International Journal of Cardiology 184 (2015) 380–381
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
The double burden of overweight and thinness among children and adolescents in Shandong China Ying-xiu Zhang a,⁎, Ming Lin b, Gui-zhi Sun b a b
Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China Shandong Blood Center, Shandong, China
a r t i c l e
i n f o
Article history: Received 11 January 2015 Accepted 21 February 2015 Available online 24 February 2015 Keywords: Thinness Overweight Obesity Prevalence Child and adolescent
The prevalence of childhood overweight and obesity is increasing worldwide and even developing countries are beginning to experience this trend in the last two decades. Especially, recent reports indicated that the increase in childhood obesity is much more rapid in developing countries than in developed countries [1]. The increasing prevalence of overweight and obesity has continued to dominate both national and international discussions in recent times; on the contrary, thinness has received less consideration. Shandong Province, located in the lower reaches of the Yellow River, is an important littoral province in East China. It has a total area of 156,700 km2 (about 60,500 miles2) and a total population of 95.79 million in 2010. In this article, based on provincial data in 2010, we report the distribution of body weight status among children and adolescents in Shandong, China. Data for this study were obtained from a large cross-sectional survey of schoolchildren. A total of 42,348 students (21,248 boys and 21,100 girls) from 16 districts in Shandong Province, students of Han nationality, aged 7–18 years, participated in the National Surveys on Chinese Students' Constitution and Health, which were carried out in September to October 2010. All subjects voluntarily joined this study with informed consents. The sampling method was stratified multi-stage sampling based on selected primary and secondary schools. Six public schools (two primary schools, two junior high schools and two senior high
⁎ Corresponding author at: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China, 16992 Jingshi Road, Jinan, Shandong 250014, China. E-mail address: [email protected] (Y. Zhang).
http://dx.doi.org/10.1016/j.ijcard.2015.02.076 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
schools) from each of the 16 districts in Shandong were randomly selected and invited to participate in the study. From the selected schools, two classes in each grade were selected, and all students of the selected classes were invited to join the study. All measurements were performed by well-trained health professionals in each of the 16 districts using the same type of apparatus and followed the same procedures. Height without shoes was measured using metal column height-measuring stands to the nearest 0.1 cm. Weight was measured using lever scales to the nearest 0.1 kg while the subjects wore their underwear only. Body mass index (BMI) was calculated from their height and weight (kg/m2). The BMI cutoff points recommended by the International Obesity Task Force (IOTF) were used to define overweight and obesity [2]. Thinness was defined by the international BMI cut-offs [3]. The prevalence of thinness, overweight and obesity among children and adolescents aged 7–18 years was 7.31–12.75%, 12.11–21.21% and 3.06–9.86% for boys, and 11.23–18.07%, 6.66–14.47% and 1.04–5.53% for girls, respectively. The overall prevalence of thinness, overweight and obesity was 9.78% (95% CI 9.38–10.18), 16.33% (95% CI 15.83–16.83) and 6.41% (95% CI 6.08–6.74) for boys, and 15.07% (95% CI 14.59–15.55), 10.69% (95% CI 10.27–11.11) and 2.12 (95% CI 1.93–2.31) for girls, respectively, boys had lower prevalence of thinness and higher prevalence of overweight and obesity than girls (P b 0.01). The prevalence of thinness, overweight and obesity by gender and age groups was shown in Table 1. For boys, children (aged 7–12 years) had lower prevalence of thinness than adolescents (aged 13–18 years) (8.72 vs. 10.88%, P b 0.01); for girls, children (aged 7–12 years) had similar prevalence to adolescents (aged 13–18 years) (14.90 vs. 15.25%, P N 0.05). For both boys and girls, children (aged 7–12 years) had higher prevalence of overweight and obesity than adolescents (aged 13–18 years) (P b 0.01). Fig. 1 shows the distribution of weight status of children and adolescents in Shandong, China. The percentage of normal weight was 67.48% for boys and 72.12% for girls, approximately one-third of boys and onefourth of girls were thinness or overweight (including obesity). Increased rates of overweight and obesity, as well as associated chronic diseases, have been recently observed in many countries [4–6]. China has now joined the world epidemic of overweight and obesity with its rapid economic growth and urbanization. Although the prevalence of overweight and obesity is receiving considerable attention in terms of both policy and practice in China, however, our study suggests that thinness is also an important overlooked phenomenon. As suggested
Y. Zhang et al. / International Journal of Cardiology 184 (2015) 380–381
381
Table 1 Prevalence of thinness, overweight and obesity among children and adolescents in Shandong, China. Gender
Age/years
n
Thinness
Overweight
Obesity
Boys
7–12 13–18 7–12 13–18
10,785 10,463 10,733 10,367
8.72 (8.19–9.25) 10.88 (10.28–11.48)# 14.90 (14.23–15.57)⁎ 15.25 (14.56–15.94)⁎
18.71 (17.97–19.45) 13.87 (13.21–14.53)# 13.13 (12.49–13.77)⁎ 8.17 (7.64–8.70)⁎#
8.26 (7.74–8.78) 4.50 (4.10–4.90)# 3.02 (2.70–3.34)⁎ 1.19 (0.98–1.40)⁎#
Girls
Data presented as percentage (95% CI). ⁎ Significant difference between boys and girls (P b 0.01). # Significant difference between the two age groups (P b 0.01).
