Isotemporal substitution of accelerometer-derived sedentary behavior and physical activity on physical fitness in young children.

This study investigates the effects of different types of physical activity (PA) on the physical fitness (PF) of young children in Japan, with a particular focus on how substituting sedentary behavior (SB) with active behaviors influences PF. We conducted a cross-sectional analysis of 1843 participants aged 3-6 years from northeastern Japan. Using triaxial accelerometers, we quantified PA, and PF was assessed via standardized tests. The innovative application of isotemporal substitution modeling (ISM) allowed us to analyze the impact of reallocating time from SB to more active states, specifically moderate-to-vigorous physical activity (MVPA) and light physical activity (LPA). Our findings reveal a robust association between increased MVPA and enhanced PF outcomes, underscoring the health benefits of reducing SB. Notably, replacing SB with LPA also showed beneficial effects on certain PF metrics, indicating LPA's potential role in early childhood fitness. These results highlight the critical importance of promoting MVPA and minimizing sedentary periods to bolster PF in young children. The study offers vital insights for shaping public health policies and emphasizes the need to cultivate an active lifestyle from an early age to secure long-term health advantages.

The Association between 24 h Movement Guidelines and Internalising and Externalising Behaviour Problems among Chinese Preschool Children.

This study examined the relationship between adherence to 24 h movement guidelines (24 h MGs) and internalising and externalising behavioural problems in Chinese children aged 3-6 years, with a specific focus on the differences between weekdays and weekends. The guidelines include recommendations for physical activity (PA), screen time (ST), and sleep duration (SD). The results indicated a stronger association between adherence to these guidelines and behavioural problems on weekends compared to weekdays. Specifically, the odds of experiencing internalising problems were 1.33 higher (95% CI: 1.05-1.69) when not satisfying all three behaviours compared to not satisfying one or two. Moreover, on weekends, when ST was not fulfilled, there was a higher likelihood of externalising behaviour problems compared to when it was fulfilled (OR, 1.18, 95% CI, 1.01-1.38), and when all three behaviours were not met, the likelihood was even higher (OR, 1.50, 95% CI, 1.04-2.18). Children who met all three guidelines had fewer internalising and externalising behavioural problems, suggesting a potential beneficial effect on mental health. The study revealed that a higher adherence to these recommendations corresponded to a lower risk of mental health problems. Additionally, higher screen time was linked to an increase in externalising behavioural issues. These findings underscore the importance of adherence to 24 h MGs for optimal mental health in children. Future interventions should consider these behavioural factors and incorporate strategies to promote adherence to these guidelines, particularly on weekends.

Reliability and validity of the Körperkoordinationstest Für Kinder in Chinese children.

Background: The Körperkoordinationstest Für Kinder (KTK) is a reliable and low-cost motor coordination test tool that has been used in several countries. However, whether the KTK is a reliable and valid instrument for use in Chinese children has not been assessed. Additionally, because the KTK was designed to incorporate locomotor, object control, and stability skills, and there is a lack of measurement tools that include stability skills assessment for Chinese children, the KTK's value and validity are worth discussing. Methods: A total of 249 primary school children (131 boys; 118 girls) aged 9-10 years from Shanghai were recruited in this study. Against the Test of Gross Motor Development-3 (TGMD-3), the concurrent validity of the KTK was assessed. We also tested the retest reliability and internal consistency of the KTK. Results: The test-retest reliability of the KTK was excellent (overall: r = 0.951; balancing backwards: r = 0.869; hopping for height: r = 0.918; jumping sideways: r = 0.877; moving sideways: r = 0.647). Except for the boys, the internal consistency of the KTK was higher than the acceptable level of Cronbach's α > 0.60 (overall: α = 0.618; boys: α = 0.583; girls: α = 0.664). Acceptable concurrent validity was found between the total scores for the KTK and TGMD-3 (overall: r = 0.420, p < 0.001; boys: r = 0.411, p < 0.001; girls: r = 0.437, p < 0.001). Discussion: The KTK is a reliable instrument for assessing the motor coordination of children in China. As such, the KTK can be used to monitor the level of motor coordination in Chinese children.

