Cohort Profile: Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study): rationale, progress and perspective

Exploring the association between human breast milk lipids and early adiposity rebound in children: A case-control study

OBJECTIVES

Adiposity rebound (AR) corresponds to the start of the second rise in the body mass index curve during infant growth. Early AR (before age 5) confers increased risk of adiposity and metabolic disorders but is less likely to occur in breastfed infants. Although lipids in breast milk are important in child growth, information is limited regarding which lipids are involved in AR. The object of this study was to explore the association between breast milk lipids and AR status in children.

METHODS

We designed a case-control study of 184 mother-child pairs (AR cases: n = 93; controls: n = 91) included from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Breast milk was collected 1 month postpartum and comprehensive lipid analysis was performed. Partial least square-discriminant analysis was used to explore candidate lipids, and multivariable logistic regression analysis was used to evaluate associations with the AR status of children.

RESULTS

We detected 667 lipid molecules in 12 lipid classes in breast milk. Partial least square-discriminant analysis revealed the association of fatty acid-hydroxy fatty acid (FAHFA) and cholesterol ester (ChE) with AR status. Multivariable logistic regression analysis showed that in pairs with exclusive breastfeeding at 1 month postpartum, FAHFA (odds ratio 1.57 [95% confidence interval, 1.06-2.32]) was positively associated with early AR, and ChE (odds ratio 0.55 [95% confidence interval, 0.36-0.86]) was negatively associated.

CONCLUSIONS

Breast milk lipids (FAHFA, ChE) associated with the AR status of children, indicating the potential to regulate a child's adiposity and possible metabolic disorders in adulthood.

Prevalence and Associations of Epiretinal Membrane by OCT in a Japanese Population-Based Cohort: Tohoku Medical Megabank Organization Eye Study

Purpose

To examine the prevalence of epiretinal membrane (ERM) according to the OCT-based severity scales, and to describe associations focusing on the impact of smoking and axial length of the globe.

Design

Cross-sectional study.

Participants

The baseline examination cohort comprised participants from the Tohoku Medical Megabank community cohort recruited from 2013 to 2017.

Methods

In total, 38 118 eyes of 19 486 participants were classified with ERM staging. The characteristics of ERM severity were analyzed, and the association between the prevalence of ERM and ocular and systemic parameters was investigated using logistic regression models. Cubic spline models were constructed to visualize the relationships with lifetime smoking exposure and axial lengths. Regarding ERM severity, the associations between stage 1 and stage 2 or more were analyzed with multivariate analysis.

Main Outcome Measures

Epiretinal membrane prevalence at each stage determined via OCT and factors associated with ERM presence and severity.

Results

The prevalence of ERM was 2.3% per eye (3.6% per person), with a predominance at stage 1. The presence of severe ERM stages was higher in older individuals. The multivariate logistic analysis revealed that older age, female sex, and long axial length were associated with a higher prevalence of ERM. In a multivariate analysis stratified by sex, glaucoma was also identified as a significant factor associated with the prevalence of ERM in women. In the cubic spline model, no consistent trend was observed between smoking and ERM prevalence. However, a U-shaped relationship was indicated between axial length and ERM prevalence. Epiretinal membrane severity highlighted older age, alcohol consumption, and very long axial length as significantly associated compared with stage 1.

Conclusions

Epiretinal membrane prevalence was significantly associated with older age, female sex, and long axial length.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Profiling of runs of homozygosity from whole-genome sequence data in Japanese biobank

Runs of homozygosity (ROHs) are widely observed across the genomes of various species and have been reported to be associated with many traits and common diseases, as well as rare recessive diseases, in human populations. Although single nucleotide polymorphism (SNP) array data have been used in previous studies on ROHs, recent advances in whole-genome sequencing (WGS) technologies and the development of nationwide cohorts/biobanks are making high-density genomic data increasingly available, and it is consequently becoming more feasible to detect ROHs at higher resolution. In the study, we searched for ROHs in two high-coverage WGS datasets from 3552 Japanese individuals and 192 three-generation families (consisting of 1120 family members) in prospective genomic cohorts. The results showed that a considerable number of ROHs, especially short ones that may have remained undetected in conventionally used SNP-array data, can be detected in the WGS data. By filtering out sequencing errors and leveraging pedigree information, longer ROHs are more likely to be detected in WGS data than in SNP-array data. Additionally, we identified gene families within ROH islands that are associated with enriched pathways related to sensory perception of taste and odors, suggesting potential signatures of selection in these key genomic regions.

Synergistic effects of cardiovascular health and social isolation on adverse pregnancy outcomes

Adverse pregnancy outcomes (APOs) affect approximately 20% pregnant women, and their incidence is increasing. The aim of this study was to investigate the effect of cardiovascular health (CVH) during pregnancy on APOs. We analyzed data from 14,930 pregnant women in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. CVH status during pregnancy was assessed using the eight components of Life's Essential 8. APOs were defined as composite outcomes encompassing preeclampsia, gestational diabetes mellitus, preterm birth, and small for gestational age. The numbers of participants with high, moderate, and low CVH status were 2891 (19.4%), 11,498 (77.0%), and 541 (3.6%), respectively. Poisson regression analyses with robust error variance, which adjusted for maternal age at conception, alcohol consumption, conception via in vitro fertilization, parity, psychological distress, social isolation, and household income, showed a positive association between moderate and low CVH levels and APOs (risk ratio and 95% confidence interval 1.15 [1.03-1.28] and 2.14 [1.78-2.58], respectively). Among pregnant women with low CVH, those who reported social isolation had a higher prevalence of APOs than did those without social isolation (36.4% vs. 27.4%). This difference was attenuated for pregnant women with high CVH status (13.6% vs. 13.1%). In conclusion, CVH status may be useful for assessing the risk of APOs. Socially isolated pregnant women are more vulnerable to the effects of low CVH status.

Autoantibodies against endothelial protein C receptor and integrin αvβ6 predict the development of ulcerative colitis

BACKGROUND

A method for predicting ulcerative colitis (UC) onset has not been established. Serum autoantibodies have been suggested as potential predictive biomarkers for UC onset. We aimed to validate the risks associated with serological and environmental factors and construct a model for predicting UC development.

METHODS

Using the population-based cohort studies (n > 83,000), we identified 42 individuals who were diagnosed with UC later in life and compared them with matched healthy controls. We analyzed serum anti-integrin αvβ6 antibody (anti-αvβ6) and anti-endothelial protein C receptor antibody (anti-EPCR) titers, and lifestyle and dietary habits to explore UC onset predictors. The predictive performance of the models was evaluated based on these predictors.

RESULTS

The sensitivity and specificity of anti-EPCR for predicting UC onset were 51.4% and 97.8%, respectively, comparable to those of anti-αvβ6 (52.5% and 97.6%, respectively). The proportion of individuals with insomnia was significantly higher in the preclinical UC group (adjusted odds ratio = 2.14, 95% confidence interval [CI] 1.11-4.04, p = 0.019). The predictive performance of anti-EPCR alone was high with an area under the curve (AUC) of 0.89 (95%CI 0.83-0.96), and that of anti-EPCR combined with anti-αvβ6 was even better with an AUC of 0.92 (95%CI 0.87-0.97); the lifestyle model had lower predictive accuracy (AUC = 0.65, 95%CI 0.55-0.74).

CONCLUSIONS

Anti-EPCR and anti-αvβ6 each strongly predict UC onset. The combined anti-EPCR and anti-αvβ6 model had stronger predictive performance than the single models.

Genetic effects on gestational diabetes mellitus and their interactions with environmental factors among Japanese women

Gestational diabetes mellitus (GDM) is common in Japanese women, posing serious risks to mothers and offspring. This study investigated the influence of maternal genotypes on the risk of GDM and examined how these genotypes modify the effects of psychological and dietary factors during pregnancy. We analyzed data from 20,399 women in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort. Utilizing two customized SNP arrays for the Japanese population (Affymetrix Axiom Japonica Array v2 and NEO), we performed a meta-analysis to combine the datasets. Gene-environment interactions were assessed by modeling interaction terms between genome-wide significant single nucleotide polymorphisms (SNPs) and psychological and dietary factors. Our analysis identified two SNP variants, rs7643571 (p = 9.14 × 10-9) and rs140353742 (p = 1.24 × 10-8), located in an intron of the MDFIC2 gene, as being associated with an increased risk of GDM. Additionally, although there were suggestive patterns for interactions between these SNPs and both dietary factors (e.g., carbohydrate and fruit intake) and psychological distress, none of the interaction terms remained significant after Bonferroni correction (p < 0.05/8). While nominal significance was observed in some models (e.g., psychological distress, p = 0.04), the data did not provide robust evidence of effect modification on GDM risk once adjusted for multiple comparisons. These findings reveal novel genetic associations with GDM in Japanese women and highlight the importance of gene-environment interactions in its etiology. Given that previous genome-wide association studies (GWAS) on GDM have primarily focused on Western populations, our study provides new insights by examining an Asian population using a population-specific array.

