Social Detachment Influenced Muscle Mass and Strength during the COVID-19 Pandemic in Japanese Community-Dwelling Older Women

Unveiling the detrimental vicious cycle linking skeletal muscle and COVID-19: A systematic review and meta-analysis

OBJECTIVE

Skeletal muscle catabolism supports multiple organs and systems during severe trauma and infection, but its role in COVID-19 remains unclear. This study investigates the interactions between skeletal muscle and COVID-19.

METHODS

The PubMed, EMbase, and The Cochrane Library databases were systematically searched from January 2020 to August 2023 for cohort studies focusing on the impact of skeletal muscle on COVID-19 prevalence and outcomes, and longitudinal studies examining skeletal muscle changes caused by COVID-19. Skeletal muscle quantity (SMQN) and quality (SMQL) were assessed separately. The random-effect model was predominantly utilized for statistical analysis.

RESULTS

Seventy studies with moderate to high quality were included. Low SMQN/SMQL was associated with an increased risk of COVID-19 infection (OR = 1.62, p < 0.001). Both the low SMQN and SMQL predicted COVID-19-related mortality (OR = 1.53, p = 0.016; OR = 2.18, p = 0.001, respectively). Mortality risk decreased with increasing SMQN (OR = 0.979, p = 0.009) and SMQL (OR = 0.972, p = 0.034). Low SMQN and SMQL were also linked to the need for intensive care unit/mechanical ventilation, increased COVID-19 severity, and longer hospital stays. Significant skeletal muscle wasting, characterized by reduced volume and strength, was observed during COVID-19 infection and the pandemic.

CONCLUSIONS

This study reveals a detrimental vicious circle between skeletal muscle and COVID-19. Effective management of skeletal muscle could be beneficial for treating COVID-19 infections and addressing the broader pandemic. These findings have important implications for the management of future virus pandemics.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023395476.

Types and frequency of social participation and comprehensive frailty among community-dwelling older people in Japan

Although research has established social participation as important for preventing frailty in older people, the association between the type and frequency of social participation and comprehensive frailty remains unclear. This study aimed to reveal the associations between types and frequency of social participation and comprehensive frailty among community-dwelling older people. This was a cross-sectional study conducted in four cities and towns (Inabe City, Nabari City, Odai Town, and Kiho Town) of Mie Prefecture, Japan, among adults who were: (i) aged ≥65 years and (ii) not certified as needing long-term care. We measured comprehensive frailty using the participants' total scores on the Kihon Checklist, developed by Ministry of Health, Labour and Welfare of Japan, which divides frailty status into three categories: robust (0-3 points), prefrail (4-7), and frail (8-25). Types and frequency of social participation were explanatory variables, and ordered logistic regression analysis adjusted for potential confounding factors identified the associations. The frailty status of the 296 participants (age 65-74 years: 44.3 %; female: 74.0 %) was as follows: frail, 21.3 %; prefrail, 40.2 %; and robust, 38.5 %. Lower level of frailty was associated with interaction using smartphones 2-3 times per month, participating in sports ≥4 times per week, participating in local improvement activities several times per year, and engaging in activities for children 2-4 times per month. Social participation among older adults at appropriate frequencies were associated with the lower level of comprehensive frailty. However, future longitudinal studies are needed using populations from more diverse countries or regions and from different cultures.

Frailty after COVID-19: The wave after?

The COVID-19 pandemic poses an ongoing public health challenge, with a focus on older adults. Given the large number of older persons who have recovered from COVID-19 and reports of long-lasting sequelae, there is reasonable concern that the COVID-19 pandemic may lead to a long-term deterioration in the health of older adults, i.e., a potential "wave of frailty." Therefore, it is critical to better understand the circumstances surrounding the development of frailty as a result of COVID-19, as well as the underlying mechanisms and factors contributing to this development. We conducted a narrative review of the most relevant articles published on the association between COVID-19 and frailty through January 2023. Although few studies to date have addressed the effects of COVID-19 on the onset and progression of frailty, the available data suggest that there is indeed an increase in frailty in the elderly as a result of COVID-19. Regarding the underlying mechanisms, a multicausal genesis can be assumed, involving both direct viral effects and indirect effects, particularly from the imposed lockdowns with devastating consequences for the elderly: decreased physical activity, altered diet, sarcopenia, fatigue, social isolation, neurological problems, inflammation, and cardiovascular morbidity are among the possible mediators. Since the COVID-19 pandemic is leading to an increase in frailty in the elderly, there is an urgent need to raise awareness of this still little-known problem of potentially great public health importance and to find appropriate prevention and treatment measures.

