nonlinear relationship was found between QIS and the AIS score even after adjusting for clinical characteristics. In addition, it was shown that QIS decreased significantly as the AIS score increased up to 6, which is the cutoff value for discriminating sleep disturbances (Figure).

Conclusion

Higher AIS scores were independently associated with decreased QIS among patients on HD. Future studies should investigate the causality between QIS and sleep disturbance in patients undergoing HD.

The effects of amino acid/protein supplementation in patients undergoing hemodialysis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

We evaluated the efficacy of the intervention consisting of amino acid/protein supplementation on muscle mass, muscle strength and physical function in patients on hemodialysis.

METHODS

This systematic review and meta-analysis identified potential studies through a systematic search of 4 electronic databases and references from eligible studies from database inception to August 2020. We included only randomized controlled trials reporting the efficacy of amino acid/protein supplementation on muscle mass, muscle strength and physical function in patients on hemodialysis.

RESULTS

Of 6529 unique citation records, 4 studies including 243 participants were selected for inclusion in the meta-analysis. Although there were no significant differences in muscle mass and muscle strength between the intervention and control groups, amino acid/protein supplementation was shown to significantly improve physical function (shuttle walk, MD 32.7, 95% CI 21.7 to 43.7, P < 0.001; gait speed, MD 0.07, 95% CI 0.01 to 0.13, P = 0.02; timed up and go, MD -0.42, 95% CI -0.68 to -0.15, P = 0.002) in patients on hemodialysis.

CONCLUSIONS

We confirmed the positive effect of amino acid/protein supplementation on physical function in people undergoing hemodialysis. However, there is still insufficient evidence, and more rigorously designed randomized controlled trials with high quality are needed.

Impact of Physical Activity on Dialysis and Nondialysis Days and Clinical Outcomes Among Patients on Hemodialysis

OBJECTIVE

Patients undergoing hemodialysis (HD) have different physical activity (PA) patterns on HD and non-HD days. Nonetheless, whether these differences are associated with clinical outcomes remains unclear. We examined the association of PA levels on HD and non-HD days with cardiovascular (CV) hospitalizations and mortality.

METHODS

Outpatients undergoing HD from 2002 to 2019 were retrospectively enrolled. The number of steps performed over 3 HD days and 4 non-HD days was recorded via accelerometry. Outcomes were all-cause mortality and a composite of CV hospitalizations and mortality. Patients were divided into two groups, each according to the median number of steps performed on HD (2371 steps/day) and non-HD days (3752 steps/day). Further, we categorized them into 4 groups according to each median values: "more active on HD/more active on non-HD (MM)," "more active on HD/less active on non-HD (ML)," "less active on HD/more active on non-HD (LM)," and "less active on HD/less active on non-HD (LL)." Cox and mixed-effects Poisson regression models were used for these outcomes.

RESULTS

We analyzed 512 patients (median follow-up, 3.4 years). Higher PA on HD (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.54-0.65), and non-HD (HR, 0.84; 95% CI, 0.80-0.88) was associated with lower mortality risk, respectively. Further, the ML group (HR, 1.20; 95% CI, 1.13-1.28), LM group (HR, 1.82; 95% CI, 1.53-2.17), and LL group (HR, 1.83; 95% CI, 1.65-2.02) had higher mortality risks than the MM group. Associations of PA with multiple CV hospitalizations and mortality were similar to those between PA and mortality.

CONCLUSIONS

Higher PA on HD and non-HD days was associated with lower risks of CV hospitalizations and mortality. However, higher PA levels on either HD or non-HD days alone did not improve clinical outcomes.

Modified Creatinine Index and Clinical Outcomes of Hemodialysis Patients: An Indicator of Sarcopenia?

OBJECTIVE

Sarcopenia (especially muscle mass assessed using gold standard techniques) has been suggested as a poorer predictor of mortality than muscle function in patients undergoing hemodialysis. Appropriate methods to estimate muscle mass for use as a good predictor of clinical outcomes remain to be established. We investigated whether the modified creatinine index (mCI), which is a surrogate marker of muscle mass, could predict mortality and cardiovascular (CV) hospitalizations independent of muscle function and other confounders in patients on hemodialysis.

