Mediation effects of social support on relationships of perceived environment and self-efficacy with school-based physical activity: A structural equation model tailored for Japanese adolescent girls

Background: Identifying correlates of physical activity that can be targeted as potential mediators is important for developing interventions to promote physical activity in adolescent girls. However, the mediated effects of multilevel correlates of physical activity remain poorly understood. Therefore, the present study aimed to examine direct and mediated effects of personal, social and perceived school physical environmental factors on school-based physical activity of Japanese adolescent girls. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 344 junior high school girls were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), perceived school physical environment (equipment, facilities and safety) and physical activity at school (min per week during lunch time and after- school hours). Structural equation modeling analysis controlling for age was performed to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-hours physical activity. Results: The final structural model demonstrated an acceptable fit for each context-specific physical activity. During lunch recess, perceived equipment and friend support exhibited direct effects on physical activity;perceived facilities, safety, and self-efficacy were indirectly associated with physical activity through friend support. During after-school hours, both family and friend support directly affected physical activity at school;perceived safety, facilities and self-efficacy exhibited indirect effects on physical activity through family or friend support. However, there were no significant associations between equipment and after-school-hours physical activity. Regardless of contexts, BMI had neither direct nor indirect effects on physical activity. Conclusion: Social support from family and friends was identified as factors mediating the effects of perceived environment and self-efficacy on school-based physical activity among Japanese adolescent girls. This finding encourages the future development of effective interventions to promote physical activity through family and friend support in the future.

Walking-friendly built environments and objectively measured physical function in older adults

Background:Few studies have examined the associations between urban design attributes and older adults’physical function.Especially,it is not well known how built-environment attributes may influence physical function in Asian cities.The aim of this study was to examine associations between objectively measured environmental attributes of walkability and objectively assessed physical function in a sample of Japanese older adults.Methods:Cross-sectional data collected in 2013 from 314 older residents(aged 65-84 years)living in Japan were used.Physical function was estimated from objectively measured upper-and lower-body function,mobility,and balance by a trained research team member.A comprehensive list of built-environment attributes,including population density,availability of destinations,intersection density,and distance to the nearest public transport station,were objectively calculated.Walk Score as a composite measure of neighborhood walkability was also obtained.Results:Among men,higher population density,availability of destinations,and intersection density were significantly associated with better physical function performance(1-legged stance with eyes open).Higher Walk Score was also marginally associated with better physical function performance(1-legged stance with eyes open).None of the environmental attributes were associated with physical function in elderly women.Conclusion:Our findings indicate that environmental attributes of walkability are associated with the physical function of elderly men in the context of Asia.Walking-friendly neighborhoods can not only promote older adults’active behaviors but can also support their physical function.

Changes of shear-wave velocity by interferon-based therapy in chronic hepatitis C

AIM: To evaluate the changes of shear-wave velocity(Vs) by acoustic radiation force impulse after treatment in chronic hepatitis C.METHODS: Eighty-seven patients with chronic hepatitis C were consecutively treated with combinations of interferon(IFN) plus ribavirin(RBV). Vs value(m/s) was measured with acoustic radiation force impulse before treatment, at end of treatment(EOT), 1 year after EOT, and 2 years after EOT.RESULTS: In patients with a sustained virological response(SVR)(n = 41), Vs significantly decreased at EOT [1.19(1.07-1.37), P = 0.0004], 1 year after EOT [1.10(1.00-1.22), P = 0.0001], and 2 years after EOT [1.05(0.95-1.16), P < 0.0001] compared with baseline [1.27(1.11-1.49)]. In patients with a relapse(n = 26), Vs did not significantly decrease at EOT [1.23(1.12-1.55)], 1 year after EOT [1.20(1.12-1.80)], and 2 years after EOT [1.41(1.08-2.01)] compared with baseline [1.39(1.15-1.57)]. In patients with a nonvirological response(n = 20), Vs did not significantly decrease at EOT [1.64(1.43-2.06)], 1 year after EOT [1.66(1.30-1.95)], and 2 years after EOT [1.61(1.36-2.37)] compared with baseline [1.80(1.54-2.01)]. Among genotype 1 patients, baseline Vs was significantly lower in SVR patients [1.28(1.04-1.40)] than in non-SVR patients [1.56(1.20-1.83)](P = 0.0142).CONCLUSION: Reduction of Vs values was shown in SVR patients after IFN-plus-RBV therapy by acoustic radiation force impulse.

Direct and indirect effects of multilevel factors on school-based physical activity among Japanese adolescent boys

Purpose: Background: Physical activity is a complex behavior which involves the interaction of multilevel factors at the individual, social and environmental level. However, previous studies have largely focused on psychological and/or social environmental factors and the direct impact of such factors on physical activity. There are few studies having examined how multilevel factors may interact to influence activity level. Therefore, the purpose of the present study was to examine both direct and indirect effects of multilevel factors on school-based physical activity in Japanese adolescent boys. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 379 junior high school boys were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), school physical environment (equipment, facilities and safety) and average minutes per week of physical activity during lunch time and after-school hours occurring at school. Structural equation modeling analyses controlling for age were utilized to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-school physical activity. Results: During lunch time, self-efficacy exhibited direct positive effects on physical activity. BMI, facilities, and safety were indirectly associated with lunchtime physical activity through self-efficacy. However, there were no significant relationships of equipment and social support with lunchtime physical activity. During after-school hours, family support and facilities directly affected physical activity. Self-efficacy was indirectly related with physical activity through family support. BMI, equipment, and safety indirectly affected physical activity through self-efficacy and/or family support. Conclusion: Effects of multilevel factor on physical activity among adolescent boys differed according to context, which implies that interventions to promote physical activity should be context-specific. Findings encourage the development of future effective interventions to promote physical activity through self-efficacy during lunch time as well as family support during after-school hours.

Relationship between meeting the recommendations for physical activity and health-related quality of life in adult Chinese Internet users

Background: The benefits of a recommended level of physical activity on physiological health indicators such as morbidity and mortality are well-accepted, but few researches has addressed whether or not the association between the recommended level of physical activity and a health-related quality of life (HRQOL) exists in the Chinese adults. Purpose: The present study examined whether the recommended physical activity (PA) would be associated with HRQOL in the Chinese adults. Methods: Cross-sectional data were collected through an internet-based survey. Total of 1394 Chinese adults responded the International Physical Activity Question- naire-Chinese version examining whether individuals met the recommended ACSM/AHA PA guideline. Demographic data were also obtained. HRQOL was assessed with the Medical Outcomes Survey Short Form-36 questionnaire (SF- 36). Multivariate analyses of covariance were utilized to examine differences in multidimensional scales of the SF-36. Results: In both genders, the recommended group had significantly higher physical functioning, vitality, and mental health scores than the inactive group. Significant differences in role physical, general health, social functioning scores were only found among the recommended and insufficient male groups. Conclusion: Individuals who attained the recommended level of PA had better scores on some dimensions of HRQOL than those who did not.