How does the weekend catch-up sleep ratio affect the health and lifestyle of Korean adults? An age- and sex- matched study

The purpose of this study was to investigate the association between various levels of physical activity, self-perception, cardiometabolic risk factors, and weekend catch-up sleep ratio (CSR). Using raw data from the Korea National Health and Nutrition Examination Survey 2018 – 2021, all participants were divided into three groups (< 1.0, 1.0 ≤ CSR < 1.5, or ≥ 1.5) by CSR, which is the value calculated by dividing weekend sleep time by weekday sleep time. After matching age and sex, 2,484 Korean adults were selected as study participants. Descriptive statistics, chi-square test, ANOVA, and multinomial logistic regression analysis were performed to analyze the data. The results showed a significant association between weekend CSR and socioeconomic status, physical activity, self-perception levels, and cardiometabolic risk factors. Specifically, compared to the reference group (1 ≤ CSR < 1.5), those with a CSR < 1 were 2.42 times more likely to live in a single-family house (OR = 2.42, 95% CI = 1.77 – 3.32) and 1.71 times more likely to engage in vigorous physical activity meeting WHO guidelines (OR = 1.71, 95% CI = 1.20 – 2.46). They were also 1.33 times more likely to perceive themselves as 'obese' (OR = 1.33, 95% CI = 1.00 – 1.76). Conversely, those in the CSR ≥ 1.5 group were 3.93 times more likely to be 'pink-collar' workers (OR = 3.93, 95% CI = 2.70 – 5.71), 1.72 times more likely to perceive their stress levels as 'quite' (OR = 1.72, 95% CI = 1.20 – 2.47), and 1.87 times more likely to have diabetes (OR = 1.87, 95% CI = 0.97 – 3.60). Alterations in CSR could indicate changes in physical activity levels, sedentary behavior duration, and other health indicators, ultimately influencing overall well-being. Therefore, a comprehensive healthcare approach incorporating CSR considerations is increasingly essential.

Methods
This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) during 2018 – 2021. The KNHANES is a comprehensive national survey implemented across South Korea. Its primary objective is to consistently accumulate data annually encompassing various elements, including sociodemographic indicators, economic status, and health-related characteristics and behaviors across all age demographics. Since 2007, this body of data has undergone review and received an annual endorsement by the Research Ethics Review Committee from the Korea Centers for Disease Control and Prevention Agency (KDCA). The KNHANES data is an open-access resource for scholars, enabling further exploratory analysis and research in numerous fields.

The KNHANES for 2018 – 2021 was conducted with 30,551 respondents. However, 5,616 individuals under 20 years were excluded from the data to align with the research parameters. In addition, participants who did not respond to the critical variables under examination were also eliminated from consideration. The remaining participants were classified into three distinct groups according to their CSR (Group A: CSR < 1, Group B: 1 ≤ CSR < 1.5, Group C: 1.5 ≤ CSR). These groups contained Group A=1,112, Group B=18,743, and Group C=1,233 participants, respectively. Then, we matched participants based on age and sex, using the group A, which had the smallest sample size as the reference group. As a result of this stringent selection process, a balanced cohort of 828 participants from each group was extracted, resulting in a total study sample of 2,484 individuals.

本研究旨在探讨不同强度体力活动、自我认知、心血管代谢危险因素与周末补觉率（catch-up sleep ratio, CSR）之间的关联。本研究使用2018-2021年韩国国民健康与营养检查调查（Korea National Health and Nutrition Examination Survey, KNHANES）的原始数据，以周末睡眠时间与工作日睡眠时间的比值作为CSR的计算值，将所有参与者按CSR划分为三组（<1.0、1.0≤CSR<1.5或≥1.5）。在进行年龄与性别匹配后，最终纳入2484名韩国成年人为研究对象。本研究采用描述性统计、卡方检验、方差分析以及多项逻辑回归分析对数据进行处理。结果显示，周末CSR与社会经济地位、体力活动水平、自我认知状态及心血管代谢危险因素存在显著关联。具体而言，以参照组（1≤CSR<1.5）为基准，CSR<1组人群居住在独栋住宅的风险是参照组的2.42倍（优势比OR=2.42，95%置信区间CI=1.77–3.32），达到世界卫生组织（World Health Organization, WHO）推荐标准的高强度体力活动参与率是参照组的1.71倍（OR=1.71，95%CI=1.20–2.46），自我感知为“肥胖”的概率是参照组的1.33倍（OR=1.33，95%CI=1.00–1.76）。与之相反，CSR≥1.5组人群从事“粉领”工作的概率是参照组的3.93倍（OR=3.93，95%CI=2.70–5.71），自我感知压力水平为“较高”的概率是参照组的1.72倍（OR=1.72，95%CI=1.20–2.47），患糖尿病的概率是参照组的1.87倍（OR=1.87，95%CI=0.97–3.60）。CSR的变化可反映体力活动水平、久坐行为时长及其他健康指标的改变，最终影响整体健康状况。因此，纳入CSR考量的综合医疗保健方案愈发重要。

### 研究方法
本项横断面研究使用了2018-2021年韩国国民健康与营养检查调查（KNHANES）的数据。KNHANES是在韩国全国范围内开展的综合性国民调查，其核心目标是每年持续积累涵盖社会人口学指标、经济状况以及各年龄层人群健康相关特征与行为等多方面的数据。自2007年起，该数据集每年均通过韩国疾病控制与预防厅（Korea Centers for Disease Control and Prevention Agency, KDCA）的研究伦理审查委员会审核并获得认可。KNHANES数据面向学者开放获取，可用于众多领域的探索性分析与研究。

2018-2021年的KNHANES共回收30551份有效问卷。为契合本研究的研究范围，本研究首先排除了5616名20岁以下的受试者。此外，未对关键研究变量作出回应的参与者也被剔除。剩余参与者按照CSR划分为三个组别：A组（CSR<1）、B组（1≤CSR<1.5）、C组（≥1.5），三组参与者人数分别为1112人、18743人和1233人。随后，本研究以样本量最小的A组为参照组，基于年龄与性别进行匹配。经过严格的筛选流程，最终从每个组别中提取出828名匹配成功的受试者，总研究样本量为2484人。