Objective Assessment of Physical Activity at Home Using a Novel Floor-Vibration Monitoring System: Validation and Comparison With Wearable Activity Trackers and Indirect Calorimetry Measurements

BACKGROUND

The self-monitoring of physical activity is an effective strategy for promoting active lifestyles. However, accurately assessing physical activity remains challenging in certain situations. This study evaluates a novel floor-vibration monitoring system to quantify housework-related physical activity.

OBJECTIVE

This study aims to assess the validity of step-count and physical behavior intensity predictions of a novel floor-vibration monitoring system in comparison with the actual number of steps and indirect calorimetry measurements. The accuracy of the predictions is also compared with that of research-grade devices (ActiGraph GT9X).

METHODS

The Ocha-House, located in Tokyo, serves as an independent experimental facility equipped with high-sensitivity accelerometers installed on the floor to monitor vibrations. Dedicated data processing software was developed to analyze floor-vibration signals and calculate 3 quantitative indices: floor-vibration quantity, step count, and moving distance. In total, 10 participants performed 4 different housework-related activities, wearing ActiGraph GT9X monitors on both the waist and wrist for 6 minutes each. Concurrently, floor-vibration data were collected, and the energy expenditure was measured using the Douglas bag method to determine the actual intensity of activities.

RESULTS

Significant correlations (P<.001) were found between the quantity of floor vibrations, the estimated step count, the estimated moving distance, and the actual activity intensities. The step-count parameter extracted from the floor-vibration signal emerged as the most robust predictor (r2=0.82; P<.001). Multiple regression models incorporating several floor-vibration-extracted parameters showed a strong association with actual activity intensities (r2=0.88; P<.001). Both the step-count and intensity predictions made by the floor-vibration monitoring system exhibited greater accuracy than those of the ActiGraph monitor.

CONCLUSIONS

Floor-vibration monitoring systems seem able to produce valid quantitative assessments of physical activity for selected housework-related activities. In the future, connected smart home systems that integrate this type of technology could be used to perform continuous and accurate evaluations of physical behaviors throughout the day.

[Questionnaire survey of municipalities on policies to promote physical activity among residents: An examination by administrative sector and population size]

Objectives　National policies to promote physical activity and exercise have been formulated by several ministries and agencies in Japan. This study aimed to examine the formulation and implementation of such policies in municipalities by administrative sector and population size.Methods　After stratifying all municipalities in Japan at the population level, we randomly selected 272 municipalities. We collected 1,632 cases in six sectors (health, sports, education, urban planning, transportation, and environment) within these municipalities.　A questionnaire survey on the status of policy formulation, implementation, and coordination among departments was conducted as a cross-sectional study. Differences between groups of municipalities were statistically analyzed using Fisher's exact test. The survey period was from September 2018 to March 2019.Results　A total of 616 responses were collected (response rate 37.7%). The response rates for health and education were lower than those for the other sectors. The rate of policy formulation to promote physical activity was extremely high in the health and sports sectors, and there was slight variation by population size. In contrast, formulation rates were generally low in the urban planning, transportation, and environment sectors, especially in smaller municipalities. In the sectors mentioned above, physical activity promotion projects mainly involved the development of exercise and sports infrastructures. Health, sports, and education were the primary sectors that used those environments. Regarding interdepartmental coordination in policy implementation, a cooperative relationship existed among the health, sports, and education sectors and between the urban planning and transportation sectors. However, smaller municipalities were found to have fewer opportunities for such collaboration and tended to implement policies independently.Conclusion　This study clarifies the policy formulation and implementation for promoting physical activity in municipalities at the national level in Japan. In addition, their characteristics were identified based on different administrative sectors and population size. These results are expected to be used in future local government policies.

Building on muscles: how built environment design impacts modern sports science

Sports science focuses on enhancing athletes' performance, requiring a multifaceted approach. It is evolving from a purely muscle-centred approach to an interdisciplinary one. This paper investigates built environment design science, a dimension less explored in relation to enhancing athlete performance in sports science. The discussion is divided into three categories: athlete-centric training built environment design, enhanced fan and community engagement, and improved integrative accessibility. The study also identifies future research directions, including evidence of the relative impact of the built environment, financial aspects, and performance evaluation methods. Collaboration between sports scientists and scholars in urban design, parks, transportation, landscape architecture and environmental psychology is necessary to advance this topic further.

Effects of energy loads on energy and nutrient absorption rates and gut microbiome in humans: A randomized crossover trial

OBJECTIVE

This study aimed to determine the effects of different energy loads on the gut microbiota composition and the rates of energy and nutrient excretion via feces and urine.

METHODS

A randomized crossover dietary intervention study was conducted with three dietary conditions: overfeeding (OF), control (CON), and underfeeding (UF). Ten healthy men were subjected to each condition for 8 days (4 days and 3 nights in nonlaboratory and laboratory settings each). The effects of dietary conditions on energy excretion rates via feces and urine were assessed using a bomb calorimeter.

RESULTS

Short-term energy loads dynamically altered the gut microbiota at the α-diversity (Shannon index), phylum, and genus levels (p < 0.05). Energy excretion rates via urine and urine plus feces decreased under OF more than under CON (urine -0.7%; p < 0.001, urine plus feces -1.9%; p = 0.049) and UF (urine -1.0%; p < 0.001, urine plus feces -2.1%; p = 0.031). However, energy excretion rates via feces did not differ between conditions.

CONCLUSIONS

Although short-term overfeeding dynamically altered the gut microbiota composition, the energy excretion rate via feces was unaffected. Energy excretion rates via urine and urine plus feces were lower under OF than under CON and UF conditions.

Frailty modifies the association of body mass index with mortality among older adults: Kyoto-Kameoka study

BACKGROUND & AIMS

The differences in the association of body mass index (BMI) with mortality between older adults with and without frailty remain unclear. This study investigated this association in community-dwelling older adults with and without frailty.

METHODS

This prospective study included 10,912 adults aged ≥65 years who provided valid responses to a baseline mail survey questionnaire in the Kyoto-Kameoka Study in Japan. The BMI was calculated based on self-reported height and body weight and classified into four categories: <18.5, 18.5-21.4, 21.5-24.9, and ≥25.0 kg/m2. Frailty was evaluated using the validated Kihon Checklist and defined as a score of 7 or higher out of a possible 25 points. Mortality data were collected from 30 July 2011 to 30 November 2016. Hazard ratios (HR) for all-cause mortality were calculated using a multivariable Cox proportional hazards model.

RESULTS

During the 5.3 year median follow-up period (54,084 person-years), 1352 deaths were recorded. After adjusting for confounders, including lifestyle and medical history, compared with participants with a BMI of 21.5-24.9 kg/m2, those in the lower BMI category had a higher mortality HR, while those with a higher BMI displayed an inverse association with mortality (<18.5 kg/m2: HR: 1.85, 95% confidence interval [CI]: 1.58-2.17; 18.5-21.4 kg/m2: HR: 1.38, 95% CI: 1.21-1.58; and ≥25.0 kg/m2: HR: 0.80, 95% CI: 0.67-0.96). In a model stratified by frailty status, the BMI range with the lowest HR for mortality was 23.0-24.0 kg/m2 in non-frail older adults; however, in frail older adults, a higher BMI was inversely associated with mortality.

CONCLUSIONS

The relationship between BMI and mortality varies between individuals with and without frailty, with those experiencing frailty potentially benefiting from a higher BMI compared to those without frailty. This study suggests that frailty should be assessed when considering the optimal BMI for the lowest mortality risk among older adults.

Association of skeletal muscle function, quantity, and quality with gut microbiota in Japanese adults: A cross-sectional study

AIM

The gut microbiota has emerged as a new intervention target for sarcopenia. Prior studies in humans have focused on the association between gut microbiota and skeletal muscle quantity, while the evidence on muscle function and quality is lacking. This study aimed to identify gut microbiota genera associated with skeletal muscle function, quantity, and quality in a general population of Japanese adults.

METHODS

This cross-sectional study included 164 participants aged 35-80 years, women and men recruited from urban areas of Japan. Fecal samples were collected and analyzed using 16S rRNA gene amplicon sequencing. Skeletal muscle function was measured using handgrip strength and leg extension power (LEP), while skeletal muscle mass was estimated using bioelectrical impedance analysis. Phase angle was used as a measure of skeletal muscle quality. Multivariate linear regression analysis stratified by age group was used to examine the association between the dominant genera of the gut microbiota and skeletal muscle variables.

RESULTS

A significant association was found between Bacteroides and Prevotella 9 with LEP only in the ≥60 years group. When both Bacteroides and Prevotella 9 were included in the same regression model, only Bacteroides remained consistently and significantly associated with LEP. No significant associations were observed between skeletal muscle mass, handgrip strength, and phase angle and major gut microbiota genera.

CONCLUSIONS

In this study, we observed a significant positive association between Bacteroides and leg muscle function in older adults. Further studies are required to elucidate the underlying mechanisms linking Bacteroides to lower-extremity muscle function. Geriatr Gerontol Int 2024; 24: 53-60.

