Tsuguhiko Kato

Bio: Tsuguhiko Kato is an academic researcher from Okayama University. The author has contributed to research in topics: Medicine & Mental health. The author has an hindex of 12, co-authored 29 publications receiving 344 citations.

Breastfeeding and obesity among schoolchildren: a nationwide longitudinal survey in Japan

Abstract: Importance Although it is suggested that breastfeeding is protective against obesity in children, the evidence remains inconclusive because of possible residual confounding by socioeconomic status or children’s lifestyle factors. Most of the participants in the previous studies were children in Western developed countries, so studies in a different context are awaited. Objective To examine the associations of breastfeeding with overweight and obesity among schoolchildren in Japan, with adjustment for the potential confounders. Design Secondary data analyses of a nationwide longitudinal survey ongoing since 2001, with results collected from 2001 to 2009. Setting All over Japan. Participants A total of 43 367 singleton children who were born after 37 gestational weeks and had information on their feeding during infancy. Exposures Five mutually exclusive infant feeding practice categories. Main Outcomes and Measures Underweight, normal weight (referent group), overweight, and obesity at 7 and 8 years of age defined by using international cutoff points of body mass index by sex and age. Results In multinomial logistic regression models with adjustment for children’s factors (sex, television viewing time, and computer game playing time) and maternal factors (educational attainment, smoking status, and working status), exclusive breastfeeding at 6 to 7 months of age was associated with decreased risk of overweight and obesity compared with formula feeding. The adjusted odds ratios were 0.85 (95% CI, 0.69-1.05) and 0.55 (95% CI, 0.39-0.78) for overweight and obesity, respectively, at 7 years of age. Similar results were observed at 8 years of age. Conclusions and Relevance Breastfeeding is associated with decreased risk of overweight and obesity among schoolchildren in Japan. Therefore, it would be better to encourage breastfeeding even in developed countries.

Impact of maternal and paternal smoking on birth outcomes

Abstract: Background The adverse effects of maternal and paternal smoking on child health have been studied. However, few studies demonstrate the interaction effects of maternal/paternal smoking, and birth outcomes other than birth weight have not been evaluated. The present study examined individual effects of maternal/paternal smoking and their interactions on birth outcomes. Methods A follow-up hospital-based study from pregnancy to delivery was conducted from 1997 to 2010 with parents and newborn infants who delivered at a large hospital in Hamamatsu, Japan. The relationships between smoking and growth were evaluated with logistic regression. Results The individual effects of maternal smoking are related to low birth weight (LBW), short birth length and small head circumference. The individual effects of paternal smoking are related to short birth length and small head circumference. In the adjusted model, both parents' smoking showed clear associations with LBW (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.18-2.27) and short birth length (-1 standard deviation [SD] OR = 1.38, 95% CI 1.07-1.79; -2 SD OR = 2.75, 95% CI 1.84-4.10). Conclusions Maternal smoking was significantly associated with birth weight and length, but paternal smoking was not. However, if both parents smoked, the risk of shorter birth length increased.

Neurological and neuropsychological functions in adults with a history of developmental arsenic poisoning from contaminated milk powder

Abstract: During the summer of 1955, mass arsenic poisoning of bottle-fed infants occurred in the western part of Japan due to contaminated milk powder, and more than 100 died; some childhood victims were later found to suffer from neurological sequelae in adolescence. This unique incident enabled us to explore infancy as a critical period of arsenic exposure in regard to developmental neurotoxicity and its possible persistence through adulthood. The purpose of this work is to evaluate the association between developmental arsenic exposure and the neurological outcomes more than 50 years later. We conducted a retrospective cohort study during the period from April 2012 to February 2013 in two hospitals in Okayama Prefecture, Japan. The study sample consisted of 50 individuals: 27 known poisoning victims from Okayama Prefecture, and 23 non-exposed local controls of similar age. In addition to neurological examination, we adapted a battery of neurophysiological and neuropsychological tests to identify the types of brain functions affected by early-life arsenic exposure. While limited abnormalities were found in the neurophysiological tests, neuropsychological deficits were observed. Except for Finger tapping, all test scores in the exposed group--Vocabulary and Block Design from Wechsler Adults Intelligent Scale III, Design memory subtest from Wide Range Assessment of Memory and Learning 2, and Grooved pegboard test--were substantially below those obtained by the unexposed. The exposed group showed average performance at least 1.2 standard deviations below the average for the controls. Exposed participants performed less well than controls, even after exclusion of subjects with recognized disabilities or those with a high level of education. Adults who had suffered arsenic poisoning during infancy revealed neuropsychological dysfunctions, even among those subjects not recognized as having disabilities. Developmental neurotoxicity due to arsenic likely results in permanent changes in brain functions.