Association Between Human Milk Oligosaccharides and Early Adiposity Rebound in Children: A Case-Control Study of the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

BACKGROUND

Adiposity rebound (AR) is the point when the BMI begins to rise again during early childhood. Early AR (before age 5) is associated with higher risk of lifelong obesity and metabolic disorders and may be influenced by breastfeeding. Although human milk oligosaccharides (HMOs) in breast milk are crucial for child growth, their association with AR status has not been studied.

OBJECTIVES

This study aimed to explore the association between breast milk HMOs and AR status in children.

METHODS

In this case-control study, we included 184 mother-child pairs from the Tohoku Medical Megabank Project Birth and Three-Generation (TMM BirThree) Cohort Study (93 AR cases, 91 controls). Breast milk was collected 1 mo postpartum, and the concentration of 15 HMO molecules and α-diversity index (Inverse Simpson index) were quantified. Wilcoxon rank-sum test and partial least squares-discriminant analysis identified candidate HMOs, and multivariable logistic regression analysis evaluated associations between candidate HMOs and AR status. Analyses were stratified by maternal secretor status (secretor or nonsecretor).

RESULTS

In secretor mothers, multivariable logistic regression showed that the inverse Simpson index [odds ratio (OR): 0.54; 95% CI: 0.36, 0.82), the sum of sialic acid-bound HMOs (OR: 0.61; 95% CI: 0.41, 0.91), and 3'-sialyllactose (OR: 0.67; 95% CI: 0.46, 0.98) were inversely associated with early AR in the fully adjusted model. A trend of interaction between sialyl-lacto-N-tetraose-a (LSTa) and maternal secretor status regarding AR was observed in the fully adjusted model (P-interaction = 0.051).

CONCLUSIONS

α-Diversity, sialic acid-bound HMOs, and 3'-sialyllactose may involved in inhibiting AR in children of secretor mothers, and a trend of interactive effect between LSTa and maternal secretor status regarding AR is indicated. These findings offer novel perspectives on the associations between breastfeeding and a childhood adiposity as well as potential metabolic disorders later in life. This trial is registered at https://www.umin.ac.jp/ as UMIN000047160.

Preeclampsia prediction with maternal and paternal polygenic risk scores: the TMM BirThree Cohort Study

Genomic information from pregnant women and the paternal parent of their fetuses may provide effective biomarkers for preeclampsia (PE). This study investigated the association of parental polygenic risk scores (PRSs) for blood pressure (BP) and PE with PE onset and evaluated predictive performances of PRSs using clinical predictive variables. In the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study, 19,836 participants were genotyped using either Affymetrix Axiom Japonica Array v2 (further divided into two cohorts-the PRS training cohort and the internal-validation cohort-at a ratio of 1:2) or Japonica Array NEO (external-validation cohort). PRSs were calculated for systolic BP (SBP), diastolic BP (DBP), and PE and hyperparameters for PRS calculation were optimized in the training cohort. PE onset was associated with maternal SBP-, DBP-, and PE-PRSs and paternal SBP- and DBP-PRSs only in the external-validation cohort. Meta-analysis revealed overall associations with maternal PRSs but highlighted significant heterogeneity between cohorts. Maternal DBP-PRS calculated using "LDpred2" presented the most improvement in prediction models and provided additional predictive information on clinical predictive variables. Paternal DBP-PRS improved prediction models in the internal-validation cohort. In conclusion, Parental PRS, along with clinical predictive variables, is potentially useful for predicting PE.

A scoping review of adult NCD-relevant phenotypes measured in today's large child cohort studies

BACKGROUND

Child cohort studies are important resources that can inform strategies to prevent adult noncommunicable diseases (NCDs). Technological advances now enable direct measurement of NCD-relevant phenotypes at large scale. Across contemporary large child cohorts, we aimed to provide the first comprehensive map of NCD-relevant phenotype measurement and gaps.

METHODS

We included cohorts with >8000 child participants that were recruiting in whole or part after 2010 and measuring phenotypes relevant to ten high-burden NCDs. Our database and gray literature search identified 15 cohort studies for inclusion. Details on phenotype measurement (methods, age, location) are presented in an online, searchable inventory.

RESULTS

All 15 cohorts measure body size or composition. Most cohorts measure aspects of cardiovascular health (n = 10) and neurocognition (n = 9). Fewer measure musculoskeletal phenotypes (n = 6), pulmonary function (n = 6), vision (n = 6) and glucose (n = 4). Only two cohorts measure hearing or kidney function.

CONCLUSIONS

Today's childhood cohorts are not measuring some phenotypes important to global burden of disease, notably kidney function and hearing. Given the rarity of very large contemporary child cohorts, cross-cohort coordination will be required if all major NCD precursors are to be adequately represented for future benefit.

IMPACT

This scoping review provides a comprehensive overview of NCD-relevant phenotype measurement across large, modern child cohort studies. This review has identified measurement gaps in important areas that may obviate steps to prevent and detect NCDs with high global disease burden. Findings may inform planning of collaborative projects and future data collection to address measurement gaps for greatest future benefit.

Skin health survey on atopic dermatitis among Japanese children: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

BACKGROUND

Precise skin phenotypic data are indispensable in accurately diagnosing atopic dermatitis (AD). Therefore, this study examined the interobserver concordance for AD and non-AD diagnoses between two dermatologists. AD prevalence determined by the self-reported physician diagnoses and the diagnoses determined from the United Kingdom (UK) diagnostic criteria were compared with the diagnoses made by the two dermatologists, using data from a skin health survey.

METHODS

This study included 1,638 children that participated in the skin health survey, which was part of the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. AD was assessed using dermatologist assessments, self-reported physician diagnoses, and the UK diagnostic criteria. The concordance for diagnoses was evaluated using kappa. The sensitivity and specificity of the self-reported physician diagnoses and the UK diagnostic criteria were calculated by comparing them with the two dermatologists' diagnoses.

RESULTS

Among the 1,638 children, 393 (24.0 %), 194 (11.9 %), and 597 (37.2 %) were diagnosed with AD by the two dermatologists, physicians, and the UK diagnostic criteria, respectively. The kappa (95 % CI) of the interobserver concordance for AD or non-AD diagnoses between the two dermatologists was 0.78 (0.75-0.81). The sensitivity and specificity of the self-reported physician diagnoses were 26.7 % and 94.1 %, respectively. The sensitivity and specificity of the UK diagnostic criteria were 85.0 % and 82.4 %, respectively.

CONCLUSIONS

Interobserver concordance for AD or non-AD diagnoses between the two dermatologists was substantial. Self-reported physician diagnoses exhibited low sensitivity that potentially indicated underdiagnosis of AD, whereas the UK diagnostic criteria might overdiagnose AD.

Impact of maternal smoking and secondhand smoke exposure during singleton pregnancy on placental abruption: analysis of a prospective cohort study (the Japan Environment and Children's Study)

OBJECTIVES

This study aimed to investigate the association and population-attributable fraction (PAF) of maternal smoking and secondhand smoke (SHS) exposure during pregnancy with placental abruption.

DESIGN

Prospective cohort study.

SETTING

15 regional centres in Japan.

PARTICIPANTS

Pregnant women registered between January 2011 and March 2014 from the Japan Environment and Children's Study.

OUTCOME MEASURES

Data were transcribed from medical records and two self-administered questionnaires. The outcome measure was the incidence of placental abruption. Maternal smoking exposure during pregnancy was categorised based on the number of cigarettes smoked (≤10 or ≥11 cigarettes per day). SHS exposure during pregnancy was evaluated by frequency and duration (almost never or never, 1-3 days/week and/or <1 hour/day and 4-7 days/week and ≥1 hour/day). A modified Poisson regression model, adjusted for known placental abruption risk factors, calculated the risk ratio (RR) and PAF for placental abruption with a 95% Cl.

RESULTS

Of the 81 974 eligible pregnant women, pregnant women smoking ≥11 cigarettes/day during pregnancy had a significantly higher risk of placental abruption. The adjusted RR (aRR) was 2.21 (95% CI 1.21 to 4.06), and the adjusted PAF (aPAF) was 1.90% (95% CI 0.09 to 3.71%). Pregnant women among never-smokers with SHS exposure of 4-7 days/week and ≥1 hour/day had a significantly higher risk (aRR: 2.34, 95% CI 1.29 to 4.28), and the aPAF was 1.89% (95% CI -0.05 to 3.83). Additionally, pregnant women among those who smoked during pregnancy with similar SHS exposure had a significantly higher risk (aRR: 2.21, 95% CI 1.30 to 3.76), with the aPAF of 2.29% (95% CI 0.11 to 4.48).

CONCLUSIONS

Maternal smoking and SHS exposure during pregnancy significantly contribute to the risk of placental abruption in Japan. Therefore, preventive interventions and measures to reduce exposure are required to prevent placental abruption.