Associations between cardiorespiratory fitness and lifestyle-related factors with DNA methylation-based ageing clocks in older men: WASEDA'S Health Study

DNA methylation-based age estimators (DNAm ageing clocks) are currently one of the most promising biomarkers for predicting biological age. However, the relationships between cardiorespiratory fitness (CRF), measured directly by expiratory gas analysis, and DNAm ageing clocks are largely unknown. We investigated the relationships between CRF and the age-adjusted value from the residuals of the regression of DNAm ageing clock to chronological age (DNAmAgeAcceleration: DNAmAgeAccel) and attempted to determine the relative contribution of CRF to DNAmAgeAccel in the presence of other lifestyle factors. DNA samples from 144 Japanese men aged 65-72 years were used to appraise first- (i.e., DNAmHorvath and DNAmHannum) and second- (i.e., DNAmPhenoAge, DNAmGrimAge, and DNAmFitAge) generation DNAm ageing clocks. Various surveys and measurements were conducted, including physical fitness, body composition, blood biochemical parameters, nutrient intake, smoking, alcohol consumption, disease status, sleep status, and chronotype. Both oxygen uptake at ventilatory threshold (VO2 /kg at VT) and peak oxygen uptake (VO2 /kg at Peak) showed a significant negative correlation with GrimAgeAccel, even after adjustments for chronological age and smoking and drinking status. Notably, VO2 /kg at VT and VO2 /kg at Peak above the reference value were also associated with delayed GrimAgeAccel. Multiple regression analysis showed that calf circumference, serum triglyceride, carbohydrate intake, and smoking status, rather than CRF, contributed more to GrimAgeAccel and FitAgeAccel. In conclusion, although the contribution of CRF to GrimAgeAccel and FitAgeAccel is relatively low compared to lifestyle-related factors such as smoking, the results suggest that the maintenance of CRF is associated with delayed biological ageing in older men.

Association between doubly labelled water-calibrated energy intake and objectively measured physical activity with mortality risk in older adults

BACKGROUND

Physical activity or biomarker-calibrated energy intake (EI) alone is associated with mortality in older adults; the interaction relationship between the combined use of both factors and mortality has not been examined. We evaluated the relationship between mortality and calibrated EI and step counts in older adults.

METHODS

This prospective study included 4,159 adults aged ≥65 years who participated in the Kyoto-Kameoka study in Japan and wore a triaxial accelerometer between 1 April and 15 November 2013. The calibrated EI was calculated based on a previously developed equation using EI biomarkers. The step count was obtained from the accelerometer ≥ 4 days. Participants were classified into the following four groups: low EI (LEI)/low step counts (LSC) group (EI: <2,400 kcal/day in men and <1,900 kcal/day in women; steps: <5,000 /day), n = 1,352; high EI (HEI)/LSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: <5,000 /day), n = 1,586; LEI/high step counts (HSC) group (EI: <2,400 kcal/day in men and < 1,900 kcal/day in women; steps: ≥5,000 /day), n = 471; and HEI/HSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: ≥5,000 /day), n = 750. Mortality-related data were collected until 30 November 2016. We performed a multivariable Cox proportional hazard analysis.

RESULTS

The median follow-up period was 3.38 years (14,046 person-years), and 111 mortalities were recorded. After adjusting for confounders, the HEI/HSC group had the lowest all-cause mortality rate compared to other groups (LEI/LSC: reference; HEI/LSC: hazard ratio [HR]: 0.71, 95% confidence interval [CI]: 0.41-1.23; LEI/HSC: HR: 0.59, 95% CI: 0.29-1.19; and HEI/HSC: HR: 0.10, 95% CI: 0.01-0.76). No significant interaction was observed between the calibrated EI and steps with mortality. The spline model showed that 35-42 kcal/100 steps/day of EI/100 steps was associated with the lowest mortality risk.

CONCLUSIONS

HR mortality risk was lowest at 35-42 kcal/100 steps/day, suggesting that very high (≥56 kcal) or low (<28 kcal) EI/100 steps are not inversely associated with mortality. Adherence to optimal EI and adequate physical activity may provide sufficient energy balance to explain the inverse association with mortality among older Japanese adults.

Combined Use of Sleep Quality and Duration Is More Closely Associated With Mortality Risk Among Older Adults: A Population-based Kyoto-Kameoka Prospective Cohort Study

BACKGROUND

Whether sleep quality and duration assessed from multiple domains, either individually or in combination, are strongly associated with mortality risk in older adults remains unelucidated. We aimed to clarify these relationships.

METHODS

We enrolled 7,668 older (age ≥65 years) Japanese adults in the Kyoto-Kameoka prospective cohort study who provided valid responses to the Pittsburgh Sleep Quality Index (PSQI) in a mail-in survey. Sleep quality and duration were classified into six groups using the previously validated PSQI: short sleep duration (SSD: <360 min/day)/sleep disturbance (SD: ≥5.5 PSQI points), n = 701; SSD/non-sleep disturbance (NSD: <5.5 PSQI points), n = 100; optimal sleep duration (OSD: 360-480 min/day)/NSD, n = 1,863; OSD/SD, n = 2,113; long sleep duration (LSD: >480 min/day)/NSD, n = 1,972; LSD/SD, n = 919. Mortality data were collected from February 15, 2012, to November 30, 2016. We evaluated the relationship between all-cause mortality risk and sleep quality and duration (and their combinations) using a multivariable Cox proportional hazards model that included baseline covariates.

RESULTS

The median follow-up period was 4.75 years (34,826 person-years), with a total of 616 deaths. After adjusting for confounders, compared with other groups, SSD/SD and LSD/SD had the highest hazard ratio (HR) of mortality (SSD/SD: HR 1.56; 95% confidence interval [CI], 1.10-2.19; SSD/NSD: HR 1.27; 95% CI, 0.47-3.48; OSD/NSD: reference; OSD/SD: HR 1.20; 95% CI, 0.91-1.59; LSD/NSD: HR 1.35; 95% CI, 1.03-1.77; LSD/SD: HR 1.83; 95% CI, 1.37-2.45). However, mortality risk was not associated with the interaction between sleep quality and duration.

CONCLUSION

Older adults with sleep disturbances involving SSD and LSD have a strong positive association with mortality risk, suggesting an additive effect between sleep quality and duration.

Distribution of water turnover by sex and age as estimated by prediction equation in Japanese adolescents and adults: the 2016 National Health and Nutrition Survey, Japan

BACKGROUND

Although water is essential to the maintenance of health and life, standard values for human water requirements are yet to be determined. This study aimed to evaluate the distribution of water turnover (WT) according to sex and age, estimated using a prediction equation, in Japanese adolescents and adults.

METHODS

This cross-sectional study used data from the 2016 National Health and Nutrition Survey, Japan. Data were obtained from electronically available aggregated reports in the survey's official website. Participants aged between 15 and 80 years (10,546 men, 12,355 women) were selected using stratified random sampling. WT was calculated considering lifestyle and environmental factors, and using an equation (coefficient of determination = 0.471) previously developed by the international doubly labelled water (DLW) database group. As data on physical activity levels (PAL) were not collected in the survey, we used two evaluation methods: (1) energy intake assessed by dietary records and (2) total energy expenditure measured by the DLW method reported in previous Japanese studies, divided by basal metabolic rate predicted using the equation. We evaluated the relationship between WT and age using a restricted cubic spline model.

RESULTS

The average WT for the 15-19, 20-29, 30-39, 40-49, 50-59, 60-69, and ≥ 70 years was 3291, 3151, 3213, 3243, 3205, 3104, and 2790 ml/day, respectively in men, and 2641, 2594, 2741, 2739, 2753, 2707, and 2482 ml/day, respectively in women. In the spline model, WT showed an inverse association with age in men older than 50 years, whereas women showed a reverse U-shaped relationship between WT and age (p for non-linearity < 0.001), although results differed with body weight adjustment. Similar results were found for both PAL evaluation methods, and the range of WT per body weight was 45-56 ml/day for both sexes.

CONCLUSIONS

We determined the standard values of WT in Japanese population using a prediction equation and national large-scale survey data. These findings may be useful for setting water requirements for dietary guidelines in future.

Association between physical activity and the prevalence of tumorigenic bacteria in the gut microbiota of Japanese adults: a cross-sectional study

Escherichia coli harboring polyketide synthase (pks+ E. coli) has been suggested to contribute to colorectal cancer development. Physical activity is strongly associated with lower colorectal cancer risks, but its effects on pks+ E. coli remain unclear. The aim of this study was to investigate the association between pks+ E. coli prevalence and physical activity. A cross-sectional study was conducted on 222 Japanese adults (27-79-years-old, 73.9% female). Triaxial accelerometers were used to measure light-intensity physical activity, moderate-to-vigorous intensity physical activity, the physical activity level, step-count, and time spent inactive. Fecal samples collected from participants were used to determine the prevalence of pks+ E. coli. Multivariate logistic regression analysis and restricted cubic spline curves were used to examine the association between pks+ E. coli prevalence and physical activity. The prevalence of pks+ E. coli was 26.6% (59/222 participants). The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the highest tertile with reference to the lowest tertile of physical activity variables were as follows: light-intensity physical activity (OR 0.63; 95% CI 0.26-1.5), moderate-to-vigorous intensity physical activity (OR 0.85; 95% CI 0.39-1.87), physical activity level (OR 0.69; 95% CI 0.32-1.51), step-count (OR 0.92; 95% CI 0.42-2.00) and time spent inactive (OR 1.30; 95% CI 0.58-2.93). No significant dose-response relationship was found between all physical activity variables and pks+ E. coli prevalence. Our findings did not suggest that physical activity has beneficial effects on the prevalence of pks+ E. coli. Longitudinal studies targeting a large population are needed to clarify this association.

Body Cell Mass to Fat-Free Mass Ratio and Extra- to Intracellular Water Ratio Are Related to Maximal Oxygen Uptake

Fat-free mass (FFM) is a heterogeneous compartment comprising body cell mass (BCM), intracellular water (ICW), extracellular solids, and extracellular water (ECW). The BCM/FFM and ECW/ICW ratios vary among individuals and decrease with age. This study aimed to determine whether BCM/FFM and ECW/ICW ratios are predictors of maximal oxygen uptake (V̇̇O2peak) independently of age, sex, and objectively measured physical activity (PA). A total of 115 Japanese males and females, aged 55.3 ± 8.0 years (mean ± standard deviation), were included in the study. Anthropometry, explosive leg muscle power, and V̇̇O2peak were measured, and BCM, FFM, ICW, and ECW were estimated. Step count and PA were objectively measured using a triaxial accelerometer. Blood flow volume was assessed using ultrasonography. BCM and ICW were negatively correlated with age, whereas FFM and ECW were not significantly correlated with age. FFM, ICW/ECW, BCM/FFM, step counts, moderate and vigorous PA, and leg muscle power were positively correlated with V̇̇O2peak, even after adjusting for age and sex (p < .05). Multiple regression analysis indicated that either BCM/FFM or ECW/ICW, leg power, and objectively measured PA were associated with V̇̇O2peak independent of age, sex, and FFM. Blood flow volume was significantly correlated with ECW (p < .05), but not with BCM. The BCM/FFM and ECW/ICW ratios were significant predictors of V̇̇O2peak, independent of age, sex, FFM, leg power, and objectively measured PA.

