kjhp Korean Journal of Health Promotion Korean J Health Promot 2234-2141 2093-5676 The Korean Society of Health Promotion and Disease Prevention 10.15384/kjhp.2015.15.1.16 kjhp-15-16 Original Article Association between Sleep Duration and Body Mass Index among South Korean Adolescents LeeBokim Department of Nursing, University of Ulsan College of Medicine, Ulsan, Korea ￭ Corresponding author：Bokim Lee, PhD Department of Nursing, University of Ulsan College of Medicine, 93 Daehak-ro, Nam-gu, Ulsan 680-749, Korea Tel: +82-52-259-1283, Fax: +82-52-259-1236 E-mail: bokimlee@ulsan.ac.kr 122015 19122015 151 1623 12062014 28112014 Copyright © 2015 The Korean Society of Health Promotion and Disease Prevention 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Background

Recently, there has been a growing interest in sleep duration as a risk factor for obesity. The link between sleep duration and obesity has been well established in adults, but there are limited studies in adolescents. Also, little research had been done involving South Korean adolescents. This study aimed to investigate the relationship between sleep duration and body mass index in South Korea adolescents.

 Methods

This was a secondary analysis of the data collected from the 2013 Korean Youth Risk Behavior Web-based Survey. The sample included 59,367 adolescents. The questionnaires used for this study assessed gender, age, mother's education level, academic performance, smoking, alcohol use, eating behaviors, physical activity, duration of internet use, perceived stress level, and perceived health status. Data were analyzed with χ²-test, ANOVA, and logistic regression analysis using SPSS Version 21.

 Results

The percentage of obese subjects was the greatest among respondents reporting less than 5 h of sleep (11.0%) and the lowest among those reporting 8 or more hours of sleep (8.4%). In the results of logistic regression analysis, compared with sleep duration of 8h or more, the adjusted odds ratio was 1.11 for 7-8 h, 1.19 for 6-7 h, 1.19 for 5-6 h, and 1.19 for <5 h of sleep, with other factors controlled.

 Conclusions

The results of this study showed that a shortsleep duration is significantly associated with obesity among South Korea adolescents. In managing obesity in this population, health professionals should attend to how much sleep they are getting.

