Association between trunk-to-peripheral fat ratio and renal function in elderly Japanese men: baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study.

BACKGROUND: Central obesity as measured by waist-to-hip circumference ratio (WHR) has been reported to be associated with renal hemodynamics and function. However, the adipose component of WHR, which is a composite measure of fat mass and fat-free mass, is small, particularly in nonobese subjects. Trunk-to-peripheral fat ratio as measured using dual-energy absorptiometry (DXA) is a more precise method for evaluating central fat distribution than WHR. The present study investigated the cross-sectional association between DXA-measured trunk-to-peripheral fat ratio and estimated glomerular filtration rate (eGFR) in community-dwelling elderly Japanese men. METHODS: Participants were 575 men aged ≥65 years at the time of the baseline survey of the second Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort study. Trunk-to-appendicular fat ratio (TAR) was calculated as trunk fat divided by appendicular fat (sum of arm and leg fat), and trunk-to-leg fat ratio (TLR) as trunk fat divided by leg fat. RESULTS: eGFR values significantly decreased from the lowest to the highest quintile of TAR/TLR. After adjusting for potential confounding factors including whole-body fat, the highest quintile of both TAR and TLR showed statistically significant odds ratios for the risk of eGFR <60 ml/min/1.73 m2, relative to the lowest quintile. In addition, a significant decreasing trend was observed for eGFR values from the lowest to the highest quintile of TAR/TLR after adjusting for confounding factors including whole-body fat. CONCLUSION: Elderly men with a large trunk-to-peripheral fat ratio tended to have a lower eGFR. This association occurred independently of that between whole-body fat and eGFR.

Attitude toward breakfast mediates the associations of wake time and appetite for breakfast with frequency of eating breakfast.

PURPOSE: We investigated associations among attitude toward breakfast, appetite for breakfast, wake time, personality traits, self-esteem, and frequency of eating breakfast in university students and proposed a model of factors affecting the frequency of eating breakfast. METHODS: The participants, 555 Japanese university students (177 men, 378 women), completed a questionnaire about their height and weight, living with family, wake time, frequency of eating breakfast, appetite for breakfast, attitude toward breakfast, personality traits, and self-esteem. Appetite for breakfast was evaluated with a four-point Likert-type scale. Attitude toward breakfast was assessed with a 13-item questionnaire using a five-point Likert-type scale; responses to the items were summed, and divided by the number of items to produce a score. RESULTS: Multiple linear regression analysis showed that frequency of eating breakfast was positively associated with appetite for breakfast and attitude toward breakfast, and inversely associated with wake time. Wake time was inversely associated with attitude toward breakfast, and appetite for breakfast was positively associated with attitude toward breakfast. Structural equation modeling showed that the structured model based on the multiple regression analysis was a good fit for both men (chi-square value to the degrees of freedom [χ2/df] = 1.096, root mean square error of approximation [RMSEA] = 0.023) and women (χ2/df = 1.510, RMSEA = 0.037). CONCLUSIONS: These results suggest that wake time and appetite for breakfast are directly associated with frequency of eating breakfast. Attitude toward breakfast mediates the indirect association between frequency of eating breakfast and both wake time and appetite for breakfast. LEVEL OF EVIDENCE: V, cross-sectional descriptive study.

Associations between trunk-to-peripheral fat ratio and cardiometabolic risk factors in elderly Japanese men: baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study.