Returning genetic risk information for hereditary cancers to participants in a population-based cohort study in Japan

Large-scale population cohort studies that collect genomic information are tasked with returning an assessment of genetic risk for hereditary cancers to participants. While several studies have applied to return identified genetic risks to participants, comprehensive surveys of participants' understanding, feelings, and behaviors toward cancer risk remain to be conducted. Here, we report our experience and surveys of returning genetic risks to 100 carriers of pathogenic variants for hereditary cancers identified through whole genome sequencing of 50 000 individuals from the Tohoku Medical Megabank project, a population cohort study. The participants were carriers of pathogenic variants associated with either hereditary breast and ovarian cancer (n = 79, median age=41) or Lynch syndrome (n = 21, median age=62). Of these, 28% and 38% had a history of cancer, respectively. We provided information on cancer risk, heritability, and clinical actionability to the participants in person. The comprehension assessment revealed that the information was better understood by younger (under 60 years) females than by older males. Scores on the cancer worry scale were positively related to cancer experiences and general psychological distress. Seventy-one participants were followed up at Tohoku University Hospital; six females underwent risk-reducing surgery triggered by study participation and three were newly diagnosed with cancer during surveillance. Among first-degree relatives of hereditary breast and ovarian cancer carriers, participants most commonly shared the information with daughters. This study showed the benefits of returning genetic risks to the general population and will provide insights into returning genetic risks to asymptomatic pathogenic variant carriers in both clinical and research settings.

Maternal Fasting Plasma Glucose Level in Early Gestation and Developmental Delay in 2-year-old Children

BACKGROUND

The association of maternal hyperglycemia with childhood developmental delay has been examined; however, only 2 studies used maternal blood glucose level as a continuous variable as an exposure. A present study aimed to investigate the influence of maternal fasting plasma glucose (mFPG) level in early gestation on developmental delay in children.

METHODS

This cohort study included 1541 mother-child pairs who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. mFPG level before 24 gestational weeks was obtained as a continuous and categorical variable. Developmental delay in 2-year-old children was assessed by mothers using the Ages and Stages Questionnaire (third edition). Associations between mFPG level and developmental delay in children were evaluated using multiple logistic regression analyses.

RESULTS

The prevalence of mFPG level ≥95 mg/dL was 5.2%. At 2 years old, 15.1% of the children had developmental delays. mFPG level as a continuous variable was not associated with an increased risk of developmental delay across the 5 domains in children [adjusted odds ratio (aOR), 95% confidence interval (CI): 1.004, 0.990-1.018]. mFPG level ≤70 mg/dL was associated with developmental delay across 5 domains (aOR, 95% CI: 0.464, 0.229-0.943) in children than that with a mFPG level 71 to 94 mg/dL. No association was found between mFPG level ≤70 mg/dL and ≥95 mg/dL and developmental delay in any domains among children.

CONCLUSION

mFPG level in early gestation was not associated with an increased risk of any developmental delays in 2-year-old children.

Subsequent high blood pressure and hypertension by hypertensive disorders of pregnancy: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

Hypertensive disorders of pregnancy can cause hypertension in the future. Understanding how the blood pressure values of women with and without hypertensive disorders of pregnancy differ will facilitate follow-up blood pressure monitoring in clinical settings. This study investigated the association between hypertensive disorders of pregnancy and subsequent high blood pressure and hypertension. This study used Japanese data from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Follow-up systolic and diastolic blood pressures in normotensive women during pregnancy and those with hypertensive disorders of pregnancy were estimated using analysis of covariance adjusted for women with low birthweight, history of gestational diabetes mellitus, age, body mass index, pulse rate, smoking and drinking at the follow-up assessment, paternal hypertension history, and maternal hypertension or hypertensive disorders of pregnancy history. Finally, we performed a multiple logistic regression analysis. In total, 7343 women were included in the analysis. Women with a history of hypertensive disorders of pregnancy had higher blood pressure approximately three years postpartum compared with normotensive women. Hypertensive disorders of pregnancy in the most recent pregnancy in different subgroups, such as nulliparous women, multiparous women without a history of hypertensive disorders of pregnancy, and multiparous women with a history of hypertensive disorders of pregnancy, were associated with an increased risk of subsequent hypertension. Women's birthweight was also weakly associated with hypertension. Even one experience of hypertensive disorders of pregnancy may contribute to elevated blood pressure and hypertension approximately three years postpartum. In addition, women's birthweights may have a weak relationship with increasing blood pressure.

Respiratory syncytial virus infection, non-respiratory syncytial virus respiratory infections, and later wheezing

BACKGROUND

Studies investigating whether respiratory syncytial virus (RSV) infection, non-RSV respiratory infections, respiratory-related disorders, and non-respiratory-related disorders are associated with subsequent wheezing are limited in Japan. We aimed to elucidate the relationship between hospitalization for RSV infection, non-RSV respiratory infections, respiratory-related disorders, as well as non-respiratory-related disorders and subsequence wheezing in Japanese children.

METHODS

This study included 7340 children and was conducted under the TMM BirThree Cohort Study (Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study). Data was collected from birth records and questionnaires. We categorized hospitalization history into five categories: "no hospitalization," hospitalizations for "RSV infection," "non-RSV respiratory infections," "respiratory-related disorders," and "non-respiratory-related disorders." The association of the five categories with later wheezing at 3 years of age was evaluated using multivariable logistic regression analysis.

RESULTS

After adjusting for covariates, an association was shown between hospitalization under 2 years of age and later wheezing (odds ratio [OR] = 2.78; 95% confidence interval [CI] = 1.97-3.88 for "RSV infection"; OR = 2.61; 95% CI = 1.44-4.57 for "non-RSV respiratory infections"; and OR = 3.33; 95% CI = 2.43-4.54 for "respiratory-related disorders").

CONCLUSION

Hospitalization of children under 2 years of age for RSV infection as well as non-RSV respiratory infections and respiratory-related disorders were associated with subsequent wheezing.

Has the impact of cigarette smoking on mortality been underestimated by overlooking second-hand smoke? Tohoku medical megabank community-based cohort study

Objectives

Previous studies have assessed the impact of active smoking on mortality using the population-attributable fraction (PAF). However, these studies have not included second-hand smoking (SHS), potentially underestimating smoking's impact. We compared the PAF from active smoking alone with the PAF, including SHS exposure.

Design

Prospective cohort study.

Setting

A community-based cohort study in Japan.

Participants

40 796 participants aged ≥20 years.

Main outcome measures

SHS was defined as inhaling someone else's cigarette smoke at the workplace or home in the past year. We classified smoking status and SHS into ten categories: never-smoker without SHS, never-smoker with SHS, past smoker without SHS, past smoker with SHS, current smoker 1-9 cigarettes/day without SHS, current smoker 1-9 cigarettes/day with SHS, 10-19 cigarettes/day without SHS, 10-19 cigarettes/day with SHS, ≥20 cigarettes/day without SHS and ≥20 cigarettes/day with SHS. The main outcome was all-cause mortality.

Results

During the median follow-up period of 6.5 (5.7-7.5) years, 788 men and 328 women died. For men, compared with never-smokers without SHS, past smokers without SHS (HR, 1.39 [95% CI, 1.11 to 1.73]) and past smokers with SHS (HR, 1.48 (95% CI, 1.10 to 2.00)) were associated with all-cause mortality. For women, never-smokers with SHS had a significantly higher risk of all-cause mortality (HR, 1.36 (95% CI, 1.00 to 1.84)). Without considering SHS, 28.0% and 2.3% of all-cause mortality in men and women, respectively, were attributable to past and current smoking. Including SHS, PAF increased to 31.3% in men and 8.4% in women.

Conclusions

We clarified that smoking's impact was underestimated by not accounting for SHS, especially in women. Information on SHS is crucial for understanding smoking's health impact. This study supports the importance of avoiding smoking and preventing SHS.

Population Proteomics: A Tool to Gain Insights Into the Inflamed Periodontium

Periodontitis, characterized by inflammatory loss of tooth-supporting tissues associated with biofilm, is among the most prevalent chronic diseases globally, affecting approximately 50% of the adult population to a moderate extent and cases of severe periodontitis surpassing the one billion mark. Proteomics analyses of blood, serum, and oral fluids have provided valuable insights into the complex processes occurring in the inflamed periodontium. However, until now, proteome analyses have been primarily limited to small groups of diseased versus healthy individuals. The emergence of population-scale analysis of proteomic data offers opportunities to uncover disease-associated pathways, identify potential drug targets, and discover biomarkers. In this review, we will explore the applications of proteomics in population-based studies and discuss the advancements it brings to our understanding of periodontal inflammation. Additionally, we highlight the challenges posed by currently available data and offer perspectives for future applications in periodontal research. This review aims to explain the ongoing efforts in leveraging proteomics for elucidating the complexities of periodontal diseases and paving the way for clinical strategies.