 Adolescent Body mass index Sleep REFERENCES Jee SH Pastor-Barriuso R Appel LJ Suh I Miller III ER Guallar E Body mass index and incident ischemic heart disease in South Korean men and women Am J Epidemiol 20051621 428 Ministry of Health and Welfare, Korea Centers for Disease Control and Prevention Korea Heatlh Statistics 2012: Korea National Health and Nutrition Examination Survey (KNHANES V-3) Seojong Ministry of Health and Welfare 2013 p.52. Korea Ministry of Education, Korean Ministry of Health and Welfare, & Korea Centers for Disease Control and Prevention 2013 Korean Youth Risk Behavior Web-Based Survey statistics Seoul KCDC 2014 1745 Kiess W Galler A Reich A Müller G Kapellen T Deutscher J Clinical aspects of obesity in childhood and adolescence Obes Rev 200121 2936 Brooks-Gunn J Fink C Paxson C Obesity. In: Gullotta TP & Adams GR (Eds.), Handbook of adolescent behavioral problems: Evidence-based approaches to prevention and treatment NY Springer 2005 387412 Spiegel K Tasali E Penev P Van Cauter E Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite Ann Intern Med 200414111 84650 Chen MY Wang EK Jeng YJ Adequate sleep among adolescents is positively associated with health status and health-related behaviors BMC Public Health 20066 59 Seicean A Redline S Seicean S Kirchner HL Gao Y Sekine M Storfer-Isser, Association between short sleeping hours and overweight in adolescents: results from a US suburban high school survey Sleep Breath 2007114 28593 Choi SM Seo WS Sung HM Koo BH Kim KK Kim SY Sleep duration and body mass index in Korean children J Korean Acad Child Adolesc Psychiatry 2009203 14651 Park S Association between short sleep duration and obesity among South Korean adolescents West J Nurs Res 2011332 20723 Kageyama T Kobayashi T Abe-Cotoh A Correlates to sleepiness on night shift among male workers engaged in three-shift work in a chemical plant: its association with sleep practice and job stress Ind Health 2011495 63441 Duncan AE Grant JD Bucholz KK Madden PA Heath AC Relationship between body mass index, alcohol use, and alcohol misuse in a young adult female twin sample J Stud Alcohol Drugs 2009703 45866 Leatherdale ST Wong SL Manske SR Colditz GA Susceptibility to smoking and its association with physical activity, BMI, and weight concerns among youth Nicotine Tob Res 2008103 499505 Koval JJ Pederson LL Zhang X Mowery P McKenna M Can young adult smoking status be predicted from concern about body weight and self-reported BMI among adolescents? Results from a ten-year cohort study Nicotine Tob Res 2008109 144955 Van den Bulck J Television viewing, computer game playing, and Internet use and self-reported time to bed and time out of bed in secondary-school children Sleep 2004271 1014 Sekine M Chandola T Martikainen P Marmot M Kagamimori S Work and family characteristics as determinants of socioeconomic and sex inequalities in sleep: The Japanese Civil Servants Study Sleep 2006292 20616 Unalan D Ozturk A Ismailogullari S Akgul N Aksu M The effect of sleep duration and quality on academical success of the elementary school children in Kayseri Turkey J Pak Med Assoc 2013635 57680 Glozier N Martiniuk A Patton G Ivers R Li Q Hickie I Short sleep duration in prevalent and persistent psychological distress in young adults: the DRIVE study Sleep 2010339 113945 Bae J Joung H Kim JY Kwon KN Kim YT Park SW Test-retest reliability of a questionnaire for the Korea youth risk behavior web-based survey J Prev Med Public Health 2010435 40310 Leung SO Xu ML Single-item measures for subjective academic performance, self-esteem, and socioeconomic status J Soc Serv Res 2014394 51120 Soh HK Lee EJ Choi BS The development of nutrition education program for improvement of body perception of middle school girls (I); The analysis of problems according to the body perception of middle school girls Korean J Food Culture 2008233 4039 Nixon GM Thompson JM Han DY Becroft DM Clark PM Robinson E Short sleep duration in middle childhood: risk factors and consequences Sleep 2008311 718 Roche A Sun S Human growth: Assessment and interpretation Cambridge Cambridge University Press 2003 17287 Morgenstern M Sargent JD Hanewinkel R Relation between socioeconomic status and body mass index: evidence of an indirect path via television use Arch Pediatr Adolesc Med 20091638 7318 Rashmi Jaswal S Obesity and Academic performance in adolescents Int J Edu Sci 201243 2758 Rouhani MH Mirseifinezhad M Omrani N Esmaillzadeh A Azadbakht L Fast food consumption, quality of diet, and obesity among Isfahanian adolescent girls J Obes 20122012 597924 Moon SS Lee YS Comparison of dietary habits, exercise, recognized body shapes and weight control between obesity and underweight of adolescents Korean J Hum Ecol 2009186 133748 Matusitz J McCormick J Sedentarism: the effects of Internet use on human obesity in the United States Soc Work Public Health 2012273 25069 Torres SJ Nowson CA Relationship between stress, eating behavior, and obesity Nutrition 20072311-12 88794 Trakas K Oh PI Singh S Risebrough N Shear NH The health status of obese individuals in Canada Int J Obes Relat Metab Disord 2001255 6628 Figures and Tables

General characteristics of the study sample according to BMI (N [%] or mean ± SDa)

