The onset of star formation 250 million years after the Big Bang.

A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang1-3. The abundance of star-forming galaxies is known to decline4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD1 6 , a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.

Independent Association between Cognitive Frailty and Cardio-Ankle Vascular Index in Community-Dwelling Older Adults.

INTRODUCTION: Although arterial stiffness has been suggested to be associated with poor physical function and mild cognitive impairment (MCI), its association with cognitive frailty (CF), a comorbidity of both, is unclear. This study aims to examine the association between CF and arterial stiffness in community-dwelling older adults. METHODS: A cross-sectional analysis of 511 community-dwelling older adults aged 65 years or older (mean age 73.6 ± 6.2 years, 63.6% women), who participated in a community cohort study (Tarumizu Study, 2019), was conducted. Poor physical function was defined as either slowness (walking speed <1.0 m/s) or weakness (grip strength <28 kg for men and <18 kg for women). MCI was defined by the National Center for Geriatrics and Gerontology Functional Assessment Tool as a decline of at least 1.5 standard deviation from age- and education-adjusted baseline values in any one of the four cognitive domains (memory, attention, executive, and information processing). CF was defined as the combination of poor physical function and MCI. Arterial stiffness was measured using the Cardio-Ankle Vascular Index (CAVI), and the average of the left and right sides (mean CAVI) was used. RESULTS: Multinomial logistic regression analysis adjusted for covariates was performed with the four groups of robust, poor physical function, MCI, and CF as dependent variables and mean CAVI as an independent variable. Using the robust group as reference, the poor physical function and MCI groups showed no significant relationship with the mean CAVI. The mean CAVI was significantly higher in the CF group (odds ratio 1.62, 95% confidence interval: 1.14-2.29). CONCLUSION: A significant association was found between CF and the higher CAVI (progression of arterial stiffness). Careful observation and control of CAVI, which is also an indicator of arterial stiffness, may be a potential target for preventive interventions for CF.

[Cowden syndrome in a male patient with metachronous triple cancers and various clinical features:a case report].

A 66-year-old male patient with a thyroid and nasopharyngeal cancer history visited our hospital because of a positive fecal occult blood test. Total colonoscopy detected sessile or subpedunculated polyps in the ascending colon, sigmoid colon, and rectum. These polyps were endoscopically resected, and the rectal polyp was pathologically diagnosed as adenocarcinoma in adenoma and the others as adenomas. Additionally, multiple sessile lesions were revealed in the sigmoid colon and rectum. A complete gastrointestinal tract examination revealed multiple foci of glycogenic acanthosis in the esophagus, multiple sessile lesions in the stomach, multiple sessile lesions, clubbings (rod-shaped lesions), and venous malformations in the small bowel. Mucocutaneous examination indicated hemangiomas on the body trunk, patchy pigmentation on the glans penis, and keratotic papules in the inguinal region. The National Comprehensive Cancer Network diagnostic criteria for Cowden syndrome were used in this case. The patient met four major and two minor criteria;thus, Cowden syndrome was diagnosed. Moreover, the patient was had phosphatase and tensin homolog deleted on chromosome 10 gene mutation. This is the first reported case of metachronal triple cancers in a male patient with Cowden syndrome, and our results indicate the importance of cancer surveillance.

Efficacy of Therapeutic Exercise on Activities of Daily Living and Cognitive Function Among Older Residents in Long-term Care Facilities: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVES: This study aimed to systematically analyze the efficacy of therapeutic exercise on activities of daily living (ADL) and cognitive function among older residents in long-term care facilities. DATA SOURCES: PubMed, Cochrane Central of Register Trials, Physiotherapy Evidence Database, OTseeker, and Ichushi-Web were searched from inception until December 2018. STUDY SELECTION: Databases were searched to identify randomized controlled trials (RCTs) of therapeutic exercise for long-term care facility residents aged 60 years and older, focusing on ADL and cognitive function as outcomes. DATA EXTRACTION: Two independent reviewers extracted the key information from each eligible study. Two reviewers independently screened and assessed all studies for eligibility, extracting information on study participants, details of interventions, outcome characteristics, and significant outcomes. Any discrepancies were resolved by a third reviewer. DATA SYNTHESIS: A total of 11 RCTs with 1280 participants were eligible for analyses. Therapeutic exercise had a significant benefit on ADL (standard mean difference [SMD]=0. 22, 95% confidence interval [CI]: 0.02, 0.42, P=.03). Subgroup analyses indicated that interventions conducted ≥3 days per week [SMD=0.42, 95% CI 0.02, 0.82, P=.04] had a significant benefit on ADL. For cognitive function, group exercise and ≥3 days/week of intervention had a significant benefit (group exercise: mean difference [MD]=3.36, 95% CI 0.91, 5.80, P=.007; ≥3 days/week of intervention: MD=2.28, 95% CI 0.07, 4.49, P=.04). CONCLUSIONS: Therapeutic exercise conducted 3 or more days per week may be effective for improving ADL and cognitive function among older residents in long-term care facilities. This meta-analysis suggested that group exercise for cognitive functions was effective. However, the effective method of intervention delivery for ADL was unclear.

