Estimation of obesity in schoolchildren by measuring skinfold thickness

Eating Fast and Until Full Is Associated with Elevated Alanine Aminotransferase Activity in Japanese Schoolchildren: A Cross-Sectional Study

Alanine aminotransferase (ALT) activity has been recognized as a marker for monitoring the risk of metabolic syndrome, diabetes and non-alcoholic fatty liver disease in children. Higher ALT activity was reported to be associated with eating fast in Japanese adults, but the association in children is unclear. Moreover, eating fast and eating until full are reported to be associated with being overweight. This study examined the association between elevated ALT and eating behaviors (eating fast and eating until full) among population-based schoolchildren (aged 9-10 years) in Ina Town, Saitama, Japan. Data for eating behaviors were obtained from a self-written questionnaire. Blood samples were drawn to measure ALT. Elevated ALT was defined as > 30 U/L in boys and > 19 U/L in girls. Logistic regression models and structural equation models were used to calculate the effect of eating behaviors on elevated ALT. Final data analysis was carried out for 1,870 boys and 1,739 girls. "Eating fast and eating until full" was significantly associated with elevated ALT in each sex. "Eating fast and not eating until full" was significantly associated with elevated ALT in boys, but after adjusting for exercise and body mass index, this association was not significant. In conclusion, "eating fast and eating until full" was associated with elevated ALT in schoolchildren. A sex difference in the association of "eating fast and not eating until full" with elevated ALT was observed. Modifying the behaviors of eating fast and eating until full is important for schoolchildren to prevent ALT elevation.

Measurement of Visceral Fat, Abdominal Circumference and Waist-hip Ratio to Predict Health Risk in Males and Females

BACKGROUND AND OBJECTIVE

Obesity is a risk factor for a broad range of diseases. This study aimed to estimate association between selected variables (visceral fat, abdominal circumference and waist-hip ratio) and health risk in between male and female.

MATERIALS AND METHODS

The university student based cross-sectional study was conducted among male and female students. The anthropometric measurements were taken through the auto-calibrated digital scale. Bioelectrical impedance analyzer device was used to determine visceral fat area, abdominal circumference and waist-hip ratio. Independent t-test and Pearson Chi-Square was used for statistical analysis. To see the association among the all three variables, scatter plots were also drawn.

RESULTS

The results showed that 28.3% male and 9.4% female at risk for visceral fat, for the abdominal circumference 16.9% male and 6% female at risk and for waist-hip ratio 27.5% male and 6% female fell under risk category. There was a significant relationship among all variable for male and female.

CONCLUSION

Findings suggested that visceral fat area, abdominal circumference and waist-hip ratio were strong predictors of health risk. Male were more prone to health risk than female participants.

Effect of recovery from obesity on cardiovascular risk factors among Japanese schoolchildren: the Iwata population-based follow-up study

BACKGROUND

The effect of recovery from obesity on cardiovascular risk factors is not well understood in Japanese children.

METHODS

We analyzed follow-up data from the Iwata city population-based study of schoolchildren in Japan. The Iwata Board of Education conducted health screenings of children aged 10 and 14 years. A total of 914 children aged 10 years (451 boys and 463 girls, 87.1% of all children in the city in 1997) were followed until 14 years of age and classified by pattern of obesity as Normal, Recovered, Worsened, or Persistent.

RESULTS

Of the 914 children, 111 (12%) were obese at 10 years of age. Of those children, 44 (40%) were no longer obese at 14 years (ie, Recovered). At follow-up, Recovered boys had the greatest decrease in non-HDL cholesterol (mean ± SE, -21.3 ± 3.6 mg/dL) among the 4 groups, and Recovered girls had a significantly lower level of non-HDL cholesterol (Recovered, 107.1 ± 5.4 mg/dL vs. Persistent, 126.1 ± 4.5 mg/dL). The Recovered boys also had a significantly higher level of HDL cholesterol at age 14 (Recovered, 67.2 ± 2.7 mg/dL vs. Persistent, 53.3 ± 2.1 mg/dL). In the Recovered group, 68% of children who were dyslipidemic at baseline had normal cholesterol levels at age 14. The recovery rate from dyslipidemia was significantly higher in the Recovered group (cumulative incidence rate ratio, 2.5; 95% confidence interval, 1.4-4.7) as compared with the Persistent group.