BMI category Underweight (n=3,387) Normal (n=47,370) Overweight (n=2,719) Obese (n=5,891) Total (n=59,367) χ2 (P)e
Gender 609.59 (<0.001)
Male 1,829 (6.4) 23,082 (78.2) 640 (2.0) 3,937 (13.4) 29,488 (100.0)
Female 1,558 (5.3) 24,288 (81.7) 2,079 (6.8) 1,954 (6.2) 29,879 (100.0)
Mother's education level 67.02 (<0.001)
≤Middle school 121 (6.0) 1,627 (76.5) 104 (4.6) 271 (12.9) 2,123 (100.0)
High school diploma 1,480 (5.9) 20,469 (79.0) 1,223 (4.5) 2,730 (10.6) 25,902 (100.0)
≥Bachelor’s degree 1,229 (5.6) 18,181 (81.2) 941 (4.1) 2,030 (9.2) 22,381 (100.0)
Unknown 557 (6.2) 7,093 (79.5) 451 (4.8) 860 (9.5) 8,961 (100.0)
Age, y 15.41±0.05 14.96±0.03d 14.12±0.06d 15.38±0.03c 14.99±0.03 205.55 (<0.001)
Economic statusb 3.15±0.04d 3.18±0.03d 3.15±0.04 3.11±0.02c 3.17±0.02 10.56 (<0.001)
Academic performanceb 2.95±0.04d 3.03±0.03d 2.93±0.04d 2.85±0.02c 3.00±0.02 40.11 (<0.001)

Abbreviations: BMI, body mass index; SD, standard deviation.

N: non-weighted, %: weighted, mean: weighted, SD: weighted.

1(low)-5(high).

Reference category.

Significantly different group from the reference category.

Calculated by chi-square test or analysis of variance.

Health behavior characteristics of the study sample according to BMI (N [%] or mean±SDa)

BMI category Underweight Normal Overweight Obese Total χ2 (P)b
Smoking 102.07 (<0.001)
Yes 323 (6.1) 4,306 (80.3) 108 (1.9) 628 (11.7) 5,365 (100.0)
No 3,064 (5.8) 43,064 (79.8) 2,611 (4.6) 5,263 (9.8) 54,002 (100.0)
Alcohol use 36.22 (<0.001)
Yes 524 (5.7) 7,573 (79.7) 297 (2.9) 1,094 (11.7) 9,488 (100.0)
No 2,863 (5.9) 39,797 (79.9) 2,422 (4.6) 4,797 (9.6) 49,879 (100.0)
Eat vegetables 73.02 (<0.001)
None 131 (7.0) 1,643 (80.1) 84 (4.1) 185 (8.8) 2,043 (100.0)
1-2 times/wk 623 (6.9) 7,406 (80.5) 394 (4.1) 805 (8.6) 9,228 (100.0)
3-4 times/wk 820 (6.0) 11,276 (79.9) 634 (4.3) 1,368 (9.9) 14,098 (100.0)
5-6 times/wk 486 (5.9) 6,618 (79.7) 382 (4.5) 816 (9.9) 8,302 (100.0)
1 serving/d 374 (5.2) 5,931 (80.3) 336 (4.1) 755 (10.3) 7,396 (100.0)
2 serving/d 437 (5.3) 6,585 (79.3) 405 (4.6) 907 (10.7) 8,334 (100.0)
≥3serving/d 516 (5.3) 7,911 (79.4) 484 (4.6) 1,055 (10.7) 9,966 (100.0)
Eat a snack 146.24 (<0.001)
None 507 (4.9) 8,014 (77.2) 542 (4.8) 1,347 (13.1) 10,410 (100.0)
1-2 times/wk 1,315 (5.2) 20,341 (79.3) 1,297 (4.8) 2,754 (10.7) 25,707 (100.0)
3-4 times/wk 1,037 (6.6) 13,210 (81.3) 646 (3.8) 1,333 (8.3) 16,226 (100.0)
5-6 times/wk 268 (6.9) 3,342 (83.7) 130 (3.0) 269 (6.3) 4,009 (100.0)
1 serving/d 178 (9.5) 1,684 (81.4) 69 (3.2) 117 (6.0) 2,048 (100.0)
2 serving/d 47 (8.3) 506 (82.5) 17 (2.5) 42 (6.7) 612 (100.0)
≥serving/d 35 (9.2) 273 (78.3) 18 (3.6) 29 (8.9) 355 (100.0)
Eat fast food 111.58 (<0.001)
None 963 (5.3) 14,450 (78.7) 955 (5.0) 2,025 (11.0) 18,393 (100.0)
1-2 times/wk 1,941 (5.9) 26,948 (80.3) 1,491 (4.1) 3,183 (9.6) 33,563 (100.0)
3-4 times/wk 363 (6.6) 4,782 (80.6) 217 (3.7) 548 (9.1) 5,910 (100.0)
5-6 times/wk 68 (7.2) 761 (82.0) 34 (3.3) 70 (7.5) 933 (100.0)
1 serving/d 31 (10.2) 264 (74.9) 14 (4.0) 40 (10.9) 349 (100.0)
2 serving/d 14 (12.7) 76 (75.3) 4 (5.1) 8 (7.0) 102 (100.0)
≥serving/d 7 (5.4) 89 (77.6) 4 (2.7) 17 (14.3) 117 (100.0)
Exercise (d/wk) 2.67±0.07c 2.88±0.06c 2.79±0.08c 2.00±0.03d 1.87±0.03 23.17 (<0.001)
Walking time (min/d) 61.02±2.74 61.80±2.06 60.77±2.95 60.79±1.00d 61.61±2.11 0.48 (0.684)