Association of Sleep Quality Status With Worsening Low Back or Knee Pain During The COVID-19 State of Emergency Among Old-Old Adults.

BACKGROUND: Poor sleep quality has a negative effect on pain among older adults. During the coronavirus disease 2019 (COVID-19) state of emergency, lifestyle changes can cause psychologic stressors and lead to poor sleep quality. AIM: This study examined whether sleep quality status was associated with low back or knee pain changes during the COVID-19 state of emergency among community-dwelling Japanese old-old adults. DESIGN: Cross-sectional investigation. METHODS: In July 2020, during the COVID-19 epidemic, we conducted a postal survey for old-old adults aged ≥77 years and collected data on 597 participants. For those who had low back or knee pain at the time of the survey (in July), characteristics such as low back pain, knee pain, changes in pain status, and sleep quality status during the COVID-19 state of emergency (in March) were assessed. RESULTS: Data from 597 participants showed the prevalence of low back pain (50.6%) and knee pain (40.7%) in July. Of those with low back or knee pain, 374 had pain changes during the state of emergency, with 12.3% worsening. Of these, 23.9% had poor sleep quality in March compared to non-change (p = .008). In a multivariate logistic regression model adjusted for potential confounders, poor sleep quality was significantly associated with pain worsening (odds ratio 2.80, 95% confidence interval 1.26-6.22). CONCLUSIONS: During the COVID-19 state of emergency, poor sleep quality was associated with worsening low back or knee pain. This may indicate the need to pay attention to poor sleep quality to prevent the exacerbation of pain among old-old adults.

[A case of chronic enteropathy associated with SLCO2A1 gene diagnosed by capsule endoscopy and successfully treated by ferric carboxymaltose].

Chronic non-specific multiple ulcers of the small intestine is a disease condition postulated in Japan. It is an uncommon gastrointestinal disease that causes chronic anemia and hypoalbuminemia by causing numerous ulcers without any histopathologically identifiable features. In recent years, it has been revealed that the mutations of SLCO2A1, which codes the prostaglandin transporter protein, are the cause of this disease;it is called the new name "chronic enteropathy associated with SLCO2A1 gene." The ileum, except the terminal ileum, is the most common place making it difficult to identify major lesions. Other than conservative treatments, such as nutrition therapy and iron supplements, no effective treatment has been identified so far. We present a case of chronic non-specific multiple ulcers of the small intestine diagnosed by capsule endoscopy and effectively treated by ferric carboxymaltose. A 48-year-old female had chronic iron deficiency anemia since around the age of 15. Because of severe anemia, the patient had upper and lower endoscopy at the age of 47 to find the source of the bleeding, but it was not detected. Except for the terminal ileum, the capsule endoscopy revealed ring-like ulcers, tape-like ulcers, and oblique ulcer scars in the ileum. Genetic analysis showed a homozygous mutation in intron 7, c.940+1G>A, indicating a definitive diagnosis of non-specific multiple ulcers of the small intestine. Anemia and anemia-related symptoms such as general malaise persisted despite continuous oral administration of iron drugs. Three intravenous injections of ferric carboxymaltose increased hemoglobin and enhanced the symptoms.

Design and Evaluation of a Proxy-Based Monitoring System for OpenFlow Networks.

Software-Defined Networking (SDN) has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a network monitoring mechanism is necessary. In this paper, we focus on OpenFlow which is a core technology to realize SDN. We propose, design, implement, and evaluate a network monitoring system for OpenFlow networks. Our proposed system acts as a proxy between an OpenFlow controller and OpenFlow switches. Through experimental evaluations, we confirm that our proposed system can capture packets and monitor traffic information depending on administrator's configuration. In addition, we show that our proposed system does not influence significant performance degradation to overall network performance.