BACKGROUND: Body mass-independent parameters might be more appropriate for assessing cardiometabolic abnormalities than weight-dependent indices in Asians who have relatively high visceral adiposity but low body fat. Dual-energy X-ray absorptiometry (DXA)-measured trunk-to-peripheral fat ratio is one such body mass-independent index. However, there are no reports on relationships between DXA-measured regional fat ratio and cardiometabolic risk factors targeting elderly Asian men. METHODS: We analyzed cross-sectional data of 597 elderly men who participated in the baseline survey of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study, a community-based single-center prospective cohort study conducted in Japan. Whole-body fat and regional fat were measured with a DXA scanner. Trunk-to-appendicular fat ratio (TAR) was calculated as trunk fat divided by appendicular fat (sum of arm and leg fat), and trunk-to-leg fat ratio (TLR) as trunk fat divided by leg fat. RESULTS: Both TAR and TLR in the group of men who used ≥ 1 medication for hypertension, dyslipidemia, or diabetes ("user group"; N = 347) were significantly larger than those who did not use such medication ("non-user group"; N = 250) (P < 0.05). After adjusting for potential confounding factors including whole-body fat, both TAR and TLR were significantly associated with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, fasting serum insulin, and the insulin resistance index in the non-user group and non-overweight men in the non-user group (N = 199). CONCLUSION: The trunk-to-peripheral fat ratio was associated with cardiometabolic risk factors independently of whole-body fat mass. Parameters of the fat ratio may be useful for assessing cardiometabolic risk factors, particularly in underweight to normal-weight populations.

Determinants of bone health in elderly Japanese men: study design and key findings of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort study.

BACKGROUND: The Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study was launched to investigate risk factors for osteoporotic fractures, interactions of osteoporosis with other non-communicable chronic diseases, and effects of fracture on QOL and mortality. METHODS: FORMEN baseline study participants (in 2007 and 2008) included 2012 community-dwelling men (aged 65-93 years) in Nara prefecture, Japan. Clinical follow-up surveys were conducted 5 and 10 years after the baseline survey, and 1539 and 906 men completed them, respectively. Supplemental mail, telephone, and visit surveys were conducted with non-participants to obtain outcome information. Survival and fracture outcomes were determined for 2006 men, with 566 deaths identified and 1233 men remaining in the cohort at 10-year follow-up. COMMENTS: The baseline survey covered a wide range of bone health-related indices including bone mineral density, trabecular microarchitecture assessment, vertebral imaging for detecting vertebral fractures, and biochemical markers of bone turnover, as well as comprehensive geriatric assessment items. Follow-up surveys were conducted to obtain outcomes including osteoporotic fracture, cardiovascular diseases, initiation of long-term care, and mortality. A complete list of publications relating to the FORMEN study can be found at https://www.med.kindai.ac.jp/pubheal/FORMEN/Publications.html .

Maternal pre-pregnancy underweight is associated with underweight and low bone mass in school-aged children.

INTRODUCTION: A number of studies have reported that pre-pregnancy overweight status is associated with offspring obesity, yet only a few studies have examined pre-pregnancy underweight status as it associates with offspring health. The aim of the present study was to assess the effect of pre-pregnancy underweight status in a mother on health outcomes in her offspring. To this end, the primary outcome examined in the present study was underweight status in the offspring, with a secondary outcome of offspring low bone mass. MATERIALS AND METHODS: The present retrospective cohort study, conducted from 2008 to 2011, targeted a source population of all students registered as fifth-graders at three public elementary schools in Hamamatsu and Fukuroi cities. Maternal height and weight before and after pregnancy and offspring weight and height at birth were obtained from the Maternal and Child Health Handbook. Offspring weight and height at age 10 years were measured using standard procedures. Offspring total body less head (TBLH) bone mineral content (BMC) was determined with a dual-energy X-ray absorptiometry scanner. RESULTS: Pre-pregnancy underweight status was found to be associated with an increased risk of an underweight status in female offspring (OR = 2.88, 95% CI 1.06-7.81). Offspring TBLH BMC in the underweight mother group was significantly lower than that in the non-underweight mother group. CONCLUSIONS: We determined that pre-pregnancy underweight status was more likely to lead to an underweight status and low TBLH BMC in school-aged offspring.

Trends in Serum Lipid Levels of a 10- and 13-Year-Old Population in Fukuroi City, Japan (2007-2017).

