한국 성인의 수면 시간, 취침 시각, 그리고 사회적 시차가 비만에 미치는 영향 = The effects of sleep duration, sleep timing, and social jet lag on obesity among South Korean adults

다국어 초록 (Multilingual Abstract)

Background: Obesity, recognized as a disease by the World Health Organization (WHO) in 1998 and declared a global epidemic in 2000, has become a significant public health concern. In South Korea, the increasing prevalence of adult obesity and its associated socioeconomic burden have emerged as critical public health challenges. While previous studies have demonstrated associations between obesity and multiple sleep parameters, including sleep duration, sleep timing, and social jetlag, comprehensive research examining these multiple sleep-related factors remains limited. Therefore, this study aimed to examine the associations between obesity and multiple sleep parameters, including sleep duration, sleep timing, and social jetlag.

Methods: This cross-sectional study analyzed data from the 2021 Korea National Health and Nutrition Examination Survey (KNHANES). Of 7,090 initial participants, 5,192 adults were included in the final analysis after applying exclusion criteria: those under 19 years (n=719) and participants with incomplete data on key variables (n=41). Obesity was operationalized through Body Mass Index (BMI), calculated as weight (kg) divided by height (m²). Sleep parameters were assessed via self-reported questionnaires: sleep duration was stratified into four clinically relevant categories (<6, 6-<7, 7-<8, and ≥8 hours), and sleep timing was classified into three distinct periods (02:00-19:59, 20:00-23:59, and 00:00-01:59). Social jetlag was quantified as the differential between mid-sleep times on working and non-working days, categorized into three groups (0, 0<!-- Not Allowed Tag Filtered --><SJL><2, and ≥2 hours). Data were analyzed using SPSS (version 26.0), with statistical significance established at p<0.05.

Results : Approximately 19.4% of males and 19.7% of females reported sleeping less than six hours. The proportion of participants with late bedtime (00:00-01:59) was 37.6% for males and 41.3% for females. Social jetlag of two or more hours was observed in 7.5% of males and 5.4% of females. Obesity prevalence differed by gender, with 42.0% in males and 31.0% in females. After adjusting for demographic characteristics, health behaviors, disease history, and mental health, significant associations between sleep parameters and obesity emerged. Women sleeping less than six hours demonstrated a statistically significant association with obesity (Adjusted Odds Ratio [AOR]: 1.443, 95% Confidence Interval [CI]: 1.113–1.871). Young adult women with bedtime between 00:00-01:59 showed a significant association with obesity after controlling for confounding variables and sleep duration (AOR: 1.667, 95% CI: 1.000–2.812). Participants with social jetlag of two or more hours exhibited notable obesity risks. After adjusting for confounding variables, sleep duration, and bedtime, middle-aged men (AOR: 2.352, 95% CI: 1.214–4.555) and women (AOR: 1.606, 95% CI: 1.087–2.372) showed significant associations. Particularly, middle-aged women with substantial social jetlag demonstrated the highest obesity risk (AOR: 3.432, 95% CI: 1.717–6.858).

Conclusions : In this study, sleep duration less than 6 hours and social jet lag exceeding two hours emerged as significant risk factors for obesity among females. Lifecycle analysis revealed that female young adults with bedtime between 00:00-01:59 demonstrated increased obesity risk. Among middle-aged groups, social jet lag of two or more hours significantly elevated obesity prevalence in both males and females, with the most pronounced association observed in middle-aged women. These findings underscore the necessity of developing targeted public health intervention strategies that account for gender and lifecycle variations. The research highlights sleep circadian rhythm management as a potential key intervention strategy for chronic disease prevention, particularly emphasizing the importance of personalized health management approaches for middle-aged women.

Keywords : Obesity, Sleep duration, Timing of sleeping, Social jet lag

목차 (Table of Contents)

• Ⅰ. 서론 3
• 1. 연구 배경 및 필요성 3
• 2. 연구 목적 6
• 3. 문헌 고찰 6
• 1) 수면 시간
• 2) 취침 시각
• 3) 사회적 시차
• Ⅱ. 연구 방법 10
• 1. 연구 설계 10
• 2. 연구 자료 11
• 3. 연구 대상 11
• 4. 분석 변수 12
• 1) 종속 변수 12
• 2) 독립 변수 12
• 3) 통제 변수 13
• (1) 인구사회학적 변수
• (2) 건강행태 변수
• (3) 정신건강 변수
• (4) 질병력 변수
• 5. 통계 분석 방법 15
• 6. 생명윤리 15
• Ⅲ.연구 결과 16
• 1. 연구대상자들의 일반적인 특성 16
• 2. 연구대상자들의 비만과 수면의 특성 21
• 3. 연구대상자들의 성별 및 연령층별 수면 변수에 따른 BMI 분포 27
• 4. 연구대상자들의 수면 변수와 비만의 연관성 39
• Ⅳ. 논의 52
• 1. 수면 시간 52
• 2. 취침 시각 54
• 3. 사회적 시차 55
• Ⅴ. 결론 58
• 참고문헌 59
• ABSTRACT 63
• 부록 66