Tracking pedestrians across multiple microcells based on successive Bayesian estimations.

We propose a method for tracking multiple pedestrians using a binary sensor network. In our proposed method, sensor nodes are composed of pairs of binary sensors and placed at specific points, referred to as gates, where pedestrians temporarily change their movement characteristics, such as doors, stairs, and elevators, to detect pedestrian arrival and departure events. Tracking pedestrians in each subregion divided by gates, referred to as microcells, is conducted by matching the pedestrian gate arrival and gate departure events using a Bayesian estimation-based method. To improve accuracy of pedestrian tracking, estimated pedestrian velocity and its reliability in a microcell are used for trajectory estimation in the succeeding microcell. Through simulation experiments, we show that the accuracy of pedestrian tracking using our proposed method is improved by up to 35% compared to the conventional method.

Association of olfactory and gustatory function with memory among community-dwelling independent older adults.

Background: This study examined the association between memory function and reduced olfactory and gustatory function among independent community-dwelling older adults. Methods: This cross-sectional study included 127 older adults (65.4% women). We assessed their memory, odor, and taste identification skills. Open essence (OE) test and taste strips (TS) were used to identify hyposmia (OE test ≤6) and hypogeusia (TS test ≤8), respectively. Results: Participants with severe hyposmia had significantly poorer memory functions compared to participants without severe hyposmia. After adjusting for covariates, multivariate logistic regression models revealed a significant association between immediate recognition performance and a decreased likelihood of severe hyposmia (odds ratio = 0.65, 95% confidence interval = 0.47-0.90). We observed no significant association between taste function and memory. Conclusions: Memory function may be associated with olfactory impairment but not with gustatory function in older adults.

Associations of eating out and dietary diversity with mild cognitive impairment among in community-dwelling older adults.

Background: Dementia is a critical later life health issue that occurs among members of aging societies. This study examined the relationships between eating out, dietary diversity, and mild cognitive impairment (MCI) among community-dwelling older adults. Methods: We analyzed data from 597 older adults (median age 73.0 years [interquartile range 69.0-78.0] and 62.6% females). We applied the Food Frequency Score (FFS) to evaluate diet variety and the weekly consumption frequencies of ten food items were determined. The Functional Assessment Tool from the National Center for Geriatrics and Gerontology was used to evaluate MCI. Finally, we asked the participants how often they ate out each month; those who replied 'none' were categorized into the "non-eating out" group. Results: The overall prevalence of MCI was 122 (20.4%), with a higher prevalence in the low dietary diversity group than in the high dietary diversity group (28.6% vs. 18.6%). After adjusting for covariates, the participants who self-described as not eating out were independently associated with low dietary diversity (odds ratio [OR]: 1.97, 95% confidence interval [CI]: 1.20-3.20), while low dietary diversity was associated with MCI (OR: 1.72, 95% CI: 1.02-2.87). Structural equation models revealed that not eating out had no direct effect on MCI but was associated with MCI via low dietary diversity (root mean square error of approximation = 0.030, goodness-of-fit index=0.999, and adjusted goodness-of-fit index = 0.984). Conclusions: Although non-eating out may not have a direct effect on MCI, an indirect relationship may exist between eating-out habits and MCI via dietary diversity status.

Arginase 2 attenuates ulcerative colitis by antioxidant effects of spermidine.

BACKGROUND: Spermidine suppress oxidative stress and is involved in various disease pathogenesis including ulcerative colitis (UC). Arginase 2 (ARG2) plays a central role in the synthesis of spermidine. This study aimed to clarify the effect of endogenously produced spermidine on colitis. METHODS: The physiological role of ARG2 and spermidine was investigated using Arg2-deficient mice with reduced spermidine. Immunohistochemical staining of the rectum was used to analyze ARG2 expression and spermidine levels in healthy controls and UC patients. RESULTS: In mice with dextran sulfate sodium-induced colitis, ARG2 and spermidine levels were increased in the rectal epithelium. Spermidine protects colonic epithelial cells from oxidative stress and Arg2 knockdown cells reduced antioxidant activity. Organoids cultured from the small intestine and colon of Arg2-deficient mice both were more susceptible to oxidative stress. Colitis was exacerbated in Arg2-deficient mice compared to wild-type mice. Supplementation with spermidine result in comparable severity of colitis in both wild-type and Arg2-deficient mice. In the active phase of UC, rectal ARG2 expression and spermidine accumulation were increased compared to remission. ARG2 and spermidine levels were similar in healthy controls and UC remission patients. CONCLUSIONS: ARG2 produces spermidine endogenously in the intestinal epithelium and has a palliative effect on ulcerative colitis. ARG2 and spermidine are potential novel therapeutic targets for UC.

