International Journal of Cardiology 176 (2014) 1212–1213

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Letter to the Editor

Prevalence of overweight and obesity among children and adolescents is associated with urbanization in Shandong, China☆ Ying-xiu Zhang ⁎, Jin-shan Zhao, Zun-hua Chu Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China

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Article history: Received 6 July 2014 Accepted 27 July 2014 Available online 5 August 2014 Keywords: Overweight Obesity Prevalence Urbanization Child and adolescent

Prevalence of obesity is an increasing problem in children and adolescents worldwide. Childhood obesity is widely recognized as a risk factor for coronary heart disease, hypertension, diabetes and many other health problems in adult. Especially, recent reports indicated that the increase in childhood obesity is much more rapid in developing countries than in developed countries [1]. China is the largest developing country in the world, and the rising prevalence of childhood obesity was observed in the recent decades [2]. In most developing countries, urbanization has been shown to be a major factor associated with high prevalence of obesity. A study from Tunisia has shown that the prevalence of general obesity (assessed by BMI) and abdominal obesity (assessed by WC) increased with the degrees of urbanization in adult women, the prevalence of general and abdominal obesity were 9.5% and 16.5% in rural dispersed areas, 19.4% and 24.8% in rural clustered areas, 25.9% and 32.4% in other cities and 30.2% and 36.6% in big cities [3]. In this article, based on provincial data in 2010, we report the prevalence of overweight and obesity among children and adolescents in different urbanization districts. Data for this study were obtained from a large cross-sectional survey of schoolchildren. A total of 42,296 students (21,218 boys and 21,078 girls) from 16 districts in Shandong Province, students of Han nationality, aged 7–18 years, participated in the National Surveys on Chinese

☆ There are no conflicts of interest on behalf of any of the authors. ⁎ Corresponding author at: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, 16992 Jingshi Road, Jinan 250014, Shandong, China. Tel./fax: +86 531 82679413. E-mail address: [email protected] (Y. Zhang).

http://dx.doi.org/10.1016/j.ijcard.2014.07.222 0167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved.

Students' Constitution and Health, which were carried out in September to October 2010. 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 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. The population information of the 16 districts in 2010 was collected from the Shandong Statistical Yearbook [4], and the 16 districts were divided into four groups according to the percentage of urban population (20%∽, 30%∽, 40%∽ and 50%∽). All measurements were conducted by a team of trained technicians in each of the 16 districts using the same type of apparatus and followed the same procedures. Each technician is required to pass a training course for anthropometric measurement organized by the investigation team in Shandong. 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), overweight and obesity were defined by WGOC criteria (BMI reference for screening overweight and obesity in Chinese school-aged children) [5]. Z-score of BMI for children and adolescents was calculated from the national reference values [6].

0.5 0.41

boys

0.4

BMI Z-score

a r t i c l e

girls

0.33

0.32 0.3

0.25 0.21

0.2

0.28 0.22

0.18

0.1 0.0

20̚

30̚

40̚

50̚

Percentage of urban population Fig. 1. BMI Z-scores of children and adolescents in different urbanization districts.

Y. Zhang et al. / International Journal of Cardiology 176 (2014) 1212–1213

1213

35 30

Obesity Overweight

25

%

20

14.13 10.64

11.18

9.66

15

13.65

15.14

15.69

8.88

9.64

10.19

11.56

20̚

30̚ Girls

40̚

50̚

16.39

5 0

6.02

4.88

10

20̚

30̚ 40̚ Boys

6.70

5.56

50̚

Percentage of urban population Fig. 2. The prevalence of overweight and obesity in different urbanization districts.

