Profiles of anemia among school-aged children categorized by body mass index and waist circumference in Shandong, China.

BACKGROUND: The prevalence of childhood obesity has been increasing worldwide. The connection between iron deficiency and obesity has received much research interest. The present study examined the profiles of anemia among school-aged children categorized by obesity-related index in Shandong, China. METHODS: A total of 20,172 children aged 7, 9, 12, and 14 years participated in the study, whose hemoglobin (Hb) concentration was measured by laboratory technicians. The prevalence rates of anemia among children within each subgroup categorized by body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) were determined. RESULTS: On the whole, 3.99% of boys and 6.68% of girls suffer from anemia. Disparities in the prevalence of anemia were observed between different subgroups categorized by BMI, WC and WHtR. For both boys and girls, the prevalence of anemia increased with the severity of thinness and obesity, suggesting that both severe thinness and severe obesity are associated with an elevated prevalence of anemia. CONCLUSION: In the era of the obesity pandemic, obesity could potentially add to the burden of anemia, suggesting that obese children should not be ignored when establishing strategies targeted at preventing anemia.

Screening of central obesity among normal-weight children and adolescents in Shandong, China.

The prevalence of central obesity in the total population has been reported in numerous studies. However, information on the prevalence of central obesity within normal-category BMI is scant. In the present study, we examined the profiles of central obesity among normal-weight children and adolescents. A total of 29 516 (14 226 boys and 15 290 girls) normal-weight children and adolescents (excluding underweight, overweight and obesity) aged 7-18 years were included in the final analysis. Central obesity was defined by the international age- and sex-specific cut-offs of waist circumference (WC) and threshold of waist:height ratio (WHtR ≥ 0·5). All subjects were classified into four groups (Q1-Q4) according to the age- and sex-specific quartiles of BMI, those in the upper fourth (Q4) were defined as 'high-normal BMI' and those in the lower fourth (Q1) were defined as 'low-normal BMI'. The prevalence of central obesity as measured by WC was 9·90 (95 % CI 9·41, 10·39) % for boys and 8·11 (95 % CI 7·68, 8·54) % for girls; by WHtR was 2·97 (95 % CI 2·69, 3·25) % for boys and 2·44 (95 % CI 2·20, 2·68) % for girls. Subjects in the Q4 group had a much higher prevalence of central obesity than their counterparts in the Q1 group (P < 0·01). Our findings suggest that the health risks of children with normal-weight central obesity may be missed when BMI is used alone as a measure; it is meaningful to include WC in clinical practice and to include the simple message 'Keep your waist to less than half your height'.

High blood pressure in Chinese youth across categories of BMI and waist circumference.

BACKGROUND: BMI and waist circumference (WC) have commonly been used to identify obesity in practice. The aim of the present study was to assess the blood pressure (BP) status among Chinese college students categorized by BMI and WC. METHODS: A total of 4226 college students (2107 males and 2119 females) aged 19-22 years included in the study. The WHO BMI cutoffs were used to define underweight, normal weight and overweight. The WC cutoffs (90 cm for man and 80 cm for woman) were used to define central obesity. High BP was defined as SBP/DBP ≥140/90 mmHg. The BP status of subjects within each category across BMI and WC were assessed. RESULTS: When subjects were categorized by BMI, overweight males and females had a higher prevalence of high BP than their nonoverweight counterparts. When WC was used to diagnose central obesity, subjects with central obesity had a higher prevalence of high BP than those with normal WC. A positive association between BMI, WC and BP was also observed even in normal-weight subjects, with 'high normal BMI' subgroup (BMI = 23.7-24.9) had a higher BP level and prevalence of high BP than 'low normal BMI' subgroups (BMI = 18.5-19.7 and BMI = 19.8-21.0, P < 0.05). CONCLUSION: Prevention of overweight/obesity in youth may be an effective approach for preventing the development of hypertension in the future; for normal-weight youth, it is essential to keep their BMI at a lower level within normal range.

Profiles of BMI and blood pressure in young adults categorized by their components of height.