DESIGN AND METHODS

In this retrospective study, outpatients (n = 542; mean age, 65.3 years; 60% men; median dialysis vintage, 29 months; mean BMI, 22.0 kg/m²) undergoing hemodialysis were investigated. The mCI, handgrip strength, and gait speed were assessed and related to all-cause mortality and a composite of CV hospitalizations and all-cause mortality. Cox proportional and mixed-effects negative binomial models were fit for mortality and the composite outcomes.

RESULTS

Patients were followed up for a median 3 years (interquartile range: 1.5-5.7). Each per SD increase of mCI (HR:0.63, 95% CI:0.62-0.65), handgrip strength (HR:0.51, 95% CI:0.48-0.54), and gait speed (HR:0.60, 95% CI:0.56-0.64) were significantly associated with lower all-cause mortality rates after adjusting for covariates. The mCI was consistently found to be an independent predictor of mortality after additional adjustment for handgrip strength or gait speed. Furthermore, sarcopenic conditions [i.e., lower mCI, and lower handgrip strength (HR:3.79, 95% CI:2.09-6.87) or slower gait speed (HR:4.20, 95% CI:2.38-7.41)] were significantly associated with a higher risk of mortality after adjusting for covariates. Associations of mCI with multiple CV hospitalizations and mortality were similar to those between mCI and mortality.

CONCLUSION

The mCI was a good predictor of clinical outcomes and was comparable to muscle function, including handgrip strength and gait speed. The mCI is likely to provide additional diagnostic and prognostic values for sarcopenia in patients on hemodialysis.

The effects of amino acid/protein supplementation in hemodialysis patients: study protocol for a systematic review and meta-analysis

Background

Multiple factors including older age, comorbidities, inflammation, metabolic acidosis, dialysis-related hypercatabolism and anabolic resistance of skeletal muscle, extraction of circulating amino acids through hemodialysis and inadequate dietary protein intake due to anorexia, and strictly limited dietary phosphorus intake are likely to contribute to the high prevalence of malnutrition and metabolic abnormalities, more aptly called protein-energy wasting, in patients on hemodialysis. The consensus from the International Society of Renal Nutritional and Metabolism states that nutritional supplementation is effective for replenishing protein and energy stores. Although we hypothesize that amino acid/protein supplementation can overcome the anabolic resistance of skeletal muscle tissue and attenuate or even prevent the accelerated loss of skeletal muscle mass and strength through nutritional status improvement in patients on hemodialysis, whether amino acid and/or protein administration is associated with improvements in these outcomes is unknown. The main objective of this study is to systematically review the impact of amino acid/protein supplementation on skeletal muscle mass, muscle strength, physical function, and quality of life in end-stage renal disease patients requiring hemodialysis.

Methods

Published randomized controlled trials (RCTs) assessing the effectiveness of amino acid/protein supplementation in hemodialysis patients with respect to body composition, muscle mass, muscle strength, physical function, and quality of life will be included. The bibliographic databases include MEDLINE, the Web of Science, the Cochrane Central Register of Controlled Trials, and Embase. The risk of bias of the included RCTs will be assessed using the Cochrane Collaboration’s tool by two independent reviewers. The primary outcome will be skeletal muscle mass, muscle strength, and physical function, and the secondary outcome will be quality of life. This review protocol is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) 2015 checklist.

Ethics and dissemination

Ethical approval is not required because this study does not include confidential personal data or involve patient interventions. This review is expected to inform readers on the effect of amino acid/protein supplementation in patients undergoing hemodialysis. The findings will be presented at conferences and submitted to a peer-reviewed journal for publication.

Trial registration

The trial registration number is (CRD42020181087), and the trial was registered on 5 July 2020.

Association Between Social Network and Physical Function in Community-Dwelling Older Adults in Japan

OBJECTIVE

A poor social network and the decline of physical function are known to be critical risk factors for functional decline in older adults. The aim of this study was to investigate the relationships between social network and physical function in Japanese community-dwelling older adults.