Spanking and subsequent behavioral problems in toddlers: A propensity score-matched, prospective study in Japan

Abstract: Harsh or frequent spanking in early childhood is an established risk factor for later childhood behavioral problems as well as mental disorder in adulthood in Western societies. However, few studies have been conducted in Asian populations, where corporal punishment is relatively accepted. Moreover, the impacts of occasional spanking on subsequent behavioral problems remain uncertain. This study sought to investigate prospectively the association between the frequency of spanking of toddlers and later behavioral problems in Japanese children using national birth cohort data. We used data from the Longitudinal Survey of Newborns in the 21st Century, a population-based birth cohort data set collected by the Japanese Ministry of Health, Labour, and Welfare (N=29,182). Frequency of spanking ("never", "sometimes" and "always") and child behavioral problems were assessed via a caregiver questionnaire when the child was 3.5 years old and again at 5.5 years. Propensity score matching was used to examine the association between frequency of spanking and child behavioral problems, adjusting for parental socioeconomic status, child temperament and parenting behaviors. Compared to children who were never spanked, occasional spanking ("sometimes") showed a higher number of behavioral problems (on a 6-point scale) (coefficient: 0.11, 95% CI: 0.07-0.15), and frequent spanking ("always") showed an even larger number of behavioral problems compared with "sometimes" (coefficient: 0.08, 95% CI:0.01-0.16). Spanking of any self-reported frequency was associated with an increased risk for later behavioral problems in children.

Association of sleep habits with behavior problems and resilience of 6- to 7-year-old children: results from the A-CHILD study

Abstract: Background Childhood sleep habits are associated with mental health development; however, little is known about the impact of irregular bedtimes on the mental health of early school-aged children. The aims of this study were to examine the effect of weekday sleep habits (varying bedtimes depending on the night of the week and later than 22:00 h bedtime) on behavior problems, prosocial behavior, and resilience of children aged 6–7 years. Methods Data were taken from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, which involved the participation of 4291 caregivers of first-grade children (6–7 years old) living in Adachi City, Tokyo. Resilience (using the Children's Resilient Coping Scale), behavior problems (using the Strength and Difficulties Questionnaire), both modified to range 0–100, and sleep habits were measured via a questionnaire filled out by caregivers. Propensity-score matching was used to determine the associations between irregular and late bedtime, behavior problems, prosocial behavior, and resilience. Results A total of 320 (7.5%) children showed irregular bedtime on school nights and 540 (13.6%) children went to bed later than 22:00 h. Children with irregular bedtimes on weekdays showed lower resilience (β = −3.50, 95% confidence interval (CI) = −5.90 to −1.10) and higher levels of behavior problems (β = 3.29, 95% CI = 1.13–5.46), especially hyperactivity/inattention (β = 5.76, 95% CI = 2.03 to 9.49) and peer relationship problems (β = 3.79, 95% CI = 1.02–6.55). On the other hand, no association between bedtime after 22:00 h and resilience or behavior problems was found. Conclusion Among early school-aged children, irregular bedtime on weekdays may be a risk factor for lower resilience and behavior problems.

Nudge: Improving Decisions about Health, Wealth, and Happiness

Abstract: NUDGE: IMPROVING DECISIONS ABOUT HEALTH, WEALTH, AND HAPPINESS by Richard H. Thaler and Cass R. Sunstein Penguin Books, 2009, 312 pp, ISBN 978-0-14-311526-7This book is best described formally as a general explanation of and advocacy for libertarian paternalism, a term coined by the authors in earlier publications. Informally, it is about how leaders, systems, organizations, and governments can nudge people to do the things the nudgers want and need done for the betterment of the nudgees, or of society. It is paternalism in the sense that "it is legitimate for choice architects to try to influence people's behavior in order to make their lives longer, healthier, and better", (p. 5) It is libertarian in that "people should be free to do what they like - and to opt out of undesirable arrangements if they want to do so", (p. 5) The built-in possibility of opting out or making a different choice preserves freedom of choice even though people's behavior has been influenced by the nature of the presentation of the information or by the structure of the decisionmaking system. I had never heard of libertarian paternalism before reading this book, and I now find it fascinating.Written for a general audience, this book contains mostly social and behavioral science theory and models, but there is considerable discussion of structure and process that has roots in mathematical and quantitative modeling. One of the main applications of this social system is economic choice in investing, selecting and purchasing products and services, systems of taxes, banking (mortgages, borrowing, savings), and retirement systems. Other quantitative social choice systems discussed include environmental effects, health care plans, gambling, and organ donations. Softer issues that are also subject to a nudge-based approach are marriage, education, eating, drinking, smoking, influence, spread of information, and politics. There is something in this book for everyone.The basis for this libertarian paternalism concept is in the social theory called "science of choice", the study of the design and implementation of influence systems on various kinds of people. The terms Econs and Humans, are used to refer to people with either considerable or little rational decision-making talent, respectively. The various libertarian paternalism concepts and systems presented are tested and compared in light of these two types of people. Two foundational issues that this book has in common with another book, Network of Echoes: Imitation, Innovation and Invisible Leaders, that was also reviewed for this issue of the Journal are that 1 ) there are two modes of thinking (or components of the brain) - an automatic (intuitive) process and a reflective (rational) process and 2) the need for conformity and the desire for imitation are powerful forces in human behavior. …

Evidence or Action

Abstract: The Millennium Ecosystem Assessment highlighted the importance of environmental preservation for continued economic activity and well-being of communities (Fig. 1). It inventoried services provided by ecosystems, as well as quantifying these in order to assess their contribution to human well-being. The approach is based on the conviction that it is necessary to be able to quantify the productivity of ecosystems. This will in the end enable policymakers to consider environmental protection as a parameter when determining the priorities for action within processes of arbitration between different economic development projects having greater or lesser positive impacts on the environment and human well-being.