BACKGROUND: Body proportion is an important symbol of human biology. The aim of the present study was to examine the association of components of height with BMI and blood pressure (BP) among young adults. METHODS: A total of 4135 college students (2040 males and 2095 females) aged 19-22 years participated in the study. All subjects were classified into four groups (Q1-Q4) according to their quartiles of height, sitting height and leg length, respectively, comparisons of BMI, SBP and DBP among the four groups were made. RESULTS: BMI is positively associated with sitting height and inversely associated with leg length, and the BP level is associated with sitting height rather than leg length. BMI and BP level of young adults are also associated with their body proportion, subjects with high sitting height ratio (SHR = sitting height/height × 100) had higher BMI and BP level, and more likely to have overweight/obesity and high BP. CONCLUSION: BMI and BP level of young adults are associated with their components of height, young adults with longer sitting height and higher SHR should be given special attention in the prevention of hypertension in their future lives.

Large body mass index and waist circumference are associated with high blood pressure and impaired fasting glucose in young Chinese men.

BACKGROUND: Obesity is closely related to many chronic diseases and metabolic risk factors. The present study examined the relationship of obesity-related indices to blood pressure (BP) and fasting plasma glucose (FPG) among young Chinese men. METHODS: A total of 1193 male college students aged 18-22 years participated in the study. Height, weight, waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and FPG were measured. High BP was defined as SBP ≥140 mmHg and/or DBP ≥90 mmHg. Impaired fasting glucose (IFG) was defined as FPG ≥5.6 mmol/L. RESULTS: BMI, WC and WHtR were positively correlated with BP and FPG (rBMI-SBP = 0.455, rBMI-DBP = 0.367, rBMI-FPG = 0.113, rWC-SBP = 0.445, rWC-DBP = 0.382, rWC-FPG = 0.115, rWHtR-SBP = 0.396, rWHtR-DBP = 0.302, rWHtR-FPG = 0.106, P all < 0.01). When categorized by BMI (underweight, normal weight, overweight and obesity), the mean values of SBP, DBP, FPG and the prevalence of high BP and IFG increased with BMI, significant differences were observed among the four groups (P < 0.01). When categorized by WC and WHtR, similar differences were observed, with subjects in the large WC/WHtR group had a higher BP and FPG than their counterparts in the low WC/WHtR group (P < 0.01). CONCLUSION: Large BMI and WC/WHtR are associated with high BP and IFG. Our results suggested that prevention of obesity in youth may be an effective approach for preventing the development of diabetes and hypertension in the future.

Profiles of body mass index and blood pressure among young adults categorised by waist-to-height ratio cut-offs in Shandong, China.

Background: Waist-to-height ratio (WHtR) is proposed as a valid measure of abdominal obesity and health risks in practice. The present study examined the profiles of weight status and blood pressure (BP) among young adults categorised by WHtR cut-offs.Methods: A total of 4226 college students (2107 males and 2119 females) aged 19-22 years participated in the study. The body mass index (BMI) cut-offs recommended by the Working Group on Obesity in China (WGOC) were used to define underweight, normal weight, overweight and obesity. The BMI and BP profiles within each WHtR category were examined.Results: For both males and females, 'the high WHtR group' (WHtR ≥ 0.5) had the highest, and 'the low WHtR group' (WHtR < 0.4) had the lowest BMI and BP levels. In the WHtR = 0.30-0.34 sub-group, 66.10% of males and 66.67% of females were underweight; in the WHtR ≥ 0.55 sub-group, 91.49% of males and 83.33% of females were obese; in the WHtR = 0.40-0.44 sub-group, 88.88% of males and 89.85% of females were normal weight. The prevalence of high BP in the WHtR < 0.5 group was 9.99% in males and 2.19% in females; the corresponding figures were 28.92% (males) and 14.06% (females) in the WHtR ≥ 0.5 group; the latter is significantly higher than the former (p < 0.01).Conclusion: Individuals with low WHtR were underweight and those with high WHtR were obese with high BP. Results from this study support WHtR as a simple and effective screening tool for abdominal obesity and high BP in practice.