METHODS

Participants were 339 adults aged 65 years or older (mean age : 73.0 years, women :70.2%), living independently in their communities. A self-reported questionnaire was used to assess social network on two different scales-the 6-item Lubben Social Network Scale (6LSNS) and frequency of contact with other people. Handgrip strength, knee extension strength, gait speed, Timed Up and Go Test (TUG) results, and 5-repetition chair stand test (CST) scores were used to determine physical function. A multiple regression analysis that adjusted for confounding factors was used to analyze the relationship between the social network scales and each physical function test.

RESULTS

According to the results of a multiple regression analysis, a high 6LSNS score was significantly associated with greater handgrip strength (B = 0.63, p = 0.03), faster CST (B = -0.23, p = 0.01), and faster TUG (B = -0.12, p = 0.03), and high frequency of contact was significantly associated with greater handgrip strength (B = 1.08, p = 0.01).

CONCLUSIONS

Social network was associated with muscle strength and physical performance. Consequently, older adults with poor social networks require an assessment of physical function, since their physical functions have possibly deteriorated.

P1288FACTORS ASSOCIATED WITH THE ANKLE BRACHIAL INDEX TRAJECTORY OVER TIME AMONG PATIENTS RECEIVING HAEMODIALYSIS

Background and Aims

Measurement of the ankle brachial index (ABI) is a simple, noninvasive means of diagnosing peripheral arterial disease. Additionally, a lower ABI has also been shown to be associated with a higher mortality rate. A high prevalence of a low ABI has been reported in patients with chronic renal failure, especially among patients receiving haemodialysis. Therefore, identifying factors that predict a decline in the ABI is important for developing treatment strategies. However, little is known about the factors associated with a decline in the ABI over time in patients receiving haemodialysis. Furthermore, most patients receiving haemodialysis have low levels of daily physical activity and are thus prone to arteriosclerosis. Here, we examined the factors including the level of physical activity associated with the ABI trajectory over time among patients receiving haemodialysis.

Method

The subjects were 236 outpatients (mean age of 64.2±12.0 years, 148 men, mean body mass index of 22.0±4.1 kg/m2) receiving maintenance haemodialysis thrice a week at a haemodialysis centre. The exclusion criteria for the study were as follows: major amputation of a lower extremity at baseline and lower-extremity peripheral revascularization and amputation of a lower extremity during follow-up. The ABI was determined using a blood pressure pulse-wave inspection apparatus (Form3; Omron Colin, Tokyo, Japan). The lowest values of ankle pressure were used for the calculations. As background factors for the patients, we investigated age, sex, body mass index, haemodialysis vintage, comorbidities (diabetes, cerebrovascular disease, and cardiovascular disease), serum chemistry (haemoglobin and albumin), and level of physical activity. The patients were classified with a low level of physical activity if they used a wheelchair at home or in the hospital or required walking assistance. The ABI and background factors were investigated at baseline and 1, 2, and 3 years. To determine factors associated with the ABI trajectory over time, we conducted multivariate generalised estimating equations analysis.

Results

The mean ABI at baseline was 1.12 (median = 1.16; 25th–75th percentile = 1.07–1.21). Age (-0.02 per year; 95% confidence interval, -0.003 to -0.001), cardiovascular disease (-0.06 per year; 95% confidence interval, -0.115 to -0.023), and level of physical activity (-0.09 per year; 95% confidence interval, -0.135 to -0.041) were associated with the ABI trajectory over time.

Conclusion

Increased ageing, the incidence of cardiovascular disease, and a decreased level of physical activity are independently associated with a decline in the ABI over time. Clinical attention should be paid to low physical activity levels among patients receiving haemodialysis. Studies should examine whether interventions for low physical activity levels can improve the trajectory of the ABI in patients receiving haemodialysis.

P1543FACTORS ASSOCIATED WITH CHANGE IN FUNCTIONAL STATUS IN HEMODIALYSIS PATIENTS

Background and Aims

Hemodialysis (HD) patients have poor functional capacity. Expert clinical practice guidelines strongly recommend an assessment of functional status (FS) and treatment strategies in chronic kidney disease patients. A previous study demonstrated a high level of disability in daily activities in most HD patients, and a dose-response association was seen between poor FS at baseline and adverse clinical outcomes in HD patients. Moreover, a recent study reported that patients with a decline in FS over a 1-year period are at an elevated risk of mortality. Therefore, identifying factors that predict a decline in FS is important for developing treatment strategies. The purpose of this study was to investigate the factors that predict this decline in HD patients.