BACKGROUND: Current trends in serum lipid levels among children are likely to be important predictors of future cardiovascular disease prevalence. However, no studies have examined trends in low-density lipoprotein cholesterol (LDL-C) levels in Japanese children. METHODS: We investigated trends in LDL-C levels from 2008 through 2017 and HDL-C levels from 2007 through 2017 in a population of 10- and 13-year-old children in Fukuroi City, Japan. We analyzed 17,838 children, accounting for 93.8% of all fifth and eighth graders in the entire city. Adverse lipid levels were defined as follows: 130 mg/dL or higher for LDL-C, and lower than 40 mg/dL for HDL-C. The Jonckheere-Terpstra and Cochran-Armitage tests were used to evaluate secular trends in mean serum lipid levels and prevalence of dyslipidemia, respectively. RESULTS: There were no significant trends in BMI during the study period. In children aged 10 years, serum levels of LDL-C and HDL-C showed significant positive associations with calendar year during the study period for both sexes. A significant increase in HDL-C levels was observed in girls aged 13 years. On the other hand, no significant trends were observed in the prevalence of high LDL-C or low HDL-C regardless of sex or age, while the prevalence of high non-HDL-C showed a significant increase in boys. CONCLUSIONS: In the Fukuroi population, serum levels of LDL-C and HDL-C slightly increased in both boys and girls aged 10 years, and HDL-C levels slightly increased in girls aged 13 years, during the past decade.

Psychometric properties of the Japanese version of the Dutch Eating Behavior Questionnaire for Children.

This study aimed to evaluate the psychometric properties of the 20-item Japanese version of the Dutch Eating Behavior Questionnaire for Children (DEBQ-C). A population-based sample of 502 Japanese school children who were fifth- and sixth-graders in elementary schools and first- and second-graders in junior high schools was assessed. A sample was randomly split into two subsamples, one for exploratory factor analysis (EFA) and another for confirmatory factor analysis (CFA). Internal consistency estimates for subscales (restrained, emotional, and external) were evaluated using Cronbach's alpha. Measurement invariance was examined across each subgroup (genders: boys and girls, school categories: elementary school and junior high school, body mass index (BMI) categories: underweight, normal weight, and overweight) by using multi-group CFA. The Japanese version of the DEBQ-C demonstrates good results of item analysis. The three-factor structure of the original DEBQ-C was supported by both EFA and CFA. The reliability of each factor was also satisfied (restrained: α = 0.86, emotional: α = 0.90, external: α = 0.86). Results of multi-group confirmatory factor analysis supported its metric and scalar or partial scalar measurement invariance across all subgroups. In gender subgroup, girls scored higher on restrained eating. In school subgroup, junior high school children scored higher on emotional and external eating. In BMI subgroup, overweight children scored higher on restrained eating. These findings suggest that the Japanese version of the DEBQ-C is a psychometrically valid and reliable instrument for assessing eating behaviors across gender, school categories, and BMI categories in Japanese children.

Relationships between serum leptin levels and bone mineral parameters in school-aged children: a 3-year follow-up study.

Leptin regulates bone cell differentiation and functions via direct and indirect actions in experimental settings. Epidemiologically, however, the impact of leptin on the regulation of bone metabolism remains unclear. While some studies have reported a positive relationship between leptin and bone mineral parameters, other studies found an inverse or no association. We analyzed data from a population-based follow-up survey of community-dwelling children in Hamamatsu, Japan, to investigate relationships between leptin levels and bone mineral parameters. Multiple regression analysis was performed. Multicollinearity was quantified using the variance infiltration factor (VIF). Among 408 children who participated in the baseline survey (at age 11.2 years), 254 (121 boys and 133 girls) completed the follow-up survey (at age 14.2 years). Leptin levels were strongly related to fat mass (r = 0.87 in boys, r = 0.80 in girls). Leptin levels at baseline were significantly (P < 0.05) positively related to total body less head (TBLH) areal bone mineral density (aBMD) at follow-up in girls (standardized partial regression coefficient: ß = 0.302, VIF = 2.246), after adjusting for body fat percentage (%). On the other hand, leptin levels were inversely related to TBLH aBMD in boys (ß = - 0.395, VIF = 4.116), after adjusting for body fat mass (kg). Positive relationships between leptin levels and bone mineral parameters were observed with VIF values < 4.0, whereas inverse relationships were observed with VIF values ≥ 4.0. These findings suggest that positive relationships between leptin levels and bone mineral parameters are weak, or not always observed, due to statistical problems (i.e., multicollinearity) and other factors derived from adipose tissue.