Fig. 1. Distribution of weight status of children and adolescents in Shandong, China.
by findings of previous studies from other developing countries [7–10], our results indicated that China is facing the double burden of both thinness and overweight. Therefore, it is important not to forget the public health challenge posed by thinness. Special attention should be paid to controlling the tendency of polarization in nutritional status of children and adolescents. The major strength of this study is that, based on the data from a large population, using internationally agreed standards, it examines the prevalence of thinness and overweight among children and adolescents. However, this study has two limitations. Firstly, one district (Zaozhuang) did not participate in the national survey on students' constitution and health, and thus the sample did not cover all districts of Shandong Province. Secondly, the absence of detailed information concerning living environments, nutritional status, dietary patterns and physical activity at the individual level also limited our study. Conflict of interest There are no conflicts of interest on behalf of any of the authors. Acknowledgments This study was supported by the Medical and Health Program of Shandong, China (2014WS0376). Surveys on students' constitution and health are conducted under the auspices of the Department of Education in Shandong Province, China. We thank all the team members
and all participants. Special thanks to Mr. B Yu for providing access to the survey data. References [1] M. de Onis, M. Blossner, E. Borghi, Global prevalence and trends of overweight and obesity among preschool children, Am. J. Clin. Nutr. 92 (2010) 1257–1264. [2] T.J. Cole, M.C. Bellizzi, K.M. Flegal, W.H. Dietz, Establishing a standard definition for child overweight and obesity worldwide: international study, BMJ 320 (2000) 1240–1243. [3] T.J. Cole, K.M. Flegal, D. Nicholls, A.A. Jackson, Body mass index cut offs to define thinness in children and adolescents: international survey, BMJ 335 (2007) 194–197. [4] T. Lobstein, Obesity in children and young people: a crisis in public health, Obes. Rev. 5 (Suppl. 1) (2004) 4–85. [5] Y. Wang, T. Lobstein, Worldwide trends in childhood overweight and obesity, Int. J. Pediatr. Obes. 1 (2006) 11–25. [6] P.W. Franks, R.L. Hanson, W.C. Knowler, M.L. Sievers, P.H. Bennett, H.C. Looker, Childhood obesity, other cardiovascular risk factors, and premature death, N. Engl. J. Med. 362 (2010) 485–493. [7] H. Oulamara, A.N. Agli, M.L. Frelut, Changes in the prevalence of overweight, obesity and thinness in Algerian children between 2001 and 2006, Int. J. Pediatr. Obes. 4 (2009) 411–413. [8] N.T. Tuan, T.A. Nicklas, Age, sex and ethnic differences in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Asian children, Eur. J. Clin. Nutr. 63 (2009) 1305–1312. [9] C.M. Doak, L.S. Adair, M. Bentley, C. Monteiro, B.M. Popkin, The dual burden household and the nutrition transition paradox, Int. J. Obes. 29 (2005) 129–136. [10] B.K. Le Nguyen, H. Le Thi, V.A. Nguyen Do, N. Tran Thuy, C. Nguyen Huu, T. Thanh Do, P. Deurenberg, I. Khouw, Double burden of undernutrition and overnutrition in Vietnam in 2011: results of the SEANUTS study in 0.5–11-year-old children, Br. J. Nutr. 110 (2013) S45–S56.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
The double burden of overweight and thinness among children and adolescents in Shandong China Ying-xiu Zhang a,⁎, Ming Lin b, Gui-zhi Sun b a b
Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China Shandong Blood Center, Shandong, China
a r t i c l e
i n f o
Article history: Received 11 January 2015 Accepted 21 February 2015 Available online 24 February 2015 Keywords: Thinness Overweight Obesity Prevalence Child and adolescent
The prevalence of childhood overweight and obesity is increasing worldwide and even developing countries are beginning to experience this trend in the last two decades. Especially, recent reports indicated that the increase in childhood obesity is much more rapid in developing countries than in developed countries [1]. The increasing prevalence of overweight and obesity has continued to dominate both national and international discussions in recent times; on the contrary, thinness has received less consideration. Shandong Province, located in the lower reaches of the Yellow River, is an important littoral province in East China. It has a total area of 156,700 km2 (about 60,500 miles2) and a total population of 95.79 