Method

A total of 146 outpatients (mean age of 66.1±11.0 years; 48% were female) undergoing maintenance HD thrice a week at an HD center were included. FS was assessed based on the ability to perform activities of daily living (ADLs) and instrumental ADLs (IADLs) as self-reported on the Katz Index of Independence and the Lawton-Brody IADL scale, respectively The Katz Index of Independence examines five tasks of ADLs, and the Lawton-Brody IADL scale examines eight tasks of IADLs. Both have been validated in the general population. We then calculated the FS score by combining the scores of the Katz Index of Independence and Lawton-Brody IADL scale in accordance with the algorithm developed in a previous study, and the assessments were conducted at baseline and after 1 year. We classified patients into two groups based on having or not having at least a 1-point decline in the FS score. Background factors such as age, sex, body mass index, comorbidities score, hemodialysis time, primary kidney disease, hemoglobin level, and geriatric nutritional risk index were collected at baseline. In addition, for physical function, the usual gait speed and handgrip strength and for body composition, the skeletal muscle mass by bioelectrical impedance analysis were analyzed at baseline. To investigate factors predicting a decline in FS 1 year later, logistic regression analysis was used.

Results

Over the study period, 29.5% of the patients showed a decline in the FS score. Patients who showed a decline were older (71.2 years vs. 64.0 years), had weaker handgrip strength (22.9 kg vs. 24.8 kg), and exhibited slower usual gait speed (1.06 m/s vs. 1.22 m/s) than those who did not show decline at baseline. To predict a decline in FS 1 year later, age (odds ratio: 1.07, 95% confidence interval [CI]:1.02-1.13, p=0.003) and usual gait speed (odds ratio: 0.17, 95% CI: 0.03-0.96, p=0.04) were determined as significant factors.

Conclusion

Gait speed was a predictor of a decline in FS after 1 year. These findings underscore the significance of gait speed assessment in addition to monitoring the patient's FS. Moreover, intervention in maintaining gait speed may be essential in preventing the FS from deteriorating over time.

P1583UTILITY OF THE GLOBAL LEADERSHIP INITIATIVE ON MALNUTRITION CRITERIA FOR THE DETECTION OF MALNUTRITION AND DECLINE IN PHYSICAL FUNCTION AND ADL IN JAPANESE AMBULATORY HEMODIALYSIS PATIENTS

Background and Aims

In patients who undergo hemodialysis (HD), malnutrition is a frequent complication associated with higher risk of death, extended hospital stay, physical limitation, and decline of activities of daily living (ADL). Therefore, proper assessment for malnutrition in this population is important for effective disease management. The Global Leadership Initiative on Malnutrition (GLIM) released new criteria for diagnosing and grading malnutrition. Nevertheless, only very few studies have investigated malnutrition prevalence on the basis of the GLIM criteria in hemodialysis patients. Hence, the usefulness of the GLIM criteria’s application in hemodialysis patients remains unclear.

The aims of this study were (1) to examine whether malnutrition diagnosed on the basis of the GLIM criteria will produce equivalent results with that diagnosed with the use of existing nutritional indicators and (2) to evaluate the association between the GLIM criteria and decline of physical function and ADL in Japanese patients on HD.

Method

This cross-sectional study included a total of 185 outpatients who undergo HD three times a week. We measured the existing nutritional indicators (GNRI, MNA-SF, phase angle, mid-arm muscle circumference, and calf circumference), physical function (Fried Scale, handgrip strength, usual gait speed, Short Physical Performance Battery, and physical activity), and ADL status (cumulative score of Barthel Index and instrumental ADL). On the basis of the GLIM criteria, the patients were classified into two groups (no malnutrition and malnutrition). In addition, in case of nutritional risk, nutritional assessment was performed by evaluation of the phenotypic (unintentional weight loss, low BMI, and/or reduced muscle mass) and etiologic (reduced intake or assimilation and/or inflammatory response) factors. Malnutrition was diagnosed if a patient has one or more of these items. The analysis of covariance (ANCOVA) was performed to examine the association between the GLIM criteria and existing nutritional indicators, physical function, and ADL status.