Estimated standard values of aerobic capacity according to sex and age in a Japanese population: A scoping review

Aerobic capacity is a fitness measure reflecting the ability to sustain whole-body physical activity as fast and long as possible. Identifying the distribution of aerobic capacity in a population may help estimate their health status. This study aimed to estimate standard values of aerobic capacity (peak oxygen uptake [Formula: see text] and anaerobic threshold [AT]/kg) for the Japanese population stratified by sex and age using a meta-analysis. Moreover, the comparison of the estimated standard values of the Japanese with those of other populations was performed as a supplementary analysis. We systematically searched original articles on aerobic capacity in the Japanese population using PubMed, Ichushi-Web, and Google Scholar. We meta-analysed [Formula: see text] (total: 78,714, men: 54,614, women: 24,100) and AT (total: 4,042, men: 1,961, women: 2,081) data of healthy Japanese from 21 articles by sex and age. We also searched, collected and meta-analysed data from other populations. Means and 95% confidence intervals were calculated. The estimated standard values of [Formula: see text] (mL/kg/min) for Japanese men and women aged 4-9, 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years were 47.6, 51.2, 43.2, 37.2, 34.5, 31.7, 28.6, and 26.3, and 42.0, 43.2, 33.6, 30.6, 27.4, 25.6, 23.4, and 23.1, respectively. The AT/kg (mL/kg/min) for Japanese men and women aged 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years were 21.1, 18.3, 16.8, 15.9, 15.8, and 15.2, and 17.4, 17.0, 15.7, 15.0, 14.5, and 14.2, respectively. Herein, we presented the estimated standard values of aerobic capacity according to sex and age in a Japanese population. In conclusion, aerobic capacity declines with ageing after 20-29 years of age. Additionally, aerobic capacity is lower in the Japanese population than in other populations across a wide range of age groups. Standard value estimation by meta-analysis can be conducted in any country or region and for public health purposes.

Ramen Consumption and Gut Microbiota Diversity in Japanese Women: Cross-Sectional Data from the NEXIS Cohort Study

A cross-sectional study involving 224 healthy Japanese adult females explored the relationship between ramen intake, gut microbiota diversity, and blood biochemistry. Using a stepwise regression model, ramen intake was inversely associated with gut microbiome alpha diversity after adjusting for related factors, including diets, Age, BMI, and stool habits (β = -0.018; r = -0.15 for Shannon index). The intake group of ramen was inversely associated with dietary nutrients and dietary fiber compared with the no-intake group of ramen. Sugar intake, Dorea as a short-chain fatty acid (SCFA)-producing gut microbiota, and γ-glutamyl transferase as a liver function marker were directly associated with ramen intake after adjustment for related factors including diets, gut microbiota, and blood chemistry using a stepwise logistic regression model, whereas Dorea is inconsistently less abundant in the ramen group. In conclusion, the increased ramen was associated with decreased gut bacterial diversity accompanying a perturbation of Dorea through the dietary nutrients, gut microbiota, and blood chemistry, while the methodological limitations existed in a cross-sectional study. People with frequent ramen eating habits need to take measures to consume various nutrients to maintain and improve their health, and dietary management can be applied to the dietary feature in ramen consumption.

Gut microbiota alternation with training periodization and physical fitness in Japanese elite athletes

Introduction

The gut microbiome plays a fundamental role in host homeostasis through regulating immune functions, enzyme activity, and hormone secretion. Exercise is associated with changes in gut microbiome composition and function. However, few studies have investigated the gut microbiome during training periodization. The present study aimed to investigate the relationship between training periodization and the gut microbiome in elite athletes.

Methods

In total, 84 elite athletes participated in the cross-sectional study; and gut microbiome was determined during their transition or preparation season period. Further, 10 short-track speed skate athletes participated in the longitudinal study, which assessed the gut microbiome and physical fitness such as aerobic capacity and anaerobic power in the general and specific preparation phase of training periodization. The gut microbiome was analyzed using 16S rRNA sequencing.

Results

The cross-sectional study revealed significant differences in Prevotella, Bifidobacterium, Parabacteroides, and Alistipes genera and in enterotype distribution between transition and preparation season phase periodization. In the longitudinal study, training phase periodization altered the level of Bacteroides, Blautia, and Bifidobacterium in the microbiome. Such changes in the microbiome were significantly correlated with alternations in aerobic capacity and tended to correlate with the anaerobic power.

Discussion

These findings suggest that periodization alters the gut microbiome abundance related to energy metabolism and trainability of physical fitness. Athlete's condition may thus be mediated to some extent by the microbiota in the intestinal environment.

Characteristic Gut Bacteria in High Barley Consuming Japanese Individuals without Hypertension

BACKGROUND

Barley, a grain rich in soluble dietary fiber β-glucan, is expected to lower blood pressure. Conversely, individual differences in its effects on the host might be an issue, and gut bacterial composition may be a determinant.

METHODS

Using data from a cross-sectional study, we examined whether the gut bacterial composition could explain the classification of a population with hypertension risks despite their high barley consumption. Participants with high barley intake and no occurrence of hypertension were defined as "responders" (n = 26), whereas participants with high barley intake and hypertension risks were defined as "non-responders" (n = 39).

RESULTS

16S rRNA gene sequencing revealed that feces from the responders presented higher levels of Faecalibacterium, Ruminococcaceae UCG-013, Lachnospira, and Subdoligranulum and lower levels of Lachnoclostridium and Prevotella 9 than that from non-responders. We further created a machine-learning responder classification model using random forest based on gut bacteria with an area under the curve value of 0.75 for estimating the effect of barley on the development of hypertension.

CONCLUSIONS

Our findings establish a link between the gut bacteria characteristics and the predicted control of blood pressure provided by barley intake, thereby providing a framework for the future development of personalized dietary strategies.

Longitudinal trajectory of vascular age indices and cardiovascular risk factors: a repeated-measures analysis

This study aimed to identify the modifiable cardiovascular risk factors associated with longitudinal changes, which are nine functional and structural biological vascular aging indicators (BVAIs), to propose an effective method to prevent biological vascular aging. We conducted a longitudinal study of 697 adults (a maximum of 3636 BVAI measurements) who were, at baseline, aged between 26 and 85 years and whose BVAIs were measured at least twice between 2007 and 2018. The nine BVAIs were measured using vascular testing and an ultrasound device. Covariates were assessed using validated questionnaires and devices. During the mean follow-up period of 6.7 years, the average number of BVAI measurements ranged from 4.3 to 5.3. The longitudinal analysis showed a moderate positive correlation between the common carotid intima-media thickness (IMT) and chronological age in both men (r = 0.53) and women (r = 0.54). In the multivariate analysis, BVAIs were associated with factors such as age, sex, residential area, smoking status, blood clinical chemistry test levels, number of comorbidities, physical fitness, body mass, physical activity, and dietary intake. The IMT is the most useful BVAI. Our findings suggest that modifiable cardiovascular risk factors are associated with longitudinal changes in BVAI as represented by IMT.

Regional Difference in the Impact of COVID-19 Pandemic on Domain-Specific Physical Activity, Sedentary Behavior, Sleeping Time, and Step Count: Web-Based Cross-sectional Nationwide Survey and Accelerometer-Based Observational Study

BACKGROUND

Physical activity (PA) and sedentary behavior (SB) have been affected by the COVID-19 pandemic and its restrictive environments, such as social distancing and lockdown measures. However, regional differences in the changes in domain-specific PA and SB in response to the COVID-19 pandemic are not clearly understood.

OBJECTIVE

This study aimed to examine regional differences in domain-specific PA and SB, as well as sleeping time in response to the COVID-19 pandemic in Japan.

METHODS

A web-based cross-sectional nationwide survey and an accelerometer-based longitudinal observation were conducted. In the web-based survey, we recruited 150 Japanese men and 150 Japanese women for each of the following age groups: 20s, 30s, 40s, 50s, 60s, and 70s (n=1800). A total of 1627 adults provided valid responses to web-based surveillance from June to July 2020. Participants were recruited from urban (Greater Tokyo Area, n=1028), urban-rural (regional core cities, n=459), or rural (regional small and medium cities, n=140) areas. They answered sociodemographic and health-related questions and retrospectively registered the PA data of their average day before and during the COVID-19 pandemic in a web-based PA record system. In the accelerometer-based observation, PA and step count data were obtained using a triaxial accelerometer on people living in urban (n=370) and rural (n=308) areas.

RESULTS

Before the COVID-19 pandemic, there were no significant differences between these 3 regions in the time spent sleeping, staying at home, working or studying, and exercising (P>.05). By contrast, people living in urban areas had a longer duration of SB and transportation and a shorter duration of moderate-to-vigorous PA and lying or napping time compared with people living in rural areas (P>.05). During the COVID-19 pandemic, a significant decrease was observed in transportation time in urban (-7.2 min/day, P<.001) and urban-rural (-2.0 min/day, P=.009) areas but not in rural (-0.4 min/day, P=.52) areas. The moderate-to-vigorous PA was decreased in urban (-31.3 min/day, P<.001) and urban-rural (-30.0 min/day, P<.001) areas but not in rural areas (-17.3 min/day, P=.08). A significant increase was observed in time spent sleeping in urban (+22.4 min/day, P<.001) and urban-rural (+24.2 min/day, P<.001) but not in rural areas (+3.9 min/day, P=.74). Lying or napping was increased in urban (+14.9 min/day, P<.001) but not in rural areas (-6.9 min/day, P=.68). PA and step count obtained using an accelerometer significantly decreased in urban (P<.05) but not in rural areas (P>.05).