Screen media and non-screen media habits among preschool children in Singapore, South Korea, Japan, and Finland: Insights from an unsupervised clustering approach.

The main purpose of the research was to describe the daily screen media habits and non-screen media habits like indoor and outdoor play, and sleep of preschool children aged 2 to 6 years from Singapore, South Korea, Japan, and Finland using a content-validated online questionnaire (SMALLQ®) and unsupervised cluster analysis. Unsupervised cluster analysis on 5809 parent-reported weekday and weekend screen and non-screen media habits of preschool children from the four countries resulted in seven emergent clusters. Cluster 2 (n = 1288) or the Early-screen media, screen media-lite and moderate-to-vigorous physical activity-lite family made up 22.2% and Cluster 1 (n = 261) or the High-all-round activity and screen media-late family made up 4.5%, respectively represented the largest and smallest clusters among the seven clusters that were emergent from the pooled dataset. Finland was best represented by Cluster 2 and Japan was best represented by Cluster 3 (High-screen media-for-entertainment and low-engagement family). Parents from Finland and Japan displayed greater homogeneity in terms of the screen media and non-screen media habits of preschool children than the parents from South Korea and Singapore. South Korea was best represented by Clusters 6 (Screen media-physical activity-engagement hands-off family) and 7 (Screen media-lite, screen media-late and high-physical activity family). Singapore was best represented by Clusters 4, 5, 6 and 7, and these clusters ranged from Low all-round activity-high nap time family to Screen media-lite, screen media-late and high-physical activity family. Future research should explore in-depth reasons for the across-country and within-country cluster characteristics of screen media and non-screen media habits among preschool children to allow for more targeted interventions.

Developing a Scale for Measuring the Fundamental Movement Skills of Preschool Children in China.

Children aged 3-6 years (preschool children hereafter) are in a critical and sensitive period of developing fundamental movement skills (FMS). While appropriate measurement tools can accurately evaluate their FMS development, such a scale is lacking in China. In this study, a suitable scale for measuring the FMS of preschool children in China was developed by combining process- and results-oriented evaluation methods. The subjects of this cross-sectional study included 21 experts and 358 preschool children (188 boys and 170 girls). Based on a literature review, items suitable for measuring the FMS of preschool children in China were selected, and the final measurement scale includes 12 items in three dimensions: physical locomotion skills, object control skills, and physical stability skills. After a battery of tests to assess its suitability, including inter-rater reliability, test/retest reliability, homogeneity, and construct validity, we find that the proposed measurement scale has good reliability, validity, and sensitivity. This scale reflects the development level of the FMS of preschool children in China and can be used to monitor the FMS of this population in the future.

Associations between Parents' Digital Media Habits, Engagement, Awareness, and Movement Guidelines among Preschool-Age Children: International Ipreschooler Surveillance Study.

The 24-hour movement guidelines (24-h MG) recommend behaviors (physical activity, screen time, sleep) to aid appropriate physical and mental development in early childhood. This research examined parents' digital media habits (DMH), engagement (DME), and awareness (DMA) among parents in relation to their preschool-aged children's 24-h MG in Japan and identified and compared the modifiable determinants of adherence to 24-h MG in urban and rural regions. This cross-sectional study included 867 participants and data were obtained from the International Ipreschooler Surveillance Study Among Asians and OtheRs (IISSAAR). The results revealed that adherence to weekend screen time recommendations and weekday sleep duration were higher in the urban region. The parents' digital media variables that predicted moderate-intensity to vigorous-intensity physical activity among preschool-aged children were parents' DME and DMA in the urban regions and parents' DME in the rural regions. The children's screen time was significantly associated with parents' DMH, DME, and DMA in the urban regions and with parents' DMH and DMA in the rural regions (p < 0.005, p < 0.001, respectively). This study confirmed that parents' DMH, DME, and DMA are strong predictors of adherence to 24-h MG among preschool-aged children living in both rural and urban regions in Japan.