Abbreviations: BMI, body mass index; SD, standard deviation.

N: non-weighted, %: weighted, mean: weighted, SD: weighted.

Calculated by chi-square test or analysis of variance.

Significantly different group from the reference category.

Reference category.

Psychosocial characteristics of the study sample according to BMI (N [%] or mean ± SDa)

BMI category Underweight Normal Overweight Obese Total F (P)b
Using internet (min/d) 102.98±4.56c 95.15±3.65c 89.95±4.59c 126.31±1.89d 98.48±3.74 111.53 (<0.001)
Stresse 3.31±0.05 3.32±0.03 3.45±0.04c 3.33±0.01d 3.32±0.03 16.36 (<0.001)
Health statusf 3.69±0.03c 3.89±0.03c 3.78±0.03 3.74±0.01d 3.86±0.03 39.78 (<0.001)

Abbreviations: BMI, body mass index; SD, standard deviation.

N: non-weighted, %: weighted, mean: weighted, SD: weighted.

Calculated by analysis of variance.

Significantly different group from the reference category.

Reference category.

1(never)-5(very frequently).

1(very unhealthy)-5(very healthy).

Sleep duration on school nights according to BMI (N [%]a)

Sleep duration Underweight Normal Overweight Obese Total χ2 (P)b
<5 h 454 (5.8) 6,268 (79.4) 312 (3.8) 869 (11.0) 7,903 (100.0) 98.48 (<0.001)
5h≤, <6 h 705 (5.7) 10,023 (79.8) 488 (3.7) 1,314 (10.8) 12,530 (100.0)
6h≤, <7 h 812 (5.8) 11,741 (79.6) 659 (4.2) 1,534 (10.4) 14,746 (100.0)
7h≥, <8 h 799 (5.8) 11,338 (80.1) 718 (5.0) 1,303 (9.1) 14,158 (100.0)
≥8 h 617 (6.2) 8,000 (80.4) 542 (5.0) 871 (8.4) 10,030 (100.0)

Abbreviation: BMI, body mass index.

N: non-weighted, %: weighted.

Calculated by chi-square test.

Association between sleep duration and BMIa

Sleep duration Underweight Normal Overweight Obese
OR 95% CI P OR 95% CI P OR 95% CI P OR 95% CI P
<5 h 0.58 0.50-0.67 <0.001 1.03 0.94-1.13 0.485 1.20 1.02-1.42 0.032 1.19 1.05-1.34 0.005
5h≤, <6 h 0.60 0.53-0.69 <0.001 1.03 0.96-1.11 0.432 1.11 0.95-1.29 0.186 1.19 1.07-1.32 0.001
6h≤, <7 h 0.69 0.61-0.78 <0.001 0.99 0.92-1.06 0.771 1.05 0.92-1.19 0.483 1.19 1.08-1.31 <0.001
7h≤, <8 h 0.85 0.75-0.96 0.011 0.98 0.91-1.05 0.507 1.01 0.89-1.14 0.928 1.11 1.01-1.22 0.037
≥8 h 1.00 1.00 1.00 1.00

Abbreviations: BMI, body mass index; OR, odds ratio; CI, confidence interval.

Calculated by logistic regression analysis, adjusted for gender, age, mother's education level, economic status, academic performance, smoking, alcohol use, diet habits, exercises habits, using internet, stress, and health status.