Bayesian estimation-based pedestrian tracking in microcells.

We consider a pedestrian tracking system where sensor nodes are placed only at specific points so that the monitoring region is divided into multiple smaller regions referred to as microcells. In the proposed pedestrian tracking system, sensor nodes composed of pairs of binary sensors can detect pedestrian arrival and departure events. In this paper, we focus on pedestrian tracking in microcells. First, we investigate actual pedestrian trajectories in a microcell on the basis of observations using video sequences, after which we prepare a pedestrian mobility model. Next, we propose a method for pedestrian tracking in microcells based on the developed pedestrian mobility model. In the proposed method, we extend the Bayesian estimation to account for time-series information to estimate the correspondence between pedestrian arrival and departure events. Through simulations, we show that the tracking success ratio of the proposed method is increased by 35.8% compared to a combinatorial optimization-based tracking method.

Usefulness of Serum Leucine-Rich Alpha-2 Glycoprotein as a Surrogate Marker of Small Bowel Mucosal Injury in Crohn's Disease.

Introduction: Although the importance of mucosal healing has been suggested in Crohn's disease, it is difficult to repeat endoscopy, especially for the entire small bowel. Recently, serum leucine-rich alpha-2 glycoprotein (LRG) has been used as a surrogate marker of endoscopy. However, few studies have investigated a correlation between LRG and mucosal injury of the entire small bowel. Methods: We retrospectively analyzed the clinical data of 30 patients with Crohn's disease from June 2020 to August 2022 at Yamaguchi Red Cross Hospital. All the patients were surveyed through the gastrointestinal tract by esophagogastroduodenoscopy, total colonoscopy, and capsule endoscopy (CE). Subjects with mucosal injury only in the small bowel were selected. Then, we assessed the relationship between serum biomarkers (LRG, C-reactive protein [CRP], hemoglobin, albumin) and small bowel mucosal injury scores (Lewis score [LS], Capsule Endoscopy Crohn's Disease Activity Index [CECDAI], and Crohn's Disease Activity in Capsule Endoscopy [CDACE]) calculated by CE. Results: LRG and CRP were significantly correlated with small bowel mucosal injury scores (LS, CECDAI, CDACE) (p < 0.05, Spearman's rank correlation coefficient). The degree of correlation was greater for LRG than for CRP. Conclusions: LRG is a useful surrogate marker that closely reflects small bowel mucosal injury in the entire small bowel.

Low-intensity resistance training to improve knee extension strength in community-dwelling older adults: Systematic review and meta-analysis of randomized controlled studies.

AIM: The purpose of this systematic review and meta-analysis was to investigate the effects of low-intensity resistance training on knee extension strength with respect to intensity, frequency, duration and training site in community-dwelling older adults. METHODS: A literature search was conducted for articles published up to December 2018 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Physiotherapy Evidence Database (PEDro), OTseeker and Ichushi-Web. Randomized controlled trials involving resistance training with <60 % one repetition maximum (1RM) in community-dwelling older adults aged 60 years and older were eligible. RESULTS: In total, 7 studies involving 275 participants were included in the meta-analysis. The results showed significant improvements in knee extension strength with low-intensity resistance training [standardized mean difference (SMD) 0.62, 95 % confidence interval (CI) 0.32 to 0.91]. In subgroup analyses, significant improvements were observed in the group with intensity at 50-60 % 1RM (0.83, 0.46 to 1.19), but not in the group at 40 % or less 1RM (0.30, 95%CI: -0.08 to 0.68). Concerning frequency, there were significant improvements in knee strength for those receiving training three times (0.90, 0.52 to 1.27) and two times (0.36, 0.03 to 0.69) per week, with a significant difference between the groups (p = 0.04). CONCLUSIONS: Low-intensity resistance training should be considered as an effective intervention to improve knee extension strength in community-dwelling older adults. Older adults may show more improvement in knee extension strength if intensity of the training is set at 50-60 % 1RM and frequency of training is three times per week.

