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I Research on child development considers it important to understand each childʼs developmental process as well as that of the entire population. Therefore, child development scholars must be proficient in two methodologies—longitudinal research and longitudinal analysis—with the latter based on drawing developmental trajectories. This study focuses on describing the populationʼs average developmental trajectory while capturing individual deviations from the average. To this end, this study introduces the growth curve model and latent class growth analysis, highlighting findings from the Hamamatsu Birth Cohort (HBC) Study. The growth curve model introduces the mixed-effects and latent class approaches using an example question of whether an individualʼs birth weight affects their expressive language development. Latent class growth analysis emphasizes the parallel-process approach, which processes multiple domains in parallel and the joint model, which can be used to examine links between the developmental trajectories of two outcomes. [ABSTRACT FROM AUTHOR]

Approximately 40%–65% of new fitness club (FC) members cancel their membership within 6 months. To prevent such cancellations, it is essential to identify members at high risk of doing so. This study developed a model to predict the probability of discontinuing FC membership among new members. We conducted a cohort study and enrolled participants from 17 FCs in Japan. We asked 5,421 individuals who became members from March 29, 2015 to April 5, 2016 to participate in the study; 2,934 completed the baseline survey, which was conducted when the participants became FC members. We followed up the participants until September 30, 2016. We excluded 883 participants with missing values and 69 participants under aged 18 years; thus, our analysis covered 1,982 individuals. We conducted the random survival forest to develop the prediction model. The mean follow-up period was 296.3 (standard deviation, 127.3) days; 488 participants (24.6%) cancelled their membership during the follow-up. The prediction model comprised 8 predictors: age; month of joining FC; years of education; being under medical follow-up; reasons for joining FC (health improvement, relaxation); and perceived benefits from exercise (maintaining good body weight, recognition of one’s ability by other). The discrimination and calibration were acceptable (C statistic: 0.692, continuous ranked probability score: 0.134). Our findings suggest that the prediction model could assess the valid probability for early FC cancellation among new members; however, a validation study will be needed. [ABSTRACT FROM AUTHOR]

Objective: In occupational health activities in Japan, evaluating workers' fitness for work following health checkups is a primary task. Health checkups are used to identify workers at high risk of cerebrovascular and cardiovascular diseases and conduct fit-for-work evaluations. However, identifying high-risk individuals based on a single risk factor may overlook those with multiple risk factors who have a high risk of developing cerebrovascular and cardiovascular diseases. Presently, we aimed to investigate the atherosclerotic cardiovascular disease (ASCVD) risk score from a previous study by Hisayama (Hisayama study) and examine its use in the workplace., Methods: Baseline data from health checkups conducted in 2010 of 41,815 employees (men; 34,024, women; 7,791) aged 19-64 years without previous cerebrovascular or cardiovascular disease were analyzed. The relationship between baseline ASCVD risk scores and the incidence of ASCVD > 10 years (2011-2020) was examined using Cox regression analysis with hazard ratios (HR). Receiver operating curve (ROC) analysis was conducted to evaluate the model's performance and determine optimal cut-off values for the identification of high-risk individuals in the workplace., Results: The 10-year incidence of ASCVD was 2.6% (men; 3.0%, women; 0.8%). In men, each 1% increase in ASCVD risk score was associated with a 1.5-fold increase in ASCVD incidence (HR; 1.46, 95% confidence interval [CI]; 1.42-1.51, p < .001), which was observed from age 30 and even after multivariate adjustment. In women, univariate analysis showed an association between increased ASCVD risk score and incidence (HR; 3.19, 95% CI; 2.10-4.85, p < .001); however, this was not significant after adjustment. ROC analysis identified 1.62% as the optimal cut-off (sensitivity; 58.6%, specificity; 71.9%, positive predictive value [PPV]; 5.2%)., Conclusion: The ASCVD risk score is a useful tool for risk management and prevention in the workplace, particularly for men. In women, this association disappeared after age adjustment, possibly due to reduced estrogen effects with aging. Based on the ROC analysis, stratifying at ≥ 1.5% for intervention, ≥ 2.0% (top 20%) for "high risk," and ≥ 3.5% (PPV > 10%) for "extremely high risk" is advised. However, this study may have underestimated the risk levels; therefore, companies should adapt the use of ASCVD risk scores flexibly according to their circumstances.