Trends in the prevalence of elevated skinfold thickness among children and adolescents in Shandong Province, China, 1995-2014.

OBJECTIVE: There are abundant data on secular trends in BMI; however, information on the change in subcutaneous fat is limited. The present study examined the trends in the prevalence of elevated skinfold thickness among children and adolescents over the past 19 years (1995-2014) in Shandong Province, China. DESIGN: Data for the study were obtained from two cross-sectional surveys of schoolchildren carried out in 1995 and 2014. Triceps and subscapular skinfold thicknesses (SFT) of all participants were measured. The sum of triceps and subscapular SFT (SSFT) was applied. Children and adolescents with SSFT above or equal to the national age- and sex-specific 85th percentile were defined as 'high SFT'. SETTING: Shandong Province, China. SUBJECTS: A total of 16 917 students aged 7-18 years were included. RESULTS: For both boys and girls, an increasing trend in 'high SFT' was observed between 1995 and 2014. The overall prevalence of 'high SFT' increased from 10·31 % for boys and 13·40 % for girls in 1995 to 33·94 % for boys and 29·30 % for girls in 2014 (P<0·01). CONCLUSIONS: There are more children and adolescents with very high levels of SFT. These trends describe very unfavourable changes in the body composition and should give cause for concern.

Trends in the Prevalence of Morbid Obesity among Children and Adolescents in Shandong, China, 1995-2014.

Background: Childhood obesity has increased dramatically during the past decades; however, data on the prevalence of morbid obesity is limited. The present study examined the prevalent trends in morbid obesity among children and adolescents during the past 19 years (1995-2014) in Shandong, China. Methods: Data for this study were obtained from five cross-sectional surveys (1995, 2000, 2005, 2010 and 2014) of schoolchildren in Shandong Province, China. A total of 41 500 students aged 7-18 years were included in this study. Body mass index cutoffs recommended by the International Obesity Task Force were used to define morbid obesity. Results: The prevalence of morbid obesity was increasing continuously during the past 19 years (1995-2014), from 0.25% for boys and 0.11% for girls in 1995 to 2.73% for boys and 1.29% for girls in 2014. Boys had higher prevalence of morbid obesity than girls (p<0.01). Regional socioeconomic status (SES) inequalities in morbid obesity were observed; children and adolescents from high SES district had a rapid increase in the prevalence of morbid obesity than their counterparts from moderate SES and low SES districts in the past 19 years. Conclusion: Although the current prevalence of morbid obesity was at a relatively low level, a continuous increasing trend was observed between 1995 and 2014. We should not relax our vigilance, and policymakers and experts should pay more attention to the monitoring and prevention of morbid obesity among children and adolescents in the future decades.

Truncal pattern of subcutaneous fat distribution is associated with obesity and elevated blood pressure among children and adolescents.

BACKGROUND: The association between elevated blood pressure (BP) and childhood obesity has been documented in several studies. However, little is known the difference in BP levels among children and adolescents with different patterns of fat distribution. The present study examined the association of subcutaneous fat distributional pattern with obesity and elevated BP among children and adolescents. METHODS: A total of 38,687 students (19,386 boys and 19,301 girls) aged 7-17 years participated in the study. Body mass index (BMI) cutoff points recommended by the International Obesity Task Force (IOTF) were used to define overweight and general obesity. Abdominal obesity was defined as waist-to-height ratio (WHtR) ≥ 0.5. Relatively high BP (RHBP) status was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ≥ 95th percentile for age and gender. All individuals were classified into four groups (Q1-Q4) according to the age and sex-specific quartiles of subscapular to triceps skinfold thickness ratio (STR), the prevalence rates of overweight, general obesity, abdominal obesity and RHBP among the four groups were compared. RESULTS: In both boys and girls, significant differences in the prevalence rates of overweight, general obesity, abdominal obesity and RHBP were observed among the four groups, an increasing trend was observed from the Q1 (STR <25 th) group to the Q4 (STR ≥ 75th) group (p < 0.01). Children and adolescents with high STR had higher prevalence of overweight, obesity and RHBP than their counterparts with low STR (p < 0.01). CONCLUSION: Truncal pattern of subcutaneous fat distribution is associated with obesity and elevated BP among children and adolescents. Public health attention should not only focus on the amount of body fat, but also on the distributional pattern of body fat.