Results

Malnutrition was diagnosed in 41.1% of the participants based on the GLIM criteria. In contrast, on the basis of the existing nutritional indicators (GNRI, MNA-SF, phase angle, mid-arm muscle circumference, and calf circumference), malnutrition was diagnosed in 22.2%, 58.3%, 48.6%, 57.9%, and 54.6%, respectively. The ANCOVA results, adjusted for the patient’s characteristics, revealed that the malnutrition group had significantly lower score than the non-malnutrition group in the existing nutritional indicators (all P &lt; 0.001) (Figure). Furthermore, the malnutrition group had significantly higher Fried Scale scores, lower handgrip strength results, and lower ADL status than the non-malnutrition group, even after potential confounder adjustment (all P &lt; 0.05).

Conclusion

The GLIM criteria could be one of the useful tools for screening the risk of malnutrition, frailty, lower handgrip strength, and lower ADL status in patients who undergo HD.

P1544AASSOCIATION BETWEEN PHYSICAL FRAILTY AND INSOMNIA SYMPTOMS AMONG PATIENTS ON HEMODIALYSIS

Background and Aims

Community-dwelling older adults with physical frailty have been suffering from symptoms of insomnia, which have been associated with higher risk of falling and cardiovascular events. Therefore, insomnia symptoms should be assessed for disease management. Most of patients undergoing hemodialysis (HD) have both physical frailty and insomnia symptoms. However, only a few studies reported the association between physical frailty and insomnia symptoms in patients undergoing HD. Therefore, this study aimed to investigate whether insomnia symptoms were one of the useful factors to discriminate physical frailty in patients undergoing HD.

Method

This study included 231 outpatients undergoing HD three times a week. Physical frailty was measured using the frailty screening index, consisting five components (shrinking, physical function, physical activity, forgetfulness, and exhaustion). Insomnia symptoms were measured using the Athens Insomnia Scale (AIS), a self-administered questionnaire consisting of eight questions, each scored from 0 to 3. Age, sex, body mass index (BMI), HD vintage, comorbidity score, dialysis shift, depressive symptoms, use of sleep medications, usual gait speed, and physical activity (steps/non-HD day) were also investigated. Patients were classified as frailty (the frailty screening index score ≥ 3) and non-frailty (&lt; 3). The analysis of covariance (ANCOVA) was used to compare the AIS scores between frailty and non-frailty. To examine whether the AIS score had the discriminative ability of the frailty complementary to clinical characteristics comparable to the usual gait speed and physical activity, receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was compared using four models: clinical characteristics (age, sex, BMI, and comorbidity score) only (Model 1), Model 1 plus AIS score (Model 2), Model 1 plus usual gait speed (Model 3), and Model 1 plus physical activity (Model 4).

Results

The median age was 68 (interquartile range: 59–75) years, 59% were men and 37% had frailty. In ANCOVA, the AIS score in the group of frailty was significantly higher than those of non-frailty even after adjusting age, sex, BMI, HD vintage, comorbidity score, dialysis shift, depressive symptoms, and use of sleep medications (p = 0.004). Through the ROC analysis, Model 2 [AUC: 0.70, 95% confidence intervals (CI): 0.63–0.76], Model 3 (AUC: 0.70, 95%CI: 0.63–0.77), and Model 4 (AUC: 0.69, 95%CI: 0.61–0.76) showed significantly better discriminative ability as compared to Model 1 (AUC: 0.64, 95%CI: 0.56–0.71, all P &lt; 0.05) (Figure). Moreover, AUCs were significantly increased by adding the AIS score to Model 3 (from 0.70 [95%CI: 0.63–0.77] to 0.74 [95%CI: 0.67–0.80], p &lt; 0.05). In addition, AUCs were increased by adding the AIS score to Model 4 (from 0.69 [95%CI: 0.61–0.76] to 0.73 [95%CI: 0.65–0.80], p = 0.07) with a trend toward statistical significance.