The Association of Body Mass Index and Fat Mass with Health-Related Physical Fitness among Chinese Schoolchildren: A Study Using a Predictive Model.

Body fat mass (FM) has advantages over body mass index (BMI) in terms of accuracy of fitness assessment and health monitoring. However, the relationship between FM and fitness in Chinese children has not yet been well studied. This study aimed to investigate the relationship between health-related physical fitness, BMI, and FM, which was estimated using a predictive model among elementary schoolchildren in China. This cross-sectional study included 2677 participants (boys, 53.6%; girls, 46.4%) who underwent anthropometric measurements (height, weight, BMI, and FM) and five health-related fitness tests: 50-m sprint (speed), sit and reach (flexibility), timed rope-skipping (coordination), timed sit-ups (muscular endurance), and 50-m × 8 shuttle run (endurance). In boys, BMI showed a positive correlation with speed (p < 0.001) and endurance (p < 0.006) tests and a negative correlation with flexibility (p < 0.004) and coordination (p < 0.001) tests. In girls, a positive correlation between speed (p < 0.001) and endurance (p < 0.036) tests was observed. Both BMI and FM (estimated using the predictive model) were strongly associated with the health-related physical fitness of elementary schoolchildren. Our findings indicate that health-related physical fitness was similarly affected by FM and BMI. As FM can be quantified, it could therefore be used to develop strategies and intervention programs for the prevention and management of obesity in children.

Isotemporal Substitution Analysis of Accelerometer-Derived Sedentary Behavior and Physical Activity on Cardiometabolic Health in Korean Adults: A Population-Based Cross-Sectional Study.

Reducing sedentary behavior and increasing physical activity may be important for maintaining good cardiometabolic health. However, many studies have focused on the independent effect of sedentary behavior and physical activity, but it is unclear whether replacing time spent in sedentary behavior with physical activity is beneficial for cardiometabolic health. Therefore, this population-based cross-sectional study aimed to investigate the effect of behavioral transformations between sedentary behavior and level of physical activity on cardiometabolic health in Korean adults using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2014-2017. The study participants included 2197 adults from the KNHANES. In the partition model, moderate-to-vigorous physical activity (MVPA) was significantly associated with adverse cardiometabolic health, adjusted for potential confounding factors. The odds ratio for adverse cardiometabolic health significantly decreased with the replacement of sedentary behavior and light intensity activity with MVPA in the isotemporal substitution model (p < 0.05). In the models stratified by sex, we observed significant associations between handgrip strength and cardiometabolic health in women (p < 0.001), but not in men. Thus, our findings suggest that replacing sedentary behavior with MVPA may contribute to improved cardiometabolic health.

Effects of a Workplace Sit-Stand Desk Intervention on Health and Productivity.

In Japan, standing while working has not yet become commonplace, and there is little evidence to support the benefits of standing during the workday. Therefore, this study assessed the relationship between the introduction of a sit-stand desk and its ability to reduce the negative effects of sitting too long and increase employees' general health and productivity. Seventy-four Japanese desk workers participated in this three-month intervention study. Using a randomized controlled trial, the participants were divided into intervention (n = 36) and control (n = 38) groups. The participant characteristics were ascertained using a questionnaire. The intervention effectiveness was assessed by measuring health-, physical activity-, and work-related outcomes. The results indicate that the intervention group significantly decreased their sitting time at work (p = 0.002) and had reduced neck and shoulder pain (p = 0.001). There was a significant increase in subjective health (p = 0.002), vitality in work-related engagement (p < 0.001), and self-rated work performance over a four-week period (p = 0.017). These findings indicate a significant difference between the two groups, demonstrating the effectiveness of a sit-stand desk in reducing sedentary behavior and improving workers' health and productivity. Future research can accumulate further evidence of best practice use of sit-stand desks.