Profiles of blood pressure among children and adolescents with different body mass index categories in Shandong, China.

BACKGROUND: The International Obesity Task Force recently developed an extended body mass index (BMI) cut-offs for screening thinness, overweight and obesity among children and adolescents. The present study examined the profiles of blood pressure (BP) among children and adolescents with different BMI categories in Shandong, China. METHODS: Data for this study were obtained from a large cross-sectional survey of schoolchildren. A total of 44,630 students (22,404 boys and 22,226 girls) aged 7-18 years participated in this study. The grades of body weight (thinness grade 1-3, normal weight, overweight and obesity grade 1-3) was defined by the international BMI cut-offs. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured on one occasion. High BP was defined as SBP and/or DBP ≥95th percentile for age and gender. RESULTS: The overall prevalence of thinness (grade 1-3), overweight and obesity (grade 1-3) were 7.80, 18.74 and 8.56% for boys and 11.16, 13.53 and 3.70% for girls, respectively, boys had a lower prevalence of thinness and higher prevalence of overweight and obesity than girls (p < .01). Urban boys and girls had a lower prevalence of thinness and higher prevalence of overweight and obesity than their rural counterparts (p < .01). Children and adolescents with high BMI had a higher BP levels than their counterparts with normal and low BMI. CONCLUSION: High BMI is strongly related to elevated BP. Our findings emphasize the importance of the prevention of overweight/obesity to prevent future-related problems such as hypertension in children and adolescents.

Prevalence of severe obesity and its association with elevated blood pressure among children and adolescents in Shandong, China.

BACKGROUND: Childhood obesity has increased markedly during the past decades; however, data on the prevalence of severe obesity in children and adolescents are limited. The present study examined the prevalence of severe obesity and its association with elevated blood pressure (BP) among children and adolescents in Shandong, China. PATIENTS AND METHODS: A total of 44 630 (22 404 boys and 22 226 girls) students aged 7-18 years participated in the study. BMI cut-off points recommended by the International Obesity Task Force were used to define class I-III obesity. Relatively high BP status was defined as systolic BP and/or diastolic BP of at least 95th percentile for age and sex. RESULTS: The prevalence rates of class I, class II, and class III obesity were 6.67, 1.47, and 0.42% for boys and 2.88, 0.64, and 0.18% for girls, respectively; boys had a higher prevalence than girls (P<0.01). Substantial urban-rural disparities exist in childhood obesity; urban boys and girls had a higher prevalence of class I and class II obesity than their rural peers (P<0.05). Severe obesity is associated with elevated BP; the prevalence of relatively high BP increased from 39.93% (boys) and 39.53% (girls) in the class I obese group to 50.54% (boys) and 53.66% (girls) in the class III obese group (P<0.05). CONCLUSION: Although the current prevalence of severe obesity was at a relatively low level, but we should not relax our vigilance to the obesity epidemic. Our findings also emphasize the importance of the prevention of severe obesity to prevent future-related problems such as hypertension in children and adolescents.

Recent Trends in Body Mass Index and Waist Circumference among Children and Adolescents in Shandong China.

BACKGROUND: The present study examined the recent trends in body mass index (BMI) and waist circumference (WC), and the prevalence of general and abdominal obesity among children and adolescents in Shandong, China. METHODS: Data for this study were obtained from two cross-sectional surveys of schoolchildren carried out in 2010 and 2014 in Shandong Province, China. A total of 72 755 students aged 7-18 years were included in this study. The BMI cutoff points recommended by the International Obesity Task Force were used to define overweight and general obesity. Abdominal obesity was defined as waist-to-height ratio (WHtR) ≥ 0.5. Both BMI and WHtR were used to define three types of obesity as follows: general obesity only, abdominal obesity only and combined obesity. RESULTS: For both boys and girls, an increasing trend in BMI and WC was observed between 2010 and 2014 (p < 0.01), WC has increased faster than BMI. The sum of the prevalence of the three types of obesity increased from 16.63% (boys) and 8.13% (girls) in 2010 to 20.37% (boys) and 11.61% (girls) in 2014 (p < 0.01). CONCLUSION: WC and abdominal obesity increased faster than BMI and general obesity among children and adolescents between 2010 and 2014. This study also suggested that distinguishing the types of obesity and examining the prevalence of various types of obesity are useful in practice.

