The prevalence of obesity not only among adults but also among children has been increasing globally. Furthermore, obese children reportedly go on to be obese in adulthood. Obesity is likely to cause lifestyle-related diseases not only in able-bodied individuals but also in disabled children. Specific cognitive behavior observed in disabled children often hinders the provision of lifestyle guidance, such as nutritional and physical exercise instructions. To prevent such situations, early identification of obesity is required to improve lifestyle habits through diet and exercise in disabled children. This study included 285 children with developmental disorders. To assess a childhood obesity index, three obesity-related parameters were compared: the degree of obesity in school health, which has been used to evaluate the health of school children in Japan; abdominal circumference, which is useful for predicting visceral fat obesity; and the waist-to-height ratio (WHtR), which reflects visceral fat and physique. The abdominal circumference was significantly dependent on age. The degree of obesity and WHtR did not show a significant association with age. WHtR was significantly associated with the degree of obesity in school health. The WHtR is easily calculated as compared to the degree of index in school health which needs rather complicated calculations depending on age and age-specific coefficients. The study findings suggest that WHtR might be an easy-to-use obesity index comparable to the degree of obesity in school health in children with developmental disorders.
Recently, the prevalence of obesity among adults and children has been increasing globally; however, there have been no signs of improvement. In Japan, the prevalence of obese students (elementary and junior high schools) has been nearly flat or has increased over the past 10 years [
We reported that the proportion of obese children with developmental disorders increased with age. In particular, such a tendency was observed in children with intellectual disabilities. Given that severely obesity was found in a 5-year-old child, interventions from an early age are required to improve obesity [
Obesity is known to be a risk factor for ischemic heart disease, hypertension, and diabetes. An increase in the number of obese individuals eventually leads to an increase in medical costs. A lot of obesity index have been suggested and used for early prevention of these diseases, including body mass index (BMI), an international indicator of obesity, and waist circumference (abdominal circumference), which is related to the accumulation of visceral fat. Additional criteria for identifying childhood obesity include the Kaup index (children aged < 5 years), and Rohrer index for childhood. There is another obesity index in Japan, which has been applied as a degree of obesity in school health (described in Methods section).
Previous studies involving children reported that serum leptin concentrations were highly associated with body fat concentration [
In previous studies for adults, one study assessed the validity of the obesity indices (BMI and abdominal circumference) regarding the diagnosis of dyslipidemia among a worksite population [
In this way, various indices have been proposed to detect obesity, and their significance has been discussed through the association with obesity-related biomarkers. Because childhood obesity is likely to cause lifestyle-related diseases not only in healthy but also in disabled children, early detection of obese children is required for providing dietary and/or exercise interventions. Although the specific cognitive behavior observed among disabled children frequently hinders the provision of lifestyle guidance, such as nutritional and exercise instruction, there are no studies examining obesity indicators for children with developmental disorders. In that respect, a useful obesity index is required in children with developmental disorders as simplified and easy-to-use tool.
This study evaluated obesity indices (the degree of obesity in school health, abdominal circumference, and WHtR) to determine the most useful index among children with developmental disorders for the implementation of interventions in obesity as early as possible.
This study included 285 outpatient children diagnosed with developmental disorder in the developmental disorder department of a clinic attached to Autism Disorder University “A” in Hiroshima, Japan. Their disorders were classified as Autism Disorder, Attention-deficit/hyperactivity Disorder, Learning Disability, and Mental Retardation based on the Diagnostic and Statistical Manual of Mental Disorders guidelines [
Based on physical measurements, the degree of obesity in school health, abdominal circumference, and the waist-to-height ratio (WHtR) were calculated. The degree of obesity in school health used here was derived from the difference between the measured body weight and the standard body weight with dependence on body height and age-specific coefficients, which was proposed by the “Health Checkup Manual for School Children (Revision), Japan Society of School Health, March 2006 (under the supervision of the Ministry of Education, Culture, Sports, Science and Technology)”.
