Differential patterns of reproductive and lifestyle risk factors for breast cancer according to birth cohorts among women in China, Japan and Korea.

BACKGROUND: The birth cohort effect has been suggested to influence the rate of breast cancer incidence and the trends of associated reproductive and lifestyle factors. We conducted a cohort study to determine whether a differential pattern of associations exists between certain factors and breast cancer risk based on birth cohorts. METHODS: This was a cohort study using pooled data from 12 cohort studies. We analysed associations between reproductive (menarche age, menopause age, parity and age at first delivery) and lifestyle (smoking and alcohol consumption) factors and breast cancer risk. We obtained hazard ratios (HRs) with 95% confidence intervals (CIs) using the Cox proportional hazard regression analysis on the 1920s, 1930s, 1940s and 1950s birth cohorts. RESULTS: Parity was found to lower the risk of breast cancer in the older but not in the younger birth cohort, whereas lifestyle factors showed associations with breast cancer risk only among the participants born in the 1950s. In the younger birth cohort group, the effect size was lower for parous women compared to the other cohort groups (HR [95% CI] 0.86 [0.66-1.13] compared to 0.60 [0.49-0.73], 0.46 [0.38-0.56] and 0.62 [0.51-0.77]). Meanwhile, a higher effect size was found for smoking (1.45 [1.14-1.84] compared to 1.25 [0.99-1.58], 1.06 [0.85-1.32] and 0.86 [0.69-1.08]) and alcohol consumption (1.22 [1.01-1.48] compared to 1.10 [0.90-1.33], 1.15 [0.96-1.38], and 1.07 [0.91-1.26]). CONCLUSION: We observed different associations of parity, smoking and alcohol consumption with breast cancer risk across various birth cohorts.

Association between family history with lung cancer incidence and mortality risk in the Asia Cohort Consortium.

Family history of lung cancer (FHLC) has been widely studied but most prospective cohort studies have primarily been conducted in non-Asian countries. We assessed the association between FHLC with risk of lung cancer (LC) incidence and mortality in a population of East Asian individuals. A total of 478,354 participants from 11 population-based cohorts in the Asia Cohort Consortium were included. A Cox proportional hazards regression model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 7,785 LC incident cases were identified. FHLC (any LC subtype) was associated with an increased risk of LC incidence (HR = 1.45, 95% CI = 1.30-1.63). The positive association was observed in men and women (HR = 1.44, 95% CI = 1.26-1.66 in men; HR = 1.47, 95% CI = 1.22-1.79 in women), and in both never-smokers and ever-smokers (HR = 1.43, 95% CI = 1.18-1.73 in never-smokers; HR = 1.46, 95% CI =1.27-1.67 in ever-smokers). FHLC was associated with an increased risk of lung adenocarcinoma (HR = 1.63, 95% CI: 1.36-1. 94), squamous cell carcinoma (HR = 1.88, 95% CI: 1.46-2.44), and other non-small cell LC (HR = 1.94, 95% CI: 1.02-3.68). However, we found no evidence of significant effect modification by sex, smoking status, and ethnic groups. In conclusion, FHLC was associated with increased risk of LC incidence and mortality, and the associations remained consistent regardless of sex, smoking status and ethnic groups among the East Asian population.

Association of female reproductive and hormonal factors with gallbladder cancer risk in Asia: A pooled analysis of the Asia Cohort Consortium.

The female predominance of gallbladder cancer (GBC) has led to a hypothesis regarding the hormone-related aetiology of GBC. We aimed to investigate the association between female reproductive factors and GBC risk, considering birth cohorts of Asian women. We conducted a pooled analysis of 331,323 women from 12 cohorts across 4 countries (China, Japan, Korea, and Singapore) in the Asia Cohort Consortium. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) to assess the association between reproductive factors (age at menarche, parity, age at first delivery, breastfeeding, and age at menopause) and GBC risk. We observed that a later age at menarche was associated with an increased risk of GBC (HR 1.4, 95% CI 1.16-1.70 for 17 years and older vs. 13-14 years), especially among the cohort born in 1940 and later (HR 2.5, 95% CI 1.50-4.35). Among the cohort born before 1940, women with a later age at first delivery showed an increased risk of GBC (HR 1.56, 95% CI 1.08-2.24 for 31 years of age and older vs. 20 years of age and younger). Other reproductive factors did not show a clear association with GBC risk. Later ages at menarche and at first delivery were associated with a higher risk of GBC, and these associations varied by birth cohort.