Objectives　Bonding failure is lack of parental emotional relationship between a parent and their infant. This study aims to investigate the association between father's involvements with their partner during pregnancy.Methods　A total of 1,957 partners of pregnant women who had visited three maternity hospitals in Sapporo from May 2016 to December 2017 were included in the study. Self-administered questionnaires were distributed to participants at 2,435 weeks gestation and at 6-8 weeks postpartum. The fathers who responded to both the questionnaires were included in the analysis. The participants' relationship with their partners during pregnancy was rated using two questions- whether they help their partner with personal care and household chores, and whether they consult with their partner. Answers for both questions were given on a scale of 0 to 4. A total score of 6-8 points was defined as a high-score group, 3-5 points as a mid-score group, and 0-2 points as a low-score group. Bonding failure was evaluated using the Japanese version of the Mother-Infant Bonding Scale (MIBS-J). The cut-off value was the score that included the top 10% with the highest degree of bonding disorder. A logistic regression was used to analyse the association between involvement with a partner during pregnancy and bonding failure. The confounding variables were father's age, household income, father's average working hours, previous pregnancy, history of abortion/a stillbirth/the death of the child, and partner's prepartum depression during pregnancy.Results　391 fathers responded to the initial questionnaire, and 86.4% of them filled out the second questionnaire up to 2 months postpartum, 10.6% up to 3 months, 2.5% up to 4 months, and 1.0% up to 5 months. Of these, 375 were included, excluding those with missing questionnaire items. 255 fathers were in the high score group of the involvement with partner during pregnancy, 48 had bonding failure, 35 had LA, and 17 had AR. The OR based on the high score group of involvement with partner during pregnancy for bonding failure was 4.81 (1.88-12.33) for mid-score group, and 6.89 (1.40-33.93) for low-score group, and for LA, 2.21 (0.97-5.04) for mid-score group, and 6.40 (1.54-26.68) for low-score group; however, AR showed no respectively significant association (trend P 0.0005, 0.0053, 0.6859).Conclusions　The results suggest that a father's unfavorable involvement with his partner affects the bonding with their infant. This suggests that involvement with a partner during pregnancy is an important factor in preventing bonding failure in fathers.

NK cells target variant or transformed major histocompatibility complex(MHC) class I molecules expressed on virally infected cells or neoplastic cells. NK cells do not target those cells that fail to meet the criteria including normal cells. NK deficient patients suffer severe herpes simplex virus or cytomegalovirus infection, but not from other types of viral infection. A cohort study revealed that the population in the lowest tertile of NK cell activity is at a higher risk of cancer. Those in the highest tertile of NK activity did not have any advantage. The implication of this study is that transient fluctuations of the NK cell count and activity induced by exercise, nutrition, or various types of behavior may not influence the risk of cancer. Since the NK cell count and activity is regulated through centrally regulated sympathetic nervous system activity, the NK cell count or activity may be useful not as a marker of immune status, but as a reflection of central sympathetic activity. [ABSTRACT FROM AUTHOR]

Objective　To investigate the relationship between metabolic syndrome (MetS) and stroke incidence in a rural population by a prospective cohort study over 18.6 years.Methods　From 1996 to 1998, 4,068 subjects (aged 40-74 years) underwent a health checkup in O city, Ehime Prefecture, Japan, and 3,969 subjects were included, excluding those with a history of stroke, to determine whether they had suffered a stroke or died from stroke by the end of December 2018. The subjects were stratified into six groups on the presence of high waist circumference at baseline and the number of risk factors (0, 1, or 2 or more) for high blood pressure, dyslipidemia, and high blood glucose, according to the diagnostic criteria for MetS in Japan. Kaplan-Meier analysis of MetS survival curves and Cox proportional hazards models were used to calculate sex- and age-adjusted hazard ratios and population attributable fractions (PAFs) for total stroke, hemorrhagic stroke, and cerebral infarction.Results　During the follow-up period, 376 patients were identified as having had a stroke; the percentage of MetS in the stroke group was 15.2% compared to 9.4% in the non-stroke group, a significant difference. The sex- and age-adjusted hazard ratios for total stroke and cerebral infarction were approximately 2-fold higher in the groups with 1 risk and 2 or more risks, regardless of waist circumference, than in the group with normal waist circumference and no risks. PAF to total stroke incidence was highest in the group with normal waist circumference and 1 risk factor (18.9%).Conclusions　The contribution of MetS to stroke incidence was not significant. Consistent with previous findings, the risk of stroke was increased in non-obese individuals who had at least one risk factor, such as high blood pressure.

