Objectives: To determine the relationship between obesity and cardiac autonomic nerve activity in healthy children. Methods: 16 healthy male children comprising of 9 nonobese and 7 obese subjects (body mass index > 19.1 kg/m2) aged 8−9 years were selected. Electrocardiograms were measured for 10 min. under controlled ventilation (0.25 Hz) in the supine position. Consecutive 256-second RR interval data were transformed by the Fast Fourier Transform method into power spectral data. Very low frequency (VLF; 0.003−0.04 Hz), low frequency (LF; 0.04−0.15 Hz), high frequency (HF; 0.15−0.40 Hz), and total power (TP; 0.003−0.40 Hz) were calculated and transformed into a natural logarithm (ln). Normalized units (nu) were also calculated as follows: LFnu = LF / (TP - VLF) x 100. HFnu = HF / (TP - VLF) x 100. Low/high-frequency ratio (LHR) was calculated as LF divided by HF. Unpaired t test was performed to compare the 2 groups. Results: TP ln and HFnu, reflecting cardiac parasympathetic nerve activity, in obese children were significantly lower than those in nonobese children. In contrast, LFnu and LHF, reflecting cardiac sympathetic nerve activity, in obese children were significantly higher than those in nonobese children. Conclusions: These findings suggest that obese children have higher sympathetic nerve activity and lower parasympathetic nerve activity than nonobese children.
Child ; Hz ; Cardio- ; Nerve ; With frequency

The purpose of this study is to investigate the prevalence of and to classify the types of silicosis patients who were working at that time as migrant workers in the eastern part of Toyama Prefecture. Migrant workers are known in Japanese as “dekasegi” This term refers to workers who migrate seasonally from their home towns to areas where work is more available.
Questionnaires were sent to all male inhabitants aged 30 or over in the selected five areas. Eighty-seven percent of the questionnaires were answered and returned. Based on the results, 482 inhabitants were selected as migrant workers with experience in jobs where they were exposed to large amount of dust. Chest roentgenography and subjective symptoms were examined in these subjects.
The results obtained were follows;
(1) Eight hundred and eighty-five of the respondents (41%) had worked as migrant workers.Of these, 580 men (66%) had worked in jobs with exposure to dust.
(2) Of the 482 migrant workers whose jobs exposed them to dust, 424 silicosis cases (88%) were found by chest roentgenographic examination. Silicosis is classified into four types according to the national Pneumoconiosis Law on the basis of chest roentgenographic findings. These patients included 195 cases of type 1, 123 cases of type 2, 59 cases of type 3 and 47 cases of type 4 silicosis.
(3) The prevalence of disease symptoms in the silicosis patients included ; cough 39%, phlegm 40%, shortness of breath 41%, palpitations 17% and wheezing in 20% of the cases. The silicosis patients showed a higher frequency of respiratory disease symptoms than those dust-exposed workers who did not evidence signs of silicosis.
(4) The silicosis patients were found in 98% of the migrant workers whose exposure to dust lasted a period of more than 20 years, 89% in men whose work was between 10 and 19 years and 76 % in men who had worked less than 10 years.
(5) The silicosis in 297 cases (70% of the total number of disease patients) was first detected during the examinations in the course of this research.

Objectives: The aim of this study was to identify characteristic lifestyles in children with obese parents. Methods: 8,030 children (4,072 males and 3,958 females) aged 6 to 7 years were investigated. A questionnaire relating to the lifestyles of children was distributed through elementary schools for completion by parents. The heights and weights of parents were self-reported. A parent with a body mass index (weight in kilograms divided by the square of height in meters) greater than the 90th percentile for gender (26.7 kg/m2 for fathers and 24.3 kg/m2 for mothers) was defined as an obese parent. A chi-square test for each trend was applied to evaluate an increasing trend in the frequency or level of each lifestyle in children with obese parents. Results: Children with obese parents were significantly associated with increasing trends in the proportions categorized by irregular intake of breakfast, faster eating, longer TV watching, and shorter sleeping hours. Conclusions: These lifestyles are considered to be possible risk factors for the development of obesity. These characteristic lifestyles observed in children with obese parents could strengthen the relationship between child and parental body compositions, in addition to the genetic predisposition to obesity in children with obese parents. These findings indicate that education with lifestyle modification for obese parents will be required to prevent further weight gain in children with obese parents.
Child ; Parents ; Life Style ; seconds ; trends