Changes of Oral and Physical Functions in Older Japanese Who Participated in Keyboard Harmonica and Exercise Classes during COVID-19-Related Movement Restrictions

Many older people have restricted activities or movements because of the coronavirus disease 2019 (COVID-19) pandemic, which causes concerns about secondary health problems. This study aimed to investigate how frailty-prevention activities implemented by local governments have changed the health of community-dwelling older people during the COVID-19 pandemic. In this observational study, the participants were 23 older Japanese people who took part in keyboard harmonica or exercise classes in 2021. Oral function examination and physical function tests were conducted at baseline and after 10 months of follow-up. In each class, the participants met 15 times and worked on assignments at home. The results showed that oral diadochokinesis/pa/, which represents lip dexterity, improved during 10 months (from 6.6 to 6.8 times/s, p < 0.046); however, grip strength (p < 0.005) and total skeletal muscle mass (p < 0.017) decreased in the keyboard harmonica group. In the exercise group, a statistically significant difference was found only in grip strength, which decreased (p < 0.003). The oral and physical functions of older people who participated in frailty-prevention activities implemented by local governments characteristically changed. Moreover, activity restrictions during the COVID-19 pandemic may have caused decreased grip strength.

Association between Prevention from Going Out and Incidence of Falls among Community-Dwelling Older Adults during COVID-19 Pandemic

To prevent falls, community-dwelling older adults must maintain regular physical activities. This study aimed to explore the association between the prevention from going out and the incidence of falls among community-dwelling older adults during the COVID-19 pandemic. We conducted a prospective cohort study that consisted of 381 individuals aged 65 years or older, living in a local community in Japan, and ranging from being independent to being physically and cognitively frail. The finding revealed that among those who had been going out five or more times weekly pre-pandemic, the prevention from going out at the time of the first state of emergency (SOE) (AOR = 6.84; 95%CI = 1.51-31.02), having history of falls (AOR = 7.35; 95%CI = 1.81-29.84), participating in group gatherings (AOR = 6.09; 95%CI = 1.48-25.12), living with spouses (AOR = 0.08; 95%CI = 0.02-0.40), and living with other than spouse (AOR = 0.15; 95%CI = 0.03-0.73) were associated with the incidence of falls. The study highlights the importance of providing regular opportunities to go out to community-dwelling older adults in order to prevent falls.

Characteristics of Japanese Older Adults Whose Trunk Muscle Mass Decreased during the COVID-19 Pandemic

The coronavirus (COVID-19) pandemic significantly affected the physical and mental functions in older adults, resulting in "corona-frailty". This 2-year prospective study characterized changes in quantitative measures and corona-frailty among a cohort of community-dwelling older women. Changes were evaluated using face-to-face interactions with 39 Japanese women (mean age: 76.1 ± 5.9) in 2019 (pre-pandemic baseline) and 2021 (follow-up during the pandemic). Quantitative measurements of handgrip strength, walking speed, calf circumference, body composition, and background factors were evaluated. Body weight and trunk muscle mass significantly decreased at follow-up. Multiple regression analysis, using change in trunk muscle mass as the dependent variable and background factors as independent variables, identified that decrease in trunk muscle mass was associated with "being robust at baseline" and answering "Yes" to the question of "Do you go out less frequently compared with last year"? The 2-year trunk muscle mass change for each baseline frailty stage showed a significant decrease only in the robust group (-8.0%). The decrease in trunk muscle mass might be related to pandemic-induced lifestyle restraint, suggesting that robust older adults who are healthy and active should take measures that focus on trunk muscles to avoid "corona-frailty".