National Trends in Physical Activity Among Adults in South Korea Before and During the COVID-19 Pandemic, 2009-2021.

Importance: There is a lack of comprehensive data on the association of the COVID-19 pandemic with the prevalence of physical activity in large-scale data sets. Objective: To investigate long-term trends in physical activity using information from a nationally representative survey covering 2009 to 2021. Design, Setting, and Participants: This general population-based and repeated cross-sectional study was conducted from 2009 to 2021 using the Korea Community Health Survey, a nationally representative survey in South Korea. Data from 2009 to 2021 for 2 748 585 Korean adults were obtained through a nationwide, large-scale, serial study. Data were analyzed from December 2022 through January 2023. Exposure: COVID-19 pandemic onset. Main Outcomes and Measures: The trend of sufficient aerobic physical activity was measured by prevalence and mean metabolic equivalent of task (MET) score based on World Health Organization physical activity guidelines and defined as 600 MET-min/wk or greater. The cross-sectional survey included age, sex, body mass index (BMI), region of residence, education level, income level, smoking status, alcohol consumption level, stress status, physical activity level, and history of diabetes, hypertension, and depression. Results: Among 2 748 585 Korean adults (738 934 aged 50-64 years [29.1%] and 657 560 aged ≥65 years [25.9%]; 1 178 869 males [46.4%]), the prevalence of sufficient physical activity did not change significantly during the prepandemic period (ß difference, 1.0; 95% CI, 0.6 to 1.4). During the pandemic, the prevalence of sufficient physical activity decreased significantly, from 36.0% (95% CI, 35.9% to 36.1%) in 2017 to 2019 to 30.0% (95% CI, 29.8% to 30.2%) in 2020 and 29.7% (95% CI, 29.5% to 29.9%) in 2021. Trends showed decreases in the prevalence of sufficient physical activity among older adults (ages ≥65 years; ß difference, -16.4; 95% CI, -17.5 to -15.3) and younger adults (ages 19 to 29 years; ß difference, -16.6; 95% CI, -18.1 to -15.0) during the pandemic. In particular, the trend of sufficient physical activity declined during the pandemic in females (ß difference, -16.8; 95% CI, -17.6 to -16.0), individuals in urban residences (ß difference, -21.2; 95% CI, -22.2 to -20.2), healthy participants (eg, those with normal BMI, 18.5 to 22.9: ß difference,-12.5; 95% CI, -13.4 to -11.7), and individuals at increased risk of stress (eg, history of a depressive episode; ß difference, -13.7; 95% CI, -19.1 to -8.4). Prevalence trends in mean MET score were similar to those in the main results; total mean MET score decreased from the 2017 to 2019 period (1579.1 MET-min/wk; 95% CI, 1567.5 to 1590.7 MET-min/wk) to the 2020 to 2021 period (1191.9 MET-min/wk; 95% CI, 1182.4 to 1201.4 MET-min/wk. Conclusions and Relevance: This cross-sectional study found that the national prevalence of physical activity was stable or consistent before the pandemic period, with a marked decrease during the pandemic, particularly among healthy individuals and subgroups at increased risk of negative outcomes, including older adults, females, urban residents, and those with depressive episodes. Future studies may be needed to evaluate the association between the COVID-19 pandemic and changes in physical activity.

Usefulness of universal SARS-CoV-2 PCR testing for inpatients and their caregivers during the omicron era.

