Association between accelerometer-derived physical activity and depression: a cross-sectional study using isotemporal substitution analysis.

OBJECTIVES: Depression is a significant public health concern, and physical activity has been identified as a non-pharmacological intervention. Understanding the dose-response relationship between physical activity and depression is crucial for designing effective exercise interventions and recommending physical activity to individuals with depression. The isotemporal substitution model is considered the gold standard for estimating the dose-response effects of physical activity. This study aims to investigate the dose-response association between depression and accelerometer-measured physical activity in the Korean population. DESIGN: Cross-sectional analysis. SETTING: A non-probability sample of the community population was drawn from the 2014 and 2016 Korean National Health and Nutrition Examination Survey. PARTICIPANTS: The study included 1543 adults aged 19-64 years who completed the Patient Health Questionnaire-9 (PHQ-9) and volunteered to wear an accelerometer. MAIN OUTCOME MEASURES: Physical activity was measured using a GT3X+ accelerometer for 7 consecutive days, and activity was categorised as sedentary behaviour (SB) or light, moderate or vigorous physical activity. Depression was assessed using the PHQ-9. RESULTS: Physical activity and SB were associated with depression. In the single-parameter model, moderate-vigorous physical activity (MVPA) showed a significant association with reduced odds of depression (OR: 0.817, 95% CI: 0.678 to 0.985). Substituting 30 min of SB with 30 min of MVPA (OR: 0.815, 95% CI: 0.669 to 0.992) was linked to a decrease in the odds of depression. Conversely, replacing 30 min of MVPA with 30 min of SB (OR: 1.227, 95% CI: 1.008 to 1.495) was associated with an increase in the odds of depression. CONCLUSIONS: This study provides evidence of an association between physical activity and depression in the Korean population, highlighting the importance of reducing SB and increasing MVPA to prevent and manage depression. Further research is needed to confirm causality and determine optimal levels of physical activity for preventing depression in different populations.

Association between depression, anemia and physical activity using isotemporal substitution analysis.

BACKGROUND: Depression is a leading cause of disability and mortality, with estimated number of deaths exceeding 2.2 million worldwide. We examined depression in relation to anemia and physical activity, both of which have an impact on depression mechanisms. METHODS: This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey, including 18,622 participants. Depression was measured by The Patient Health Questionnaire-9, and physical activity was assessed by the Global Physical Activity Questionnaire. Anemia was defined by World Health Organization criteria for blood hemoglobin levels. Isotemporal substitution model for physical activity was used to assess the effect of replacing sedentary behavior to each intensity level of physical activity. Logistic regression was applied to estimate the association on depression. RESULTS: Replacing sedentary behavior with moderate or vigorous physical activity was associated with a lower risk of depression in the anemic (OR: 0.875, 95% CI: 0.782-0.978) and non-anemic groups (OR: 0.943, 95% CI: 0.919-0.967). Depression risk was significantly reduced by replacing walking with moderate to vigorous physical activity in both anemic (OR: 0.877, 95% CI: 0.784-0.982) and non-anemic groups (OR: 0.951, 95% CI: 0.927-0.976). CONCLUSIONS: Moderate to vigorous physical activity had a protective association against depression in both anemic and non-anemic groups. Anemic patients are recommended to perform physical activity for any duration acceptable to them to prevent depression.

Association between tobacco industry advertising expenses and tobacco advertising exposure among Korean adolescents.

INTRODUCTION: Monitoring the activities and impacts of tobacco industries is vital for tobacco control. Based on tobacco industry financial statements and a nationally representative survey of Korean adolescents, we examined the association between tobacco industry commercial advertising expenses and advertising exposure among Korean adolescents. METHODS: The commercial advertising expenses of three major tobacco industries in Korea (KT&G, Philip Morris Korea, and British and American Tobacco Korea) were identified in a repository (Data Analysis Retrieval and Transfer System) established by the Korean Financial Supervisory Service. The yearly advertising expenses were merged with data from the Korean Youth Risk Behavior Survey (2015-2018 and 2021, total N=309 190). We used logistic regression analyses to analyse the associations between tobacco industry advertising expenses and adolescent tobacco advertisement exposure. RESULTS: In 2021, the total advertising expenses of the three companies exceeded US$260 million, and the proportion of Korean adolescents exposed to tobacco advertisements ranged from 65.9% to 78.7% during 2015-2018 and 2021. Higher advertising expense sizes were associated with the risk of exposure to tobacco advertisements in both girls and boys, with OR of 1.009 (95% CI (1): 1.008 to 1.010) and 1.010 (95% CI: 1.009 to 1.011), respectively. CONCLUSION: Tobacco industry advertising expenses are associated with tobacco marketing exposure among adolescents. We used financial data to identify the reach of tobacco advertising among Korean adolescents. It is essential to increase tobacco industry surveillance using various data sources and to regulate tobacco advertising more strongly.