Absolute quantification of eight human milk oligosaccharides in breast milk to evaluate their concentration profiles and associations with infants' neurodevelopmental outcomes

Human milk oligosaccharides (HMOs) have been positively associated with child neurodevelopment in some cohort studies. However, there is a lack of consistency in the association between HMOs and benefits to infants' brains. Moreover, the quantification methods for HMOs have not yet been standardized. In this study, we developed a quantification method for evaluating eight HMOs (2'-fucosyllactose [2'-FL], 3'-fucosyllactose [3'-FL], 3'-sialyllactose [3'-SL], 6'-sialyllactose [6'-SL], lactosialyltetrasaccharide a [LSTa], lactosialyltetrasaccharide b [LSTb], lactosialyltetrasaccharide c [LSTc], and disialyllacto-N-tetraose [DSLNT]) in breast milk. After validating the method, we applied it to 1-month breast milk samples (n = 150) from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study to assess HMO profiles in breast milk and their possible association with changes in head circumference z-score (ΔHCZ) and neurodevelopmental scores of children (as measured by the Ages and Stages Questionnaire, Third Edition). The validation demonstrated that the method had relative standard deviation ≤ 12.7% of precision and 79.5-110.9% of accuracy. Using this method, eight HMO levels (2'-FL, 0-4.74 mg/mL; 3'-FL, 0.02-1.52 mg/mL; 3'-SL, 0.07-0.32 mg/mL; 6'-SL, 0.01-0.70 mg/mL; LSTa, 0.002-0.043 mg/mL; LSTb, 0.02-0.31 mg/mL; LSTc, 0.001-0.47 mg/mL; and DSLNT, 0.09-0.71 mg/mL [min-max, all participants]) and the ratio of low secretors (16.0%) in the Japanese cohort were obtained. The obtained HMO levels in breast milk were subjected to multivariate analysis to screen for HMOs showing a positive association with ΔHCZ and neurodevelopmental scores. The results proposed that ΔHCZ was positively associated with LSTb and 2'-FL levels, whereas neurodevelopmental scores were positively associated with 2'-FL levels (among all participants) and 3'-SL and DSLNT levels (among secretor participants). This study showed that the developed method provides HMO profiles in Japanese breast milk, as well as additional information on the associations between specific HMOs and neurodevelopment, reinforcing the sum of evidence for the role of HMOs in the brain.

Evaluation of depression at 6 and 12 months postpartum by examining depressive symptoms and self-harm ideation during the early postpartum period: Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

Aim

The aim of this study was to evaluate depression at 6 and 12 months postpartum, using the Edinburgh Postpartum Depression Scale (EPDS) total score and its subitem regarding self-harm ideation (SHI) at 1 month postpartum.

Methods

A sample of 12,358 postpartum women answered the EPDS and questionaries at 1, 6, and 12 months postpartum longitudinally.

Results

For participants with postpartum depression (PPD; EPDS total score ≥9) and SHI (SHI sub-score ≥1) at 1 month postpartum, the risk of depression at 6 and 12 months postpartum (odds ratio [95% confidence interval] at 6 and 12 months postpartum: 20.03 [16.8-23.8] and 14.55 [12.3-17.2], respectively) was higher than for those with PPD but without SHI at 1 month postpartum (OR: 8.57 [7.36-10.0], and 6.24 [5.38-7.24], respectively). Additionally, SHI even without depressive symptoms at 1 month postpartum is also a risk for depression at 6 and 12 months postpartum. To support our longitudinal evaluation of depression at 6 and 12 months postpartum, these related factors were examined: traumatic events or relocations after the Great East Japan Earthquake, employment status, household income, personality traits, sleep status, psychological distress, and social networks. The result showed employment status, low household income and poor social networks were significantly associated with depression at 12 months postpartum but not at 6 months postpartum.

Conclusion

This study showed a high risk of depression at 6 and 12 months postpartum for those who had depressive symptoms with SHI at 1 month postpartum. Our findings may contribute to the precise evaluation of depression at 6 and 12 months postpartum while considering sleep status, psychological distress and social network during pregnancy.

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.

Early prediction of hypertensive disorders of pregnancy toward preventive early intervention

Background

Various disease prediction models have been developed, capitalizing on the wide use of electronic health records, but environmental factors that are important in the development of noncommunicable diseases are rarely included in the prediction models. Hypertensive disorders of pregnancy are leading causes of maternal morbidity and mortality and are known to cause several serious complications later in life.

Objective

This study aims to develop early hypertensive disorders of pregnancy prediction models using comprehensive environmental factors based on self-report questionnaires in early pregnancy.

Study Design

We developed machine learning and artificial intelligence models for the early prediction of hypertensive disorders of pregnancy using early pregnancy data from approximately 23,000 pregnancies in the Tohoku Medical Megabank Birth and Three Generation Cohort Study. We clarified the important features for prediction based on regression coefficients or Gini coefficients of the interpretable artificial intelligence models (i.e., logistic regression, random forest and XGBoost models) among our developed models.

Results

The performance of the early hypertensive disorders of pregnancy prediction models reached an area under the receiver operating characteristic curve of 0.93, demonstrating that the early hypertensive disorders of pregnancy prediction models developed in this study retain sufficient performance in hypertensive disorders of pregnancy prediction. Among the early prediction models, the best performing model was based on self-reported questionnaire data in early pregnancy (mean of 20.2 gestational weeks at filling) which consist of comprehensive lifestyles. The interpretation of the models reveals that both eating habits were dominantly important for prediction.

Conclusion

We have developed high-performance models for early hypertensive disorders of pregnancy prediction using large-scale cohort data from the Tohoku Medical Megabank project. Our study clearly revealed that the use of comprehensive lifestyles from self-report questionnaires led us to predict hypertensive disorders of pregnancy risk at the early stages of pregnancy, which will aid early intervention to reduce the risk of hypertensive disorders of pregnancy.

Identification of risk loci for postpartum depression in a genome-wide association study

AIM

Genome-wide association studies (GWAS) of postpartum depression (PPD) based on accumulated cohorts with multiple ethnic backgrounds have failed to identify significantly associated loci. Herein, we conducted a GWAS of Japanese perinatal women along with detailed confounding information to uncover PPD-associated loci.

METHODS

The first and second cohorts (n = 9260 and n = 8582 perinatal women enrolled in the Tohoku Medical Megabank Project) and the third cohort (n = 997), recruited at Nagoya University, underwent genotyping. Of them, 1421, 1264, and 225 were classified as PPD based on the Edinburgh Postnatal Depression Scale 1 month after delivery. The most influential confounding factors of genetic liability to PPD were selected, and logistic regression analyses were performed to evaluate genetic associations with PPD after adjusting for confounders.

RESULTS

A meta-analysis of GWAS results from the three cohorts identified significant associations between PPD and the following loci (P < 5 × 10-8) by integrating the number of deliveries and the number of family members living together as the most influential confounders: rs377546683 at DAB1, rs11940752 near UGT8, rs141172317, rs117928019, rs76631412, rs118131805 at DOCK2, rs188907279 near ZNF572, rs504378, rs690150, rs491868, rs689917, rs474978, rs690118, rs690253 near DIRAS2, rs1435984417 at ZNF618, rs57705782 near PTPRM, and rs185293917 near PDGFB. Pathway analyses indicated that SNPs suggestively associated with PPD were mostly over-represented in categories including long-term depression, GnRH signaling, glutamatergic synapse, oxytocin signaling, and Rap1 signaling.

CONCLUSION

The current GWAS study identified eight loci significantly associated with PPD, which may clarify the genetic structure underlying its pathogenesis.

Maternal mitochondrial DNA copy number and methylation as possible predictors of pregnancy outcomes in a Michigan pregnancy cohort

Little is understood about the roles of mitochondria in pregnancy-related adaptations. Therefore, we evaluated associations of maternal early-to-mid pregnancy mitochondrial DNA copy number (mtDNAcn) and mtDNA methylation with birth size and gestational length. Michigan women (n = 396) provided venous bloodspots at median 11 weeks gestation to quantify mtDNAcn marker NADH-ubiquinone oxidoreductase chain 1 (ND1) using real-time quantitative PCR and mtDNA methylation at several regions within four mitochondria-specific genes using pyrosequencing: MTTF (mitochondrially encoded tRNA phenylalanine), DLOOP (D-loop promoter region, heavy strand), CYTB (cytochrome b), and LDLR (D-loop promoter region, light strand). We abstracted gestational length and birthweight from birth certificates and calculated birthweight z-scores using published references. We used multivariable linear regression to evaluate associations of mtDNAcn and mtDNA methylation with birthweight and birthweight z-scores. Cox Proportional Hazards Models (PHMs) and quantile regression characterized associations of mitochondrial measures with gestational length. We also considered differences by fetal sex. Using linear regression and Cox PHMs, mtDNAcn was not associated with birth outcomes, whereas associations of mtDNA methylation with birth outcomes were inconsistent. However, using quantile regression, mtDNAcn was associated with shorter gestation in female newborns at the upper quantiles of gestational length, but with longer gestational length in males at the lower quantiles of gestational length. Maternal LDLR, DLOOP, and MTTF methylation was associated with longer gestational length in females at the upper quantiles and in males at lower gestational length quantiles. Maternal mtDNAcn and mtDNA methylation were associated with gestational length in babies born comparatively early or late, which could reflect adaptations in mitochondrial processes that regulate the length of gestation.