CONCLUSIONS

The effect of the COVID-19 pandemic on PA and SB was significantly dependent on living area, even in a single country. The effects of PA and SB were greater in the Greater Tokyo Area and regional core cities but were not observed in regional small and medium cities in Japan.

Factors associated with changes in the objectively measured physical activity among Japanese adults: A longitudinal and dynamic panel data analysis

Factors associated with dynamic changes in the objectively measured physical activity have not been well understood. We aimed to 1) evaluate the longitudinal change in the physical activity trajectory according to sex which is associated with age and to 2) determine the factors associated with the dynamic change in physical activity-related variables across a wide age range among Japanese adults. This longitudinal prospective study included 689 Japanese adults (3914 measurements) aged 26-85 years, whose physical activity data in at least two surveys were available. Physical activity-related variables, such as intensity (inactive, light [LPA; 1.5 to 2.9 metabolic equivalents (METs)], moderate-to-vigorous [MVPA; ≥3.0 METs]), total energy expenditure (TEE), physical activity level (PAL), and step count, were evaluated using a validated triaxial accelerometer. Statistical analysis involved the latent growth curve models and random-effect panel data multivariate regression analysis. During a mean follow-up period of 6.8 years, physical activity was assessed an average of 5.1 times in men and 5.9 times in women. The profiles for the inactive time, LPA (only men), MVPA, step count, PAL, and TEE showed clear curvature, indicating an accelerated rate of change around the age of 70. In contrast, other variables exhibited minimal or no curvature over the age span. The MVPA trajectory was positively associated with alcohol consumption, hand grips, leg power, and trunk flexibility and negatively associated with age, local area, body mass index (BMI), comorbidity score, and heart rate over time. Our results indicated that the physical activity trajectory revealed clear curvature, accelerated rate of change around the age of 70, and determined physical health and fitness and BMI as dynamic factors associated with physical activity changes. These findings may be useful to help support populations to achieve and maintain the recommended level of physical activity.

Dose-Response Relationships between Objectively Measured Daily Steps and Mortality among Frail and Non-frail Older Adults

PURPOSE

Whether the association between objectively assessed physical activity and mortality differs between adults with versus those without frailty is unclear. We investigated this association in community-dwelling older adults.

METHODS

This prospective study used the data of 4165 older adults aged 65 years or older from the Kyoto-Kameoka study in Japan who wore a triaxial accelerometer (EW-NK52). The number of steps was classified by quartiles using the average daily value of data obtained from the accelerometer across four or more days. Frailty was evaluated using the validated Kihon Checklist. We evaluated the association between mortality and daily steps using a multivariable Cox proportional hazards analysis and restricted spline model.

RESULTS

The average daily steps for the first, second, third, and fourth quartiles were 1786, 3030, 4452, and 7502, respectively. In total, 113 deaths were recorded during a median follow-up of 3.38 years (14061 person-years). After adjusting for confounders, the top quartile was associated with a lower hazard ratio (HR) for mortality than the bottom quartile (HR: 0.39, 95% confidence interval: 0.18-0.85). In a stratified model by frailty status, the daily step count dose-response curve at which the HR for mortality plateaued among non-frail individuals was approximately 5000-7000 steps per day. In contrast, the daily step count showed an inverse relationship with mortality at approximately 5000 steps or more per day in frail individuals.

CONCLUSIONS

The relationship between daily steps and mortality is different between those with and those without frailty, and people with frailty may require more daily steps than those with non-frailty to achieve the inverse relationship with mortality. These findings may be useful for informing future physical activity guidelines.

Relationship between intra-individual variability in nutrition-related lifestyle behaviors and blood glucose outcomes under free-living conditions in adults without type 2 diabetes

AIMS

This study determined the relationship between intra-individual variability in day-to-day nutrition-related lifestyle behaviors (meal timing, eating window, food intake, movement behaviors, sleep conditions, and body weight) and glycemic outcomes under free-living conditions in adults without type 2 diabetes.

METHODS

We analyzed 104 adults without type 2 diabetes. During the 7-day measurement period, dietary intake, movement behaviors, sleep conditions, and glucose outcomes were assessed. Daily food intake was assessed using a mobile-based health application. Movement behaviors and sleep conditions were assessed using a tri-axial accelerometer. Meal timing was assessed from the participant's daily life record. Blood glucose levels were measured continuously using a glucose monitor. Statistical analyses were conducted using a linear mixed-effects model, with mealtime, food intake, body weight, movement behaviors, and sleep conditions as fixed effects and participants as a random effect.

RESULTS

Dinner time and eating window were positively significantly correlated with mean (dinner time, p = 0.003; eating window, p = 0.001), standard deviation (SD; both at p < 0.001), and maximum (both at p < 0.001) blood glucose levels. Breakfast time was negatively associated with glucose outcomes (p < 0.01). Sedentary time was positively significantly associated with blood glucose SD (p = 0.040). Total sleep time was negatively significantly correlated with SD (p = 0.035) and maximum (p = 0.032) blood glucose levels. Total daily energy intake (p = 0.001), carbohydrate intake (p < 0.001), and body weight (p < 0.05) were positively associated with mean blood glucose levels.

CONCLUSION

Intra-individual variations in nutrition-related lifestyle behaviors, especially morning and evening body weight, and food intake, were associated with mean blood glucose levels, and a long sedentary time and total sleep time were associated with glucose variability. Earlier dinner times and shorter eating windows per day resulted in better glucose control.

Dose-Response Relationships between Diet Quality and Mortality among Frail and Non-Frail Older Adults: A Population-Based Kyoto-Kameoka Prospective Cohort Study

OBJECTIVES

Although better diet quality is inversely associated with mortality risk, the association between diet quality and mortality remains unclear in frail and non-frail older adults. Thus, we aimed to examine this association in older Japanese adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We used the data of 8,051 Japanese older adults aged ≥65 years in the Kyoto-Kameoka study.

MESUREMENTS

Dietary intake was estimated using a validated food frequency questionnaire. Diet quality was evaluated by calculating the adherence scores to the Japanese Food Guide Spinning Top (range, 0 [worst] to 80 [best]), which were stratified into quartiles. Frailty status was assessed using the validated self-administered Kihon Checklist (KCL) and the Fried phenotype (FP) model. Survival data were collected between February 15, 2012 and November 30, 2016. Statistical analysis was performed using the multivariate Cox proportional hazard analysis and the spline model.

RESULTS

During the median 4.75-year follow-up (36,552 person-years), we recorded 661 deaths. After adjusting for confounders, compared with the bottom adherence score quartile, the top quartile was associated with lower hazard ratio (HR) of mortality in frailty (HR, 0.73; 95% confidence interval [CI], 0.54-1.00) and non-frailty, as defined by the KCL (HR, 0.72; 95% CI, 0.52-1.01). In the spline model, regardless of frailty status defined by the KCL and FP model, adherence score showed a strongly dose-dependent inverse association with mortality up to approximately 55 points; however, no significant differences were observed thereafter. This association was similar to the results obtained in individuals with physical, cognitive, and depression as domains of KCL in the spline model.

CONCLUSIONS

Our findings demonstrate an L-shaped association between diet quality and mortality in both frail and non-frail individuals. This study may provide important knowledge for improving poor diet quality in older individuals with frailty or domains of frailty.

Effects of water exercise on body composition and components of metabolic syndrome in older females with sarcopenic obesity

[Purpose] Very few studies have been conducted on the benefits of water exercise for older adults with sarcopenic obesity. Whether the water exercise intervention is effective for improving sarcopenia and/or obesity remains unclear. This study aimed to investigate the effects of water exercise on body composition and components of metabolic syndrome in older females with sarcopenic obesity. [Participants and Methods] Participants (aged ≥60 years) were divided into a water exercise group and a control group. Water-based strength and endurance exercises were performed three times a week for 12 weeks. Lean soft tissue mass, fat mass, and body fat percentage were measured by dual-energy x-ray absorptiometry. [Results] Two-way analysis of variance revealed significant interactions (time × group) for total body fat percentage and leg body fat percentage. In the exercise group, leg body fat percentage significantly decreased after the intervention, but no significant change was observed in the control group. The components of metabolic syndrome showed no significant interactions in either group (time × group). [Conclusion] No significant changes were observed in the components of metabolic syndrome. However, 12-week water exercise may be effective for reducing fat mass in females with sarcopenic obesity.

Weight over-reporting is associated with low muscle mass among community-dwelling Japanese adults aged 40 years and older: a cross sectional study

Background

Weight misperception adversely affects health-related quality of life (HRQol); however, few studies have evaluated the relationship between weight misperception and muscle mass. This study aimed to examine the relationship of weight misperception with low muscle mass using skeletal muscle index (SMI) estimated by multifrequency bioelectrical impedance analysis (MF-BIA) among community-dwelling Japanese.

Methods

Participants were 525 Japanese individuals aged 40–91 years old (male 89, female 436). Misperception was calculated by subtracting measured value from self-reported weight, presented as a percentage and categorized into tertiles based on sex (under-reporters, acceptable reporters, and over-reporters). Appendicular lean mass was estimated using MF-BIA, and low muscle mass was defined using SMI values of 7.0 and 5.7 kg/m2 for males and females, respectively, based on the Asian Working Group for Sarcopenia 2019 consensus. We evaluated the association between prevalence of low muscle mass and weight misperception (under-reporters and over-reporters) using multivariate logistic regression including covariate.