Objectives　In addition to physical independence such as ADLs, higher-level functional capacity ("instrumental self-maintenance," "intellectual activity," and "social role") are necessary to lead the final stage of life as independently and for as long as possible. Accordingly, in a long-term follow-up study of the local population, we examined the association of health status (total mortality and incidence of care needs) with instrumental independence, intellectual activity, and social role.Methods　We used participant data from the Kamogawa cohort study, which included surveyed use of health service, health status, disease prevalence, and use of long-term care insurance service for Kamogawa citizens in Chiba prefecture from 2003 to 2013. We compared the differences in lifestyle and higher-level functional capacity, by status of death and using the Long-term Care Insurance service. Higher-level functional capacity was assessed with the Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC); answer to each question, each domain score, and total score were examined.Results　During the follow-up period to the end of March 2013, 810 deaths and 917 care needs were observed among the 6,503 people who consented to be followed up. The adjusted HR of higher-level functional capacity for all-cause mortality was "instrumental self-maintenance," score 4 or 5 to less than 3: 2.03 (95%CI: 1.59-2.60), "intellectual activity," score 4 to less than 3: 1.39 (95%CI: 1.09-1.77), and "social role," score 4 to less than 3: 1.28 (95%CI: 1.03-1.59). In subgroup analyses by sex, "instrumental self-maintenance" was associated with both men and women, but "intellectual activity" and "social roles" were associated with women only. The adjusted HRs for the incidence of care needs were 1.93 (95%CI: 1.55-2.40) for "instrumental self-maintenance" and 1.30 (95%CI: 1.07-1.58) for "social role." In subgroup analyses by sex, "instrumental self-maintenance" was associated with both genders, but "social role" was observed only for women.Conclusion　Higher-level functional capacity ("instrumental self-maintenance," "intellectual activity," and "social role") was significantly associated with total mortality and incidence of care needs.

Objectives　Approximately 40% of new fitness club (FC) members drop out within the first six months; however, the factors associated with FC membership resignation are largely unknown. This study aimed to identify the association between psychological attitudes toward exercise and FC membership resignation.Methods　We conducted a cohort study enrolling participants from 17 FCs. All individuals who became members at FCs between April 1st, 2015 and March 31st, 2016 (n=5,421) were invited to participate in the study, and those who agreed to participate completed a self-administered baseline questionnaire (n=2,934). We excluded participants aged <20 years (n=167) and those with missing values (n=702). Psychological factors were evaluated using the short version of the perceived benefit and barriers to exercise scale. Participants were followed until September 30th, 2016, at which time we assessed the FC membership drop-out rate. Cox proportional-hazards models were used to evaluate the association between perceived benefits/barriers of exercise and FC membership resignation. Sub-analyses were then conducted, stratifying by gender and age group.Results　A total of 2,065 participants were included in the analyses. The mean (standard deviation) age was 39.0 (15.0) years and 28.8% were male. Over 10.1 (4.4) months of newly-joined member follow-up, the FC membership drop-out rate was 24.6 instances per 1000 person-months. Multivariable analyses revealed no significant factors associated with FC membership drop-out. However, men aged 40-59 years who had a high physical benefit score and who perceived improving physical fitness as a benefit, were less likely to resign their memberships (hazard ratio [HR], 95% confidence interval [CI], 0.72 [0.52-1.00]). However, women aged <40 years with a high discomfort score and who saw discomfort as a barrier were more likely to resign membership (HR, 1.10 [1.01-1.19]). Women aged 40-59 years with high social benefit scores and who perceived social interaction as a benefit were less likely to resign their memberships, as were women with higher lack of motivation to exercise scores and who perceived lack of motivation as a barrier to exercise (HR for social benefit, 0.84 [0.74-0.97]; HR for lack of motivation, 0.85 [0.73-0.99]). Among both male and female participants aged ≥60 years, higher self-improvement scores, indicating that peer recognition was perceived as a benefit of exercise, was associated with higher HR for drop-out (men, 2.52 [1.10-5.81]; women, 1.31 [1.00-1.72]).Conclusions　The results revealed gender and age differences in the association between the perceived benefits/barriers of exercise and FC membership dropout. Implementing programs based on enrollees' characteristics and psychological factors may contribute to preventing FC dropout in the future.

Background: There are few prospective observational studies on the prevalence of atopic dermatitis (AD) in children. We aimed to prospectively investigate the dynamics of change in the prevalence of AD from early childhood to adolescence., Methods: We conducted a survey with a modified questionnaire to diagnose AD based on The International Study of Asthma and Allergies in Childhood questionnaire with 1230 13-year-old children who were born in the Minami ward, Yokohama City between May 2004 and June 2005 and had undergone physical examinations by dermatologists at 3 years of age. Among the 422 children who answered the questionnaire, 210 had undergone periodic physical examinations by dermatologists from 4 months to 3 years of age (Cohort 1), whereas 212 had undergone physical examinations only at 3 years of age (Cohort 2)., Results: The prevalence of AD was 16.9% in 422 children at 13 years of age, with 22.9%, 16.6%, 20.0% and 18.3% prevalence at 4 months, 18 months, 3 years and 13 years of age, respectively, in children who were followed up long-term. The frequency of AD occurrence per year decreased after the age of 3 years; a history of AD at this age was significantly related to AD at 13 years of age (Fisher's exact test, p<0.001)., Conclusion: In conclusion, it was suggested that AD in 3-year-old children is one of the risk factors for the development of AD in 13-year-old children.

