National trends in physical activity among adolescents in South Korea before and during the COVID-19 pandemic, 2009-2021.

With the ongoing COVID-19 pandemic, several previous studies from different countries showed that physical activity (PA) decreased during the COVID-19 outbreak. However, few studies have examined the recent tendency of PA in the adolescent population. Thus, we aimed to investigate the long-term trend of PA in Korean youth and the prevalence changes between before and during the COVID-19 pandemic. Data from Korea Youth Risk Behavior Web-Based Survey (KYRBS) was collected for consecutive years between 2009 and 2021. The period was separated into prepandemic (2009-2019), early-pandemic (2020), and mid-pandemic (2021). Self-reported amount of PA was categorized into four groups (insufficient, aerobic, muscle strengthening, and both physical activities) according to World Health Organization (WHO) PA guidelines. A total of 840 488 adolescents aged 12-18 who fully responded to the survey were selected (response rate: 95.2%). The 13-year trends in the proportion of adolescents who reported aerobic and muscle-strengthening activities met or exceeded 2020 WHO exercise guidelines for adolescents plateaued (11.9% from 2009 to 2011, 14.2% from 2018 to 2019, 14.4% from 2020, and 14.0% from 2021); however, the slope decreased during the pandemic (ßdiff , -0.076; 95% confidence interval [CI], -0.123 to -0.029). Proportion of sufficient aerobic exercise among adolescents sharply decreased midst the pandemic (28.0% from 2009 to 2011, 29.4% from 2018 to 2019, and 23.8% from 2020; ßdiff , -0.266; 95% CI, -0.306 to -0.226) but increased again in 2021 (26.0% from mid-COVID 19; 95% CI, 25.4-26.7). Similar patterns were observed in Metabolic Equivalent Task (MET) score (MET-min/week; 804.1 from 2018 to 2019, 720.9 from 2020, and 779.6 from 2021). The mean difference in MET score between pre-COVID and post-COVID was -55.4 MET-min/week (95% CI, -70.5 to -40.3). Through a nationwide representative study, there was no significant difference with regard to the number of Korean adolescents who achieved the PA guidelines (pre and postpandemic); however, the prevalence of recommended levels of PA needs to increase more based on the trend before the COVID-19 outbreak. The findings of this study suggest reinforcement of the importance of public health policies for Korean youths to be more physically active, especially during and after the pandemic.

Estimated prevalence and trends in smoking among adolescents in South Korea, 2005-2021: a nationwide serial study.

BACKGROUND: Although smoking is classified as a risk factor for severe COVID-19 outcomes, there is a scarcity of studies on prevalence of smoking during the COVID-19 pandemic. Thus, this study aims to analyze the trends of prevalence of smoking in adolescents over the COVID-19 pandemic period. METHODS: The present study used data from middle to high school adolescents between 2005 and 2021 who participated in the Korea Youth Risk Behavior Web-based Survey (KYRBS). We evaluated the smoking prevalence (ever or daily) by year groups and estimated the slope in smoking prevalence before and during the pandemic. RESULTS: A total of 1,137,823 adolescents participated in the study [mean age, 15.04 years [95% confidence interval (CI) 15.03-15.06]; and male, 52.4% (95% CI 51.7-53.1)]. The prevalence of ever smokers was 27.7% (95% CI 27.3-28.1) between 2005 and 2008 but decreased to 9.8% (95% CI 9.3-10.3) in 2021. A consistent trend was found in daily smokers, as the estimates decreased from 5.4% (95% CI 5.2-5.6) between 2005 and 2008 to 2.3% (95% CI 2.1-2.5) in 2021. However, the downward slope in the overall prevalence of ever smokers and daily smokers became less pronounced in the COVID-19 pandemic period than in the pre-pandemic period. In the subgroup with substance use, the decreasing slope in daily smokers was significantly more pronounced during the pandemic than during the pre-pandemic period. CONCLUSIONS: The proportion of ever smokers and daily smokers showed a less pronounced decreasing trend during the pandemic. The findings of our study provide an overall understanding of the pandemic's impact on smoking prevalence in adolescents. Supplementary file2 (MP4 64897 KB).

National trends in alcohol and substance use among adolescents from 2005 to 2021: a Korean serial cross-sectional study of one million adolescents.

BACKGROUND: Although previous studies have provided data on early pandemic periods of alcohol and substance use in adolescents, more adequate studies are needed to predict the trends of alcohol and substance use during recent periods, including the mid-pandemic period. This study investigated the changes in alcohol and substance use, except tobacco use, throughout the pre-, early-, and mid-pandemic periods in adolescents using a nationwide serial cross-sectional survey from South Korea. METHODS: Data on 1,109,776 Korean adolescents aged 13-18 years from 2005 to 2021 were obtained in a survey operated by the Korea Disease Control and Prevention Agency. We evaluated adolescents' alcohol and substance consumption prevalence and compared the slope of alcohol and substance prevalence before and during the COVID-19 pandemic to see the trend changes. We define the pre-COVID-19 period as consisting of four groups of consecutive years (2005-2008, 2009-2012, 2013-2015, and 2016-2019). The COVID-19 pandemic period is composed of 2020 (early-pandemic era) and 2021 (mid-pandemic era). RESULTS: More than a million adolescents successfully met the inclusion criteria. The weighted prevalence of current alcohol use was 26.8% [95% confidence interval (CI) 26.4-27.1] from 2005 to 2008 and 10.5% (95% CI 10.1-11.0) in 2020 and 2021. The weighted prevalence of substance use was 1.1% (95% CI 1.1-1.2) from 2005 to 2008 and 0.7% (95% CI 0.6-0.7) between 2020 and 2021. From 2005 to 2021, the overall trend of use of both alcohol and drugs was found to decrease, but the decline has slowed since COVID-19 epidemic (current alcohol use: ßdiff 0.167; 95% CI 0.150-0.184; substance use: ßdiff 0.152; 95% CI 0.110-0.194). The changes in the slope of current alcohol and substance use showed a consistent slowdown with regard to sex, grade, residence area, and smoking status from 2005 to 2021. CONCLUSION: The overall prevalence of alcohol consumption and substance use among over one million Korean adolescents from the early and mid-stage (2020-2021) of the COVID-19 pandemic showed a slower decline than expected given the increase during the prepandemic period (2005-2019).