Results

In total, 9.3% (49/525) of participants had low muscle mass. After adjusting for covariates, prevalence of low muscle mass was higher among over-reporters than acceptable-reporters (odds ratio [OR]; 2.37, 95% confidence interval [CI]; 1.03–5.44). Additionally, sensitivity analysis was performed on females, which confirmed that the prevalence of low muscle mass was higher in over-reporters than in acceptable-reporters (OR, 3.27; 95% CI, 1.18–9.12).

Conclusion

Weight misperception was significantly correlated with low muscle mass, especially in over-reporters.

Association of the interaction between physical activity and sitting time with mortality in older Japanese adults

PURPOSE

To examine how physical activity (PA) and sitting time (ST) are associated with mortality in older Japanese adults.

METHODOLOGY

We used the data of 10 233 older Japanese adults aged ≥65 years who provided valid responses to the International Physical Activity Questionnaire-Short Form (IPAQ-SF) by a mail survey. Both PA and ST were assessed using the IPAQ-SF. The results were classified into high or low categories using ≥3.0 metabolic equivalent PA (150 min/week) and ST (300 min/day) into the following four groups: High PA (HPA)/Low ST (LST), HPA/High ST (HST), Low PA (LPA)/LST, and LPA/HST. Mortality data were collected from July 30, 2011, to November 30, 2016. We assessed the interaction of PA and ST status with the risk of all-cause mortality using the multivariable Cox proportional-hazards model.

RESULTS

A total of 1014 people were recorded to have died during a median follow-up period of 5.3 years (51 553 person-years). After adjustment for confounders, the risk of mortality was higher in the LPA/HST group than in all other groups (HPA/LST: reference; HPA/HST group: hazard ratio [HR] 0.86 (95% confidence interval [CI]: 0.66 to 1.12); LPA/LST group: HR 1.09 (95% CI: 0.88 to 1.35); LPA/HST group: HR 1.36 (95% CI: 1.10 to 1.67); and multiplicative interaction: HR 1.44 (95% CI: 1.07 to 1.94)).

CONCLUSIONS

The risk of mortality associated with LPA/HST depends on the level of PA, duration of ST, and their interaction with each other. Our results may be useful in ameliorating the adverse effects leading to mortality in individuals with lower PA, by reducing ST.

Fat-Free Mass Index as a Surrogate Marker of Appendicular Skeletal Muscle Mass Index for Low Muscle Mass Screening in Sarcopenia

OBJECTIVES

We aimed to examine the relationship between the fat-free mass index (FFMI; FFM/height²) and appendicular skeletal muscle mass index (ASMI; ASM/height²), measured using both bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), and investigate the effects of age and obesity. We also evaluated the suitability of BIA-measured FFMI as a simple surrogate marker of the ASMI and calculated the optimal FFMI cutoff value for low muscle mass screening to diagnose sarcopenia.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

This study included 1313 adults (women, 33.6%) aged 40-87 years (mean age, 55 ± 10 years) from the WASEDA'S Health Study.

METHODS

Body composition was measured using multifrequency BIA and DXA. Low muscle mass was defined according to the criteria of the Asian Working Group for Sarcopenia 2019.

RESULTS

BIA-measured FFMI showed strong positive correlations with both BIA- (r = 0.96) and DXA-measured (r = 0.95) ASMIs. Similarly, in the subgroup analysis according to age and obesity, the FFMI was correlated with the ASMI. The areas under the receiver operating characteristic curve for screening low muscle mass defined by DXA-measured ASMI using BIA-measured FFMI values were 0.95 (95% CI 0.93-0.97) for men and 0.91 (95% CI 0.87-0.94) for women. The optimal BIA-measured FFMI cutoff values for screening low muscle mass defined by DXA-measured ASMI were 17.5 kg/m² (sensitivity 89%, specificity 88%) for men and 14.6 kg/m² (sensitivity 80%, specificity 86%) for women.

CONCLUSIONS AND IMPLICATIONS

The FFMI showed a strong positive correlation with BIA- and DXA-measured ASMIs, regardless of age and obesity. The FFMI could be a useful simple surrogate marker of the ASMI for low muscle mass screening in sarcopenia in community settings. The suggested FFMI cutoff values for predicting low muscle mass are <18 kg/m² in men and <15 kg/m² in women.

Synergistic Effect of Increased Total Protein Intake and Strength Training on Muscle Strength: A Dose-Response Meta-analysis of Randomized Controlled Trials

Background

Protein supplementation augments muscle strength gain during resistance training. Although some studies focus on the dose-response relationship of total protein intake to muscle mass or strength, the detailed dose-response relationship between total protein intake and muscle strength increase is yet to be clarified, especially in the absence of resistance training.

Objective

We aimed to assess the detailed dose-response relationship between protein supplementation and muscle strength, with and without resistance training.

Design

Systematic review with meta-analysis.

Data Sources

PubMed and Ichushi-Web (last accessed on March 23, 2022).

Eligibility Criteria

Randomized controlled trials investigating the effects of protein intake on muscle strength.

Synthesis Methods

A random-effects model and a spline model.

Results

A total of 82 articles were obtained for meta-analyses, and data from 69 articles were used to create spline curves. Muscle strength increase was significantly augmented only with resistance training (MD 2.01%, 95% CI 1.09–2.93) and was not augmented if resistance training was absent (MD 0.13%, 95% CI − 1.53 to 1.79). In the dose-response analysis using a spline model, muscle strength increase with resistance training showed a dose-dependent positive association with total protein intake, which is 0.72% (95% CI 0.40–1.04%) increase in muscle strength per 0.1 g/kg body weight [BW]/d increase in total protein intake up to 1.5 g/kg BW/d, but no further gains were observed thereafter.

Conclusion

Concurrent use of resistance training is essential for protein supplementation to improve muscle strength. This study indicates that 1.5 g/kg BW/d may be the most appropriate amount of total protein intake for maintaining and augmenting muscle strength along with resistance training.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00508-w.

Variation in human water turnover associated with environmental and lifestyle factors

Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (²H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.

Association between skeletal muscle mass or percent body fat and metabolic syndrome development in Japanese women: A 7-year prospective study

Previous cross-sectional studies have indicated that low relative appendicular lean mass (ALM) against body weight (divided by body weight, ALM/Wt, or divided by body mass index, ALM/BMI) was negatively associated with metabolic syndrome (MetS). Conversely, previous cross-sectional studies have indicated that the absolute ALM or ALM divided by squared height (ALM/Ht2) were positively associated with MetS. The aim of this longitudinal study was to investigate the association between low absolute or relative skeletal muscle mass, leg muscle power, or percent body fat and the development of MetS in Japanese women in a 7-y prospective study. The study participants included 346 Japanese women aged 26 to 85 years. The participants were divided into low and high groups based on the median values of ALM/Wt, ALM/BMI, ALM/Ht2, absolute ALM, or leg power. The longitudinal relationship between ALM indices or leg power and MetS development was examined using Kaplan-Meier curves and Cox regression models (average follow-up duration 7 years, range 1 to 10 years). During follow-up, 24 participants developed MetS. MetS incidence was higher in the low ALM/Wt group than the high ALM/Wt group even after controlling for age, obesity, waist circumference, family history of diabetes, smoking, and physical activity [adjusted hazard ratio = 5.60 (95% CI; 1.04-30.0)]. In contrast, MetS incidence was lower in the low ALM/Ht2 group than the high ALM/Ht2 group [adjusted hazard ratio = 10.6 (95%CI; 1.27-89.1)]. MetS incidence was not significantly different between the low and high ALM/BMI, absolute ALM, and leg power groups. Both ALM/Ht2 and ALM/Wt were not significant predictive variables for MetS development when fat mass or percent body fat was taken into account in the Cox model. At the very least, the results of this study underscore the importance of body composition measurements in that percent body fat, but not ALM, is associated with MetS development.

Step-count outcomes of 13 different activity trackers: Results from laboratory and free-living experiments

BACKGROUND

Many activity trackers have been developed, but steps can still be inconsistent from one monitor to another.

RESEARCH QUESTION

What are the differences and associations between the steps of 13 selected consumer-based and research-grade wearable devices during 1 standardized day in a metabolic chamber and 15-day free-living trials?

METHODS

In total, 19 healthy adults between 21 and 50 years-old participated in this study. Participants were equipped with 12 accelerometer-based active trackers and one pedometer (Yamasa) in order to monitor the number of steps per day. The devices were worn on the waist (ActiGraph, Omron, Actimarker, Lifedorder, Withings, and Yamasa) or non-dominant wrist (Fitbit, Garmin, Misfit, EPSON, and Jawbone), or placed in a pocket (Omron CaloriScan, and TANITA). Participants performed structured activities over a 24 h period in a chamber (Standardized day), and steps were monitored in the same participants in free-living trials for 15 successive days using the same monitors (free-living days).

RESULTS

When the 13 monitors were ranked by their steps, waist-worn ActiGraph was located at the center (7th) of the monitors both in the Standardized (12,252 ± 598 steps/day, mean ± SD) and free-living days (9295 ± 4027 steps/day). The correlation between the accelerometer-based devices was very high (r = 0.87-0.99). However, the steps of Yamasa was significantly lower in both trials than ActiGraph. The wrist-worn accelerometers had significantly higher steps than other devices both trials (P < 0.05). The differences between ActiGraph and Actimarker or Lifecorder was less than 100 steps/day in the Standardized day, and the differences between ActiGraph and Active Style Pro was less than 100 steps/day in the free-living days. Regression equation was also performed for inter-device compatibility.

SIGNIFICANCE

Step obtained from the wrist-worn, waist-worn, and pocket-type activity trackers were significantly different from each other but still highly correlated in free-living conditions.