Association of anthropometric status, perceived stress, and personality traits with eating behavior in university students.

PURPOSE: We investigated the association of anthropometric status, perceived stress, and personality traits with eating behavior in university students. METHODS: The participants, 1546 Japanese university students (964 males, 582 females), completed a questionnaire which asked for their current height and weight, ideal height and weight, eating behaviors, perceived stress, and personality traits. RESULTS: Restrained eating was higher in normal-weight participants compared with underweight participants in both males and females (p < 0.001, both males and females). Restrained eating in normal-weight males was significantly lower in normal-weight females (p < 0.001). In addition, normal-weight males reported less stress than normal-weight females (anxiety/uncertainty, p = 0.037; tiredness/physical responses, p < 0.001; autonomic symptoms, p < 0.001; depression/feeling, p < 0.001) and underweight males (tiredness/physical responses, p = 0.018; autonomic symptoms, p = 0.001). Moreover, among normal-weight males, neuroticism was significantly lower compared with normal-weight females (p < 0.001). In multiple regression analysis, male participants revealed positive association between restrained eating and body mass index (ß = 0.199, p < 0.001) or body mass index difference (ß = - 0.170, p = 0.001). In contrast, female revealed more significant associations between emotional and external eating and perceived stress or personality traits compared with males. CONCLUSIONS: These results indicate that associations between eating behavior and anthropometric status or psychological factors are different by each eating behavior, which is partly influenced by gender difference. LEVEL OF EVIDENCE: V, cross-sectional descriptive study.

Predicting bone mineral acquisition during puberty: data from a 3-year follow-up study in Hamamatsu, Japan.

Although most adult bone mass is acquired before adolescence, only a few studies have assessed bone turnover markers in children. Thus, the utility of bone markers to evaluate and predict bone mineral accrual in children is unclear. The present study assessed the association between serum bone markers at 11 years of age and subsequent changes in bone gain. Information on bone minerals and bone markers at baseline and at the 3-year follow-up were obtained from 121 children who registered as fifth-grade students in 2010, in Hamamatsu, Japan. Whole-body bone mineral content (WBBMC) and whole-body bone mineral density (WBBMD) were measured using dual-energy X-ray absorptiometry. Boys showed significant (P < 0.05) positive relationships between intact osteocalcin at baseline and WBBMC at follow-up (ß = 0.24), between tartrate-resistant acid phosphatase isoenzyme 5b (TRAP5b) and WBBMC (ß = 0.34), and between TRAP5b and WBBMD (ß = 0.34), after adjusting for potential confounding factors. In girls, adjusted means of 3-year gain in both WBBMC and WBBMD significantly increased from the lowest to highest quartiles of type 1 collagen cross-linked C-terminal telopeptide. In boys, adjusted means of 3-year gain in both WBBMC and WBBMD significantly increased from the lowest to highest quartiles of TRAP5b. Children with a high concentration of bone turnover markers tended to exhibit substantial accrual of bone minerals. These results suggest that serum levels of circulating biomarkers at age 11 predict subsequent bone mineral accrual.

Increased Ratio of Trunk-to-Appendicular Fat and Decreased Adiponectin: A Population-Based Study of School Children in Hamamatsu, Japan.