Genetic Risk, Lifestyle Adherence, and Risk of Developing Hyperuricaemia in a Japanese Population.

OBJECTIVE: To investigate the inter-relationships among genetic risk, healthy lifestyle adherence, and hyperuricaemia susceptibility. METHODS: This prospective cohort study was conducted with 7,241 hyperuricaemia-free individuals aged ≥ 20 years from the Tohoku Medical Megabank Community-based cohort study. A comprehensive lifestyle score included body mass index, smoking, drinking, and physical activity, and a polygenic risk score (PRS) was constructed based on uric acid loci from a previous genome-wide association study meta-analysis. A multiple logistic regression model was used to estimate the association between genetic risk, healthy lifestyle, and hyperuricaemia incidence and calculate the area under the receiver operating characteristic curve (AUROC). Hyperuricaemia was defined as a uric acid level ≥7.0 mg/dl or a self-reported history of hyperuricaemia. RESULTS: Of the 7,241 adults (80.7% females; mean [SD] age: 57.7 [12.6] years), 217 (3.0%) developed hyperuricaemia during 3.5 years of follow-up. Genetic risk correlated with hyperuricaemia development (P for interaction = 0.287), and lifestyle risks were independently associated. Those with a high genetic risk and poor lifestyle had the highest risk (odds ratio: 5.34; 95% confidence interval [CI]: 2.61-12.10). Although not statistically significant, incorporating the PRS in the model with lifestyle information improved predictive ability (AUROC = 0.771, 95% CI: 0.736-0.806 for lifestyle; AUROC = 0.785, 95% CI: 0.751-0.819 for lifestyle and PRS; p = 0.07). CONCLUSION: : A healthy lifestyle to prevent hyperuricaemia, irrespective of genetic risk, may mitigate the genetic risk. Genetic risk may complement lifestyle factors in identifying individuals at a heightened hyperuricaemia risk.

Dietary habits and plasma lipid concentrations in a general Japanese population.

INTRODUCTION: Accumulating data on the associations between food consumption and lipid composition in the body is essential for understanding the effects of dietary habits on health. OBJECTIVES: As part of omics research in the Tohoku Medical Megabank Community-Based Cohort Study, this study sought to reveal the dietary impact on plasma lipid concentration in a Japanese population. METHODS: We conducted a correlation analysis of food consumption and plasma lipid concentrations measured using mass spectrometry, for 4032 participants in Miyagi Prefecture, Japan. RESULTS: Our analysis revealed 83 marked correlations between six food categories and the concentrations of plasma lipids in nine subclasses. Previously reported associations, including those between seafood consumption and omega-3 fatty acids, were validated, while those between dairy product consumption and odd-carbon-number fatty acids (odd-FAs) were validated for the first time in an Asian population. Further analysis suggested that dairy product consumption is associated with odd-FAs via sphingomyelin (SM), which suggests that SM is a carrier of odd-FAs. These results are important for understanding odd-FA metabolism with regards to dairy product consumption. CONCLUSION: This study provides insight into the dietary impact on plasma lipid concentration in a Japanese population.

Family history and gastric cancer incidence and mortality in Asia: a pooled analysis of more than half a million participants.

BACKGROUND: The family history of gastric cancer holds important implications for cancer surveillance and prevention, yet existing evidence predominantly comes from case-control studies. We aimed to investigate the association between family history of gastric cancer and gastric cancer risk overall and by various subtypes in Asians in a prospective study. METHODS: We included 12 prospective cohorts with 550,508 participants in the Asia Cohort Consortium. Cox proportional hazard regression was used to estimate study-specific adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between family history of gastric cancer and gastric cancer incidence and mortality, then pooled using random-effects meta-analyses. Stratified analyses were performed for the anatomical subsites and histological subtypes. RESULTS: During the mean follow-up of 15.6 years, 2258 incident gastric cancers and 5194 gastric cancer deaths occurred. The risk of incident gastric cancer was higher in individuals with a family history of gastric cancer (HR 1.44, 95% CI 1.32-1.58), similarly in males (1.44, 1.31-1.59) and females (1.45, 1.23-1.70). Family history of gastric cancer was associated with both cardia (HR 1.26, 95% CI 1.00-1.60) and non-cardia subsites (1.49, 1.35-1.65), and with intestinal- (1.48, 1.30-1.70) and diffuse-type (1.59, 1.35-1.87) gastric cancer incidence. Positive associations were also found for gastric cancer mortality (HR 1.30, 95% CI 1.19-1.41). CONCLUSIONS: In this largest prospective study to date on family history and gastric cancer, a familial background of gastric cancer increased the risk of gastric cancer in the Asian population. Targeted education, screening, and intervention in these high-risk groups may reduce the burden of gastric cancer.

