No abstract

The Committee of the Japan Society for the Study of Obesity reported the new criteria for 'obesity disease' for Japanese adults in 2000. We defined the criteria for the diagnosis of obesity in children with medical problems, corresponding to the 'obesity disease' criteria in adults. Obesity in childhood was defined as follows: percentage of overweight (POW) and body fat exceeded the criteria. 'Obesity disease in childhood' was defined as obesity associated with health or medical problems, and with indications for medical intervention. Medical problems with indications for immediate intervention were grouped as A problems, which consisted of (i). hypertension; (ii). sleep apnea or hypoventilation; (iii). Type 2 diabetes mellitus or impaired glucose tolerance; and (iv). increased waist circumference or accumulation of visceral adipose tissue. Metabolic derangements or equivalent associated with obesity were grouped as B problems: (i). liver dysfunction; (ii). hyperinsulinemia; (iii). hypercholesterolemia; (iv). hypertriglyceridemia; (v). low serum high-density lipoprotein cholesterol; (vi). acanthosis nigricans, and (vii). hyperuricemia. Obese children over 5 years of age with following conditions were diagnosed as 'obesity disease in childhood': (i). any 'A problem', (ii) POW >or= 50% and any 'B problem', or (3) POW < 50% and more than one 'B problem' or equivalent. We decided to take physicosocial problems related to obesity into consideration as the criteria. The resultant criteria are proposed by the Committee for Research of Appropriate Body Build in Children*.

Changes in the daily macronutrient intake of Japanese children have been studied over the past half century to determine the effects of such changes on a child's healthy growth and development. Data from government and other reports show that in 5-y-old boys in the Tokyo metropolitan area, the intake of fat as a percentage of total energy intake was 12.6%, 20.9%, 28.4%, 33.8%, and 33.2% in 1952, 1960, 1970, 1982, and 1994, respectively. The prevalence of obesity in school-aged children is increasing; recently, nearly 10% of the children in this age group were considered obese. About 5% of obese children experience some adverse effects caused by obesity, eg, hypertension and hyperlipidemia. Nationwide surveys on serum cholesterol concentrations conducted in 1960, 1970, 1980, and 1990 showed that the cholesterol concentrations in 10-19-y-old males and females increased year after year. The height of boys and girls rapidly increased during the 15-y period from 1945 to 1960, and after 1970 the adult height in Japan was thought to have reached its maximum. The factors that contribute to the health problems facing today's Japanese children include their sedentary lifestyle, irregular intake of meals (especially skipping breakfast), and the increasing daily ratio of fat to total energy intake. Presently, changing the sedentary lifestyle is the most significant issue to be resolved.

This new criteria should prove valuable in health strategies for rational prevention and intervention in children. It should be emphasized to provide some intervention for Japanese children immediately.

The autonomic circadian rhythm plays an important role in asthma. In recent years it has become possible to evaluate autonomic nervous function (ANF) using analysis of heart rate variability (HRV). We analyzed the HRV in the 24h period following the state without an asthma attack in order to study the relationship between asthma and ANF. The HRV was analyzed in 94 asthmatic children (ages 5-15 years). These subjects were divided into groups according to the severity of their asthma. After recording a 24h ambulatory electrocardiograph (AECG), the HRV was analyzed by a computer. Evaluation of the HRV was carried out using time-domain and frequency-domain analyses. The ANF of asthma subjects was decreased in comparison to the normal group. The severity of asthma had a significant effect on the %RR50 (the proportion of cycles during which the difference is > 50 ms), the SD (standard deviation; mean of standard deviation of all normal RR intervals for all 5-minute periods), the low-frequency (LF) band (0.04 to 0.15 Hz), and the high-frequency (HF) band (0.15 to 0.4 Hz) (%RR50: F = 4.31, p = 0.01; SD: F = 3.48, p = 0.03; LF: F = 3.67, p = 0.02; HF: F = 3.41, p = 0.03). These values were lowest in the severe asthma group. With regard to the therapy grouping, the index that exhibited a significant difference was the NNA (mean of normal-to-normal RR intervals over 24h) (F = 4.43, p = 0.01). In conclusion, even in the normal condition in which the patient is free of an asthma attack, the ANF of asthma sufferers differs from that of normal children. It is possible that the different ANF of asthma sufferers is related to the severity of the asthma.