Combined use of two frailty tools in predicting mortality in older adults

We aimed to verify the combined use of two frailty tools in predicting mortality in older adults. We used the data of 10,276 Japanese older adults (aged ≥ 65 years) who provided valid responses to two frailty assessment tools in a mail survey in Japan’s Kyoto‒Kameoka Prospective cohort study. Frailty status was categorized into four groups depending on the validated frailty screening index and Kihon Checklist, respectively: Non-frailty (n = 5960), Physical frailty (n = 223), Comprehensive frailty (n = 2211), and Combination (n = 1882) groups. Mortality data were collected between July 30, 2011, and November 30, 2016. We assessed the relationship between frailty status and all-cause mortality risk using multivariate Cox proportional hazards models. During a median follow-up of 5.3 years, we recorded 1257 deaths. After adjusting for confounders, the Combination group had the highest mortality risk compared with the other groups [Non-frailty: reference; Physical frailty: hazards ratio [HR], 0.99 (95% confidence interval [CI] 0.58 to 1.70); Comprehensive frailty: 1.91 (1.63 to 2.23); Combination: 2.85 (2.44 to 3.22)]. People who are positive for frailty in both instruments have a higher risk of death than those who are positive to one model.

Evaluation of pre-Games effects of the Tokyo 2020 Olympic Games on Japanese population-level physical activity: a time-series analysis

Background

The Olympic Games represent an opportunity to create a ‘physical activity legacy’ that promotes physical activity at the population level in the host nations and cities. However, previous studies showed little increase in population-level physical activity following the Olympics. The upsurge of public interest in sports and physical activity participation before the Olympics may diminish rapidly following the Games. We examined the pre-Games effects of the Olympics on Japanese population-level physical activity after the announcement of Tokyo’s successful bid for the 2020 Olympic and Paralympic Games in September 2013.

Methods

We used publicly available data from serial cross-sectional surveys conducted with nationally or regionally representative samples in Japan seven years before and after the announcement (from 2006–2020). The outcomes were 1) daily step counts and 2) exercise habit prevalence (≥ 30 min/day, ≥ 2 days/week, and over a year) from the National Health and Nutrition Surveys Japan (NHNS-J; 14 time points; aggregated data); and 3) sports participation (at least once a week) from the National Sports-Life Survey conducted every two years (NSLS; eight time points; individual-level data of 18,867 adults) and from the Public Opinion Survey on Sports Participation of Tokyo Residents (POSSP; eight time points; aggregated data). Age- and gender-adjusted regression models were used to estimate changes in the outcomes before and after the announcement.

Results

There were no significant pre-Games effects of the Olympics on national-level physical activity participation among Japanese adults. Sports participation (56.4% and 57.5%, respectively; P = 0.518), daily steps (6,535 and 6,686 steps/day; P = 0.353), and exercise habit (30.7% and 29.1%, P = 0.309) did not change significantly before and after the announcement. Although an increase in sports participation among Tokyo residents was not found in the NSLS (61.5% and 59.3%, P = 0.227), it was observed in the POSSP (49.1% and 57.7%, P = 0.019). Nonetheless, this increase might not be related to the pre-Games effects since the trend diminished following the announcement.

Conclusions

Population-level physical activity did not show significant changes until 2020. Realising the physical activity legacy of an Olympics may require strategic promotion and cross-agency partnership implementation in the pre- and post-event period.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01332-x.

Determination of Optimal Daily Magnesium Intake among Physically Active People: A Scoping Review

Little is known about the optimal daily magnesium (Mg) intake for individuals with high levels of physical activity. The aim of this study was to clarify the optimal dietary Mg intake for people with high levels of physical activity in a scoping review. In this review, we searched MEDLINE and Japan Medical Abstracts Society for studies published up to May 31, 2020. We conducted two searches, one for studies using gold standard measurement methods such as the balance method and factorial calculation (Search 1), and the other for studies using estimation from daily food intake (Search 2). We also performed a meta-analysis of studies that compared the Mg intake among physically active people with the Mg intake among controls. After the primary and secondary screening, 31 studies were included in the final review. All of the included studies examined professional or recreational athletes. We found no studies that examined the optimal intake of Mg using gold standard measurement methods. The Mg intake among physically active individuals was below the recommended dietary allowance in most studies. In five studies that conducted meta-analyses, physically active individuals had significantly higher intakes of Mg than controls, although these levels were still below the recommended dietary allowance. The present review revealed that evidence regarding the optimal daily magnesium intake is currently scarce, and further studies are needed.

Relationship between thigh muscle cross-sectional areas and single leg stand-up test in Japanese older women

In older adults, the quantitative decline of the quadriceps femoris is associated with the augmentation of difficulty in the execution of a stand-up task. However, it is unclear whether the cross-sectional areas (CSAs) of individual thigh muscles differ between older adults who can stand up from a 40-cm-height chair on a single leg and those who cannot. To investigate this, the present study determined the CSAs of individual mid-thigh muscles in 67 Japanese women aged 60–77 years by using a magnetic resonance imaging method. Participants were asked to stand up from a 40-cm-height chair on a single leg, and those who could and could not stand up without leaning back and maintain a standing posture for 3 seconds on a single leg were allocated into the successful group (SG, n = 40) and unsuccessful group (USG, n = 27), respectively. Only the CSA of the adductors (sum of the adductor longus and adductor magnus) was significantly smaller in USG compared to SG. When CSA was expressed relative to the two-third power of body mass, the values for the four heads of the quadriceps femoris and biceps femoris long head, as well as the adductors, were significantly lower in USG than in SG. The current results indicate that in terms of the value relative to body mass, the reduced CSAs of the adductors and biceps femoris long head, as well as the four heads of the quadriceps femoris, are associated with the failure of attempts to stand up from a 40-cm-height chair on a single leg in older women. This may be due to the anatomical function of the two muscle groups, which contributes to hip extension movement involved in transitioning from a sitting position to a standing position during the stand-up task.

Dietary Vitamin B1 Intake Influences Gut Microbial Community and the Consequent Production of Short-Chain Fatty Acids

The gut microbiota is closely related to good health; thus, there have been extensive efforts dedicated to improving health by controlling the gut microbial environment. Probiotics and prebiotics are being developed to support a healthier intestinal environment. However, much work remains to be performed to provide effective solutions to overcome individual differences in the gut microbial community. This study examined the importance of nutrients, other than dietary fiber, on the survival of gut bacteria in high-health-conscious populations. We found that vitamin B1, which is an essential nutrient for humans, had a significant effect on the survival and competition of bacteria in the symbiotic gut microbiota. In particular, sufficient dietary vitamin B1 intake affects the relative abundance of Ruminococcaceae, and these bacteria have proven to require dietary vitamin B1 because they lack the de novo vitamin B1 synthetic pathway. Moreover, we demonstrated that vitamin B1 is involved in the production of butyrate, along with the amount of acetate in the intestinal environment. We established the causality of possible associations and obtained mechanical insight, through in vivo murine experiments and in silico pathway analyses. These findings serve as a reference to support the development of methods to establish optimal intestinal environment conditions for healthy lifestyles.

Classification of the Occurrence of Dyslipidemia Based on Gut Bacteria Related to Barley Intake

Barley is a grain rich in β-glucan, a soluble dietary fiber, and its consumption can help maintain good health and reduce the risk of metabolic disorders, such as dyslipidemia. However, the effect of barley intake on the risk of dyslipidemia has been found to vary among individuals. Differences in gut bacteria among individuals may be a determining factor since dietary fiber is metabolized by gut bacteria and then converted into short-chain fatty acids with physiological functions that reduce the risk of dyslipidemia. This study examined whether gut bacteria explained individual differences in the effects of barley intake on dyslipidemia using data from a cross-sectional study. In this study, participants with high barley intake and no dyslipidemia were labeled as “responders” to the reduced risk of dyslipidemia based on their barley intake and their gut bacteria. The results of the 16S rRNA gene sequencing showed that the fecal samples of responders (n = 22) were richer in Bifidobacterium, Faecalibacterium, Ruminococcus 1, Subdoligranulum, Ruminococcaceae UCG-013, and Lachnospira than those of non-responders (n = 43), who had high barley intake but symptoms of dyslipidemia. These results indicate the presence of certain gut bacteria that define barley responders. Therefore, we attempted to generate a gut bacteria-based responder classification model through machine learning using random forest. The area under the curve value of the classification model in estimating the effect of barley on the occurrence of dyslipidemia in the host was 0.792 and the Matthews correlation coefficient was 0.56. Our findings connect gut bacteria to individual differences in the effects of barley on lipid metabolism, which could assist in developing personalized dietary strategies.

Relationships between barley consumption and gut microbiome characteristics in a healthy Japanese population: a cross-sectional study

Background

Barley contains abundant soluble beta-glucan fibers, which have established health benefits. In addition, the health benefits conferred by the gut bacteria have attracted considerable interest. However, few studies have focused on the barley consumption and gut bacteria of the Japanese population. In this study, we aimed to identify the relationship between the barley consumption and gut bacteria composition of the Japanese population.

Methods

In total, 236 participants were recruited in Japan, and 94 participants with no complications of diabetes, hypertension, or dyslipidemia were selected for the study. We analyzed fecal samples from the participants, their medical check-up results, and responses to questionnaires about dietary habits. The participants were grouped according to their median barley consumption. Then, we assessed the relative abundance of 50 genera. Characteristic bacteria were evaluated for their relationship with barley consumption by multiple regression analysis, adjusted for disease and dietary habits, in all participants. We also analyzed the networks and clustering of the 20 selected genera.

Results

According to the comparison between barley groups, Bifidobacterium, Butyricicoccus, Collinsella, Ruminococcus 2, and Dialister were characteristic candidate bacterias of the group that consumed large amounts of barley (P < 0.05). The relationship between barley consumption and Bifidobacterium remained after adjusting for disease and dietary habits, and that of Butyricicoccus remained after adjusting for disease. Furthermore, network and cluster analyses revealed that barley consumption was directly correlated with Bifidobacterium and Butyricicoccus.