The mean values of BMI Z-score for children and adolescents in the four groups are shown in Fig. 1. One-way ANOVA indicated that the BMI levels increased with the degrees of urbanization (Fboys = 29.89, P b 0.01; Fgirls = 16.11, P b 0.01). The overall prevalence of overweight and obesity among children and adolescents aged 7– 18 years was 15.46%, 11.69% for boys and 10.25%, 5.92% for girls, respectively. X2 tests indicated that these figures were significantly higher in boys than in girls. Fig. 2 shows the prevalence of overweight and obesity increased with the degrees of urbanization (overweight: x 2 boys = 11.49, P b 0.01; x 2girls = 19.22, P b 0.01. obesity: x2boys = 55.85, P b 0.01; x 2girls = 13.25, P b 0.01.) Prevalence of overweight and obesity increased from 13.65%, 9.66% for boys and 8.88%, 4.88% for girls in the low urbanization districts (percentage of urban population above 20% but below 30%) to 16.39%, 14.13% for boys and 11.56%, 6.70% for girls in the high urbanization districts (percentage of urban population above 50%). It is clear that obvious changes in diet and activity in China have occurred, these changes include increased intake of edible oils, fried foods, animal-source foods and snacking, as well as declining occupational, domestic and travel activity and increasing TV time [7–10]. In the present study, we found that the prevalence of overweight and obesity increased with the degrees of urbanization in children and adolescent. One of the possible explanation for this finding may be that urbanization is associated with a variety of lifestyle and behavioral changes, including physical inactivity and high-fat, energy-rich diets. People who live in urbanized areas may be the first to have access to energy-dense foods, to have a decline in work related physical activity, and to have access to motorized transportation in a developing country [11,12]. Two limitations are noted. First, a district (Zaozhuang) did not participate in the national survey on students' constitution and health, thus the sample did not cover all districts of Shandong province. Secondly, the absence of detailed information concerning living environments, nutritional status, dietary pattern, and physical activity at the individual level limited our study. China is a developing country with highly unbalanced regional development. In this study, we found that children and adolescents in

high urbanization districts had higher prevalence of obesity than those from low urbanization districts. Considering the rapid development of urbanization in China, the prevalence of childhood obesity may be more widely, we should arouse special attention and comprehensive strategies of intervention should be implemented. 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] de Onis M, Blossner M, Borghi E. Global prevalence and trends of overweight and obesity among preschool children. Am J Clin Nutr 2010;92:1257–64. [2] Cheng TO. China's epidemic of child obesity: an ounce of prevention is better than a pound of treatment. Int J Cardiol 2014;172:1–7. [3] Beltaïfa L, Traissac P, El Ati J, Lefèvre P, Romdhane HB, Delpeuch F. Prevalence of obesity and associated socioeconomic factors among Tunisian women from different living environments. Obes Rev 2009;10:145–53. [4] Shandong Provincial Bureau of Statistics. Shandong Statistical Yearbook. Beijing: China Statistical Publishing House; 2011 61 [in Chinese]. [5] Ji CY, WGOC. Body mass index reference for screening overweight and obesity in Chinese school age children. Biomed Environ Sci 2005;18:390–400. [6] Research Section of the Constitution and Health of Chinese Students (RSCHCS). Report on the physical fitness and health research of Chinese school students. Beijing: Higher Education Press; 2012 98 [in Chinese]. [7] Ng SW, Zhai F, Popkin BM. Impacts of China's edible oil pricing policy on nutrition. Soc Sci Med 2008;66:414–26. [8] Monda KL, Adair LS, Zhai F, Popkin BM. Longitudinal relationships between occupational and domestic physical activity patterns and body weight in China. Eur J Clin Nutr 2008;62:1318–25. [9] Wang Z, Zhai F, Zhang B, Popkin BM. Trends in Chinese snacking behaviors and patterns and the social-demographic role between 1991 and 2009. Asia Pac J Clin Nutr 2012;21:253–62. [10] Popkin BM, Keyou G, Zhai F, Guo X, Ma H, Zohoori N. The nutrition transition in China: a cross-sectional analysis. Eur J Clin Nutr 1993;47:333–46. [11] Monda KL, Gordon-Larsen P, Stevens J, Popkin BM. China's transition: the effect of rapid urbanization on adult occupational physical activity. Soc Sci Med 2007;64: 858–70. [12] Popkin BM, Du S. Dynamics of the nutrition transition toward the animal foods sector in China and its implications: a worried perspective. J Nutr 2003;133(Suppl. 2): 3898–906.

Prevalence of overweight and obesity among children and adolescents is associated with urbanization in Shandong, China.

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