CONCLUSIONS

Dyslipidemia was reversed in children who recovered from obesity. Our findings suggest that reducing obesity is beneficial to the health of Japanese schoolchildren.

Cut-off values of body mass index, waist circumference, and waist-to-height ratio to identify excess abdominal fat: population-based screening of Japanese school children

Background

School-based screening and prevention programs for adiposity generally target school children in grades 4 and 6 (age 9–11 years). The aims of this study were to evaluate the validity of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in identifying abdominal adiposity in fifth-grade Japanese school children and to determine optimal cut-off values for anthropometric measures.

Methods

The target population was fifth-grade school children enrolled in 2 schools in Shizuoka, Japan between 2008 and 2010; 422 of the 466 children participated in the present study. Abdominal adiposity was defined as percent trunk fat in the 95th percentile or higher, as determined by dual-energy x-ray absorptiometry (DXA). We analyzed the validity of BMI, WC, and WHtR using receiver operating characteristic (ROC) curve analysis. The Youden index was used to determine cut-off values of BMI, WC, and WHtR that identify excess abdominal fat.

Results

Optimal cut-off values to identify abdominal adiposity were 20.8 kg/m² (BMI), 76.5 cm (WC), and 0.519 (WHtR) for boys, and 19.6 kg/m² (BMI), 73.0 cm (WC), and 0.499 (WHtR) for girls. Areas under the ROC curve were 0.983 (BMI), 0.987 (WC), and 0.981 (WHtR) for boys, and 0.981 (BMI), 0986 (WC), and 0.992 (WHtR) for girls.

Conclusions

BMI, WC, and WHtR successfully identified a high proportion of children with excess abdominal fat as measured by DXA, demonstrating that these measures are useful indices for school screening.

Height-specific serum cholesterol levels in pubertal children: data from population-based Japanese school screening

Background

Inverse associations between height and serum lipid levels in pubertal children have been reported. To develop criteria for normal serum lipid levels stratified by height in pubertal children, we examined height-specific cholesterol levels, using data from a population-based school screening.

Methods

Serum levels of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) were investigated in 10 151 children (98.9% of the target population) aged 10 and 14 years who attended public schools in Iwata City from 2002 through 2007.

Results

The 95th percentiles of TC in the lowest and highest quintiles of height were 221 and 219 mg/dL, respectively, in 10-year-old boys, 215 and 203 mg/dL in 14-year-old boys, 220 and 204 mg/dL in 10-year-old girls, and 226 and 214 mg/dL in 14-year-old girls. The fifth percentiles of HDL-C in the lowest and highest quintiles of height were 45 and 43 mg/dL in 10-year-old boys, 43 and 40 mg/dL in 14-year-old boys, 46 and 42 mg/dL in 10-year-old girls, and 47 and 44 mg/dL in 14-year-old girls.

Conclusions

This study provided height-specific levels of serum lipids in 10-year-old and 14-year-old children. Height should be considered when evaluating cholesterol levels in pubertal children.

Relationship between height and blood pressure in Japanese schoolchildren

BACKGROUND

Blood pressure examinations for health education use have been conducted at several schools in Japan. It has been reported that blood pressure is closely associated with bodyweight and height in US children. The aim of the present paper was to evaluate the association between height and blood pressure in Japanese schoolchildren.

METHODS

In Iwata city in Japan, blood pressure screening was conducted by the school administration. A total of 98.9% (10,152/10,270 children) of all fifth (10-year-olds) and ninth graders (14-year-olds) residing in the Old Iwata area from 2002 to 2007 were analyzed.