We have been conducting research with the aim of generating evidence for the safety of perinatal drugs. As a result of reviewing the records of inquiries to the Drug Information Office of our hospital, we found a large discrepancy between the description of perinatal drugs in package inserts in Japan and the description of the Pregnancy Risk Category according to the U.S. Food and Drug Administration. In the Japan Environment and Children's Study (JECS), we determined the proportion of drug and supplement use among 97464 pregnant women. We clarified that prescriptions of antihypertensive drugs for pregnant women increased during the second half of pregnancy, while prescriptions of anti-epileptic and anti-anxiety drugs decreased after pregnancy using a claims database. A survey of pharmacists and pharmacy students revealed a lack of awareness of effective folic acid intake to reduce the risk of neural tube defects in infants. The percentage of pre-pregnancy folic acid supplementation among pregnant women participating in the Babies and their Parents' Longitudinal Observation in Suzuki Memorial Hospital on Intrauterine Period (BOSHI) study, the JECS, and the Tohoku Medical Megabank (TMM) Birth and Three-Generation (BirThree) cohort study was 6.3-18.0%. As a result of close examination of the records of inquiries to the Drug Information Office of our hospital, and of cases in which our lactation plan sheet was applied, it was found that there were discrepancies between the information on the drug package insert and the information on Medications & Mother's Milk, etc. in Japan. The results obtained have been clinically applied in daily practice and we are continuing our research while taking measures.

Aim: The specific amino acid intake has been suggested to be positively associated with the cognitive function. However, few reports have investigated the association between the amino acid intake and episodic memory (EM). Therefore, we investigated this association., Methods: Data were obtained from the fourth survey (2004-2006) of the National Institute for Longevity Sciences - Longitudinal Study of Aging. We analyzed 2,082 participants 40-85 years old (50.1% male). The dietary intake was assessed by the three-day dietary records, and participants were classified into sex- and age-specific tertiles of protein and amino acid intakes. EM was assessed using the Logical Memory II of the Wechsler Memory Scale. The association of protein and amino acid intakes with EM was analyzed using the general linear model. Covariates were sex, age, body mass index, education, depressive symptoms, smoking status, employment status, living alone, and medical history in model 1. The energy intake was added to model 1 in model 2. The protein intake was added to model 2 in model 3., Results: The mean (standard deviation) age was 59.4 (12.3) years old. After adjusting for the energy intake, the EM tended to be higher with a higher protein intake (p=0.053 for group differences and p=0.015 for trends). Furthermore, after adjusting for energy and protein intake, EM was significantly higher with higher intakes of isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine, tryptophan, valine, and histidine (p< 0.05, both for group differences and trends)., Conclusion: Our findings suggest a positive association between EM and the intake of essential and semi-essential amino acids, independent of the protein and energy intake.

Objectives　Dementia prevention is an important issue in the current super-aging society. Previous studies have shown a low risk of dementia in older adults who have hobbies, especially gardening, tourism, and those that are sports-based. However, it is unclear whether the effect of dementia prevention differs according to the specific type and number of hobbies. This study aims to clarify the relationship of dementia onset with the type and number of hobbies practiced by a person.Methods　This prospective cohort study conducted between 2010 and 2016 by the Japan Gerontological Evaluation Study surveyed 56,624 functionally independent individuals aged 65 years and over who had non-missing information on age and gender. A total of 49,705 participants who provided valid answers to the question regarding hobbies, and were followed for 365 days or more, were analyzed. The primary outcome of this study was dementia, which was assessed by the nationally standardized dementia scale proposed by the Ministry of Health, Labour, and Welfare of Japan. Explanatory variables were specific types of hobbies practiced by 5% or more of older adults (males: 14 types and females: 11 types) and the number of hobbies an individual engaged in (0~5 types or more). The covariates were basic characteristics, diseases, health behavior, social support, psychology/cognition, and instrumental activities of daily living. Hazard ratios (HRs) were calculated using the Cox proportional hazards model adjusted for a total of 22 variables.Results　In total, 4,758 patients (9.6%) developed dementia during the follow-up period. The following hobbies were related to a lower risk of developing incident dementia: a) both in males and females, ground golf (HR: males, 0.80; females, 0.80) and travel (males, 0.80; females, 0.76); b) only in males, golf (0.61), use of a personal computer (0.65), fishing (0.81), and photo shooting (0.83); and c) only in females, handicrafts (0.73), and gardening (0.85). A significant trend was observed indicating that the risk of dementia was lower as the number of hobbies increased for both males and females (males, 0.84; females, 0.78).Conclusion　The results of this study suggest that both male and female older adults who engaged in ground golf and travel as a hobby had a lower risk of developing dementia, and the risk decreased as the number of hobbies increased. Providing an environment in which older adults can engage in various hobbies that are associated with less risk of developing dementia, may be an effective measure for preventing dementia.