The Use of Japanese Traditional (Kampo) Medicines Before and During Pregnancy in Japan: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

PURPOSE

Japanese traditional (Kampo) medicines are often used for pregnant women in Japan. However, no comprehensive studies have been conducted regarding the self-reported use of these medicines during pregnancy. This study investigated the use of Kampo medicines during pregnancy in Japan using the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study).

METHODS

Questionnaires were distributed to pregnant women participating in the TMM BirThree Cohort Study (July 2013 to March 2017) at approximately 12 weeks (early pregnancy) and 26 weeks (middle pregnancy). We analysed Kampo medicines use over three periods: (1) 12 months before pregnancy diagnosis, (2) the period between pregnancy diagnosis and around Week 12 of pregnancy and (3) from around Week 12 of pregnancy.

RESULTS

In total, 19 220 women were included in the analysis. The proportions using prescribed Kampo medicines were 4.1% before pregnancy diagnosis, 4.5% from diagnosis to Week 12% and 4.5% after Week 12 of pregnancy. The most frequently prescribed Kampo medicines were tokishakuyakusan (1.0%) before pregnancy diagnosis, shoseiryuto (1.3%) from diagnosis to Week 12 and shoseiryuto (1.5%) Post-week 12. Sixty of the pregnant women used Kampo medicines containing crude drugs, which should be administered cautiously during pregnancy.

CONCLUSION

The proportion of Kampo medicines use before and during pregnancy was 4%-5%. Some pregnant women used Kampo medicines containing crude drugs that should be administered cautiously during pregnancy. Further research is required to determine the safety of Kampo medicines during pregnancy.

The effect of gestational diabetes mellitus on postnatal mother-infant bonding: Findings from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

PURPOSE

Gestational diabetes mellitus (GDM) is a common complication of pregnancy and is associated with considerable psychological burden for women. In qualitative research, women with GDM describe increased awareness about their bonding with their infant, potentially resulting from the highly medicalised nature of the condition. The primary aim was to examine quantitatively whether GDM was associated with lower mother-infant bonding in the postnatal period.

METHODS

Data were analysed from 10,419 women who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study from 2013 to 2017 in Japan. GDM status was collected from hospital records and measured using the oral glucose tolerance test. Mother-infant bonding was assessed using the Japanese version of the Mother-to-Infant Bonding Scale (MIBS-J) at one-month postpartum, higher scores representing lower bonding. Data were analysed in SAS using multiple regression adjusting for relevant confounders.

RESULTS

GDM did not appear to be associated with worse mother-infant bonding scores at one-month postpartum. There was a non-significant unadjusted trend in the mean mother-infant bonding scores (1.43(SD=1.11) versus (1.75(SD1.71)), and the proportion with bonding disorder (n = 4 (4.12%) versus n = 969 (9.39%)) in the GDM versus non GDM group respectively, indicating higher self-reported bonding in the GDM group. This remained not statistically significant in the adjusted analyses.

CONCLUSIONS

We observed the reverse of our hypothesis, that there was a trend for women with GDM to self-report higher bonding compared to non-GDM women. There is need to replicate this finding in cohorts specifically designed to measure GDM-specific psychological distress.

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.

A fine-scale genetic map of the Japanese population

Genetic maps are fundamental resources for linkage and association studies. A fine-scale genetic map can be constructed by inferring historical recombination events from the genome-wide structure of linkage disequilibrium-a non-random association of alleles among loci-by using population-scale sequencing data. We constructed a fine-scale genetic map and identified recombination hotspots from 10 092 551 bi-allelic high-quality autosomal markers segregating among 150 unrelated Japanese individuals whose genotypes were determined by high-coverage (30×) whole-genome sequencing, and the genotype quality was carefully controlled by using their parents' and offspring's genotypes. The pedigree information was also utilized for haplotype phasing. The resulting genome-wide recombination rate profiles were concordant with those of the worldwide population on a broad scale, and the resolution was much improved. We identified 9487 recombination hotspots and confirmed the enrichment of previously known motifs in the hotspots. Moreover, we demonstrated that the Japanese genetic map improved the haplotype phasing and genotype imputation accuracy for the Japanese population. The construction of a population-specific genetic map will help make genetics research more accurate.

Combination of taking neuropsychiatric medications and psychological distress in pregnant women, with behavioral problems in children at 2 years of age: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

Aim

To examine the association of the combination of taking neuropsychiatric medications from the onset of pregnancy to mid-pregnancy and maternal psychological distress at mid-pregnancy, with children's behavioral problems.

Methods

Neuropsychiatric medication use from the onset of pregnancy to mid-pregnancy was defined by the self-reported name of the neuropsychiatric medication in the questionnaire in early and mid-pregnancy. Maternal psychological distress was defined by the Kessler Psychological Distress Scale (K6) ≥13 on the questionnaire in mid-pregnancy. We classified the participants into four categories based on the combination of taking neuropsychiatric medications and psychological distress: "None," "Medications only," "K6 ≥ 13 only," and "Both." Children's behavioral problems were assessed using the Child Behavior Checklist for Ages 1½-5 (CBCL) at 2 years of age. The clinical ranges of the internalizing and externalizing scales of the CBCL were defined as behavioral problems. We conducted a multivariable logistic regression analysis to examine the associations between the four categories of maternal exposure and children's behavioral problems.

Results

Compared with the "None" category (n = 9873), the "K6 ≥ 13 only" category (n = 308) was statistically significantly associated with internalizing and externalizing problems. In contrast, the "Medications only" (n = 93) and "Both" (n = 22) categories were not statistically significantly associated with internalizing and externalizing problems, although the point estimates of the odds ratio in the "Both" category were relatively high (1.58 for the internalizing problem and 2.50 for the externalizing problem).

Conclusion

The category of mothers taking neuropsychiatric medications and having no psychological distress during pregnancy was not associated with children's behavioral problems in the present population.

Genome-wide association study based on clustering by obesity-related variables uncovers a genetic architecture of obesity in the Japanese and the UK populations

Whether all obesity-related variants contribute to the onset of obesity or one or a few variants cause obesity in genetically heterogeneous populations remains obscure. Here, we investigated the genetic architecture of obesity by clustering the Japanese and British populations with obesity using obesity-related factors. In Step-1, we conducted a genome-wide association study (GWAS) with body mass index (BMI) as the outcome for eligible participants. In Step-2, we assigned participants with obesity (BMI ≥25 kg/m2) to five clusters based on obesity-related factors. Subsequently, participants from each cluster and those with a BMI <25 kg/m2 were combined. A GWAS was conducted for each cluster. Several previously identified obesity-related genes were verified in Step-1. Of the genes detected in Step-1, unique obesity-related genes were detected separately for each cluster in Step-2. Our novel findings suggest that a smaller sample size with increased homogeneity may provide insights into the genetic architecture of obesity.

Child-parent associations of hematocrit in trios of Japanese adulthood confirmed by the random family method: The TMM BirThree Cohort Study

To examine child-parent associations of HCT among Japanese adults and their parents. Factors associated with hematocrit (HCT) were analyzed in 3,574 sons and 7,203 daughters using Pearson's correlation coefficient and Student's t-test. Multiple linear regression analysis, adjusted by the factors identified by univariate analyses and by living with parents, was performed on 242 son-parent trios and 587 daughter-parent trios. When a child-parent association was observed in the multiple linear regression analysis, it was validated using the random family method (RFM). In univariate analyses, the son's HCT was associated with age (correlation coefficient = -0.072), white blood cell (WBC) (0.19), alanine aminotransferase (ALT) (0.20), triglyceride (0.11), and estimated glomerular filtration rate (eGFR) (- 0.087). The daughter's HCT was associated with WBC (0.014), ALT (0.18), and eGFR (- 0.17). In multiple linear regression analysis, the son's HCT was associated with the son's WBC (coefficient = 3.48 × 10-4), the son's eGFR (0.031), the father's HCT (0.11), and the mother's HCT (0.17). RFM confirmed the association between the son's and father's HCT (p = 0.0070) and between the son's and mother's HCT (p = 0.0011). The daughter's HCT was associated with WBC (2.6 × 10-4), ALT (0.037), and the mother's HCT (0.14). RFM confirmed the association between the daughter's and mother's HCT (p = 0.00043). Child-parent association of HCT was confirmed between son-father, son-mother, and daughter-mother relationships, and differed depending on the sex of the child and the parents.