million in 2010. In this article, based on provincial data in 2010, we report the distribution of body weight status among children and adolescents in Shandong, China. Data for this study were obtained from a large cross-sectional survey of schoolchildren. A total of 42,348 students (21,248 boys and 21,100 girls) from 16 districts in Shandong Province, students of Han nationality, aged 7–18 years, participated in the National Surveys on Chinese Students' Constitution and Health, which were carried out in September to October 2010. All subjects voluntarily joined this study with informed consents. The sampling method was stratified multi-stage sampling based on selected primary and secondary schools. Six public schools (two primary schools, two junior high schools and two senior high
⁎ Corresponding author at: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China, 16992 Jingshi Road, Jinan, Shandong 250014, China. E-mail address: [email protected] (Y. Zhang).
http://dx.doi.org/10.1016/j.ijcard.2015.02.076 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
schools) from each of the 16 districts in Shandong were randomly selected and invited to participate in the study. From the selected schools, two classes in each grade were selected, and all students of the selected classes were invited to join the study. All measurements were performed by well-trained health professionals in each of the 16 districts using the same type of apparatus and followed the same procedures. Height without shoes was measured using metal column height-measuring stands to the nearest 0.1 cm. Weight was measured using lever scales to the nearest 0.1 kg while the subjects wore their underwear only. Body mass index (BMI) was calculated from their height and weight (kg/m2). The BMI cutoff points recommended by the International Obesity Task Force (IOTF) were used to define overweight and obesity [2]. Thinness was defined by the international BMI cut-offs [3]. The prevalence of thinness, overweight and obesity among children and adolescents aged 7–18 years was 7.31–12.75%, 12.11–21.21% and 3.06–9.86% for boys, and 11.23–18.07%, 6.66–14.47% and 1.04–5.53% for girls, respectively. The overall prevalence of thinness, overweight and obesity was 9.78% (95% CI 9.38–10.18), 16.33% (95% CI 15.83–16.83) and 6.41% (95% CI 6.08–6.74) for boys, and 15.07% (95% CI 14.59–15.55), 10.69% (95% CI 10.27–11.11) and 2.12 (95% CI 1.93–2.31) for girls, respectively, boys had lower prevalence of thinness and higher prevalence of overweight and obesity than girls (P b 0.01). The prevalence of thinness, overweight and obesity by gender and age groups was shown in Table 1. For boys, children (aged 7–12 years) had lower prevalence of thinness than adolescents (aged 13–18 years) (8.72 vs. 10.88%, P b 0.01); for girls, children (aged 7–12 years) had similar prevalence to adolescents (aged 13–18 years) (14.90 vs. 15.25%, P N 0.05). For both boys and girls, children (aged 7–12 years) had higher prevalence of overweight and obesity than adolescents (aged 13–18 years) (P b 0.01). Fig. 1 shows the distribution of weight status of children and adolescents in Shandong, China. The percentage of normal weight was 67.48% for boys and 72.12% for girls, approximately one-third of boys and onefourth of girls were thinness or overweight (including obesity). Increased rates of overweight and obesity, as well as associated chronic diseases, have been recently observed in many countries [4–6]. China has now joined the world epidemic of overweight and obesity with its rapid economic growth and urbanization. Although the prevalence of overweight and obesity is receiving considerable attention in terms of both policy and practice in China, however, our study suggests that thinness is also an important overlooked phenomenon. As suggested
Y. Zhang et al. / International Journal of Cardiology 184 (2015) 380–381
381
Table 1 Prevalence of thinness, overweight and obesity among children and adolescents in Shandong, China. Gender
Age/years
n
Thinness
Overweight
Obesity
Boys
7–12 13–18 7–12 13–18
10,785 10,463 10,733 10,367
8.72 (8.19–9.25) 10.88 (10.28–11.48)# 14.90 (14.23–15.57)⁎ 15.25 (14.56–15.94)⁎
18.71 (17.97–19.45) 13.87 (13.21–14.53)# 13.13 (12.49–13.77)⁎ 8.17 (7.64–8.70)⁎#
8.26 (7.74–8.78) 4.50 (4.10–4.90)# 3.02 (2.70–3.34)⁎ 1.19 (0.98–1.40)⁎#
Girls
Data presented as percentage (95% CI). ⁎ Significant difference between boys and girls (P b 0.01). # Significant difference between the two age groups (P b 0.01).