Conclusions

Barley consumption generates changes in the intestinal bacteria of the Japanese population. We found that Bifidobacterium and Butyricicoccus abundance was positively associated with barley consumption.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00500-3.

Diet quality and physical or comprehensive frailty among older adults

Purpose

While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-based cohort of older adults.

Methods

We conducted cross-sectional analyses using baseline data of 7022 participants aged ≥ 65 years in the Kyoto-Kameoka study. Diet quality was assessed by calculating the adherence scores to the Japanese Food Guide Spinning Top using a validated questionnaire; the participants were stratified into quartile groups based on these scores. Physical and comprehensive frailty was assessed using the Fried phenotype model-based Frailty Screening Index and the Kihon Checklist, respectively. Multivariable logistic regression and the restricted cubic spline model were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for associations between adherence scores and frailty prevalence.

Results

Higher adherence scores signified a higher intake of vitamin C, vegetables, dairy products, and fruits. Physical and comprehensive frailty prevalence was 14.2 and 35.8%, respectively. In a multivariable adjusted model, compared with the bottom adherence score quartile, the top quartile was associated with lower ORs of physical (OR 0.64; 95% CI 0.52–0.80) and comprehensive frailty (OR 0.60; 95% CI 0.51–0.71). These relationships were similar to results in the spline model.

Conclusions

This study shows an inverse dose–response relationship between diet quality and prevalence of both physical and comprehensive frailty in older adults.

Association Between Temporal Changes in Diet Quality and Concurrent Changes in Dietary Intake, Body Mass Index, and Physical Activity Among Japanese Adults: A Longitudinal Study

Background

Many cross-sectional studies have identified modifiable factors such as dietary intake, physique, and physical activity associated with diet quality but were unable to determine how a specific individual's diet quality changes with these factors. These relationships may vary depending on an individual's dietary intake. We aimed to determine the association between temporal changes in diet quality and concurrent changes in dietary intake, body mass index (BMI), and physical activity according to the diet quality trajectory pattern.

Methods

This longitudinal prospective study included 697 Japanese adults aged 26–85 years, at baseline, with available data from at least two dietary intake surveys (4,118 measurements). Dietary intake and physical activity were evaluated using validated dietary questionnaires and a triaxial accelerometer. Diet quality was calculated using the Nutrient-Rich Food Index 9.3 (NRF9.3), while physical activity was calculated based on the duration of activity performed at each level of intensity (sedentary, light, moderate, and vigorous). Body mass index was calculated from the measured height and weight. Statistical analyses involved latent class growth models (LCGM) and random-effect panel data analysis.

Results

During a mean follow-up period of 6.8 years, NRF9.3 scores were assessed, on average, 5.4 times in men and 6.1 times in women. Based on the NRF9.3 score, three separate trajectory groups—“low-increasing,” “medium-increasing,” and “high-stable”—among individuals aged 26–90 years were identified using LCGM. In the multivariate analysis, the NRF9.3 score trajectory was positively associated with intake of energy, protein, dietary fiber, vitamins A and C, magnesium, and food items, such as fruits and vegetables, and was negatively associated with BMI and the intake of added sugar, saturated fats, sodium, and food items, such as meat and sugar and confectioneries, even after adjusting for covariates. These relationships displayed heterogeneity across the identified NRF9.3 score trajectory groups. In the low-increasing group, an inverse relationship was observed between sedentary behavior and NRF9.3 score trajectory.

Conclusions

We identified modifiable factors associated with temporal changes in diet quality across a wide age range; however, these factors may vary according to the diet quality trajectories. Our findings may help develop effective strategies for improving diet quality, according to the trajectory of diet quality.

The MOTS-c K14Q polymorphism in the mtDNA is associated with muscle fiber composition and muscular performance

Human skeletal muscle fiber is heterogenous due to its diversity of slow- and fast-twitch fibers. In human, slow-twitched fiber gene expression is correlated to MOTS-c, a mitochondria-derived peptide that has been characterized as an exercise mimetic. Within the MOTS-c open reading frame, there is an East Asian-specific m.1382A>C polymorphism (rs111033358) that changes the 14th amino acid of MOTS-c (i.e., K14Q), a variant of MOTS-c that has less biological activity. Here, we examined the influence of the m.1382A>C polymorphism causing MOTS-c K14Q on skeletal muscle fiber composition and physical performance. The myosin heavy chain (MHC) isoforms (MHC-I, MHC-IIa, and MHC-IIx) as an indicator of muscle fiber composition were assessed in 211 Japanese healthy individuals (102 men and 109 women). Muscular strength was measured in 86 physically active young Japanese men by using an isokinetic dynamometer. The allele frequency of the m.1382A>C polymorphism was assessed in 721 Japanese athletes and 873 ethnicity-matched controls. The m.1382A>C polymorphism genotype was analyzed by TaqMan SNP Genotyping Assay. Individuals with the C allele of the m.1382A>C exhibited a higher proportion of MHC-IIx, an index of fast-twitched fiber, than the A allele carriers. Men with the C allele of m.1382A>C exhibited significantly higher peak torques of leg flexion and extension. Furthermore, the C allele frequency was higher in the order of sprint/power athletes (6.5%), controls (5.1%), and endurance athletes (2.9%). Additionally, young male mice were injected with the MOTS-c neutralizing antibody once a week for four weeks to mimic the C allele of the m.1382A>C and assessed for protein expression levels of MHC-fast and MHC-slow. Mice injected with MOTS-c neutralizing antibody showed a higher expression of MHC-fast than the control mice. These results suggest that the C allele of the East Asian-specific m.1382A>C polymorphism leads to the MOTS-c K14Q contributes to the sprint/power performance through regulating skeletal muscle fiber composition.

Intestinal microbe-dependent ω3 lipid metabolite αKetoA prevents inflammatory diseases in mice and cynomolgus macaques

Dietary ω3 fatty acids have important health benefits and exert their potent bioactivity through conversion to lipid mediators. Here, we demonstrate that microbiota play an essential role in the body's use of dietary lipids for the control of inflammatory diseases. We found that amounts of 10-hydroxy-cis-12-cis-15-octadecadienoic acid (αHYA) and 10-oxo-cis-12-cis-15-octadecadienoic acid (αKetoA) increased in the feces and serum of specific-pathogen-free, but not germ-free, mice when they were maintained on a linseed oil diet, which is high in α-linolenic acid. Intake of αKetoA, but not αHYA, exerted anti-inflammatory properties through a peroxisome proliferator-activated receptor (PPAR)γ-dependent pathway and ameliorated hapten-induced contact hypersensitivity by inhibiting the development of inducible skin-associated lymphoid tissue through suppression of chemokine secretion from macrophages and inhibition of NF-κB activation in mice and cynomolgus macaques. Administering αKetoA also improved diabetic glucose intolerance by inhibiting adipose tissue inflammation and fibrosis through decreased macrophage infiltration in adipose tissues and altering macrophage M1/M2 polarization in mice fed a high-fat diet. These results collectively indicate that αKetoA is a novel postbiotic derived from α-linolenic acid, which controls macrophage-associated inflammatory diseases and may have potential for developing therapeutic drugs as well as probiotic food products.

Compliance with a physical activity guideline among junior high school students

BACKGROUND

There were no nationwide moderate- to vigorous-intensity physical activity (MVPA) data relating to Japanese adolescents. This study assessed compliance with an MVPA guideline by adolescents, using a random sampling survey in Japan. The factors associated with compliance with the guideline were also examined.

METHODS

Participants were first- to third-grade Japanese junior high school students (307 boys and 255 girls). We analyzed data from the National Sports-Life Survey of Teens 2019, which used the Japanese version of physical activity (PA) questions in the World Health Organization Health Behavior in School-aged Children survey and potential correlates of MVPA.

RESULTS

Compliance with the PA guideline by the World Health Organization for Japanese students was 19.0% (95% confidence interval (CI), 15.8-22.3). The compliance of boys was significantly higher than that of girls (23.1%; 95% CI, 18.4-27.8; vs 14.1%; 95% CI, 9.8-18.4). The odds of meeting the PA guideline were significantly higher for boys in the second grade than boys in the first grade (odds ratio (OR) 1.78; 95% CI, 1.02-3.09), liking PA (for all: OR: 2.97; 95% CI, 1.32-6.69; for girls: OR: 2.99; 95% CI, 1.01-8.81), and sports participation (for all: OR: 4.77; 95% CI, 2.32-9.80; for boys: OR: 6.00; 95% CI, 1.81-19.89; for girls: OR: 4.08; 95% CI, 1.63-10.21).

CONCLUSIONS

The results suggest that more than 80% of junior high school students were insufficiently physically active in Japan. Preferences for PA and sports participation may be important correlates of sufficient PA.

Leisure-time physical activity and incidence of objectively assessed hearing loss: The Niigata Wellness Study

Previous cohort study reported that high physical activity was associated with a low risk of self-reported hearing loss in women. However, no studies have examined the association between physical activity and the development of hearing loss as measured using an objective assessment of hearing loss in men and women. Here, we used cohort data to examine the association between leisure-time physical activity and incidence of objectively assessed hearing loss in men and women. Participants included 27 537 Japanese adults aged 20-80 years without hearing loss, who completed a self-administered physical activity questionnaire between April 2001 and March 2002. The participants were followed up for the development of hearing loss as measured by audiometry between April 2002 and March 2008. During follow-up, 3691 participants developed hearing loss. Compared with the none physical activity group, multivariable adjusted hazard ratios (HRs) for developing hearing loss were 0.93 (95% confidence interval (CI), 0.86-1.01) and 0.87 (0.81-0.95) for the medium (<525 MET-min/week) and high (≥525 MET-min/week) physical activity groups, respectively (p for trend = 0.001). The magnitude of risk reduction was slightly greater in vigorous-intensity activity than in moderate-intensity activity (p for interaction = 0.01). Analysis by sound frequency showed that the amount of physical activity was inversely associated with high frequency hearing loss development (p for trend <0.001), but not with low frequency hearing loss development (p for trend = 0.19). Higher level of leisure-time physical activity was associated with lower incidence of hearing loss, particularly for vigorous-intensity activities and high sound frequencies.