Objective: To assess the validity of a questionnaire for evaluating the physical activity of young children as reported by parents. Methods: Twenty-one male 1st grade elementary school children were the study subjects. The questionnaire contained 3 questions relating to the physical activity of children and was completed by their parents. These questions were: preference for physical activity: like very much, like, don't like; physical activity compared to peers: more than, the same as, less than peers; time spent on exercise activity per day: <30 min, 30—60 min, 60 min or more. We also assessed physical activity more objectively, using a small instrument for calculating total steps, energy expenditure originating from exercise, and total energy expenditure per day. The contribution of the questionnaire items to the objective indices was evaluated by linear regression analysis. Results: Preference for physical activity was significantly associated with all the objective indices. Physical activity compared with peers had links with total energy expenditure. Time spent in activity was related to total steps and energy expenditure from exercise. Conclusion: All the questionnaire items were valid measures for evaluating the physical activity level in young children and could be applied to a large epidemiological survey.
Physical activity ; Questionnaires ; Energy Metabolism ; Child ; Minute of time

OBJECTIVESTo examine the relationships between body image, body satisfaction and dieting behavior in the context of pubertal changes in Japanese preadolescents.

METHODSA cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12-13) born in Toyama prefecture.

RESULTSThe percentages of those who perceived themselves fat, wanted to be thinner, and had tried dieting, which increased with body mass index (BMI), were significantly higher in girls than in boys (34.2% vs. 20.0%, 58.0% vs. 26.0%, and 17.3% vs. 5.7%, respectively). Independent of sex and BMI, those who wanted to be thinner and those who had tried dieting were more frequently observed in those who perceived themselves fat, and those who had tried dieting were more frequently observed in those who wanted to be thinner. Pubertal changes were significantly associated with dieting behavior, but their relationships to body image and body satisfaction differed between sexes; for boys, those who perceived themselves fat were more frequently observed in those without pubertal changes; whereas for girls, those who wanted to be thinner were more frequently observed in those with pubertal changes.

CONCLUSIONSDieting behavior of Japanese preadolescents was associated with whether they perceived themselves fat and wanted to be thinner, sometimes independent of whether they were actually overweight. Pubertal changes might induce a positive perspective of growing fat among boys and a desire to be thinner among girls, with the consequence that dieting behavior would be reinforced in those with pubertal changes.

OBJECTIVESTo examine parental influence on the development of obesity in 9-year-old Japanese children.

METHODSA 6-year follow-up study of obesity among 6,102 children born in Toyama prefecture.

RESULTSAfter adjusting for obesity at age 3, either paternal obesity or maternal obesity at the age 3 survey more than double the risk of obesity at age 9 in both genders. Increases in parental body mass indexes (BMIs) from the age 3 survey through the age 9 survey were significantly associated with obesity at age 9 in girls.

CONCLUSIONSNot only parental obesity but also increases in parental BMIs were likely to be associated with development of obesity in children.

OBJECTIVETo assess the validity of a questionnaire for evaluating the physical activity of young children as reported by parents.

METHODSTwenty-one male 1st grade elementary school children were the study subjects. The questionnaire contained 3 questions relating to the physical activity of children and was completed by their parents. These questions were: preference for physical activity: like very much, like, don't like; physical activity compared to peers: more than, the same as, less than peers; time spent on exercise activity per day: <30 min, 30-60 min, 60 min or more. We also assessed physical activity more objectively, using a small instrument for calculating total steps, energy expenditure originating from exercise, and total energy expenditure per day. The contribution of the questionnaire items to the objective indices was evaluated by linear regression analysis.

RESULTSPreference for physical activity was significantly associated with all the objective indices. Physical activity compared with peers had links with total energy expenditure. Time spent in activity was related to total steps and energy expenditure from exercise.

CONCLUSIONAll the questionnaire items were valid measures for evaluating the physical activity level in young children and could be applied to a large epidemiological survey.

OBJECTIVESTo analyze the path to dieting behavior in Japanese preadolescents.

METHODSA cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12-13) born in Toyama prefecture.

RESULTSWhile increasing with body mass index (BMI), the percentage of those who had tried dieting was higher in those who perceived themselves fat than in those who perceived themselves thin or average. Of those who wanted to be thinner, 16.1% of boys and 26.8% of girls had tried dieting. Path analysis in nonobese subjects (2,116 boys and 2,334 girls) showed that (1) body image was primarily based on BMI, (2) body image led to body dissatisfaction, and (3) body dissatisfaction led to dieting behavior. Pubertal changes had a significant effect on body image (path coefficient <0)for boys and body satisfaction (path coefficient >0) for girls, in addition to that on BMI. Maternal BMI had a significant effect on BMI but not on body image, body satisfaction, or dieting behavior.

CONCLUSIONSBody image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents. Pubertal changes may reinforce dieting behavior, but the mechanism may differ by sex.