Pearson’s product-moment correlation coefficients were calculated to estimate the associations among age and obesity indices.
In advance of the study, the participants received an explanation about the
| Gender | Type of Developmental Disorders | Age (yrs.) | Total (%) | ||
|---|---|---|---|---|---|
| 5 - 8 | 9 - 12 | 13 - 17 | |||
| Men | Autism Disorder | 49 | 24 | 12 | 85 (37.6) |
| Attention-deficit/hyperactivity Disorder | 33 | 22 | 8 | 63 (27.9) | |
| Learning Disability | 8 | 4 | 2 | 14 (6.2) | |
| Mental Retardation | 20 | 37 | 7 | 64 (28.3) | |
| Women | Autism Disorder | 15 | 5 | 3 | 23 (39.0) |
| Attention-deficit/hyperactivity Disorder | 7 | 2 | 0 | 9 (15.2) | |
| Learning Disability | 4 | 2 | 2 | 8 (13.6) | |
| Mental Retardation | 7 | 11 | 1 | 19 (32.2) | |
study’s objective, methodology, the freedom to participate in the study, and privacy considerations. The informed consent was obtained individually in writing from the participants.
This study was conducted under the approval of the Ethics Review Committee of this university (No. 25, Date Nov 25, 2008).
relationship between age and WHtR by gender. WHtR was not significantly associated with age in men or women.
In comparison with three obesity indices (abdominal circumference, waist-to-hip ratio, and WHtR) in 85 male and female volunteers aged 40 to 60 who participated in a health checkup, Arai indicated that abdominal circumference primarily reflected the subcutaneous fat amount rather than the visceral fat amount [
One previous study reported that serum leptin concentrations, which increase with obesity, were positively correlated with BMI, abdominal circumference, and body fat percentage in junior high school students. In particular, body fat percentage showed the highest positive association with serum leptin concentrations [
The criteria for metabolic syndrome in children include an abdominal circumference ≥ 80 cm for junior high school students and ≥75 cm for elementary school students and/or WHtR ≥ 0.5 [
However, to our knowledge, no studies have evaluated the WHtR as an obesity index for children, still less for children with developmental disorders.
The degree of obesity in school health has traditionally been used as an index of childhood obesity. Its calculation, however, is relatively complicated in terms of using standard body weight derived based on body height and age-specific coefficients.
The present study suggested that WHtR might be a useful and effective obesity index of children with developmental disorders in consideration for easy calculation and high association with the degree of obesity in school health.
The present study had several limitations. The first is the small sample size of the study participants. This is because the subjects consisted of children with developmental disorders who were diagnosed in one clinic in a limited region. However, all children with developmental disorders whose physical measurements were available participated in the study. The results observed here might provide one suggestion of the effectiveness of WHtR as obesity index. Future studies need to examine on a larger number of participants in other regions and facilities so as to reproducibly observe the effectiveness of WHtR. The study was based on a cross-sectional association among physical measurements. A study based on the association with obesity-related biomarkers might strengthen the effectiveness of WHtR as obesity index. Furthermore, given that posture of children with high-grade obesity during measurement may affect abdominal circumference, sufficient instruction should be provided prior to measurement in children with developmental disorders.
The useful obesity index is important in children with developmental disorders for preventing the life-related diseases from the childhood. The present study suggests that the WHtR is more appropriate than the degree of obesity in school health and abdominal circumference as a simple and useful index of obesity in children with developmental disorders. In order to work to improve obesity in children with developmental disorders, it is necessary to provide support including diet and exercise during early childhood of 5 to 6 years of age, and to maintain a support system in collaboration with family members and teachers.
The author declares no conflicts of interest regarding the publication of this paper.
Kasagi, K. (2021) Evaluating Obesity Index among Children with Developmental Disorders. Open Journal of Nursing, 11, 57-64. https://doi.org/10.4236/ojn.2021.112006