RESULTS

In 10-year-old and 14-year-old boys, regression analysis indicated that a positive correlation between weight and blood pressure was the strongest among the three body size indices (height, weight, and body mass index), but the association between height and blood pressure was also significant. For girls from both the 10 and 14 year age groups, the correlation of weight and blood pressure was stronger than those for the other body size indices, but there were also significant associations between height and blood pressure, except for height and diastolic blood pressure in the 14-year-olds.

CONCLUSIONS

There is a significant positive relationship between height and blood pressure. Further study is necessary to provide a blood pressure reference based on height in the Japanese program to prevent children from developing lifestyle-related risk factors.

Relationship of body mass index to percent body fat and waist circumference among schoolchildren in Japan--the influence of gender and obesity: a population-based cross-sectional study

Background

Although the correlation coefficient between body mass index (BMI) and percent body fat (%BF) or waist circumference (WC) has been reported, studies conducted among population-based schoolchildren to date have been limited in Japan, where %BF and WC are not usually measured in annual health examinations at elementary schools or junior high schools. The aim of the present study was to investigate the relationship of BMI to %BF and WC and to examine the influence of gender and obesity on these relationships among Japanese schoolchildren.

Methods

Subjects included 3,750 schoolchildren from the fourth and seventh grade in Ina-town, Saitama Prefecture, Japan between 2004 and 2008. Information about subject's age, sex, height, weight, %BF, and WC was collected from annual physical examinations. %BF was measured with a bipedal biometrical impedance analysis device. Obesity was defined by the following two criteria: the obese definition of the Centers for Disease Control and Prevention, and the definition of obesity for Japanese children. Pearson's correlation coefficients between BMI and %BF or WC were calculated separately for sex.

Results

Among fourth graders, the correlation coefficients between BMI and %BF were 0.74 for boys and 0.97 for girls, whereas those between BMI and WC were 0.94 for boys and 0.90 for girls. Similar results were observed in the analysis of seventh graders. The correlation coefficient between BMI and %BF varied by physique (obese or non-obese), with weaker correlations among the obese regardless of the definition of obesity; most correlation coefficients among obese boys were less than 0.5, whereas most correlations among obese girls were more than 0.7. On the other hand, the correlation coefficients between BMI and WC were more than 0.8 among boys and almost all coefficients were more than 0.7 among girls, regardless of physique.

Conclusions

BMI was positively correlated with %BF and WC among Japanese schoolchildren. The correlations could be influenced by obesity as well as by gender. Accordingly, it is essential to consider gender and obesity when using BMI as a surrogate for %BF and WC for epidemiological use.

High blood pressure in obese and nonobese Japanese children: blood pressure measurement is necessary even in nonobese Japanese children

Background

Although the prevalences of obesity and hypertension (HT) are increasing in children, there have been few epidemiological studies of HT in Japanese children. We evaluated the prevalences of HT and high-normal blood pressure (HNBP), and examined the relationship between blood pressure (BP) and body mass index (BMI), in Japanese children.

Methods

The subjects of this study were 2420 children living in the town of Ina, Saitama Prefecture, Japan during the period from 2006 through 2008. Body height, weight, and BP were measured. HT and HNBP were defined according to the HT criteria for Japanese children. Children with HNBP or HT were defined as having high blood pressure (HBP).

Results

The prevalences of HBP were 15.9% and 15.8% in fourth-grade boys and girls, respectively, and 11.1% and 10.8% in seventh-grade boys and girls, respectively. Irrespective of sex or grade level, a higher BMI was associated with a higher prevalence of HBP (P < 0.001). When compared with the <50th percentile BMI category, the crude odds ratios (ORs) were statistically significant for the 75th to 84th percentile category in fourth-grade boys (OR: 4.54, 95% CI: 2.36–8.76), the ≥95th percentile in fourth-grade girls (13.29, 5.93–29.77), the 85th to 94th percentile (3.16, 1.46–6.84) in seventh-grade boys, and the ≥95th percentile (7.96, 3.18–19.93) in seventh-grade girls.