Risk of Diabetes in Patients with Long-Standing Graves' Disease: A Longitudinal Study.

BACKGROUND: The detrimental effects of excessive thyroid hormone on glucose metabolism have been widely investigated. However, the risk of diabetes in patients with long-standing hyperthyroidism, especially according to treatment modality, remains uncertain, with few longitudinal studies. METHODS: The risk of diabetes in patients with Graves' disease treated with antithyroid drugs (ATDs) for longer than the conventional duration (≥2 years) was compared with that in age-and sex-matched controls. The risk was further compared according to subsequent treatment modalities after a 24-month course of ATD: continuation of ATD (ATD group) vs. radioactive iodine ablation (RIA) group. RESULTS: A total of 4,593 patients were included. Diabetes was diagnosed in 751 (16.3%) patients over a follow-up of 7.3 years. The hazard ratio (HR) for diabetes, after adjusting for various known risk factors, was 1.18 (95% confidence interval [CI], 1.10 to 1.28) in patients with hyperthyroidism. Among the treatment modality groups, the RIA group (n=102) had a higher risk of diabetes than the ATD group (n=4,491) with HR of 1.56 (95% CI, 1.01 to 2.42). Further, the risk of diabetes increased with an increase in the ATD treatment duration (P for trend=0.019). CONCLUSION: The risk of diabetes was significantly higher in patients with long-standing Graves' disease than in the general population, especially in patients who underwent RIA and prolonged ATD treatment. Special attention to hyperglycemia during follow-up along with effective control of hyperthyroidism may be necessary to reduce the risk of diabetes in these patients.

Overwork-related disorders and recent improvement of national policy in South Korea.

OBJECTIVES: Recently, overwork-related disorders have become a major public health concern in Korea. This study investigated the current trends of working hours, causes of death in the working population, and compensation rates. METHODS: We reviewed the current trends of working hours, cause of death statistics in the working population, industrial accident compensation insurance (IACI) statistics, issues of compensation and prevention of work-related cerebro-cardio vascular diseases (CCVDs), mental disorders, and suicide. RESULTS: Although weekly working hours and the proportion of long working days have decreased, workers in small companies with fewer than five employees and those in the service sector continue to work long hours. The age standardized mortality due to CCVD and suicide was highest among those with managerial roles. In total, 589 CCVD cases and 104 mental disorder or suicide cases were compensated as occupational diseases in 2017. Between 2016 and 2017, 61% of 59 compensated suicides were related to overwork, specifically: long working hours, increased responsibility, or increased workload. The Korean government has introduced various policies to reduce working hours and to increase compensation approval rate for overwork-related CCVDs. Stakeholders have called for the introduction of independent laws to prevent overwork-related disorders, change organizational culture, and address the blind spots of the IACI Act and Labor Standard Act. CONCLUSIONS: Prevention and compensation policies have improved working conditions in Korea, but there remains much to be done. This review significantly contributes to the understanding of the overall policies and research to prevent overwork-related disorders in Korea.

Herceptin-conjugated temperature-sensitive immunoliposomes encapsulating gemcitabine for breast cancer.

Gemcitabine (2',2'-difluorodeoxycytidine, GCT) is an analog of deoxycytidine with cytotoxicity for breast cancer cells. However, because of its hepatotoxicity and other side effects, an efficient drug delivery system is needed for better therapeutic outcomes. A temperature-sensitive PEGylated immunoliposome (TSL) with trastuzumab (or Herceptin) attached encapsulating GCT (Her-PEG-TSL-GCT) was prepared. The mean diameter of the liposome was about 200 nm and the prepared immunoliposome showed the capacity to deliver the payload to the hyperthermic environment. The actual number of antibody molecules attached to one single liposome is about 19, with the GCT encapsulation efficiency of 54.6 ± 3.50 %. This immunoliposome shows a temperature-dependent drug release at around 41-43 °C. Anticancer activity of Her-PEG-TSL-GCT was determined using HER-2 expressing breast cancer cells, SK-BR-3, in vitro and resulted in increased cytotoxicity compared to free GCT (IC20 11.7 nM) or conventional liposome lacking the targeting antibody. In conclusion, these data show that improved delivery of GCT to breast cancer cells can be achieved by Her-PEG-TSL-GCT in vitro, and this strategy could be used for breast cancer therapy with further studies.