Harunobu Nakamura

Cut-off Values of Body Mass Index, Waist Circumference, and Waist-to-Height Ratio to Identify Excess Abdominal Fat: Population-Based Screening of Japanese Schoolchildren

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.

Trends in Body Mass Index, Blood Pressure, and Serum Lipids in Japanese Children : Iwata Population-Based Annual Screening (1993-2008)

Background Current trends in body size, blood pressure, and serum lipids in children are predictors of future disease prevalence. However, there have been no studies of blood pressure and high-density lipoprotein cholesterol (HDL-C) levels in Japanese children. Methods We investigated trends in body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), non-HDL-C, and HDL-C using data from annual screenings in 1993 through 2008. The subjects were 14 872 (98.8% of the target population) fifth-graders enrolled in all public schools in the Original Iwata area in Iwata City, Japan. The same examination protocol was used throughout to ensure the uniformity of quality control and the precision of assessment. Trends in the variables in relation to the calendar year were analyzed by using regression models. Results In boys, the 95th percentile of BMI increased by 0.09 kg/m2/year. In both sexes, the 5th percentile of BMI decreased by 0.02 to 0.03 kg/m2/year. There was a significant negative correlation between SBP and calendar year, and the 95th percentile of SBP decreased by 0.52 mm Hg/year in boys and by 0.40 mm Hg/year in girls. There was also a significant reduction DBP. However, there were no trends in TC, non-HDL-C, or HDL-C. Conclusions The increase in obese and underweight children in Original Iwata was consistent with the findings of a nationwide survey. Although high blood pressure and related risk factors were formerly a serious problem in Japan, blood pressure levels have decreased in schoolchildren from Iwata over the past 15 years.

Effects of dietary restriction on spontaneous dermatitis in NC/Nga mice.

In laboratory animals, dietary restriction prolongs life span, improves physiologic function, and prevents or lessens severity of several diseases including some experimental inflammatory states. We investigated the effect of dietary restriction on a spontaneously occurring mouse model of atopic dermatitis, an inflammatory skin disease. NC/Nga mice were assigned to a group fed ad libitum or to a restricted diet group receiving 60% of the amount of food consumed by the other group. Dermatitis was characterized according to extent, intensity, and scratching time. We then used computer-assisted image analysis to quantify immunologic findings in skin sections. Extent, intensity score, and scratching time in mice with restriction increased more gradually than in mice fed ad libitum. Infiltrating Inflammatory cells (CD4-positive T cells, CD8-positive T cells, eosinophils, and mast cells) as well as interleukin-4 and −5 secreted into tissue were reduced in mice with restriction. In conclusion, dietary restriction delayed onset and progression of spontaneous dermatitis in NC/Nga mice, an effect possibly involving inhibition of inflammatory infiltration cell and cytokine secretion.

Dietary restriction: effects of short-term fasting on protein uptake and cell death/proliferation in the rat liver

Dietary restriction (DR) is known to prolong life in laboratory animals. Intermittent (alternate-day) fasting or short-term repeated fasting has also been reported to increase the life span of animals. In the present study, we investigated the changes or induction of abnormalities of protein metabolism in rats during fasting, and measured asialoglycoprotein uptake and cell death/proliferation in the liver of rats receiving fasting and refeeding. In the results, liver weight decreased significantly after 48 h of fasting and increased during the refeeding period, returning to the pre-fasting level by 12 h of refeeding. Cell death, determined by single stranded DNA (ssDNA) staining method, increased during the fasting period, and returned to the pre-fasting level during the refeeding period. Cell proliferation, determined using antibodies (Ab) against proliferating cell nuclear antigen, decreased during the fasting period, and increased during the refeeding period. Changes in cell death and cell proliferation were inversely related. However, there was no significant difference in asialoglycoprotein uptake by the whole liver between the ad libitum (AL)-fed rats and 48 h fasted rats. Thus, neither the changes in liver weight nor cell death/proliferation affected asialoglycoprotein uptake on a living body. These results suggest that episodes of 48 h fasting do not induce protein metabolism abnormalities in the liver.

The relationship of oxidative DNA damage marker 8-hydroxydeoxyguanosine and glycoxidative damage marker pentosidine.

OBJECTIVES 8-hydroxydeoxyguanosine (8-OHdG) is a biomarker of oxidative DNA damage. Pentosidine is a biomarker of glycoxidation reaction. In this study, we investigated relationships among 8-OHdG, pentosidine and age. DESIGN AND METHODS We determined the urinary concentrations of 8-OHdG and pentosidine in adults with mild hypercholesterolemia or/and mild hypertension (hypercholesterolemia group, n = 31; hypertension group, n = 25; hypercholesterolemia and hypertension group, n = 7). RESULTS The strength of the relationship between 8-OHdG and age was the same as that between pentosidine and age (the correlation coefficient between 8-OHdG and age was 0.33, pentosidine and age was 0.37). In addition, there was a positive and significant correlation between 8-OHdG and pentosidine. On the other hand, mean values of 8-OHdG and pentosidine showed no significant difference among the three groups. CONCLUSION The results of the present study indicate that both 8-OHdG and pentosidine levels increase similarly in degenerative pathologic conditions.