Blood pressure profiles of children and adolescents categorized by waist-to-height ratio cutoffs: study in a large sample in Shandong, China.

BACKGROUND: Waist-to-height ratio (WHtR) is proposed as a simple and effective screening tool for abdominal obesity and cardiovascular disease risk factors. The present study examined the profiles of blood pressure (BP) among children and adolescents categorized by WHtR cutoffs. PATIENTS AND METHODS: A total of 28 074 (14 015 boys and 14 059 girls) students aged 7-17 years participated in the study. Height, waist circumference and BP of all patients were measured, and WHtR was calculated. Relatively high blood pressure (RHBP) status was defined as systolic BP and/or diastolic BP of at least the 95th percentile for age and sex. All patients were divided into three groups (low, moderate and high) according to their WHtR. BP level and the prevalence of RHBP among the three groups were compared. RESULTS: In both boys and girls, significant differences in BP level and the prevalence of RHBP were observed among the three groups (P<0.01). Children and adolescents aged 7-17 years in the 'high WHtR group' (≥0.5) had higher systolic BP and diastolic BP compared with those in the 'low WHtR group' (<0.4) by 6.07-11.49 and 3.28-6.34 mmHg for boys and 5.62-9.76 and 3.14-5.95 mmHg for girls; the 'high WHtR group' had the highest (34.02% for boys and 30.87% for girls) and the 'low WHtR group' had the lowest prevalence of RHBP (15.23% for boys and 12.53% for girls). CONCLUSION: High WHtR is associated with elevated BP. These findings emphasize the importance of the prevention of abdominal obesity to prevent future problems such as hypertension in children and adolescents.

The current prevalence and regional disparities in general and central obesity among children and adolescents in Shandong, China.

BACKGROUND: Childhood obesity has increased dramatically during the past decades, both in developing and developed countries. The present study examined the prevalence and regional disparities in general and central obesity among children and adolescents in Shandong, China. METHODS: A total of 30,459 students (15,249 boys and 15,210 girls) aged 7-18years participated in the study. Height, weight and waist circumference (WC) of all subjects were measured, body mass index (BMI) and waist-to-height ratio (WHtR) were calculated. The BMI cutoff points recommended by the International Obesity Task Force (IOTF) were used to define general obesity. Central obesity was defined as WHtR≥0.5. Both BMI and WHtR were used to define three types of obesity as follows: general obesity only, central obesity only and combined obesity. RESULTS: The overall prevalences of general obesity only, central obesity only and combined obesity were 10.99, 8.47 and 8.70% for boys and 9.47, 5.12 and 3.19% for girls, respectively. The sum of the prevalence of the three types of obesity was 28.16% for boys and 17.78% for girls, boys had higher prevalence of obesity than girls (P<0.01). Substantial urban-rural and regional disparities exist in childhood obesity, children and adolescents from urban, coastal and high socioeconomic status (SES) districts showed a higher prevalence of obesity than their counterparts from rural, inland and low SES districts (P<0.01). CONCLUSION: The widespread prevalence of obesity in children and adolescents has become an important public health concern. Results from this study also suggested that the additional measurement of WC (WHtR) is better than BMI alone to identify obese individuals, distinguishing the types of obesity and examining the prevalence of various types of obesity is useful in practice.

Profiles of body mass index and the nutritional status among children and adolescents categorized by waist-to-height ratio cut-offs.