A principal component analysis of metabolome and cognitive decline among Japanese older adults: cross-sectional analysis using Tohoku Medical Megabank Cohort Study.

BackgroundDementia is the leading cause of disability and imposes a significant burden on society. Previous studies have suggested an association between metabolites and cognitive decline. Although the metabolite composition differs between Western and Asian populations, studies targeting Asian populations remain scarce.MethodsThis cross-sectional study used data from a cohort survey of community-dwelling older adults aged ≥ 60 years living in Miyagi, Japan, conducted by Tohoku Medical Megabank Organization between 2013 and 2016. Forty-three metabolite variables quantified using nuclear magnetic resonance spectroscopy were used as explanatory variables. Dependent variable was the presence of cognitive decline (≤ 23 points), assessed by the Mini-Mental State Examination. Principal component (PC) analysis was performed to reduce the dimensionality of metabolite variables, followed by logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for cognitive decline.ResultsA total of 2,940 participants were included (men: 49.0%, mean age: 67.6 years). Among them, 1.9% showed cognitive decline. The first 12 PC components (PC1-PC12) accounted for 71.7% of the total variance. Multivariate analysis showed that PC1, which mainly represented essential amino acids, was associated with lower odds of cognitive decline (OR = 0.89; 95% CI, 0.80-0.98). PC2, which mainly included ketone bodies, was associated with cognitive decline (OR = 1.29; 95% CI, 1.11-1.51). PC3, which included amino acids, was associated with lower odds of cognitive decline (OR = 0.81; 95% CI, 0.66-0.99).ConclusionAmino acids are protectively associated with cognitive decline, whereas ketone metabolites are associated with higher odds of cognitive decline.

Combined Fat Mass and Fat-free Mass Indices and Lung Function Among Japanese Population: The Tohoku Medical Megabank Community-based Cohort Study.

BACKGROUND: Although fat mass index (FMI) and fat-free mass index (FFMI) affect lung function, FMI and FFMI are not independent of each other, since FMI and FFMI were calculated as fat mass and fat-free mass divided by height squared, respectively. We aimed to examine the association of combined FMI and FFMI with lung function. METHODS: In this cross-sectional study, lung function was evaluated using forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) measured using spirometry. Both FMI and FFMI were classified into sex-specific quartiles (16 groups). Analysis of covariance was used to assess the associations of combined FMI and FFMI with lung function. The trend test was conducted by stratifying the FMI and FFMI, scoring the categories from 1-4 (lowest-highest), and entering the number as a continuous term in the regression model. RESULTS: This study included 3,736 men and 8,821 women aged ≥20 years living in Miyagi Prefecture, Japan. The mean FEV1 was 3.0 (standard deviation [SD], 0.7) L for men and 2.3 (SD, 0.5) L for women. The mean FVC was 3.8 (SD, 0.7) L for men and 2.8 (SD, 0.5) L for women. FMI was inversely associated with lung function among all FFMI subgroups in both sexes. Conversely, FFMI was positively associated with lung function in all FMI subgroups in both sexes. CONCLUSION: Higher FMI was associated with lower lung function independent of FFMI; higher FFMI was associated with higher lung function independent of FMI. Reducing FMI and maintaining FFMI might be important for respiratory health.

GWAS meta-analysis of kidney function traits in Japanese populations.