Association between cognitive frailty and higher-level competence among community-dwelling older adults.

OBJECTIVES: The purpose of this cross-sectional study was to examine the association between cognitive frailty (CF) and higher-level competence among community-dwelling older adults. METHODS: Data from 871 older adults (aged ≥ 65 years, mean age 74.3 years, 61.5% women) who had participated in a community-based health check survey (Tarumizu Study 2018-2019) were analyzed. CF was defined as comorbid physical frailty and mild cognitive impairment (MCI). We defined physical frailty as either slow walking speed or poor grip strength. MCI was defined as values below the age- and education-adjusted reference threshold in several tests. Participants were categorized into four groups: robust, physical frailty, MCI, and CF. Higher-level competence was assessed using the Japan Science and Technology Agency Index of Competence (JST-IC). The JST-IC consists of 16 items and four subscales (technology usage, information practice, life management and social engagement). The bottom 20-30% score of the JST-IC and each subscale corresponded to poor higher-level competence. RESULTS: The prevalence of CF was 14.4%. Multivariate logistic regression analysis showed that, CF was significantly associated with poor higher-level competence (odds ratio 1.92, 95% confidence interval 1.18-3.13) after adjusting for covariates. Using a similar analysis to assess the JST-IC subscales, CF was associated with limitations on technology usage (odds ratio 2.29, 95% confidence interval 1.36-3.85) and low social engagement (odds ratio 1.62, 95% confidence interval 1.00-2.61). CONCLUSIONS: This study suggests that CF is associated with poor higher-level competence, especially limitations on technology usage and low social engagement.

Associations of the Alpha-Actinin Three Genotype with Bone and Muscle Mass Loss among Middle-Aged and Older Adults.

Bone and muscle mass loss are known to occur simultaneously. The alpha-actinin three (ACTN3) genotype has been shown to potentially affect bone and muscle mass. In this study, we investigated the association between the ACTN3 genotype and bone and muscle mass loss in community-dwelling adults aged ≥ 60 years. This study was a cross-sectional analysis of data from 295 participants who participated in a community health checkup. The ACTN3 genotypes were classified as RR, RX, or XX types. Bone mass loss was defined as a calcaneal speed of sound T-score of <−1.32 and <−1.37, and muscle mass loss was defined as an appendicular skeletal muscle index of <7.0 kg/m2 and <5.7 kg/m2 in men and women, respectively. The percentages of XX, RX, and RR in the combined bone and muscle mass loss group were 33.8%, 30.8%, and 16.7%, respectively, with a significantly higher trend for XX. Multinomial logistic regression analysis showed that XX had an odds ratio of 3.00 (95% confidence interval 1.05−8.54) of being in the combined bone and muscle mass loss group compared to the RR group (covariates: age, sex, grip strength, and medications). The ACTN3 genotype of XX is associated with a higher rate of comorbid bone and muscle mass loss. Therefore, ACTN3 genotyping should be considered for preventing combined bone and muscle mass loss.

Association of self-rated health with type and frequency of social interaction during the declaration of COVID-19 state of emergency among Japanese community-dwelling oldest-old adults.

AIM: To investigate whether the type and frequency of social interaction during the state of emergency due to coronavirus disease were associated with self-rated health (SRH) after the state of emergency. METHODS: Data from a cross-sectional study were collected for 889 oldest-old adults in Bibai City, Hokkaido, Japan. In total, 612 participants (mean age: 83.0 ± 4.3 years; women: 51.8%) were included in the analysis, taking biological sex into account. The self-reported questionnaire included questions about demographic variables, SRH (July 2020, after the emergency), and the type and frequency of social interaction (March 2020, during the state of emergency). RESULTS: There was no significant association between social interaction and SRH in men (P > 0.05). Women who had social interactions (both face-to-face and non-face-to-face) more than once a week during the state of emergency reported higher SRH after the emergency than those who did not (odds ratio 2.17, 95% confidence interval 1.07-4.41). CONCLUSIONS: Having both types of interaction more than once a week during the state of emergency was related to higher SRH after the emergency among oldest-old women. It is suggested that having opportunities for both types of interaction at least once a week would potentially be beneficial for high SRH in women, even in situations where the declaration of a state of emergency restricts face-to-face interaction. Geriatr Gerontol Int 2022; 22: 405-411.