Suppressive Effects on Allergic Contact Dermatitis by Short-Term Fasting

Fasting alters various hormonal and immune conditions. It has been reported that delayed type immune response to the injection of keyhole limpet hemocyanin was depressed by short-term fasting. In this study, we adopted the computer-assisted image analyzer for histopathological analysis and evaluated the infl uence of short-term fasting on allergic contact dermatitis induced by 2,4-dinitrofluorobenzene (DNFB). Mice were sensitized by painting of DNFB to the abdomen. After the sensitization, mice were challenged by DNFB painting to the ear. Fasting started 24 hour before (48-hour fasted group) or immediately after (24-hour fasted group) the challenging. Fasting without DNFB treatment did not induce remarkable change of ear thickness, ear tissue, serum albumin, serum total protein, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, or serum creatine phosphokinase. In contrast, fasting suppressed the increment of ear thickness in the DNFB-treated group in this study. We could also demonstrate, using the computerized image analyzer, that both lymphocyte infi ltration and the edema in the dermis were suppressed in fasted mice treated with DNFB. Further, edema in the dermis was inhibited more strongly in 48-hour fasted mice than in 24-hour fasted mice. These fi ndings indicate that short-term fasting induce histopathological changes in the state of contact dermatitis.

Vitamin D status and body fat measured by dual-energy X-ray absorptiometry in a general population of Japanese children

OBJECTIVE For a general population of children, data on the relationship between vitamin D status and adiposity are limited. The aim of this study was to assess the relationships between the serum concentration of 25-hydroxyvitamin D (25-OH-D) and body fat variables measured by dual-energy X-ray absorptiometry (DXA) in a general population of Japanese children, including underweight, normal, and overweight children. METHODS The source population comprised 521 fifth-grade children who attended either of the two public schools in Hamamatsu, Japan. Total and regional body fat mass (FM) measured by DXA were evaluated along with the serum concentration of 25-OH-D. RESULTS We were able to analyze the FM and 25-OH-D data of 400 of the 521 children. Among boys, significant inverse relationships were observed between serum vitamin D levels and body fat variables (total FM, r = -0.201; trunk FM, r = -0.216; appendicular FM, r = -0.187; P < 0.05 for all values). Mean values of total FM and trunk FM in the vitamin D-deficient group (25-OH-D <50 nmol/L) were larger than those in the vitamin D-sufficient group (25-OH-D ≥75 nmol/L) after adjusting for confounding factors, such as sedentary behavior (P < 0.05). No relationship was observed between vitamin D status and FM among girls. CONCLUSIONS Vitamin D deficiency was associated with higher total and trunk adiposities in a general population of Japanese children, particularly boys.

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.

Relationship Between Body Mass Index at Age 3 Years and Body Composition at Age 11 Years Among Japanese Children: The Shizuoka Population-Based Study

Background A few studies reported an association between body weight during early childhood and body composition in later life, as measured by dual-energy X-ray absorptiometry (DXA); however, none of those studies investigated an East Asian population. In a Japanese population, we examined the association between body weight at age 3 years and body composition at age 11 years, as measured using DXA. Methods The source population was 726 fifth-grade school children enrolled at 3 public schools in Shizuoka Prefecture, Japan from 2008–2010. All children who lived in the study area went to 1 of these 3 schools. DXA was used to obtain data on body composition, and the Maternal and Child Health Handbook was used to calculate body mass index (BMI). The general linear model was used for statistical analysis. Results We were able to analyze data on body composition at age 11 years and BMI in early childhood for 550 children. BMI at age 3 and change in BMI z-score from birth to age 3 were positively associated with bone mineral content (BMC), fat-free soft tissue mass (FFSTM), and fat mass (FM) at age 11. After adjusting for confounding factors, mean BMC, FFSTM, and FM were significantly lower among children who were underweight at age 3 and significantly higher among children who were overweight at age 3, as compared with values for normal-weight children at age 3. Conclusions Among Japanese children, body weight at age 3 years predicts body composition at age 11 years.

Combined influence of media use on subjective health in elementary school children in Japan: a population-based study

BackgroundIn recent years in Japan, electronic games, home computers, and the internet have assumed an important place in people’s lives, even for elementary school children. Subjective health complaints have also become a problem among children. In the present study, we investigated the relationship between media use and health status in elementary school children in Japan.MethodsA cross-sectional school-based population survey was conducted in 2009 with a sample of fourth-, fifth-, and sixth-grade children (age range: 10–12 years old) in elementary schools in Japan (n = 3,464). Self-reported health, lifestyle habits, and time spent using media were assessed.ResultsThe use of games, television, and personal computers was significantly associated with lifestyle (p < 0.05) and subjective health (p < 0.05). In addition, the use of games, the use of television, and the use of personal computers were mutually associated. The greater the number of media used for more than 1 hour was, the higher the odds ratio of the association of media use with unhealthy lifestyle and subjective health complaints was. The plural use of these media had stronger associations with unhealthy lifestyle and subjective health complaints.ConclusionsGame, television, and personal-computer use were mutually associated, and the plural use of these media had stronger associations with unhealthy lifestyle and subjective health complaints. Excessive use of media might be a risk for unhealthy lifestyle and subjective health complaints.