Medication use before and during pregnancy in Japan: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

PURPOSE

To elucidate the status of medication use among pregnant women in Japan, by means of a multigenerational genome and birth cohort study: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study).

METHODS

Questionnaires were distributed to pregnant women participating in the TMM BirThree Cohort Study (from July 2013 to March 2017) around 12 weeks (early pregnancy) and 26 weeks (middle pregnancy). We analysed medication use over three periods: (1) 12 months prior to pregnancy diagnosis, (2) the period between pregnancy diagnosis and around week 12 of pregnancy, and (3) post around week 12 of pregnancy.

RESULTS

In total, 19,297 women were included in the analysis. The proportion of pregnant women using medications was 49.0% prior to pregnancy diagnosis, 52.1% from diagnosis to week 12, and 58.4% post week 12 of pregnancy. The most frequently prescribed medications were loxoprofen sodium hydrate (5.5%) prior to pregnancy diagnosis, magnesium oxide (5.9%) from diagnosis to week 12, and ritodrine hydrochloride (10.5%) post week 12 of pregnancy. The number of women who used suspected teratogenic medications during early pregnancy was 96 prior to pregnancy diagnosis, 48 from diagnosis to week 12, and 54 post week 12 of pregnancy.

CONCLUSION

We found that ~ 50% of the pregnant women used medications before and during pregnancy and some took potential teratogenic medications during pregnancy. In birth genomic cohort study, it is expected that investigations into the safety and effectiveness of medications used during pregnancy will advance.

How Healthy Lifestyle Habits Have Interacted with SARS-CoV-2 Infection and the Effectiveness of COVID-19 Vaccinations: Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

Introduction

To examine the interaction between lifestyle habits and the COVID-19 vaccinations for preventing SARS-CoV-2 infection, we analyzed 11,016 adult participants registered in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study.

Methods

Lifestyle variables, including regular exercise, smoking and drinking habits, sleep status, body mass index, and daily breakfast consumption, were assessed from 2014 to 2019 using baseline questionnaires. Information on SARS-CoV-2 infection and the COVID-19 vaccination were also collected from March 2020 to May 2023. The study period was divided into two in the postvaccination phase: the first period (the beginning of the vaccination program) and the second period (the fourth shot onward).

Results

In the Cox proportional-hazards model analysis, the five-time vaccinations group showed a significantly lower risk of SARS-CoV-2 infection adjusted age, sex, underlying health condition, and lifestyle variables (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.76-0.86). Logistic regression analysis revealed that a higher number of vaccinations was significantly associated with a low risk of SARS-CoV-2 infection regardless of lifestyle habits (three times in the first period: odds ratio [OR] 0.19, 95% CI 0.15-0.24; five times in the second period: OR 0.07, 95% CI 0.05-0.11 vs. none). Regarding lifestyle habits, the risk reduction in those who had sleep satisfaction (OR 0.12, 95% CI 0.08-0.18) was slightly larger than in those who had sleep dissatisfaction (OR 0.23, 95% CI 0.17-0.32) in the group with the highest number of vaccinations in the first period; however, this interaction was hardly confirmed in the second period when the number of infected cases significantly increased.

Conclusions

Our findings indicated that a higher number of COVID-19 vaccinations was associated with reduced risk of SARS-CoV-2 infection; otherwise, we may need to understand the advantages and limitations of a healthy lifestyle for preventing infection depending on the situation with vaccinations and infection spreading.

Urgent Notification Intervention of Home Blood Pressure in Cohort Studies of the Tohoku Medical Megabank Project

Introduction

The Tohoku Medical Megabank (TMM) was established for creative reconstruction from the Great East Japan Earthquake and tsunami in 2011. Two prospective genome cohort studies in Miyagi prefecture have successfully recruited approximately 127,000 participants. The health status of these individuals was evaluated at the initial recruitment, and follow-up health checkups have been conducted every 5 years. During these health checkups, unexpected critical values were encountered, which prompted us to develop an urgent notification system.

Methods

We analyzed the frequency of critical values observed in home blood pressure (HBP) test in an urgent notification office (UNO). We returned the critical values by urgent notification before the notifications of regular results. In addition, the impact of the TMM urgent notification on the participants was evaluated.

Results

We issued urgent notifications of the critical values of extremely high HBP. Of the 21,061 participants who underwent HBP measurements, 256 (1.2%) met the criteria for urgent notification. It was found that abnormalities in blood sugar levels, renal function, and lipid values were frequently concurrent with the abnormal HBP readings. Annual questionnaires administered after the urgent notification, approximately 60% of those went to hospitals or clinics.

Conclusions

The urgent notification system for hypertensive emergency with HBP in the TMM was well accepted by the participants and encouraged them to seek medical care. The system has been useful in addressing the prolonged healthcare problems and in promoting health care in large-scale disaster damaged areas.

Identifying critical age and gender-based metabolomic shifts in a Japanese population of the Tohoku Medical Megabank cohort

Understanding the physiological changes associated with aging and the associated disease risks is essential to establish biomarkers as indicators of biological aging. This study used the NMR-measured plasma metabolome to calculate age-specific metabolite indices. In doing so, the scope of the study was deliberately simplified to capture general trends and insights into age-related changes in metabolic patterns. In addition, changes in metabolite concentrations with age were examined in detail, with the period from 55-59 to 60-64 years being a period of significant metabolic change, particularly in men, and from 45-49 to 50-54 years in females. These results illustrate the different variations in metabolite concentrations by sex and provide new insights into the relationship between age and metabolic diseases.

Self-administered generational surveys combine with genetic analysis to reveal foundations of depression in Japanese adults

BACKGROUND

Major depressive disorder is a prevalent psychiatric illness characterized by mood disturbances and influenced by various environmental and genetic factors, yet its etiology remains largely unknown.

METHODS

We profiled a self-reported depressive population in Japan with a focus on sociodemographic background, lifestyle, comorbidities, and genetic background, using data from two cohorts, a population-based cohort and a three-generation cohort, recruited by the Tohoku Medical Megabank Organization until December 2021.

RESULTS

Our findings revealed that depression in the Japanese population is strongly associated with certain sociocultural features prevalent in Japan, such as social isolation, neuroticism, and introversion, as well as with well-known risk factors that include age and gender. Environmental factors related to the Great East Japan Earthquake, considered as cohort characteristics, were also strongly associated with the onset of depression. Moreover, using GWAS analysis of whole-genome sequencing data, we identified novel candidate genetic risk variants located on chromosomes 21 and 22 that are associated with depression in Japanese individuals; further validation of these risk variants is warranted.

LIMITATIONS

Our study has limitations, including uncertain clinical relevance resulting from the use of self-reported questionnaires for depression assessment. Additionally, the cohort exhibited a population bias, with greater representation of women than men.

CONCLUSIONS

Our results provide holistic insights into depression risk factors in Japanese adults, although their associations with depression are correlations. This supports the idea that targeted interventions and individualized approaches are important for addressing depression in the Japanese population.

The potential and translational application of infant genetic research

In the current genomic revolution, the infancy life stage is the most neglected. Although clinical genetics recognizes the value of early identification in infancy of rare genetic causes of disorders and delay, common genetic variation is almost completely ignored in research on infant behavioral and neurodevelopmental traits. In this Perspective, we argue for a much-needed surge in research on common genetic variation influencing infant neurodevelopment and behavior, findings that would be relevant for all children. We now see convincing evidence from different research designs to suggest that developmental milestones, skills and behaviors of infants are heritable and thus are suitable candidates for gene-discovery research. We highlight the resources available to the field, including genotyped infant cohorts, and we outline, with recommendations, special considerations needed for infant data. Therefore, infant genetic research has the potential to impact basic science and to affect educational policy, public health and clinical practice.

Hypertensive disorders of pregnancy, neonatal outcomes and offspring developmental delay in Japan: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

INTRODUCTION

Developmental delay at an early age indicates the probability of continued problems after school age. Hypertensive disorders of pregnancy (HDP) are associated with developmental delays in offspring, with inconsistent outcomes. Neonatal outcomes vary according to HDP exposure and are relevant to development in later years. Here we aimed to clarify the relationship between HDP and developmental delay in offspring and whether neonatal outcomes mediate this association.

MATERIAL AND METHODS

We used data from 5934 mother-child pairs from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study, a prospective cohort study conducted in Japan between July 2013 and March 2017. The Ages and Stages Questionnaires, third edition, at 24 and 42 months of age, measured developmental delay in five areas. We performed multivariate quasi-Poisson regression and causal mediation analysis by neonatal outcomes.