Association of Deforestation With Severe Fever With Thrombocytopenia Syndrome.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) virus was first isolated in China in 2009 and has since spread to several Asian countries. SFTS is closely related to environmental factors that accelerate vector growth. We evaluated the associations of SFTS and deforestation with environmental variables. METHODS: For this observational study, we generated multiple Poisson models using national SFTS outbreak data (2013-2018) and official environmental data for Korea. We included established risk factors as variables. Deforestation was used as the main variable. All variables were analyzed according to their spatial characteristics using the R-INLA package. RESULTS: SFTS cases increased over time and peaked in 2017, at 272, followed by a decrease in 2018. Disease mapping showed a high incidence of SFTS nationwide, with particular risks in Gangwon and Gyeonggi Provinces in the north, and Jeju in the south of South Korea. Deforestation was significantly associated with a higher risk of SFTS in the final model (relative risk, 1.751 [95% confidence interval, 1.125-2.743]). CONCLUSIONS: SFTS outbreaks are associated with deforestation. Therefore, deforestation in Gyeonggi, Gangwon, and Jeju provinces of South Korea needs to be considered in vector-control strategies and active surveillance of SFTS occurrence.

Tobacco consumption, sales, and output as monitoring indicators in the era of the tobacco endgame: a Korean example.

OBJECTIVES: The consumption, sales, and output of tobacco products each suggest different areas of intervention for tobacco control. In the era of the tobacco endgame, as increasingly stronger supply-side measures are implemented, multifaceted indicators that assess both supply and/or demand are required. We aimed to estimate the consumption of cigarette and heated tobacco products (HTPs) and sought agreement between the various indicators. METHODS: The annual cigarette and HTP consumption in 2014-2020 was calculated using the frequency and intensity of cigarette use from representative surveys of adults and adolescents by sex and age. Sales and output data were acquired from governmental sources. Spearman correlation coefficients and Bland-Altman plots were used to compare the indicators. RESULTS: Tobacco output, cigarette sales, and cigarette consumption were greatest in 2014. The HTP consumption calculated for 2020 was 292.28 million packs. Cigarette consumption and sales correlated significantly, as did tobacco output and tobacco sales. A Bland-Altman plot comparing the difference between cigarette consumption and sales showed that this difference was largest in 2014, immediately before cigarette prices increased. With the exception of a single year, all cigarette consumption values were within the limits of agreement for cigarette sales and tobacco output. CONCLUSIONS: Our analyses showed agreement between demand-side (tobacco consumption) and supply-side (sales and output) indicators. We recommend using all indicators to monitor the impacts of tobacco control on both demand and supply sides. The systematic use of various indicators is critical to achieve the end of the tobacco epidemic.

Associations of symptom combinations with in-hospital mortality of coronavirus disease-2019 patients using South Korean National data.

BACKGROUND: There are various risk factors for death in coronavirus disease-2019 (COVID-19) patients. The effects of symptoms on death have been investigated, but symptoms were considered individually, rather than in combination, as predictors. We examined the effects of symptom combinations on in-hospital mortality. METHODS: Data from the Korea Disease Control and Prevention Agency were analyzed. A cohort of 5,153 patients confirmed with COVID-19 in South Korea was followed from hospitalization to death or discharge. An exploratory factor analysis was performed to identify symptom combinations, and the hazard ratios (HRs) of death were estimated using the Cox proportional hazard model. RESULTS: Three sets of symptom factors were isolated for symptom combination. Factor 1 symptoms were cold-like symptoms, factor 2 were neurological and gastrointestinal symptoms, and factor 3 were more severe symptoms such as dyspnea and altered state of consciousness. Factor 1 (HR 1.14, 95% confidence interval [95% CI] 1.01-1.30) and factor 3 (HR 1.25, 95% CI 1.19-1.31) were associated with a higher risk for death, and factor 2 with a lower risk (HR 0.71, 95% CI 0.71-0.96). CONCLUSIONS: The effect on in-hospital mortality differed according to symptom combination. The results are evidence of the effects of symptoms on COVID-19 mortality and may contribute to lowering the COVID-19 mortality rate. Further study is needed to identify the biological mechanisms underlying the effects of symptom combinations on mortality.

The Unequal Effects of Social Distancing Policy on Subway Ridership during the COVID-19 Pandemic in Seoul, South Korea.

In the Republic of Korea, social distancing policies relied on voluntary participation by citizens and exhibited short-term changes. In this situation, the effects of such policies varied depending on each community's capacity to comply. Here, we collected subway ridership data for 294 stations on nine Seoul Metro lines and aggregated the data for each station to the 184 smallest administrative areas. We found that the mean percent change in subway ridership was fitted by an additive model of the log-transformed percent ratio of the restaurant industry (estimated degrees of freedom (EDF) = 3.24, P < 0.001), the Deprivation Index (DI) (EDF = 3.66, P = 0.015), and the proportion of essential workers (ß = - 0.10 (95% confidence interval - 0.15 to - 0.05, P < 0.001). We found a distinct decrease in subway ridership only in the least deprived areas, suggesting that social distancing is costly.