Conclusions

BMI was associated with HBP in Japanese school children. In addition, some children in the lower BMI categories also had HBP.

Changes in body mass index, leptin and adiponectin in Japanese children during a three-year follow-up period: a population-based cohort study

Objective

The study examined changes in and relationship between body mass index (BMI), leptin and adiponectin levels over a 3-year period in a pediatric population-based cohort.

Study design

A 3-year prospective cohort study of 268 boys and 251 girls aged 9–10 in Ina, Saitama, Japan.

Results

Median body mass index (BMI) significantly increased from baseline (age 9–10) to follow up (age 12–13) in boys from 17.1 to 18.3 kg/m² (P < 0.001) and in girls from 16.5 to 18.5 kg/m² (P < 0.001), respectively. Adiponectin values significantly decreased from baseline to follow up in boys (13.5 to 8.9 μg/ml, respectively) (P < 0.001) and in girls (12.4 to 9.5 μg/ml, respectively) (P < 0.001). Leptin values at follow up significantly decreased from baseline in boys (4.9 to 2.3 ng/dl, respectively) (P < 0.001) and also in girls (5.3 to 5.1 ng/dl, respectively) (P = 0.049).

A relatively strong correlation was seen in BMI (Spearman's correlation coefficient, r = 0.864, P < 0.001 in boys; r = 0.873, P < 0.001 in girls), adiponectin (r = 0.705, P < 0.001 in boys; r = 0.695, P < 0.001 in girls), and leptin (r = 0.449, P < 0.001 in boys; r = 0.610, P < 0.001 in girls) before and after the three-year period.

The ratio of follow up to baseline BMI was negatively correlated with that for adiponectin (r = -0.224, P < 0.001 in boys; r = -0.165, P = 0.001 in girls) and positively correlated with that for leptin (r = 0.518, P < 0.001 in boys; r = 0.609, P < 0.001 in girls).

Conclusion

This study demonstrated that baseline adiponectin, leptin and BMI values measured at ages 9–10 correlated with those measured three years later. However, adiponectin values decreased and leptin values increased in those subjects whose BMI increased during over this period.

Gender differences in the relationship between percent body fat (%BF) and body mass index (BMI) in Japanese children

The purpose of the present study was to examine whether gender differences exist in the relationship between percent body fat (%BF) and body mass index (BMI) in Japanese children using a population-based cohort. Subjects are comprised of 187 boys and 163 girls aged 9-10, and 137 boys and 155 girls aged 12-13. Percent BF was measured using a bipedal biometrical impedance analysis (BIA) device. The relationship between %BF and BMI was investigated as a function of age and gender with Pearson's correlation coefficient. Strong linear relationships existed between %BF and BMI, especially in girls (9-10-year-old boys: r=0.779, P<0.0001; 9-10-year-old girls: r=0.975, P<0.0001; 12-13-year-old boys: r=0.786, P<0.0001; 12-13-year-old girls: r=0.975, P<0.000l). These results indicate that %BF can be predicted from BMI in Japanese children aged 9-10 and 12-13 years. The correlations in boys were not as strong as those observed in girls, that is, less variability was explained for girls than for boys. Further study will be necessary to ascertain whether the strong correlation seen among girls will be observed in different age or ethnic groups, and to ascertain the mechanism that produces this gender difference.