BACKGROUND: Genetic epidemiological evidence for the kidney function traits in East Asian population including Japanese remain still relatively unclarified. Especially, the number of GWASs for kidney traits reported still remains limited, and the sample size of each independent study is relatively small. Given the genetic variability between ancestries/ethnicities, implementation of GWAS with sufficiently large sample sizes in specific population of Japanese is considered meaningful. METHODS: We conducted the GWAS meta-analyses of kidney traits by leveraging the GWAS summary data of the representative large genome cohort studies with about 200,000 Japanese participants (n = 202,406 for estimated glomerular filtration rate [eGFR] and n = 200,845 for serum creatinine [SCr]). RESULTS: In the present GWAS meta-analysis, we identified 110 loci with 169 variants significantly associated with eGFR (on chromosomes 1-13 and 15-22; p < 5×10-8), whereas we also identified 112 loci with 176 variants significantly associated with SCr (on chromosomes 1-22; p < 5×10-8), of which one locus (more than 1Mb distant from known loci) with one variant (CD36 rs146148222 on chromosome 7) for SCr was considered as the truly novel finding. CONCLUSIONS: The present GWAS meta-analysis of largest genome cohort studies in Japanese provided some original genomic loci associated with kidney function in Japanese, which may contribute to the possible development of personalized prevention of kidney diseases based on genomic information in the near future.

Progress Report of the Tohoku Medical Megabank Community-based Cohort Study: Study Profile of the Repeated Center-based Survey During Second Period in Miyagi Prefecture.

BACKGROUND: The purpose of this study was to report the basic profile of the Miyagi Prefecture part of a repeated center-based survey during the second period of the Tohoku Medical Megabank Community-Based Cohort Study (TMM CommCohort Study), as well as the participants' characteristics based on their participation type in the baseline survey. METHODS: The second period survey, conducted from June 2017 to March 2021, included participants of the TMM CommCohort Study (May 2013 to March 2016). In addition to the questionnaire, blood, urine, and physiological function tests were performed during the second period survey. There were three main ways of participation in the baseline survey: Type 1, Type 1 additional, or Type 2 survey. The second period survey was conducted in the same manner as the Type 2 survey, which was based on the community support center (CSC). RESULTS: In Miyagi Prefecture, 29,383 (57.7%) of 50,967 participants participated in the second period survey. The participation rate among individuals who had visited the CSC was approximately 80%. Although some factors differed depending on the participation type in the baseline survey, the second period survey respondents in the Type 1 and Type 2 survey groups at baseline had similar traits. CONCLUSION: The second period survey of the TMM CommCohort Study provided detailed follow-up information. Following up on the health conditions of the participants will clarify the long-term effects of disasters and contribute to personalized prevention.

Study Profile of the Tsuruoka Metabolomics Cohort Study (TMCS).

The Tsuruoka Metabolomics Cohort Study (TMCS) is an ongoing population-based cohort study being conducted in the rural area of Yamagata Prefecture, Japan. This study aimed to enhance the precision prevention of multi-factorial, complex diseases, including non-communicable and aging-associated diseases, by improving risk stratification and prediction measures. At baseline, 11,002 participants aged 35-74 years were recruited in Tsuruoka City, Yamagata Prefecture, Japan, between 2012 and 2015, with an ongoing follow-up survey. Participants underwent various measurements, examinations, tests, and questionnaires on their health, lifestyle, and social factors. This study uses an integrative approach with deep molecular profiling to identify potential biomarkers linked to phenotypes that underpin disease pathophysiology and provide better mechanistic insights into social health determinants. The TMCS incorporates multi-omics data, including genetic and metabolomic analyses of 10,933 participants, and comprehensive data collection ranging from physical, psychological, behavioral, and social to biological data. The metabolome is used as a phenotypic probe because it is sensitive to changes in physiological and external conditions. The TMCS focuses on collecting outcomes for cardiovascular disease, cancer incidence and mortality, disability and functional decline due to aging and disease sequelae, and the variation in health status within the body represented by omics analysis that lies between exposure and disease. It contains several sub-studies on aging, heated tobacco products, and women's health. This study is notable for its robust design, high participation rate (89%), and long-term repeated surveys. Moreover, it contributes to precision prevention in Japan and East Asia as a well-established multi-omics platform.

Prospective associations of screen time at age 2 with specific behavioral subscales at age 3: a cohort study.

BACKGROUND: We aim to discover which, if any, of the subscales of internalizing and externalizing behavioral problems at age 3 are still associated with screen time (ST) at age 2 after adjusting for behavioral problems scores at age 2. METHODS: This study was conducted under the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Information was gathered prospectively, with 7207 mother-child pairs included in the analysis. Children's ST was categorized in hours a day at age 2 (<1, 1-<2, 2-<4, ≥4). We assessed children's behavioral problems using the Child Behavior Checklist for Ages 1½-5 (CBCL) at ages 2 and 3. 'Having behavioral problems' was defined by them being within a clinical range for internalizing behaviors (withdrawn, somatic complaints, anxious/depressed and emotionally reactive) and externalizing behaviors (attention problems and aggressive behaviors) at age 3. Continuous scores on each of the behavioral problem scales at age 2 were used as covariates. RESULTS: Greater ST for children at age 2 was associated with specific subscales for emotionally reactive and aggressive behaviors at age 3. CONCLUSIONS: This study found that ST is prospectively associated with some behavioral scales but not others.