Very few epidemiological studies have examined the relative impact of visceral fat and subcutaneous fat on serum adiponectin levels. Trunk-to-extremity fat ratio is reportedly a better surrogate for visceral fat than for subcutaneous fat. In the present study, we investigated the association between adiponectin and trunk-to-appendicular fat ratio (TAR) in a school population. The source population was all fifth graders (799 pupils) enrolled in the 2 elementary schools in Hamamatsu, Japan. Of the source population, we analyzed cross-sectional data from 609 children (mean age: 11.2 yr). TAR was evaluated by dual-energy X-ray absorptiometry and calculated as trunk fat mass divided by appendicular (arms and legs) fat mass. After stratification by tertiles of total body fat, multiple regression analysis was used to examine the relationships between adiponectin and TAR adjusted for potential confounding factors. In the highest tertile of total body fat, increasing TARs were significantly (p < 0.05) associated with decreasing serum adiponectin levels after stratification by total body fat (ß = -0.32 in boys; ß = -0.31 in girls). In the second tertile of total body fat, TAR in girls also showed significant inverse relationships with serum adiponectin levels (ß = -0.27). Data from this population-based study demonstrated that an increased proportion of trunk fat is associated with decreased adiponectin in relatively overweight children, and also demonstrated that girls with a normal volume of body fat that follows a more centralized distribution show decreased adiponectin.

Trunk-to-Peripheral Fat Ratio Predicts Subsequent Blood Pressure Levels in Pubertal Children With Relatively Low Body Fat　- Three-Year Follow-up Study.

BACKGROUND: Only a few studies have examined the relationship between fat distribution measured by dual-energy X-ray absorptiometry (DXA) and blood pressure (BP), and no cohort study has targeted a pediatric population. METHODS AND RESULTS: The source population comprised all students registered as fifth graders in the 2 elementary schools in Hamamatsu, Japan. Of these, 258 children participated in both baseline (at age 11) and follow-up (at age 14) surveys. Body fat distribution was assessed using trunk-to-appendicular fat ratio (TAR) and trunk-to-leg fat ratio (TLR) measured by DXA. Relationships between BP levels and fat distribution (TAR or TLR) were examined after stratification by tertiles of whole-body fat.Systolic BP at follow-up was significantly (P<0.05) associated with both TAR (boys, ß=0.33; girls ß=0.36) and TLR (girls ß=0.35) at baseline, after adjusting for confounding factors such as baseline BP in the lowest tertile of whole-body fat. Moreover, adjusted means of systolic and diastolic BPs in girls showed a significant increase from the lowest to highest tertile of TAR within the lowest tertile of whole-body fat. CONCLUSIONS: Body fat distribution in childhood could predict subsequent BP levels in adolescence. Children with a relatively low body fat that is more centrally distributed tended to show relatively high BP later on. (Circ J 2016; 80: 1838-1845).

Cardiovascular response to short-term fasting in menstrual phases in young women: an observational study.

BACKGROUND: Menstrual cycle-related symptoms are an important health issue for many women, and some may affect cardiac autonomic regulation. In the present study, we evaluated the cardiovascular and physiological stress response to 12-h short-term fasting in the menstrual phases of healthy young women. METHODS: We performed a randomized crossover study. Subjects were seven female university students (age: 22.3 ± 1.0 years). The experiments comprised four sessions: meal intake in the follicular phase, meal intake in the luteal phase, fasting in the follicular phase, and fasting in the luteal phase. All subjects participated in a total of four experimental sessions during two successive phases (follicular and luteal phase in the same menstrual cycle, or luteal phase and follicular phase in the next menstrual cycle) according to a randomized crossover design. R-R intervals were continuously recorded before and after meals, and power spectral analysis of heart rate variability was performed. Other physiological data were obtained before and 20, 40, 60, and 80 min after meal intake or after the corresponding time point of meal intake (fasting in the follicular or luteal phase). RESULTS: Heart rate decreased during fasting in the follicular and luteal phases. High frequency power increased during fasting in the follicular and luteal phases. In addition, salivary cortisol concentrations decreased during fasting in the luteal phase. CONCLUSIONS: In the present study, short-term fasting resulted in higher parasympathetic activity and lower cortisol levels in the luteal phase in these young women. These results indicate a possibility to produce an anti-stress effect in the luteal phase, which may reduce menstrual symptoms.

Eating behavior and perception of body shape in Japanese university students.