Effects of Substituting Types of Physical Activity on Body Fat Mass and Work Efficiency among Workers.

Low levels of physical activity (PA) not only increase healt h risks but also affect employee productivity. Although daily activity is interdependent with work productivity and personal health, few studies have examined how substituting physical activities would affect health and work efficiency. The present study aimed to investigate how substituting sedentary behaviors (SB) with increased PA and increasing the intensity of low-level activities during waking times affects the body fat mass and work efficiency of employees. Data were collected from 224 Japanese employees. SB, light physical activity (LPA), moderate physical activity (MPA), and vigorous physical activity (VPA) were measured using a tri-axial accelerometer, and body fat mass and work efficiency were also assessed. Analyses of the effects of substituting behaviors were based on the methods used in the isotemporal substitution model. Body fat mass decreased after substituting behaviors for 30 min per day: from SB to VPA (ß = -4.800, 95% CI = -7.500; -2.100), from LPA to VPA (ß = -4.680, 95% CI = -7.350; -1.980), and from MPA to VPA (ß = -4.920, 95% CI = -7.680; -2.190). For work efficiency and physical activities, a higher work efficiency score was observed when substituting SB with LPA (ß = 0.120, 95% CI = 0.030; 0.240), and a lower work efficiency score was observed when substituting LPA with VPA (ß = -0.660, 95% CI = -1.350; -0.030). These results should help achieve greater results in promoting health and increasing work productivity by properly distributing and practicing daily physical activities during work hours.

The Influence of a Table Tennis Physical Activity Program on the Gross Motor Development of Chinese Preschoolers of Different Sexes.

Gross motor locomotion is the basis of various sensory motor locomotion. Interventions helping preschoolers develop gross motor skills (GMS) could provide a solid foundation for complex motor skills. This study analyzed a table tennis physical activity program's influence on preschoolers' GMS development with 104 preschoolers (experimental group (EG): N = 52, 25 boys, 27 girls; control group (CG): N = 52, 25 boys, 27 girls). The EG conducted table tennis physical activities three times per week for 12 weeks. Preschoolers' GMSs were assessed using the Test of Gross Motor Development (second edition). After 12 weeks, both the male and female EGs had significantly improved scores for GMS, locomotor subtest, gallop, hop, leap, slide, object control subtest, strike a stationary ball, stationary dribble, catch, overarm throw, and underhand roll (p < 0.05, p < 0.01, p < 0.001). The female EG also showed significant improvement for the run, horizontal jump, and catch in the post-test. Both the male and female EGs significantly outperformed the control group in their post-test scores for GMS, locomotor subtest, object control subtest, strike a stationary ball, overarm throw, and underhand roll (p < 0.05). The female EG also showed significant differences in slide scores (p < 0.05). Therefore, table tennis physical activities can promote preschoolers' GMS development, especially object control skills. The research results provide an empirical basis for preschoolers' physical education. Meanwhile, our findings have important implications for preschoolers' GMS development and table tennis' popularization in Chinese kindergartens.

Associations between Adherence to Combinations of 24-h Movement Guidelines and Overweight and Obesity in Japanese Preschool Children.

The interactions between movement behaviors (physical activity, screen time, and sleep) affect the health of preschool children. Therefore, we examined the status of adherence to combinations of 24-hour movement guidelines (24-h MG) in Japanese preschool children and determined the associations between overweight/obesity and adherence to these 24-h MG. This cross-sectional study was conducted with 421 children aged 3-5 years (216 boys and 199 girls) living in the northeastern region of Japan. To evaluate the 24-h MG, physical activity over one week was measured using a three-axis accelerometer. For screen time and sleep duration, a questionnaire survey was conducted. Children who failed to meet all the 24-h MG had a higher probability of overweight/obesity than those who met all the 24-h MG (odds ratio 1.139, 95% confidence interval: 1.009, 1.285). The percentage of adherence to the 24-h MG was 91.6% for physical activity, 82.5% for sleep duration, and 33.7% for screen time, and only 21.5% of the children adhered to all three areas of the guidelines. Our findings have important implications for developing public health policies and effective intervention programs for preschool children.