RESULTS

At 24 months of age, compared to offspring born from normotensive mothers, offspring born from HDP-affected mothers were more likely to experience developmental delay (risk ratio [RR] 1.29, 95% confidence interval [CI]: 1.09-1.52) in the areas of communication (RR 1.21, 95% CI: 1.00-1.45) and personal-social (RR 1.15, 95% CI: 1.03-1.28). This association was mediated by neonatal outcomes: preterm birth, neonatal asphyxia, NICU admission, and neonatal small head circumference. No association was observed between HDP and developmental delay at 42 months of age.

CONCLUSIONS

Exposure to HDP during fetal life is associated with offspring developmental delay. This association is partly mediated by neonatal outcomes.

Risk of Major Congenital Malformations Associated with the Use of Japanese Traditional (Kampo) Medicine Containing Ephedra During the First Trimester of Pregnancy

BACKGROUND

Japanese traditional (Kampo) medicines containing ephedra may be used to treat colds during pregnancy. There are reports that ephedrine, a component of ephedra, has a risk of teratogenicity; however, the evidence remains equivocal.

OBJECTIVE

This study aimed to evaluate the risk of major congenital malformations (MCMs) associated with exposure to Kampo medicines containing ephedra during the first trimester of pregnancy using the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study).

METHODS

To 23,730 mother-infant pairs who participated in the TMM BirThree Cohort Study from July 2013 to March 2017, questionnaires in early and middle pregnancy were distributed approximately at weeks 12 and 26 of pregnancy, respectively. Infants' risk of MCMs in women who used Kampo medicines containing ephedra or acetaminophen during the first trimester was assessed, and the odds ratios (ORs) were estimated with unadjusted and adjusted analyses.

RESULTS

Among 20,879 women, acetaminophen and Kampo medicines containing ephedra were used in 665 (3.19%) and 376 (1.80%) women, respectively, in the first trimester. Among the infants born to the mothers who used acetaminophen or Kampo medicine containing ephedra during the first trimester, 11 (1.65%) and 8 (2.13%), respectively, had overall MCMs. OR of overall MCMs was higher in women who used Kampo medicines containing ephedra than in those who used acetaminophen in the first trimester (adjusted OR, 1.45; 95% confidence interval (CIs), 0.57-3.71); however, the difference was not statistically significant.

CONCLUSIONS

In this study, there was no statistically significant association between the use of Kampo medicines containing ephedra during the first trimester of pregnancy and the risk of MCMs. Although some point estimates of ORs exceeded 1.00, the absolute magnitude of any increased risks would be low.

Relationship between traditional risk factors for hypertension and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study

Risk factors for hypertension have been emphasized in the Japanese Society of Hypertension Guidelines for the Management of Hypertension. However, large-scale studies on the association of smoking, potassium excretion, and gamma-glutamyl transferase level with BP in the Japanese population are limited. We conducted a cross-sectional study to examine the association between hypertension risk factors and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study (23,446 men and 38,921 women aged ≥20 years). A model adjusted for age, body mass index, smoking status, drinking status, estimated daily salt intake, potassium excretion, (or urinary sodium-to-potassium ratio), gamma-glutamyl transferase, physical activity, education level, status of damage to homes during the Great East Japan Earthquake, and residential areas was used. The average age and systolic blood pressure were 62.5 (10.3) years for men and 59.6 (11.3) years for women, 128.9 (16.7) mmHg for men and 124.7 (17.5) mmHg for women, respectively. Body mass index estimated daily salt intake, urinary sodium-to-potassium ratio and gamma-glutamyl transferase levels were positively associated with systolic blood pressure. Compared with never-drinkers, current drinkers who consumed 23-45 g/day and ≥46.0 g/day had significantly increased systolic blood pressure. Conversely, current smokers (1-10 cigarettes/day and 11-20 cigarettes/day) were inversely associated with systolic blood pressure compared to never-smokers. Overall, systolic blood pressure was associated with gamma-glutamyl transferase and hypertension risk factors, including body mass index, alcohol consumption, estimated daily salt intake, urinary sodium-to-potassium ratio, and potassium excretion. Our findings support the notion that lifestyle modifications should be attempted to prevent hypertension.

Whole blood transcriptome analysis for age- and gender-specific gene expression profiling in Japanese individuals

Whole blood transcriptome analysis is a valuable approachin medical research, primarily due to the ease of sample collection and the richness of the information obtained. Since the expression profile of individual genes in the analysis is influenced by medical traits and demographic attributes such as age and gender, there has been a growing demand for a comprehensive database for blood transcriptome analysis. Here, we performed whole blood RNA sequencing (RNA-seq) analysis on 576 participants stratified by age (20-30s and 60-70s) and gender from cohorts of the Tohoku Medical Megabank (TMM). A part of female segment included pregnant women. We did not exclude the globin gene family in our RNA-seq study, which enabled us to identify instances of hereditary persistence of fetal hemoglobin based on the HBG1 and HBG2 expression information. Comparing stratified populations allowed us to identify groups of genes associated with age-related changes and gender differences. We also found that the immune response status, particularly measured by neutrophil-to-lymphocyte ratio (NLR), strongly influences the diversity of individual gene expression profiles in whole blood transcriptome analysis. This stratification has resulted in a data set that will be highly beneficial for future whole blood transcriptome analysis in the Japanese population.

Maternal birth weight is an indicator of preterm delivery: the Japan environment and children's study

This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118-1.218) for PTD, 1.174 (95% CI: 1.070-1.287) for early PTD and 1.151 (95% CI: 1.098-1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

The association between blood pressure control in women during pregnancy and adverse perinatal outcomes: the TMM BirThree Cohort Study

Blood pressure (BP) control in pregnancy is essential to prevent adverse outcomes. However, BP levels for hypertension treatment are inconsistent among various guidelines. This study investigated the association between BP control and adverse perinatal outcomes. A total of 18,155 mother-offspring pairs were classified into four groups according to BP after 20 gestational weeks: normal BP (<140/90 mmHg without antihypertensive drugs), high BP (≥140/90 mmHg without antihypertensive drugs), controlled BP (<140/90 mmHg with antihypertensive drugs), and uncontrolled BP (≥140/90 mmHg with antihypertensive drugs). The prevalence of small for gestational age was 1,087/17,476 offspring in normal BP, 78/604 in high BP, 5/42 in controlled BP, and 7/33 in uncontrolled BP. Compared to normal BP, adjusted odds ratios (ORs) (95% confidence intervals (CIs)) were 1.76 (1.32-2.35) for high BP, 2.08 (0.79-5.50) for controlled BP, and 2.34 (0.94-5.85) for uncontrolled BP (multiple logistic regression analysis). Similarly, the adjusted ORs (95% CIs) were 1.80 (1.35-2.41), 3.42 (1.35-8.63), and 5.10 (1.93-13.45) for high, controlled, and uncontrolled BPs for low birth weight, respectively; 1.99 (1.48-2.68), 2.70 (1.12-6.50), and 6.53 (3.09-13.82) for high, controlled, and uncontrolled BPs for preterm birth, respectively; 1.64 (1.19-2.24), 2.17 (0.88-5.38), and 2.12 (0.80-5.65) for high, controlled, and uncontrolled BPs for admission to the Neonatal Intensive Care Unit or Growing Care Unit, respectively; and 1.17 (0.70-1.95), 2.23 (0.65-7.68), and 0.91 (0.20-4.16) for high, controlled, and uncontrolled BPs for 1-min Apgar score < 7, respectively. BP ≥ 140/90 mmHg might be taken care for preventing various adverse perinatal outcomes.

Genome-wide association study of nausea and vomiting during pregnancy in Japan: the TMM BirThree Cohort Study

BACKGROUND

Nausea and vomiting during pregnancy (NVP) and hyperemesis gravidarum (HG), common conditions affecting most pregnant women, are highly heritable and associated with maternal and fetal morbidity. However, the pathologies underlying NVP and HG and their associated loci are scarce.

METHODS

We performed genome-wide association studies (GWAS) of NVP in pregnant women (n = 23,040) who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study in Japan from July 2013 to March 2017. Participants were divided into discovery (n = 9,464) and replication (n = 10,051) stages based on the platform used for their genotyping. Loci that achieved the genome-wide significance level (p < 5.0 × 10- 8) in the discovery stage were selected for genotyping in the replication stage. A meta-analysis integrating the discovery and replication stage results (n = 19,515) was conducted. NVP-related variables were identified as categorical or continuous.

RESULTS

GWAS analysis in the discovery phase revealed loci linked to NVP in two gene regions, 11q22.1 (rs77775955) and 19p13.11 (rs749451 and rs28568614). Loci in these two gene regions have also been shown to be associated with HG in a White European population, indicating the generalizability of the GWAS analyses conducted in this study. Of these, only rs749451 and rs28568614 at 19p13.11 reached the genome-wide suggestive level (p < 1.0 × 10- 5) in the replication stage; however, both loci were significant in the meta-analysis.

CONCLUSIONS

NVP-related loci were identified in the Japanese population at 11q22.1 and 19p13.11, as reported in previous GWAS. This study contributes new evidence on the generalizability of previous GWAS on the association between genetic background and NVP.