BACKGROUND: Waist-to-height ratio (WHtR) is proposed as a simple, valid and convenient measure of abdominal obesity and health risks in practice. The present study examined the distribution of nutritional status among children and adolescents categorized by WHtR cut-offs. METHODS: A total of 30,459 students (15,249 boys and 15,210 girls) aged 7-18years participated in the study. Height, weight and waist circumference (WC) of all subjects were measured, body mass index (BMI) and WHtR were calculated. The grades of nutritional status (thinness, normal weight, overweight and obesity) was defined by the international BMI cut-offs. All subjects were divided into three groups (low, moderate and high) according to their WHtR, BMI level and the distribution of nutritional status among the three groups were compared. RESULTS: In both boys and girls, significant differences in BMI level and the nutritional status were observed among the three groups. Children and adolescents aged 7-18years in the 'high WHtR group' (≥0.5) had higher BMI than those in the 'low WHtR group' (<0.4) by 6.00-10.15kg/m2 for boys and 5.24-9.51kg/m2 for girls. 'low WHtR group' had higher prevalence of thinness, and 'high WHtR group' had higher prevalence of overweight and obesity. The optimal distribution of nutritional status is found in the 'moderate WHtR group' (between 0.4 and 0.5) with the highest proportion of normal weight and low prevalence of thinness and obesity. CONCLUSION: WHtR is associated with nutritional status, which could be an indicator of nutritional status and early health risk. It is necessary to develop optimal boundary values in the future.

Profiles of blood pressure among children and adolescents categorized by BMI and waist circumference.

BACKGROUND: BMI and waist circumference (WC) are two commonly used measurements for defining general and central obesity. The present study examined the profiles of blood pressure (BP) among children and adolescents categorized by BMI and WC in Shandong, China. PARTICIPANTS AND METHODS: A total of 38 810 students (19 453 boys and 19 357 girls) aged 7-17 years participated in this study. Height, weight, WC, and BP of all participants were measured, and BMI was calculated. Relatively high BP status was defined as systolic BP and/or diastolic BP ≥95th percentile for age and sex. All individuals were classified into four groups (Q1-Q4) according to the age-specific and sex-specific quartiles of BMI and WC; the BP level and the prevalence of relatively high BP among the four groups were compared. RESULTS: In both boys and girls, significant differences in BP level and the prevalence of relatively high BP were observed among the four groups categorized by BMI and WC separately (P<0.01). Children and adolescents in the high BMI group (Q4) had higher systolic BP and diastolic BP than their counterparts in the low BMI group (Q1) in all age groups (P<0.01), the range of differences being 5.7-10.3, 3.6-5.6 mmHg for boys and 3.9-8.7, 2.2-5.3 mmHg for girls, respectively. Similar differences were also observed among different groups categorized by WC. CONCLUSION: High BMI and WC are associated with elevated BP. Our findings emphasize the importance of the prevention of general and central obesity to prevent future-related problems such as hypertension in children and adolescents.

Children and adolescents with low body mass index but large waist circumference remain high risk of elevated blood pressure.

BACKGROUND: Body mass index (BMI) and waist circumference (WC) are two commonly used measurements for defining general and central obesity. The present study examined the profiles of blood pressure (BP) among children and adolescents with low BMI but large WC in a large population in Shandong, China. METHODS: A total of 38,810 students (19,453 boys and 19,357 girls) aged 7-17years participated in this study. Height, weight, WC, and BP of all subjects were measured, and BMI was calculated. Relatively high BP (RHBP) status was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ≥95th percentile for age and gender. 'Low BMI with large WC' was defined as BMI<25th and WC≥75th. RESULTS: The Z-scores for SBP and DBP in the 'low BMI with large WC' group were 0.21 and 0.31 for boys and 0.19 and 0.35 for girls respectively, significantly higher than the average level of the total sample (P<0.01). The prevalence of RHBP in the 'low BMI with large WC' group was significantly higher than the average level of the total sample (34.1% vs. 26.2% for boys and 29.5% vs. 20.3% for girls). CONCLUSION: Children and adolescents with low BMI but large WC might have an increased risk of elevated BP, their health risks would be underestimated if screening by BMI alone. These findings suggest that measurement of WC may be an assistive tool when using BMI to identify high BP risks.