Effect of a 1-year intervention comprising brief counselling sessions and low-dose physical activity recommendations in Japanese adults, and retention of the effect at 2 years: a randomized trial

Background

In an effort to increase people’s adherence to active lifestyles, contemporary physical activity (PA) guidelines now include low-dose PA.

Methods

PA was evaluated in 583 participants of the Nutritional and Physical Activity Intervention Study (NEXIS) cohort (30–65 years old); 349 inactive participants (MVPA, 2.7 ± 1.0 MET-h/day) were randomly assigned to the intervention or control groups, and 235 active participants participated in follow-up visits. The intervention aimed to increase MVPA and comprised five brief counseling sessions over 1 year. The 1-year target for the participant was increasing their step-count to 10,000 steps/d or +3000 steps/d, relative to the baseline score. The counseling sessions were designed to stimulate progressive changes in physical behaviors by recommendations promoting small and/or light-intensity bouts of PA. PA was measured at baseline, the end of the intervention, and 1 year after the intervention ended. Additionally, several nutrition, health, and fitness parameters were measured.

Results

Participants in the intervention group significantly increased their step-count from 8415 ± 1924 at baseline to 9493 ± 2575 at the end of the 1-year period. During the same period, MVPA significantly increased by 0.9 MET-h. The daily time spent in ≥ 3, ≥ 4 and ≥ 5 MET activities increased by 11, 6, and 3 min, respectively. This increase in PA remained observable 1 year after intervention concluded. The active group maintained higher physical activity levels throughout the two years. The intervention group showed smaller energy intakes at the end of the 2-year period. Significant correlations were noted between the 1-year change in MVPA and the change in resting heart rate (r =  − 0.22), and between the 2-year change in MVPA and the change in waist circumference (r =  − 0.08) and peak oxygen consumption capacity (r = 0.23) in the intervention group only.

Conclusions

A prolonged and progressive PA intervention promoting small bouts of light-to-moderate PA may be used in healthy, not-optimally-active people to increase PA beyond the strict period of the intervention. Further studies are necessary to understand whether low-dose PA messages can be effective in initiating a progressive increase toward larger amounts of PA.

Trial registration: Clinical Trials.gov, NCT00926744, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-021-00360-7.

Development and validation of a simple anthropometric equation to predict appendicular skeletal muscle mass

BACKGROUND & AIMS

A limited number of studies have developed simple anthropometric equations that can be implemented for predicting muscle mass in the local community. Several studies have suggested calf circumference as a simple and accurate surrogate maker for muscle mass. We aimed to develop and cross-validate a simple anthropometric equation, which incorporates calf circumference, to predict appendicular skeletal muscle mass (ASM) using dual-energy X-ray absorptiometry (DXA). Furthermore, we conducted a comparative validity assessment of our equation with bioelectrical impedance analysis (BIA) and two previously reported equations using similar variables.

METHODS

ASM measurements were recorded for 1262 participants (837 men, 425 women) aged 40 years or older. Participants were randomly divided into the development or validation group. Stepwise multiple linear regression was applied to develop the DXA-measured ASM prediction equation. Parameters including age, sex, height, weight, waist circumference, and calf circumference were incorporated as predictor variables. Total error was calculated as the square root of the sum of the square of the difference between DXA-measured and predicted ASMs divided by the total number of individuals.

RESULTS

The most optimal ASM prediction equation developed was: ASM (kg) = 2.955 × sex (men = 1, women = 0) + 0.255 × weight (kg) - 0.130 × waist circumference (cm) + 0.308 × calf circumference (cm) + 0.081 × height (cm) - 11.897 (adjusted R² = 0.94, standard error of the estimate = 1.2 kg). Our equation had smaller total error and higher intraclass correlation coefficient (ICC) values than those for BIA and two previously reported equations, for both men and women (men, total error = 1.2 kg, ICC = 0.91; women, total error = 1.1 kg, ICC = 0.80). The correlation between DXA-measured ASM and predicted ASM by the present equation was not significantly different from the correlation between DXA-measured ASM and BIA-measured ASM.

CONCLUSIONS

The equation developed in this study can predict ASM more accurately as compared to equations where calf circumference is used as the sole variable and previously reported equations; it holds potential as a reliable and an effective substitute for estimating ASM.

A community-wide intervention to promote physical activity: A five-year quasi-experimental study

Evidence on the effects of a community-wide intervention (CWI) on population-level physical activity (PA), especially in the long term, is limited. Therefore, we evaluated the five-year effect of CWI on promoting PA through information dissemination, education, and community support primarily targeting older adults, by incorporating Japanese guidelines, in Fujisawa City, from 2013. To assess the effect of the whole-city intervention, we distributed questionnaires in 2013, 2015, and 2018 to three independent random samples of 3,000 community-dwelling adults (aged ≥ 20 years) using a quasi-experimental study design. Three separate samples responded to the survey (41% at baseline, 46% at the two-year mark, and 48% at the five-year follow-up). The primary outcome was change in PA participation. At the five-year follow-up, PA (median: 120 minutes/day) was significantly higher than at baseline (86 minutes/day) and the two-year follow-up (90 minutes/day). The results of the multivariate analysis indicated that PA among older adults-the primary target population of the CWI-increased significantly at the five-year follow-up, compared to those aged 20-64 (mean difference of change between groups: 14.7 minutes/day, P= 0.029). Among older adults, PA was significantly lower in those with poorer perceived economic status than in their more well-off counterparts at the two-year follow-up (P= 0.003); however, there was no significant difference at the five-year follow-up (P= 1.000). There was a positive interaction between group and period (mean difference of change between groups: 40.9 minutes/day, P= 0.001). In conclusion, the five-year CWI targeting older adults, incorporating national guidelines, improved population-level PA.

Mother-to-infant transmission of the carcinogenic colibactin-producing bacteria

BACKGROUND

The Escherichia coli strain that is known to produce the genotoxic secondary metabolite colibactin is linked to colorectal oncogenesis. Therefore, understanding the properties of such colibactin-positive E. coli and the molecular mechanism of oncogenesis by colibactin may provide us with opportunities for early diagnosis or prevention of colorectal oncogenesis. While there have been major advances in the characterization of colibactin-positive E. coli and the toxin it produces, the infection route of the clb + strain remains poorly characterized.

RESULTS

We examined infants and their treatments during and post-birth periods to examine potential transmission of colibactin-positive E. coli to infants. Here, analysis of fecal samples of infants over the first month of birth for the presence of a colibactin biosynthetic gene revealed that the bacterium may be transmitted from mother to infant through intimate contacts, such as natural childbirth and breastfeeding, but not through food intake.

CONCLUSIONS

Our finding suggests that transmission of colibactin-positive E. coli appears to be occurring at the very early stage of life of the newborn and hints at the possibility of developing early preventive measures against colorectal cancer.

Validating muscle mass cutoffs of four international sarcopenia-working groups in Japanese people using DXA and BIA

BACKGROUND

The Asian Working Group for Sarcopenia (AWGS) 2019 recommended the use of dual-energy X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) to assess appendicular lean mass (ALM). AWGS, European Working Group on Sarcopenia in Older People 2 (EWGSOP2), Foundation for the National Institutes of Health Sarcopenia Project (FNIH), and International Working Group on Sarcopenia (IWGS) reported different cutoff values for sarcopenia. We aimed to validate these cutoff values in a Japanese population using DXA and two different devices of segmental multi-frequency BIA (MF-BIA).

METHODS

We examined the data of Japanese individuals aged 18-86 years using the DXA (n = 756) and two 8-electrode MF-BIA devices (InBody and TANITA MC) (n = 1884). To validate these cutoff values, we used a population aged 18-40 years, and calculated the 95% confidence intervals (CIs) of [mean-2SD].

RESULTS

In DXA, the 95%CIs of [mean-2SD] for ALM/Ht² were 5.2-5.8 and 6.6-7.3 kg/m² in women and men, respectively. The AWGS (<5.4 in women and <7.0 in men), and IWGS (≤5.67 in women and ≤7.23 in men) cutoffs were acceptable. Regarding TANITA MC, the 95%CIs of [mean-2SD] for ALM/Ht² were 5.6-6.0 and 6.9-7.4 kg/m² in women and men, respectively. The AWGS (<5.7 in women and <7.0 in men), EWGSOP2 (<6.0 in women and <7.0 in men), and IWGS cutoffs were acceptable. Regarding InBody, the 95%CIs of [mean-2SD] for ALM/Ht² were 4.8-5.2 and 6.4-6.8 kg/m² in young women and men, respectively. All cutoff values were too high compared to those measured by InBody. InBody and TANITA MC were highly correlated (P < 0.001), but the values by InBody were significantly lower than those by TANITA MC or DXA. Using Yamada's equation for InBody raw data, the AWGS, EWGSOP2, or IWGS cutoffs were acceptable. The BMI-adjusted muscle mass cutoff values were <0.60 and <0.82 m² in women and men, respectively. We also obtained the 20th percentile in older adult population (ALM/Ht² , <6.2 in women and <7.5 in men for TANITA MC; <5.4 in women and <7.0 in men for InBody).

CONCLUSIONS

The AWGS and IWGS cutoffs were valid for DXA, and the AWGS, IWGS, and EWGSOP2 cutoffs were valid for TANITA MC in Japanese population. Because the prevalence of sarcopenia is too low particularly in women when using those criteria, the 20th percentile might be a good alternative criteria. If the ALM original InBody values are used, the cutoffs should be <5.0 kg/m² in women and <6.6 kg/m² in men.