The Associations between Outdoor Playtime, Screen-Viewing Time, and Environmental Factors in Chinese Young Children: The "Eat, Be Active and Sleep Well" Study.

The purpose of this study is to identify regional differences in outdoor activity time and screen-viewing time of preschool children in urban and rural areas and to provide data on the environmental factors to identify modifiable determinants for each region. This cross-sectional study was conducted on 1772 out of 2790 children between the age of 3 to 6 years living in northern China, with their consent. A cross-sectional study was conducted among preschool children living in urban (n = 1114) and rural areas (n = 658) in northern China. To assess environmental factors, the International Physical Activity Questionnaire was used for neighborhood environments, and the questionnaire included three items each for the physical home environment and socio-cultural environment domains. We observed the associations between outdoor play for urban children and sidewalks in the neighborhood, paths for cycles, aesthetic qualities, and "motor vehicles. In addition, in rural areas, screen-viewing time and environmental factors were found to be positively correlated with traffic, limited place and method of outdoor play, and were negatively correlated with the importance of academics and need for company in outdoor play. This has important implications for the development of effective intervention programs for preschool children in China in the future.

The Neighborhood Environment Walkability Scale for the Republic of Korea: Reliability and Relationship with Walking.

BACKGROUND: The aim of the study was to analyze the reliability of the Korean version of the NEWS and to investigate the relationship between walking and environmental factors by gender. METHODS: A total of 1407 Korean adults, aged 20-59 yr, participated in the study. Data were collected between Sep 2013 and Oct 2013. To examine the test-retest reliability, 281 of the 1407 participants were asked to answer the same questionnaire (Korean NEWS-A scale) after a 7-d interval. RESULTS: The ICC range of the entire questionnaire was 0.71-0.88. The item on land use mix-diversity had the highest ICC, and that on physical barriers had the lowest. In addition, presents the partial correlation coefficients for walking and the NEWS-A score, adjusted for social demographic variables. Overall, land use mix-diversity (P<0.034) and land use mix-access (P<0.014) showed a positive relationship with walking. DISCUSSION: Examination of the reliability of the Korean NEWS-A scale based on Korean adults who reside in large cities showed that all items had statistically satisfactory reliability. Korean NEWS-A scale may be a useful measure for assessing environmental correlates of walking among population in Korea.

11ß-HSD1 reduces metabolic efficacy and adiponectin synthesis in hypertrophic adipocytes.

Mitochondrial dysfunction in hypertrophic adipocytes can reduce adiponectin synthesis. We investigated whether 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) expression is increased in hypertrophic adipocytes and whether this is responsible for mitochondrial dysfunction and reduced adiponectin synthesis. Differentiated 3T3L1 adipocytes were cultured for up to 21 days. The effect of AZD6925, a selective 11ß-HSD1 inhibitor, on metabolism was examined. db/db mice were administered 600 mg/kg AZD6925 daily for 4 weeks via gastric lavage. Mitochondrial DNA (mtDNA) content, mRNA expression levels of 11 ß -H sd1 and mitochondrial biogenesis factors, adiponectin synthesis, fatty acid oxidation (FAO), oxygen consumption rate and glycolysis were measured. Adipocyte hypertrophy in 3T3L1 cells exposed to a long duration of culture was associated with increased 11 ß -Hsd1 mRNA expression and reduced mtDNA content, mitochondrial biogenesis factor expression and adiponectin synthesis. These cells displayed reduced mitochondrial respiration and increased glycolysis. Treatment of these cells with AZD6925 increased adiponectin synthesis and mitochondrial respiration. Inhibition of FAO by etomoxir blocked the AZD6925-induced increase in adiponectin synthesis, indicating that 11ß-HSD1-mediated reductions in FAO are responsible for the reduction in adiponectin synthesis. The expression level of 11 ß -Hsd1 was higher in adipose tissues of db/db mice. Administration of AZD6925 to db/db mice increased the plasma adiponectin level and adipose tissue FAO. In conclusion, increased 11ß-HSD1 expression contributes to reduced mitochondrial respiration and adiponectin synthesis in hypertrophic adipocytes.