Background: Since January 2022, the Omicron variant has become the dominant strain in South Korea, and COVID-19 cases among hospitalized patients and their guardians or caregivers have increased. We evaluated the usefulness of universal periodic screening for SARS-CoV-2 in patients and resident caregivers in a South Korean tertiary care hospital. Methods: We evaluated the reason for testing in COVID-19 confirmed patients and resident caregivers during their hospitalization from March 3 to 31, 2022. The rate of positive PCR universal testing in hospital (or residency) (HD) on days 3 and 7 in asymptomatic patients and caregivers were evaluated. The test for SARS-CoV-2 was done by RT-PCR. Results: During the study period, 677 patients were diagnosed with COVID-19. The reasons for testing were the symptoms (226 (33%)), pre-admission test (183 (27%)), exposure to COVID-19 (124 (18%)), universal testing on HD 3 (94 (14%)), and that on HD 7 (34 (5%)). Caregivers (n = 340) were tested during their residency due to exposure to COVID-19 cases, 103 (30%); universal testing on HD 3, 90 (26%); symptom development, 46 (14%); pre-stay, 39 (11%); and universal testing on HD 7, 29 (9%). The positive test rates of inpatients and caregivers on HD 3 and HD 7 were as follows: 1.4% (93/6553) and 2.1% (55/2646) in inpatients, and 1.3% (79/5989) and 1.7% (35/2106) in caregivers, respectively. Conclusions: Universal testing, regardless of symptom or epidemiologic link, is useful for detecting pre-symptomatic and asymptomatic COVID-19 cases among hospitalized patients and caregivers and preventing a nosocomial outbreak during the Omicron era.

Sedentary Time and Fast-Food Consumption Associated With Weight Gain During COVID-19 Lockdown in Children and Adolescents With Overweight or Obesity.

BACKGROUND: The coronavirus disease pandemic is predicted to have adverse health effects on children and adolescents who are overweight or obese due to restricted school activity and stay-at-home orders. The purpose of this observational study was to determine the factors associated with weight gain in children and adolescents with overweight and obesity during coronavirus disease 2019 (COVID-19) lockdown. METHODS: Ninety-seven participants (sex- and age-specific body mass index (BMI) ≥ 85th percentile) were included. A baseline examination was conducted pre-COVID-19 (August 2019 to January 2020), and re-examination was performed post-lockdown (June to September 2020) and the results were compared. Correlation and regression analyses were conducted to investigate the association among changes in cardiometabolic markers and lifestyle behaviors with changes in BMI z-score. RESULTS: During the COVID-19 pandemic, an increase in BMI z-score (2.56 [2.01-2.94] to 2.62 [2.03-3.18]) was noticed in children and adolescents with obesity. Changes in cardiometabolic markers including liver enzymes, triglycerides (r = 0.398), leptin (r = 0.578), and adiponectin (r = -0.326), as well as muscular strength (r = -0.212), were correlated with the increase in BMI z-score. According to a multivariate regression analysis, changes in sedentary time (B = 0.016; 95% confidence interval [CI], 0.001-0.032) and fast-food consumption (B = 0.067; 95% CI, 0.013-0.122) were the lifestyle variables associated with BMI z-score increase. CONCLUSION: Changes in lifestyle behaviors including fast-food consumption and sedentary time during the COVID-19 pandemic may be associated with weight gain. In order to prevent health-related risks in children and adolescents with obesity during the pandemic, it is important to maintain the level of physical activity and healthy dietary habits.

Development of Optimized Vitrification Procedures Using Closed Carrier System to Improve the Survival and Developmental Competence of Vitrified Mouse Oocytes.

The open carrier system (OC) is used for vitrification due to its high efficiency in preserving female fertility, but concerns remain that it bears possible risks of cross-contamination. Closed carrier systems (CC) could be an alternative to the OC to increase safety. However, the viability and developmental competence of vitrified/warmed (VW) oocytes using the CC were significantly lower than with OC. We aimed to improve the efficiency of the CC. Metaphase II oocytes were collected from mice after superovulation and subjected to in vitro fertilization after vitrification/warming. Increasing the cooling/warming rate and exposure time to cryoprotectants as key parameters for the CC effectively improved the survival rate and developmental competence of VW oocytes. When all the conditions that improved the outcomes were applied to the conventional CC, hereafter named the modified vitrification/warming procedure using CC (mVW-CC), the viability and developmental competence of VW oocytes were significantly improved as compared to those of VW oocytes in the CC. Furthermore, mVW-CC increased the spindle normality of VW oocytes, as well as the cell number of blastocysts developed from VW oocytes. Collectively, our mVW-CC optimized for mouse oocytes can be utilized for humans without concerns regarding possible cross-contamination during vitrification in the future.