Associations between leisure time, non-leisure time physical activity, and kidney function in Japanese adults: a cross-sectional study.

BACKGROUND: Chronic kidney disease (CKD) contributes to decreased life expectancy. We examined the association between leisure-time physical activity (LTPA), non-leisure-time physical activity (non-LTPA) and kidney function. METHODS: This was a cross-sectional study including 32 162 community-dwelling adults aged ≥ 20 years from the Tohoku Medical MegaBank community-based cohort study. Kidney function was evaluated using cystatin C-based estimated glomerular filtration rate (eGFR) as well as self-reported LTPA and non-LTPA. CKD was defined as either eGFR decline (≤ 60 mL/min/1.73 m2) or presence of albuminuria (albumin-creatinine ≥ 30 mg/g). The association between domain-specific physical activity and kidney function, and CKD prevalence was examined using multivariable-adjusted ordinary least squares and modified Poisson models. RESULTS: The mean eGFR was 98.1 (± 13.2) mL/min/1.73 m2. 3 185 (9.9%) participants were classified as having CKD. The mean LTPA and non-LTPA levels were 2.9 (± 4.2) and 16.6 (± 14.2) METs-hour/day, respectively. For LTPA, in the adjusted model, the quartile groups with higher levels had a higher kidney function (ß, 0.36; 95% confidence intervals [CI], [0.06, 0.66]; p = 0.019 for the 2nd quartile, ß, 0.82; 95% CI, [0.51, 1.14]; p < 0.001 for the 3rd quartile, and ß, 1.16; 95% CI, [0.83, 1.49]; p < 0.001 for the 4th quartile), whereas there were no apparent associations for prevalence of CKD. For non-LTPA, 4th quartile was associated with decreased eGFR (ß, -0.42; 95% CI, [-0.72, -0.11]; p = 0.007) and higher prevalence of CKD prevalence (Prevalence ratio, 1.12; 95% CI, [1.02, 1.24]; p = 0.022). These associations with kidney function remained consistent in the subgroup analyses divided by demographic and biological variables. CONCLUSIONS: We observed a positive association between higher LTPA levels and better kidney function, but not association with CKD prevalence. In contrast, higher non-LTPA was negatively associated with both kidney function and CKD prevalence. These findings suggest that promoting LTPA is beneficial for kidney function.

Relationship between parity and the prevalence of chronic kidney disease in Japan considering hypertensive disorders of pregnancy and body mass index.

BACKGROUND: Global studies exploring the relationship between parity and chronic kidney disease (CKD) are scarce. Furthermore, no study has examined the relationship between parity and CKD in Japan. Therefore, this study aimed to examine the relationship between parity and the prevalence of CKD in a Japanese population, considering the clinical history of hypertensive disorders of pregnancy (HDP) and current body mass index (BMI) based on menopausal status. METHODS: This cross-sectional study included 26,945 Japanese multiparous women (5,006 premenopausal and 21,939 postmenopausal women) and 3,247 nulliparous women (1,599 premenopausal and 1,648 postmenopausal women). Participants were divided into two groups based on their menopausal status (premenopausal and postmenopausal women). The relationship between parity and the prevalence of CKD was evaluated using a multiple logistic regression model adjusted for several covariates, including a clinical history of HDP and current BMI. RESULTS: The relationship between parity and the prevalence of CKD was not statistically significant in either premenopausal or postmenopausal multiparous women. A clinical history of HDP was significantly associated with an increased risk of CKD in premenopausal and postmenopausal multiparous women. However, the relationship between a clinical history of HDP and CKD in premenopausal women was weakened after adjusting for current BMI. Furthermore, the current BMI was significantly associated with an increased risk of CKD in both premenopausal and postmenopausal women. CONCLUSIONS: Parity is not significantly associated with the prevalence of CKD in premenopausal and postmenopausal multiparous women. A clinical history of HDP is a risk factor for CKD in both premenopausal and postmenopausal women. Current BMI is also associated with an increased risk of CKD in premenopausal and postmenopausal women. Therefore, continuous surveillance and preventive measures against CKD should be provided to women with a clinical history of HDP. In addition, maintaining an appropriate body weight is beneficial in reducing the risk of CKD.