PURPOSE: We investigated the relationship between eating behavior measured by the Dutch Eating Behaviour Questionnaire (DEBQ) and perception of body shape, examining the current physical status and 'ideal' physical parameters in females and males. METHODS: The participants, 548 Japanese university students (age 19.2 ± 0.9 years, mean ± SD; 252 males, 296 females), completed a questionnaire which asked for their current physical status (e.g., weight and height), their ideal physical parameters, their perception of their current body shape, their ideal body shape, and their eating behaviors. RESULTS: The ideal weight and ideal body mass index (BMI) were significantly higher than the current weight and BMI in the males, but significantly lower in the females. Among the females, the ideal body shape was smaller than their perception of current body shape. The DEBQ scores for restrained, emotional, and external eating were higher in the females than the males among the normal-weight participants, and among the underweight participants, the restrained eating and external eating scores were higher in the females than the males. Restrained eating was negatively associated with the discrepancy between the current and ideal weight, BMI, and body shape in both the males and females. Emotional eating was negatively associated with the discrepancy in current/ideal BMI and body shape only in the females. CONCLUSIONS: At least in Japanese university students, the gender differences in ideal body shape are related to eating behavior.

Maternal weight status at conception predicts offspring body fat at age 11 years: population data from the Japan Kids Body Composition Study using dual-energy X-ray absorptiometry.

BACKGROUND: Maternal preconception overweight status has been reported to be associated with an increased risk of overweight offspring. However, there are no published population-based studies on the association between maternal preconception weight and offspring body fat measured by dual-energy X-ray absorptiometry (DXA). The present population-based retrospective cohort study aimed to examine the association between maternal weight at conception and offspring body fat measured by DXA. METHODS: The source population consisted of 5th-grade students (1244 students aged 11 years) registered at 8 municipal elementary schools in Kitakata, Fukuroi, Hamamatsu, and Himeji in Japan. The present analyses included 964 participants who provided complete information. Maternal body mass index (BMI) at conception was calculated using records in the Mother and Child Health Handbook (MCHH). Offspring body fat at age 11 years was measured with the same QDR-4500A DXA instrument in a mobile test room that was brought to each school. With regard to the prediction of excess fat in offspring, the area under the curve (AUC) calculated with receiver operating characteristic curve analysis was used to quantify the diagnostic accuracy of maternal BMI at conception. RESULTS: Adjusted odds ratios for excess body fat in offspring of the overweight mother group (odds ratios, 4.93 to 15.32) were significantly higher than those in the non-overweight mother group. For the prediction of excess offspring fat, AUCs and 95% confidence intervals for maternal BMI at conception were greater than 0.5. CONCLUSION: Maternal overweight status at conception might be a risk factor for excess body fat in offspring. Maternal BMI values calculated using MCHH data have the potential to distinguish between the presence and absence of excess fat in the next generation.

Relationship of a desire of thinness and eating behavior among Japanese underweight female students.

OBJECTIVE: We conducted a questionnaire survey among Japanese female students to explore the influence of a desire for thinness and dietary behaviors on the development of eating disorders. METHODS: Self-reported measures of socio-demographic characteristics, body weight perception, height and weight, and dietary and exercise behavior were completed by 631 female university students at 6 universities in Kyoto, Japan. RESULTS: Many students had a desire for thinness (underweight students, 51.7 %; normal-weight students, 88.8 %), whereas ideal weight and body mass index were lower in the students with a desire for thinness than the students without a desire for thinness, and were also lower in the underweight students than the normal-weight students. The eating attitude test (EAT-26) scores of underweight students with a desire for thinness were higher than those of the normal-weight students with a desire for thinness. As a result of a logistic regression analysis, underweight, desire for thinness, and experience with weight control were positively associated with eating problems. Further, the association of eating problems increased along with the increase in the number of factors (underweight, desire for thinness, and experience with weight control). CONCLUSIONS: These results indicate that underweight females have strong associations with eating problems.

Associations among perceived health competence, effortful control, self-control, and personality traits in Japanese university students.