Conclusion

This study examined the association between physical frailty and insomnia symptoms in patients undergoing HD. The AIS score had the discriminative ability of the frailty complementary to clinical characteristics comparable to the usual gait speed and physical activity. Future studies should investigate the causal relationship between physical frailty and insomnia symptoms in patients undergoing HD in detail.

g Factor of the ^{99}Zr (7/2^{+}) Isomer: Monopole Evolution in the Shape-Coexisting Region

The gyromagnetic factor of the low-lying E=251.96(9)  keV isomeric state of the nucleus ^{99}Zr was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of J^{π}=7/2^{+}, with a half-life of T_{1/2}=336(5)  ns. The isomer was produced and spin aligned via the abrasion-fission of a ^{238}U primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μ_{N} was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd_{5/2} composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution.

Identification of a major glucose transporter in Flavobacterium johnsoniae: Inhibition of F. johnsoniae colony spreading by glucose uptake

Many members of the phylum Bacteroidetes, such as Flavobacterium johnsoniae, can glide over a solid surface: an ability called gliding motility. It can be usually observed on agar plates as thin, flat, spreading colonies with irregular, feathery edges; this phenomenon is called colony spreading. Colony spreading of F. johnsoniae on 1.5% agar plates containing poor nutrients is dose-dependently inhibited by addition of D-glucose, as previously reported. Accordingly, here, we created mutants (by transposon mutagenesis) that partially suppressed glucose-mediated inhibition of colony spreading. Among the isolates, we found that one had a transposon insertion in Fjoh_4565, tentatively named mfsA, which encodes a major facilitator superfamily (MFS) transporter previously shown to be required for growth on glucose, N-acetyl-glucosamine, and chitin. We constructed an mfsA deletion mutant and found that the mutant showed no glucose-mediated acceleration of growth or glucose uptake. The mfsA gene complemented the phenotype of a glucose-negative Escherichia coli. These results suggest that the mfsA gene encodes the sole MFS transporter of glucose in F. johnsoniae and that glucose uptake is partially required for the glucose-mediated inhibition of F. johnsoniae colony spreading.

Work-related psychosocial factors and metabolic syndrome onset among workers: a systematic review and meta-analysis

BACKGROUND

Work-related psychosocial factors have been associated with metabolic syndrome. However, no systematic reviews or meta-analyses have evaluated this association.

METHODS

A systematic literature search was conducted, using PubMed, Embase, PsycINFO, PsycARTICLES and the Japan Medical Abstracts Society. Eligible studies included those that examined the previously mentioned association; had a longitudinal or prospective cohort design; were conducted among workers; provided sufficient data for calculating odds ratios, relative risks or hazard ratios with 95% confidence intervals; were original articles in English or Japanese; and were published no later than 2016. Study characteristics, exposure and outcome variables and association measures of studies were extracted by the investigators independently.

RESULTS

Among 4,664 identified studies, 8 were eligible for review and meta-analysis. The pooled risk of adverse work-related stress on metabolic syndrome onset was significant and positive (RR = 1.47; 95% CI, 1.22-1.78). Sensitivity analyses limiting only the effects of job strain and shift work also indicated a significant positive relationship (RR = 1.75; 95% CI, 1.09-2.79; and RR = 1.59; 95% CI, 1.00-2.54, P = 0.049 respectively).

CONCLUSION

This study reveals a strong positive association between work-related psychosocial factors and an elevated risk of metabolic syndrome onset. The effects of job strain and shift work on metabolic syndrome appear to be significant.

An Acid-Responsive Single Trichromatic Luminescent Dye That Provides Pure White-Light Emission

A novel acid‐responsive single trichromatic luminescent dye capable of emitting pure white light (WL) is reported. A newly designed p‐phenylene‐bridged bipyrrole bearing N‐alkylimino groups (1 a) specifically provides WL emission upon mixing with trifluoroacetic acid (TFA) in a CH₂Cl₂ solution. The emission originates from the trichromatic luminescent behavior of 1 a upon protonation of the imino groups. The blue‐light‐emitting 1 a exhibits dramatic color changes in fluorescence to orange and green upon mono‐ and diprotonation, respectively, providing a wide emission band in the range of λ=400–800 nm that provide WL when the compound is in a dynamic equilibrium between the three states. The sample also exhibits low self‐absorption of the emitted light and a high fluorescence quantum yield upon excitation with UV light.