Low-volume walking program improves cardiovascular-related health in older adults.

Although numerous sources of evidence show that regular physical activity is beneficial to health, most individuals do not engage in a sufficient amount of physical activity to meet the guidelines set out by expert panels. In addition, the minimum amount of physical activity associated with reduced cardiovascular disease risk markers is not clear in older adults. The purpose of this study was to determine the effects of a 12-week walking program involving an exercise volume below the current minimum physical activity recommendation on cardiovascular disease risk markers in older adults. The participants were recruited from the following two groups separately: a walking group (n = 14) and a control group (n = 14). In the walking group, participants walked 30 to 60 minutes per session on 2 days per week for 12 weeks (average walking time, 49.4 ± 8.8 min/session). Plasma oxidised low-density lipoprotein concentrations tended to be lower than baseline values in the walking group after 12 weeks (paired t-test, p = 0.127). The ratio of oxidised low-density lipoprotein to high-density lipoprotein cholesterol was significantly lower than the baseline ratio in the walking group after 12 weeks (paired t-test, p = 0.035). Resting systolic blood pressure and diastolic blood pressure were significantly lower than baseline values in the walking group after 12 weeks (paired t-tests, p = 0.002, p < 0.0005, respectively). Our findings demonstrate that a 12-week walking program comprising a low volume of physical activity confers a benefit to cardiovascular-related health in older adults. Key PointsIt is important to consider baseline physical activity levels when evaluating physical activity program.Being physically active is important to reduce the potential risk marker of cardiovascular disease in older adults.These data imply that a small volume of 12-week walking program confers a benefit to cardiovascular-related health in older adults.

The association between physical activity and sex-specific oxidative stress in older adults.

Oxidative stress increases with advancing age and is a mediator of several diseases including cancer, cardiovascular disease, and diabetes. Moreover, postmenopausal women have a lower estrogen concentration, which is associated with elevated oxidative stress. However, there is no definitive evidence regarding the relationship between daily physical activity and oxidative stress status in older adults, including postmenopausal women. Twenty-nine adults (age, 70.1 ± 1.0 years, mean ± SE; 12 women and 17 men) were examined in this cross-sectional study. Prior to blood collection, the participants were asked to wear a uniaxial accelerometer for 4 consecutive weeks to determine their level of physical activity. After a 48-h period of physical activity avoidance and a 10-h overnight fast, venous blood samples were obtained from each participant. Fasting plasma derivatives of reactive oxygen metabolites (d-ROMs) and malondialdehyde (MDA) concentrations of oxidative stress markers were negatively correlated with the amount of physical activity in women (d-ROMs; r = -0.708, p = 0.002) (MDA; r = -0.549, p = 0. 028), but not in men. Fasting plasma biological antioxidant potential of antioxidant capacity marker was positively correlated with the amount of physical activity in women (BAP; r = 0.657, p = 0.006) (GSH; r = 0.549, p = 0.028), but not in men. Moreover, superoxide dismutase activity of antioxidant capacity marker was positively correlated with the amount of physical activity in men (r = 0.627, p = 0.039), but not in women. There were no associations between physical activity and other oxidative stress markers (reduced and oxidized glutathione, glutathione peroxidise, thioredoxin). These findings suggest that regular physical activity may have a protective effect against oxidative stress by increasing total antioxidant capacity, especially in postmenopausal women. Key PointsIt is important to consider daily physical activity status when evaluating antioxidant capacity.Sex differences affect the alteration of oxidative stress markers induced by daily physical activity.Regular physical activity may have a protective effect against oxidative stress by increasing total antioxidant capacity, especially in postmenopausal women.