Perceived health competence is thought to contribute to lifelong healthy behavior. However, the factors that affect perceived health competence have not been investigated. We investigated the associations among perceived health competence, effortful control, self-control, and personality traits in university students and proposed a model of how these factors affect perceived health competence. The participants were 320 Japanese university students who completed a questionnaire regarding their height, weight, perceived health competence, effortful control, self-control, and personality traits. The three-step multiple regression analysis showed that effortful control was positively associated with the perceived health competence, and self-control was positively with, and impulsivity was inversely associated with effortful control respectively, indicating that effortful control was an intermediate factor. Structural equation modeling showed a good fit for both genders, with a common path for both genders to perceived health competence via effortful control and a different involvement of personality traits for men and women. These results suggest that effortful control is directly associated with perceived health competence; in addition, both self-control and impulsiveness are indirectly associated with perceived health competence via effortful control.

Similarities and discrepancies between commercially available bioelectrical impedance analysis system and dual-energy X-ray absorptiometry for body composition assessment in 10-14-year-old children.

A variety of easy-to-use commercial bioelectrical impedance appliances are available. The aim of this study was to examine the usefulness of a commercially available body composition meter using bioelectrical impedance analysis (BIA) by comparing its measurement results with those obtained from dual-energy X-ray absorptiometry (DXA). The participants were 443 children aged from 10 to 14 years (226 boys and 217 girls). Fat mass, fat-free mass, lean body mass, percentage of body fat, and bone mineral contents were evaluated for all participants using BIA and DXA. The agreement in the anthropometric data obtained from both devices was analyzed using correlation analysis, intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC), Bland-Altman plots, and ordinary least products regression analysis. Equivalence between both devices was tested by two one-sided t-test. All measured indicators showed strong linear correlations between the two measurement systems (r, 0.853-1.000). Fat mass, fat-free mass, and lean body mass showed absolute concordance (ICC, 0.902-0.972; Lin's CCC, 0.902-0.972). BIA overestimated bone mineral content (62.7-66.5%) and underestimated percentage of body fat (- 8.9 to - 0.8%), lean body mass (- 3.5 to - 1.8%), and body mass (- 0.8 to - 0.5%). For fat mass and fat-free mass, the overestimate or underestimate varied according to the sex and statistical analysis test. Bland-Altman analysis and ordinary least products analysis showed fixed bias and proportional bias in all indicators. Results according to quartiles of body mass index showed poor agreement for fat mass and percentage of body fat in both boys and girls in the lowest body mass index quartile. The present results revealed strong linear correlations between BIA and DXA, which confirmed the validity of the present single-frequency BIA-derived parameters. Our results suggest that BIA cannot provide the exact same values as DXA for some body composition parameters, but that performance is sufficient for longitudinal use within an individual for daily health management and monitoring.

Increased ratio of trunk to appendicular fat and increased blood pressure: study of a general population of Hamamatsu children.

BACKGROUND: Body fat distribution is defined as the pattern of fat deposits in different regions of the body and usually expressed as a ratio. There are few studies on the relationship between blood pressure and the ratio of central fat measured on dual-energy X-ray absorptiometry (DXA) in childhood. METHODS AND RESULTS: The source population consisted of 521 fifth-grade children who attended elementary school in Hamamatsu, Japan, with 401 (77.0%) included in the study. Regional fat was determined using a DXA scanner in a mobile test room. The ratio of trunk to appendicular fat was calculated as trunk fat mass divided by appendicular (arms and legs) fat mass. In boys, the trunk-to-appendicular fat ratio was significantly related to systolic blood pressure and diastolic blood pressure after adjusting for confounding factors such as height and pubic hair appearance. In addition, an increase in trunk-to-appendicular fat ratio was related to an increase in blood pressure after adjusting for confounding factors including whole body fat volume and trunk fat volume. The relationship between fat distribution and blood pressure was not observed in girls. CONCLUSIONS: An excessive proportion of trunk fat was related to increased blood pressure in the boys in a general population of Japanese children. The relationship between fat distribution and blood pressure was independent of the relationship between fat volume and blood pressure.

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

BACKGROUND: In 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. METHODS: A 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. RESULTS: The 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. CONCLUSIONS: Game, 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.