Physical Activity and Perceived Physical Fitness during the COVID-19 Epidemic: A Population of 40- to 69-Year-Olds in Japan.

The COVID-19 pandemic has caused an abrupt change in lifestyle for many people with restrictions, often leading to a decrease in physical activity (PA), and thus contributing to a negative perception of health status. The purpose of this study was to examine the effects of the COVID-19 epidemic on physical activity and perceived physical fitness in Japanese adults aged 40 to 69 years. Data were collected from an online survey conducted between October 19 and 28, 2020. The analytic sample consisted of 1989 Japanese adults (mean age, 50.1 ± 6.9 years; women, 38.9%) who were aged between 40 and 69 years and completed the online survey. Overall, the PA time per week decreased by 32.4% between October 2019 and April 2020. A decrease in PA time was recorded in October 2020; however, a decline of 15.5% was observed. Compared to individuals who did not perceive a decline in physical fitness, individuals who perceived declining physical fitness during the COVID-19 state of emergency demonstrated a greater decrease in PA time in April 2020 (-50.5%), and this trend continued into October 2020 (-25.0%). These findings may indicate that Japanese adults aged 40 to 69 years who perceived declining physical fitness experienced a greater decrease in physical activity.

The Association between Dietary Variety and Physical Frailty in Community-Dwelling Older Adults.

The aim of this cross-sectional study was to examine the association between diet variety and physical frailty in community-dwelling older adults. Data of 577 older adults (mean age: 74.0 ± 6.3 years, women: 62.5%) were analyzed. Diet variety was assessed using the Food Frequency Score (FFS) (maximum, 30 points). The FFS assessed the one-week consumption frequency of ten foods (meat, fish/shellfish, eggs, milk & dairy products, soybean products, green & yellow vegetables, potatoes, fruits, seafood, and fats & oil). Physical frailty was assessed using Fried's component (slowness, weakness, exhaustion, low physical activity, and weight loss). The participants were classified into frail, pre-frail, and non-frail groups. The prevalence of physical frailty was 6.6%. This study found significant associations between physical frailty and low FFS after adjusting for covariates (odds ratio (OR) 0.90, 95% confidence interval (CI) 0.84-0.97, p < 0.01). The optimal cutoff point of the FFS for physical frailty was ≤16 points. FFS lower than the cutoff point were significantly associated with physical frailty after adjusting for covariates (OR 3.46, 95% CI 1.60-7.50, p < 0.01). Diet variety assessed using the FFS cutoff value of ≤16 points was related to the physical frailty status in community-dwelling older adults.

Associations of alpha-actinin-3 genotype with thigh muscle volume and physical performance in older adults with sarcopenia or pre-sarcopenia.

BACKGROUND: This cross-sectional study aimed to investigate the relationship of the ACTN3 genotype with thigh muscle volume and physical performance in older adults with sarcopenia or pre-sarcopenia. METHODS: Data from 64 older Japanese adults (mean age 74.4 ± 6.9 years, women 71.9%) with sarcopenia or pre-sarcopenia were analyzed. Sarcopenia and pre-sarcopenia were defined using the Asian Working Group for Sarcopenia. We collected oral mucosa samples to determine the ACTN3 genotype. Thigh muscle volumes were measured using magnetic resonance imaging. Physical performance was assessed using the usual and maximum gait speed, timed up and go test, and five-repetition sit-to-stand test. Muscle strength was assessed using grip strength. RESULT: The ACTN3 genotype proportions were 20.3% for RR, 51.6% for RX, and 28.1% for XX. Participants with the RR genotype showed greater thigh muscle volume/ht2 compared to those with the RX and XX ACTN3 genotypes (p < 0.05). The multiple linear regression analysis revealed that RX (p < 0.01) and XX (p < 0.01) ACTN3 genotypes, compared to RR, were associated with lower thigh muscle volume/ht2 and with age, sex (reference; men), weight and maximum walking speed. There was no significant difference between physical performance and muscle strength between the ACTN3 genotypes. CONCLUSION: The ACTN3 genotype of the X allele was associated with decreased thigh muscle volume compared to the ACTN3 genotype of RR in older adults with sarcopenia or pre-sarcopenia.