Fig. 1. Distribution of weight status of children and adolescents in Shandong, China.
by findings of previous studies from other developing countries [7–10], our results indicated that China is facing the double burden of both thinness and overweight. Therefore, it is important not to forget the public health challenge posed by thinness. Special attention should be paid to controlling the tendency of polarization in nutritional status of children and adolescents. The major strength of this study is that, based on the data from a large population, using internationally agreed standards, it examines the prevalence of thinness and overweight among children and adolescents. However, this study has two limitations. Firstly, one district (Zaozhuang) did not participate in the national survey on students' constitution and health, and thus the sample did not cover all districts of Shandong Province. Secondly, the absence of detailed information concerning living environments, nutritional status, dietary patterns and physical activity at the individual level also limited our study. Conflict of interest There are no conflicts of interest on behalf of any of the authors. Acknowledgments This study was supported by the Medical and Health Program of Shandong, China (2014WS0376). Surveys on students' constitution and health are conducted under the auspices of the Department of Education in Shandong Province, China. We thank all the team members
and all participants. Special thanks to Mr. B Yu for providing access to the survey data. References [1] M. de Onis, M. Blossner, E. Borghi, Global prevalence and trends of overweight and obesity among preschool children, Am. J. Clin. Nutr. 92 (2010) 1257–1264. [2] T.J. Cole, M.C. Bellizzi, K.M. Flegal, W.H. Dietz, Establishing a standard definition for child overweight and obesity worldwide: international study, BMJ 320 (2000) 1240–1243. [3] T.J. Cole, K.M. Flegal, D. Nicholls, A.A. Jackson, Body mass index cut offs to define thinness in children and adolescents: international survey, BMJ 335 (2007) 194–197. [4] T. Lobstein, Obesity in children and young people: a crisis in public health, Obes. Rev. 5 (Suppl. 1) (2004) 4–85. [5] Y. Wang, T. Lobstein, Worldwide trends in childhood overweight and obesity, Int. J. Pediatr. Obes. 1 (2006) 11–25. [6] P.W. Franks, R.L. Hanson, W.C. Knowler, M.L. Sievers, P.H. Bennett, H.C. Looker, Childhood obesity, other cardiovascular risk factors, and premature death, N. Engl. J. Med. 362 (2010) 485–493. [7] H. Oulamara, A.N. Agli, M.L. Frelut, Changes in the prevalence of overweight, obesity and thinness in Algerian children between 2001 and 2006, Int. J. Pediatr. Obes. 4 (2009) 411–413. [8] N.T. Tuan, T.A. Nicklas, Age, sex and ethnic differences in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Asian children, Eur. J. Clin. Nutr. 63 (2009) 1305–1312. [9] C.M. Doak, L.S. Adair, M. Bentley, C. Monteiro, B.M. Popkin, The dual burden household and the nutrition transition paradox, Int. J. Obes. 29 (2005) 129–136. [10] B.K. Le Nguyen, H. Le Thi, V.A. Nguyen Do, N. Tran Thuy, C. Nguyen Huu, T. Thanh Do, P. Deurenberg, I. Khouw, Double burden of undernutrition and overnutrition in Vietnam in 2011: results of the SEANUTS study in 0.5–11-year-old children, Br. J. Nutr. 110 (2013) S45–S56.