Association of physiological factors with grip and leg extension strength: tohoku medical megabank community-based cohort study.

BACKGROUND: Upper and lower extremity muscle strength can be used to predict health outcomes. However, the difference between the relation of upper extremity muscle and of lower extremity muscle with physiological factors is unclear. This study aimed to evaluate the association between physiological data and muscle strength, measured using grip and leg extension strength, among Japanese adults. METHODS: We conducted a cross-sectional study of 2,861 men and 6,717 women aged ≥ 20 years living in Miyagi Prefecture, Japan. Grip strength was measured using a dynamometer. Leg extension strength was measured using a hydraulic isokinetic leg press machine. Anthropometry and physiological data, including blood pressure, calcaneal ultrasound bone status, pulmonary function, carotid echography, and blood information, were assessed. We used a general linear model adjusted for age, body composition, and smoking status to evaluate the association between muscle strength and physiological factors. RESULTS: Grip and leg extension strength were positively associated with bone area ratio, vital capacity, forced vital capacity, forced expiratory volume in one second, and estimated glomerular filtration rate, and negatively associated with waist circumference and percentage body fat mass in both the sexes. Diastolic blood pressure was positively associated with grip strength in both the sexes and leg extension strength in men, but not women. High-density lipoprotein cholesterol and red blood cell counts were positively associated with grip and leg extension strength in women, but not men. In both the sexes, pulse rate, total cholesterol, and uric acid were consistently associated with only leg extension strength, but not grip strength. In women, glycated hemoglobin demonstrated negative and positive associations with grip and leg extension strength, respectively. CONCLUSIONS: Grip and leg extension strength demonstrated similar associations with anthropometry, pulmonary function, and estimated glomerular filtration rate, but the associations with the other factors were not always consistent.

Age at menarche by birth cohort: A pooled analysis of half a million women in Asia.

OBJECTIVES: To evaluate changes in the age at menarche in Asian populations. STUDY DESIGN: Retrospective cohort study. METHODS: We included 548,830 women from six countries in Asia. The data were sourced from 20 cohorts participating in the Asia Cohort Consortium (ACC) and two additional cohort studies: Japan Multi-institutional Collaborative Cohorts (J-MICC), and Japan Nurse Health Study (JNHS) with data on age at menarche. Joinpoint regression was used to evaluate changes in age at menarche by birth year and by country. RESULTS: The study includes data from cohorts in six Asian countries namely, China, Iran, Japan, Korea, Malaysia and Singapore. Birth cohorts ranged from 1873 to 1995. The mean age of menarche was 14.0 years with a standard deviation (SD) of 1.4 years, ranged from 12.6 to 15.5 years. Over 100 years age at menarche showed an overall decrease in all six countries. China showed a mixed pattern of decrease, increase, and subsequent decrease from 1926 to 1960. Iran and Malaysia experienced a sharp decline between about 1985 and 1990, with APC values of -4.48 and -1.24, respectively, while Japan, South Korea, and Singapore exhibited a nearly linear decline since the 1980s, notably with an APC of -3.41 in Singapore from 1993 to 1995. CONCLUSIONS: Overall, we observed a declining age at menarche, while the pace of the change differed by country. Additional long-term observation is needed to examine the contributing factors of differences in trend across Asian countries. The study could serve as a tool to strengthen global health campaigns.

Number of teeth and functional disability in community-dwelling older adults.

INTRODUCTION: This study determined whether tooth loss was associated with the development of functional disability and estimated the population attributable fraction (PAF) of functional disability due to tooth loss, along with risk factors for functional disability such as physical function and cognitive impairment. METHODS: The participants were 838 community-dwelling older adults aged ≥70 years living in the Tsurugaya district in Japan in 2003. The exposure variable was the number of remaining teeth (counted by trained dentists). Other variables were age, sex, depressive symptoms, cognitive impairment, educational attainment, physical function and social support. The Cox proportional hazards model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the incidence of functional disability for each risk factor, such as tooth loss. The functional disability PAF due to tooth loss was estimated, and risk factors for functional disability were identified. RESULTS: In total, 619 (73.9%) participants developed functional disability during follow-up. A multivariable model showed that those with <20 teeth (HR, 1.28; 95% CI, 1.08-1.53) were more likely to develop functional disability than those with 20 teeth or more. PAF estimation for functional disability was shown to have decreasing values in the following order: age, female sex, tooth loss and reduced physical function. CONCLUSIONS: Tooth loss was associated with the development of functional disability in community-dwelling older Japanese adults. While retaining teeth may be a potential strategy for avoiding functional disability, clinical studies on the effect of dental treatment on preventing functional disability are warranted.