Childhood obesity and its relation to serum adiponectin and leptin: a report from a population-based study

This study examined the relationships between serum adiponectin (AD) and leptin (LP) levels, and obesity using a population-based cohort consisted of 315 (9-10 year olds: G1) and 308 (12-13 year olds: G2) school children. Serum AD, LP and other markers were compared according to the presence of obesity. The prevalence rates of obesity were 14.9% in G1 and 9.4% in G2. The medians of serum AD (microg/dl: non-obese/obese) were statistically lower in obese children (9.6/8.3 in G1, p<0.05; 8.9/6.6 in G2, p<0.05), and the medians of serum LP (ng/dl) were statistically higher in obese children (3.7/12.5 in G1, p<0.05; 2.9/8.4 in G2, p<0.05). The serum LP levels were significantly positively correlated with percent overweight (POW) irrespective of age and sex, and the serum AD levels were significantly negatively correlated with POW except for boys in G1. Multivariate regression analyses revealed that LP, LDL-cholesterol and gender in G1, and LP, AD, blood pressure and gender in G2 were significantly correlated with POW. A large-scale, population-based study revealed that AD was lower and LP higher in obese children, and that the obese status in G2 was related to a worse metabolic profile than the case in G1.

Waist circumference estimation from BMI in Japanese children

Waist circumference, not BMI, is one of the factors in the definition of metabolic syndrome in adults. In children, waist circumference is also a well known predictor of metabolic syndrome. However, waist circumference measurement is not as commonly recorded as weight and height measurements in physical examinations in schools. This means BMI data is available for every child, but waist circumference is not. Therefore, we investigated whether there is an alternative way to estimate waist circumference even in those children whose waist circumference measurement has not been taken. We evaluated the relationship between BMI and the waist circumference of schoolchildren using a relatively large-scale population-based cohort in Japan. There was a significant linear relationship between BMI and waist circumference noted in each age- and sex-divided group [9-10-year-old boys: waist=13.99+2.63BMI (r=0.940, p<0.001), 9-10-year-old girls: waist=15.09+2.61BMI (r=0.933, p<0.001), 12-13-year-old boys: waist=23.67+2.22BMI (r=0.880, p<0.001), 12-13-year-old girls: waist=23.83+2.15BMI (r=0.859, p<0.001)]. This means it is possible to estimate waist circumference from height and weight, at least among those age groups of children in Japan. This estimation could be an alternative way and useful in detecting childhood metabolic syndrome or obesity disease in which a waist circumference figure is necessary.

Glycated albumin is low in obese, non-diabetic children

The current study evaluates the indices of glucose control for diabetics (i.e., glycated albumin (GA), hemoglobin A1c (HbA1c), plasma glucose (PG) and immuno-reactive insulin (IRI)) in non-diabetic children from a population-based cohort, and compares those values according to the presence of obesity to examine any differences in these indices. GA, HbA1c, casual PG and casual IRI in obese children (n = 209) were compared to those of non-obese children (n = 1060) in Ina town, Saitama Prefecture, in 2002-2003. In obese children, the levels of HbA1c, PG and IRI were statistically higher when compared to those of non-obese children. In contrast, the median and intra-quartile range (IQR) of GA of obese children (13.6%: 12.6-14.7) was statistically lower when compared to that of non-obese children (14.3%: 13.5-15.4, p < 0.001). The low GA (%) in obese children is mainly due to the low absolute value of GA (g/dl) rather than a higher albumin value (g/dl). This is the first report to reveal that GA levels are low in obese, non-diabetic children. Additional data collection and an experimental approach are necessary to reveal the reasons behind lower GA levels in obese children.

Association of reduction in parental overweight with reduction in children's overweight with a 3-year follow-up

BACKGROUND

Parental overweight has been reported to be a risk factor predicting obesity of their children. However, the effect of changes in parental overweight on the changes in children's overweight is not yet characterized.

METHODS

Six hundred five children of 9-10 years underwent physical examinations and a survey concerning parents' body mass index (BMI) with a 3-year follow-up.

RESULTS

In families where both parents' BMI was above 25 at baseline, when either parents' BMI decreased to less than 25 kg/m(2), children improved their adiposity, atherosclerosis index (AI), and systolic blood pressure (SBP). No such improvement was observed in children both of whose parents maintained BMI > or =25 kg/m(2).

CONCLUSIONS

Improving parental overweight possibly reduced the risk of overweight in their children. Changes in parental overweight status were associated with changes in overweight status of their children.