Effects of low-volume walking programme and vitamin E supplementation on oxidative damage and health-related variables in healthy older adults.

BACKGROUND: Both exercise and vitamin E supplementation have been shown to reduce oxidative stress and cardiovascular disease risk in older adults, and when combined there is evidence suggesting that they act synergistically. The currently recommended amount of exercise for older adults is 150 min/week of moderate-intensity exercise; however, the minimum amount of exercise necessary to achieve health benefits is not known. The purpose of this study was to investigate the effects of 12 weeks of participation in a low-volume walking exercise programme (i.e. 90 min/week) combined with daily vitamin E supplementation on thiobarbituric acid reactive substances (TBARS) and oxidised low-density lipoprotein (LDL) concentrations in older adults. METHODS: The participants were recruited from the following four groups separately: 1) control (CG, n = 14), 2) vitamin E supplementation (SG, n = 10), 3) walking (WG, n = 7), or 4) walking + supplementation (WSG, n = 7). In the CG, participants were advised to maintain their normal lifestyle during the study. Participants in both the SG and WSG received 450 IU (300 mg) /day of α-tocopherol for 12 weeks. The exercise programme for the WG and WSG consisted of two 30-60 minute sessions weekly for 12 weeks (average walking time was 44.5 ± 1.6 min/session). Blood samples were collected at baseline and at 12 weeks. RESULTS: Delta plasma oxidised LDL concentrations did not differ among four groups (One-factor ANOVA, P = 0.116). However, negative delta plasma TBARS, a marker of oxidative damage, concentrations were observed in the WG, WSG and SG relative to the CG at the end of the study period (One-factor ANOVA, P = 0.001; post hoc tests; CG compared with WG, WSG and SG, P = 0.005; P = 0.021; P = 0.024, respectively). CONCLUSION: These findings suggest that a low-volume of physical activity and/or vitamin E supplementation may be an effective intervention strategy for reducing TBARS concentrations of older adults. TRIAL REGISTRATION: UMIN000008304.

Antimicrobial effect of alexidine and chlorhexidine against Enterococcus faecalis infection.

A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine. The aim of this study was to compare the antimicrobial activity of 1% alexidine with that of 2% chlorhexidine using Enterococcus faecalis-infected dentin blocks. Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each. E. faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2% chlorhexidine or 1% alexidine solutions for 5 and 10 min, respectively. Sterile saline was used as a control. The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope. Significantly fewer bacteria were observed in the 2% chlorhexidine- or 1% alexidine-soaked groups than in the control group (P<0.05). However, there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups (P>0.05). Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups. In conclusion, 10-min soaking with 1% alexidine or 2% chlorhexidine can be effective against E. faecalis infection.

Low-volume exercise training attenuates oxidative stress and neutrophils activation in older adults.

The purpose of this study was to investigate the effects of low-volume exercise training (100 min/week) on oxidative stress and neutrophils activation markers in older adults. Twenty-eight older adults (age range 65-78 years) were assigned into control (n = 14) or exercise (n = 14) groups. The exercise program consisted of walking 30-60 min/session, 2 days each week for 12 weeks. Blood samples were taken before starting the sessions (baseline) and when they ended. Fasting plasma and serum oxidative stress and inflammatory markers were measured using commercial kits. Cell surface expression of adhesion molecules on circulating leukocytes (CD66b and CD62L) was determined using flow cytometry. The concentrations of derivatives of reactive oxygen metabolites tended to be lower than the baseline values only in the exercise group (P = 0.05). The biological antioxidant potential, thioredoxin concentrations, and glutathione peroxidase activities significantly increased only in the exercise group (P < 0.05 for all). While CD66b expression tended to decrease only in the exercise group, CD62L expression significantly increased (P < 0.05). Our findings indicate that exercise training below the current recommended level of at least 150 min/week attenuates basal oxidative stress and neutrophil activation in older adults. Thus, our findings may encourage more people to incorporate a small amount of physical activity into their lives.