Effects of greenery at different heights in neighbourhood streetscapes on leisure walking: a cross-sectional study using machine learning of streetscape images in Sendai City, Japan.

BACKGROUND: It has been pointed out that eye-level greenery streetscape promotes leisure walking which is known to be a health -positive physical activity. Most previous studies have focused on the total amount of greenery in the eye-level streetscape to investigate its association with walking behaviour. While it is acknowledged that taller trees contribute to greener environments, providing enhanced physical and psychological comfort compared to lawns and shrubs, the examination of streetscape metrics specifically focused on greenery height remains largely unexplored. Therefore, this study examined the relationship between objective indicators of street greenery categorized by height from a pedestrian viewpoint and leisure walking time. METHODS: We created streetscape indices of street greenery using Google Street View Images at 50-m intervals in an urban area in Sendai City, Japan. The indices were classified into four ranges according to the latitude of the virtual hemisphere centred on the viewer. We then investigated their relationship to self-reported leisure walking. RESULTS: Positive associations were identified between the street greenery in higher positions and leisure walking time, while there was no significant association between the greenery in lower positions. CONCLUSION: The findings indicated that streets with rich greenery in high positions may promote residents' leisure walking, indicating that greenery in higher positions contributes to thermally comfortable and aesthetic streetscapes, thus promoting leisure walking. Increasing the amount of greenery in higher positions may encourage residents to increase the time spent leisure walking.

Design and Progress of Child Health Assessments at Community Support Centers in the Birth and Three-Generation Cohort Study of the Tohoku Medical Megabank Project.

The Tohoku Medical Megabank Project (TMM) has been conducting a birth and three-generation cohort study (the BirThree Cohort Study). We recruited 73,529 pregnant women and their family members for this cohort study, which included 23,143 newborns and 9,459 of their siblings. We designed and are in the process of conducting three-step health assessments for each newborn at approximately ages of 5, 10 and 16. These health assessments are administered at seven community support centers. Trained genome medical research coordinators conduct physical examinations of and collect biological specimens from each participant. The Sendai Children's Health Square has been established as the headquarters for these child health assessments and is utilized to accumulate knowledge that can facilitate the proper practice of child health assessments. We designed all the relevant health assessments facilities to allow parents and their children to participate in the health assessments concomitantly. Our centers serve as places where child participants and their parents can feel at ease as a result of the implementation of safety measures and child hospitality measures. The TMM BirThree Cohort Study is in the process of conducting strategically detailed health assessments and genome analysis, which can facilitate studies concerning the gene-environment interactions relevant to noncommunicable diseases. Through these operations, our study allows for a significant depth of data to be collected in terms of the number of biospecimens under study and the comprehensiveness of both basic and clinical data alongside relevant family information.

The return of individual genomic results to research participants: design and pilot study of Tohoku Medical Megabank Project.

Certain large genome cohort studies attempt to return the individual genomic results to the participants; however, the implementation process and psychosocial impacts remain largely unknown. The Tohoku Medical Megabank Project has conducted large genome cohort studies of general residents. To implement the disclosure of individual genomic results, we extracted the potential challenges and obstacles. Major challenges include the determination of genes/disorders based on the current medical system in Japan, the storage of results, prevention of misunderstanding, and collaboration of medical professionals. To overcome these challenges, we plan to conduct multilayer pilot studies, which deal with different disorders/genes. We finally chose familial hypercholesterolemia (FH) as a target disease for the first pilot study. Of the 665 eligible candidates, 33.5% were interested in the pilot study and provided consent after an educational "genetics workshop" on the basic genetics and medical facts of FH. The genetics professionals disclosed the results to the participants. All positive participants were referred to medical care, and a serial questionnaire revealed no significant psychosocial distress after the disclosure. Return of genomic results to research participants was implemented using a well-prepared protocol. To further elucidate the impact of different disorders, we will perform multilayer pilot studies with different disorders, including actionable pharmacogenomics and hereditary tumor syndromes.