Ryuzo Takaya

Criteria for medical intervention in obese children: A new definition of ‘Obesity disease’ in Japanese children

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 ≥ 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 * .

COMPARISON OF BIOELECTRICAL IMPEDANCE ANALYSIS AND DUAL ENERGY X-RAY ABSORPTIOMETRY FOR ASSESSMENT OF BODY COMPOSITION IN CHILDREN

Abstract Background: There are a variety of methods for assessing body composition. Bioelectrical impedance analysis (BIA) is an easy and non‐invasive technique, but has limitations in underweight and overweight subjects. Few reports have investigated the validity of BIA in children. In this report, the characteristics of BIA, especially in overweight and underweight children, are assessed and the results are compared with those of dual energy X‐ray absorptiometry (DXA), as a reliable method for assessing body composition.

Association of Uric Acid with Obesity and Endothelial Dysfunction in Children and Early Adolescents

Background: Hyperuricemia in adults is known to be associated with hypertension, the metabolic syndrome and cardiovascular disease. The purpose of this study was to elucidate the factors associated with hyperuricemia in obese children and early adolescents and to investigate the threshold serum level of uric acid (UA) for the metabolic syndrome in children. Methods: We assessed anthropometric measurements, blood pressure, body composition and biochemical data in 1,559 obese children. To assess endothelial dysfunction, flow-mediated dilatation (FMD) was measured in 92 children. The correlations between serum UA levels and various parameters were examined. The threshold serum UA level for the metabolic syndrome was calculated by receiver-operating characteristic (ROC) curve analysis. Results: Serum UA levels were positively correlated with lipids in both boys and girls, and they were inversely correlated with FMD in the boys but not the girls. The threshold serum UA level for the metabolic syndrome was 5.25 mg/dl in boys and 5.05 mg/dl in girls. However, the specificity and sensitivity of ROC curve analysis are not so striking. Conclusion: The correlation between UA and FMD showed gender differences and might be affected by the hormonal status. The cutoff level of serum UA as a marker of the metabolic syndrome in obese children was affected by both age and gender.

Efficacy of high sodium intake in a boy with instantaneous orthostatic hypotension.

Abstract We report the case of a 14-year-old boy with instantaneous orthostatic hypotension (INOH) with symptoms of orthostatic intolerance. We investigated the effect of high sodium intake on hemodynamics and circulatory responses to orthostatic stress using Portapres. Moreover, a multifrequency bioelectrical impedance method was used to confirm increased plasma volume. Although we began treatment with an alpha-adrenoceptor agonist after his admission into our hospital, the effect was not sufficient. We, therefore, began a regimen of high sodium intake (NaCl 3 g two times a day per os in addition to regular diet, NaCl 5–6 g /day) to increase plasma volume. As a result, 48 hours after sodium intake, orthostatic tolerance was markedly improved with a concomitant increase in blood pressure in the orthostatic test. By measuring the patients body water before and after the high sodium intake, we were able to document the increase in plasma volume. We conclude that high sodium intake is an effective treatment for orthostatic hypotension in combination with vasoactive drugs.

Delayed onset congenital hypothyroidism in a patient with DUOX2 mutations and maternal iodine excess

Congenital hypothyroidism (CH), one of the most common congenital endocrine disorders, causes irreversible intellectual disability in untreated patients. Today, the vast majority of patients receive early diagnosis and treatment in the context of newborn screening for CH, and achieve satisfactory cognitive development. However, a subset of patients with delayed onset are undetectable by newborn screening, and miss benefit from early intervention. Here, we report on a delayed‐onset CH patient that had two contributing factors in the pathogenesis of CH simultaneously, i.e., a genetic defect and iodine excess. The patient was exposed to excessive iodine in utero because her mother consumed massive amounts of seaweed during pregnancy. Surprisingly, the patient had a negative result in newborn screening, but developed overt CH at age 3 months. She received thyroxine supplementation until when normalization of the thyroid function was confirmed at age 3 years (i.e., transient CH). Mutation screening for DUOX2, a causative gene for transient CH, showed biallelic mutations (p.[E327X] + [H678R]). This report provides a new example of environmental modification of phenotypes of CH due to a genetic defect, which can potentially distort screening results.

HLA-class II and class I genotypes among Japanese children with Type 1A diabetes and their families

Sugihara S, Ogata T, Kawamura T, Urakami T, Takemoto K, Kikuchi N, Takubo N, Tsubouchi K, Horikawa R, Kobayashi K, Kasahara Y, Kikuchi T, Koike A, Mochizuki T, Minamitani K, Takaya R, Mochizuki H, Nishii A, Yokota I, Kizaki Z, Mori T, Shimura N, Mukai T, Matsuura N, Fujisawa T, Ihara K, Kosaka K, Kizu R, Takahashi T, Matsuo S, Hanaki K, Igarashi Y, Sasaki G, Soneda S, Teno S, Kanzaki S, Saji H, Tokunaga K, Amemiya S, and The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT). HLA‐class II and class I genotypes among Japanese children with Type 1A diabetes and their families.

Identification of INS and KCNJ11 gene mutations in type 1B diabetes in Japanese children with onset of diabetes before 5 yr of age

The etiology of type 1 diabetes (T1D) is heterogeneous and is according to presence or absence of pancreatic autoantibodies divided into two subtypes: type 1A (autoimmune‐mediated) and type 1B (non‐autoimmune‐mediated). Although several genes have been linked to type 1A diabetes, the genetic cause of type 1B diabetes in Japanese individuals is far from understood.

Quantitative study on cerebral blood volume determined by a near-infrared spectroscopy during postural change in children

Aim: To investigate changes in cerebral blood volume during standing in healthy children with or without abnormal cardiovascular responses.

FUT2 non-secretor status is associated with Type 1 diabetes susceptibility in Japanese children

To examine the contribution of the FUT2 gene and ABO blood type to the development of Type 1 diabetes in Japanese children.

Association of thyroid hormones with obesity and metabolic syndrome in Japanese children

Obesity is associated with health consequences, and thyroid dysfunction may be an adaption to the increased energy expenditure in obesity. With the rising prevalence of obesity in childhood, the prevalence of metabolic syndrome may also increase. In the current study, we have shown gender differences in the association of thyroid hormones with obesity, and attempted to elucidate the relationship between thyroid hormones and anthropometric parameters and biochemical data in obese Japanese children. We analyzed anthropometric measurements, blood pressure, body composition, thyroid hormones, and lipid profiles in 283 obese children. The association between thyroid hormones and several parameters differed by gender. The free T3 to free T4 ratio (fT3/fT4) in boys was negatively associated with the quantitative insulin sensitivity check index, whereas in girls, thyroid-stimulating hormone levels were positively correlated with levels of glucose, diastolic blood pressure, and non-high density lipoprotein-cholesterol, and fT3/fT4 was positively correlated with uric acid levels. FT3/fT4 in boys with metabolic syndrome was relatively higher than in those without metabolic syndrome. The cause of gender differences is unknown. Therefore, further studies with larger sample sizes and a long-term follow-up period are needed to address the influence of thyroid hormones on various parameters.