The relationships between social participation before the COVID-19 pandemic and preventive and health-promoting behaviors during the pandemic: the JAGES 2019-2020 longitudinal study.

BACKGROUND: People's preventive behavior is crucial for reducing the infection and transmission of a novel coronavirus, especially in aging societies. Moreover, since behavioral restrictions may lead to high risks of secondary health impacts among older people, health-promoting behaviors, including proper nutrition intake and regular exercise, should also be encouraged. Although various studies have reported the positive association between social participation and health among older people, whether their social participation relates to preventive and health-promoting behaviors during the COVID-19 pandemic was uncertain. This study examined the relationships between social participation before the COVID-19 pandemic and preventive and health-promoting behaviors during the pandemic among older people in Japan. METHODS: We obtained longitudinal data from the Japan Gerontological Evaluation Study (JAGES), which conducted baseline and follow-up surveys from November 2019 to January 2020 (pre-pandemic) and from November 2020 to February 2021 (during the pandemic) in ten municipalities. In total, 10,523 responses were analyzed. Preventive and health-promoting behaviors were measured by nine actions (e.g., wash/disinfect hands, wear masks, do exercise), and the total of these actions was divided into two (highly implemented ≥7 or not highly implemented <7). Social participation was assessed by nine activities (e.g., participating in volunteering, sports clubs, had paid work). Adjusted for covariates, we examined the relationships between each social participation and preventive and health-promoting behavior by the logistic regression analysis or the Poisson regression analysis. RESULTS: Older people who participated in social activities pre-pandemic showed a tendency to implement preventive and health-promoting behaviors during the pandemic. Especially, participations in "sports" and "Kayoi-no-ba" were positively related to "do exercise." Only "had paid work" was negatively related to highly implemented preventive and health-promoting behaviors. CONCLUSIONS: There were the positive relationships between social participation and preventive and health-promoting behavior. This study also indicated that older people who did not participate in social activities or had paid work before the COVID-19 pandemic may have higher risks of infection and secondary health impacts. Taking into account such old people's lifestyles as well as their workplace conditions, promoting appropriate behaviors need to be considered.

Strength, Carbonation Resistance, and Chloride-Ion Penetrability of Cement Mortars Containing Catechol-Functionalized Chitosan Polymer.

There have been numerous recent studies on improving the mechanical properties and durability of cement composites by mixing them with functional polymers. However, research into applying modified biopolymer such as catechol-functionalized chitosan to cement mortar or concrete is rare to the best of our knowledge. In this study, catechol-functionalized chitosan (Cat-Chit), a well-known bioinspired polymer that imitates the basic structures and functions of living organisms and biological materials in nature, was synthesized and combined with cement mortar in various proportions. The compressive strength, tensile strength, drying shrinkage, accelerated carbonation depth, and chloride-ion penetrability of these mixes were then evaluated. In the ultraviolet-visible spectra, a maximum absorption peak appeared at 280 nm, corresponding to catechol conjugation. The sample containing 7.5% Cat-Chit polymer in water (CPW) exhibited the highest compressive strength, and its 28-day compressive strength was ~20.2% higher than that of a control sample with no added polymer. The tensile strength of the samples containing 5% or more CPW was ~2.3-11.5% higher than that of the control sample. Additionally, all the Cat-Chit polymer mixtures exhibited lower carbonation depths than compared to the control sample. The total charge passing through the samples decreased as the amount of CPW increased. Thus, incorporating this polymer effectively improved the mechanical properties, carbonation resistance, and chloride-ion penetration resistance of cement mortar.

Effects of daily walking on intermuscular adipose tissue accumulation with age: a 5-year follow-up of participants in a lifestyle-based daily walking program.

PURPOSE: Intermuscular adipose tissue (IMAT) accumulates with age. However, there has been no long-term intervention study examining whether daily walking prevents or decreases the age-related IMAT accumulation. The purpose of this study was to determine effects of a long-term lifestyle-based daily walking program on age-related IMAT accumulation after a 5-year follow-up. METHODS: Using a pedometer, daily step count was evaluated for 5 years in 24 middle-aged and elderly male and female participants. Using magnetic resonance imaging, thigh muscle, thigh subcutaneous adipose tissue, IMAT, abdominal subcutaneous adipose tissue, and visceral adipose tissue were examined at baseline and after 5 years. RESULTS: After 5 years, there was no significant increase in IMAT in all participants. In addition, IMAT significantly decreased in participants with a daily step count of > 9000 (4.0 ± 2.1 vs. 3.1 ± 1.6 cm2; p < 0.05). Moreover, changes in IMAT within 5 years correlated with changes in daily step counts, even after adjusting for confounding factors (p < 0.05). CONCLUSIONS: Long-term lifestyle-based daily walking program prevented the age-related IMAT accumulation in middle-aged and elderly adults. Furthermore, increased daily walking correlated with decreased IMAT over 5 years.

Relationship between thigh intermuscular adipose tissue accumulation and number of metabolic syndrome risk factors in middle-aged and older Japanese adults.

BACKGROUND: To evaluate the association between thigh intermuscular adipose tissue accumulation and number of metabolic syndrome risk factors in middle-aged and older Japanese adults. METHODS: Thigh muscle cross-sectional area, subcutaneous adipose tissue, thigh intermuscular adipose tissue, abdominal subcutaneous adipose tissue, and visceral adipose tissue were measured in 166 middle-aged and older (mean age, 69years) Japanese adults using magnetic resonance imaging. Daily physical activity was calculated using pedometers, and energy intake per day was evaluated using 3-day dietary records. Multiple linear regression analysis was used to assess the association between intermuscular adipose tissue and the number of metabolic syndrome risk factors. RESULTS: Multiple regression analysis indicated that intermuscular adipose tissue was significantly associated with the number of metabolic syndrome risk factors, after adjusting for age, sex, body mass index, daily physical activity, energy intake, thigh muscle cross-sectional area, and visceral adipose tissue (p<0.05). CONCLUSIONS: Thigh intermuscular adipose tissue accumulation was significantly associated with the number of metabolic syndrome risk factors in middle-aged and older Japanese adults, independent of age, sex, body mass index, daily physical activity, energy intake, thigh muscle cross-sectional area, and visceral adipose tissue.