Risk Factors, Prognosis, Influence on the Offspring, and Genetic Architecture of Perinatal Depression Classified Based on the Depressive Symptom Trajectory

This study is aimed at revealing the risk factors, prognosis, influence on offspring, and genetic architecture of perinatal depression (PD) classified based on the depressive symptom trajectory. Pregnant women with no history of major depressive disorder (MDD) were recruited and followed up with their offspring from 1 to 5 years postpartum. Using four self-report questionnaires in the perinatal period, PD was classified into four subtypes: pregnancy, early postpartum, late postpartum, and chronic PD. Risk factors, depressive symptom trajectory from 1 to 5 years postpartum, and child behavior problems were compared among the four PD subtypes. Genome-wide association studies (GWASs) were conducted for each subtype. The relationships between the PD subtypes and polygenic risk scores (PRS) for MDD, a psychiatric disorder, and premenstrual syndrome (PMS), a hormonal disorder, were examined. Among 12,338 participants, 1,145 (9.3%) developed pregnancy PD, 856 (6.9%) developed early postpartum PD, 382 (3.1%) developed late postpartum PD, and 1,048 (8.5%) developed chronic PD. Depressive symptoms decreased to 61.0%-73.3% in the 5 years postpartum. The relationship between risk factors and PD varied based on the PD subtype. Additionally, chronic PD increased the risk of child behavior problems by 2- to 3-fold. The GWASs uncovered five significant variants in different loci depending on PD subtypes, suggesting a subtype-specific genetic architecture. The PRS for MDD was related to pregnancy, early postpartum, and chronic PD, while that for PMS was related to late postpartum PD. It was concluded that PD is heterogeneous depending on the depressive symptom trajectory. Thus, specific prevention and treatment strategies are needed.

The developmental origins of health and disease and intergenerational inheritance: a scoping review of multigenerational cohort studies

Epidemiologic research has increasingly acknowledged the importance of developmental origins of health and disease (DOHaD) and suggests that prior exposures can be transferred across generations. Multigenerational cohorts are crucial to verify the intergenerational inheritance among human subjects. We carried out this scoping review aims to summarize multigenerational cohort studies' characteristics, issues, and implications and hence provide evidence to the DOHaD and intergenerational inheritance. We adopted a comprehensive search strategy to identify multigenerational cohorts, searching PubMed, EMBASE, and Web of Science databases from the inception of each dataset to June 20th, 2022, to retrieve relevant articles. After screening, 28 unique multigenerational cohort studies were identified. We classified all studies into four types: population-based cohort extended three-generation cohort, birth cohort extended three-generation cohort, three-generation cohort, and integrated birth and three-generation cohort. Most cohorts (n = 15, 53%) were categorized as birth cohort extended three-generation studies. The sample size of included cohorts varied from 41 to 167,729. The study duration ranged from two years to 31 years. Most cohorts had common exposures, including socioeconomic factors, lifestyle, and grandparents' and parents' health and risk behaviors over the life course. These studies usually investigated intergenerational inheritance of diseases as the outcomes, most frequently, obesity, child health, and cardiovascular diseases. We also found that most multigenerational studies aim to disentangle genetic, lifestyle, and environmental contributions to the DOHaD across generations. We call for more research on large multigenerational well-characterized cohorts, up to four or even more generations, and more studies from low- and middle-income countries.

Maternal social isolation and behavioral problems in preschool children: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

It is essential to clarify factors associated with mental health and behavioral problems in early childhood, because children are critical stages of life for mental health. We aimed to prospectively examine the associations between maternal social isolation and behavioral problems in preschool children. We analyzed data from 5842 mother-child pairs who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. The Lubben Social Network Scale-abbreviated version was used to assess social isolation (defined as scores < 12) one year after delivery. The Child Behavior Checklist 1½-5 was used to assess behavioral problems, and its subscales were used to assess internalizing and externalizing problems in children at 4 years of age. Multiple logistic regression analyses were conducted to examine the associations between social isolation and behavioral problems, after adjustment for age, education, income, work status, marital status, extraversion, neuroticism, depressive symptoms, child sex, and number of siblings. Multiple logistic regression analyses were also conducted for internalizing problems and externalizing problems. The prevalence of maternal social isolation was 25.4%. Maternal social isolation was associated with an increased risk of behavioral problems in children: the odds ratio (OR) was 1.37 (95% confidence interval [CI] 1.14-1.64). Maternal social isolation was also associated with increased risks of internalizing problems and externalizing problems in children: the ORs were 1.33 (95% CI, 1.12-1.59) and 1.40 (95% CI, 1.18-1.66), respectively. In conclusion, maternal social isolation one year after delivery was associated with behavioral problems in children at 4 years of age.

Prevalence, Associated Factors, and Inter-Eye Differences of Refractive Errors in a Population-Based Japanese Cohort: The Tohoku Medical Megabank Eye Study

PURPOSE

To investigate the prevalence, associated factors, and inter-eye differences of myopia and astigmatism in an adult Japanese population-based cohort.

METHODS

A total of 4282 participants from the Tohoku Medical Megabank Organization Eye Study (ToMMo Eye Study) underwent comprehensive ocular examinations as well as extensive physiological tests and a lifestyle questionnaire. The spherical equivalent (SE) and cylinder power were obtained as refractive parameters. The age- and gender-stratified prevalences of high myopia (SE < -5D), myopia (SE < -0.5D), hyperopia (SE > 0.5D), astigmatism (cylinder power < -0.5D), and anisometropia (SE difference >1D) were calculated. Multivariable analyses were performed to identify associated factors for refractive error (RE). Distribution and associated factors of the inter-eye difference in RE were also investigated.

RESULTS

The age-adjusted prevalence of high myopia, myopia, hyperopia, astigmatism, and anisometropia was 15.9%, 63.5%, 14.7%, 51.1%, and 14.7%, respectively. Both myopia and high myopia were more prevalent in the younger age group, while astigmatism was more prevalent in the older age group. Age, education, blood pressure, intraocular pressure, and corneal thickness are significantly associated with myopic refraction. Age, gender, intraocular pressure, and corneal thickness are correlated with astigmatism. Older age was associated with against-the-rule astigmatism. Older age, myopia, and longer education showed a significant correlation with large inter-eye differences in SERE.

CONCLUSIONS

This study demonstrated the high prevalence of myopia in young Japanese, which may be caused by a generational shift. This study also confirmed the influence of age and education on both the prevalence and inter-eye differences of RE.

jMorp: Japanese Multi-Omics Reference Panel update report 2023

Modern medicine is increasingly focused on personalized medicine, and multi-omics data is crucial in understanding biological phenomena and disease mechanisms. Each ethnic group has its unique genetic background with specific genomic variations influencing disease risk and drug response. Therefore, multi-omics data from specific ethnic populations are essential for the effective implementation of personalized medicine. Various prospective cohort studies, such as the UK Biobank, All of Us and Lifelines, have been conducted worldwide. The Tohoku Medical Megabank project was initiated after the Great East Japan Earthquake in 2011. It collects biological specimens and conducts genome and omics analyses to build a basis for personalized medicine. Summary statistical data from these analyses are available in the jMorp web database (https://jmorp.megabank.tohoku.ac.jp), which provides a multidimensional approach to the diversity of the Japanese population. jMorp was launched in 2015 as a public database for plasma metabolome and proteome analyses and has been continuously updated. The current update will significantly expand the scale of the data (metabolome, genome, transcriptome, and metagenome). In addition, the user interface and backend server implementations were rewritten to improve the connectivity between the items stored in jMorp. This paper provides an overview of the new version of the jMorp.

Effect of Nicotinamide Mononucleotide Concentration in Human Milk on Neurodevelopmental Outcome: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

(1) Background: Breast milk is the only source of nutrition for breastfed infants, but few studies have examined the relationship between breast milk micronutrients and infant neurodevelopmental outcome in exclusively breastfed infants. The aim of this study was to characterize the association between nicotinamide adenine dinucleotide (NAD)-related compounds in the breast milk of Japanese subjects and infant neurodevelopmental outcome. (2) Methods: A total of 150 mother-child pairs were randomly selected from the three-generation cohort of the Tohoku Medical Megabank in Japan. Infants were exclusively breastfed for up to 6 months. Breast milk was collected at 1 month postpartum, and the quantity of NAD-related substances in the breast milk was quantified. The mothers also completed developmental questionnaires at 6, 12, and 24 months. The relationship between the concentration of NAD-related substances in breast milk and developmental indicators was evaluated via ordinal logistic regression analysis. (3) Results: Nicotinamide mononucleotide (NMN) was quantified as the major NAD precursor in breast milk. The median amount of NMN in the breast milk was 9.2 μM. The NMN concentration in breast milk was the only NAD-related substance in breast milk that showed a significant positive correlation with neurodevelopmental outcome in infants at 24 months. (4) Conclusions: The results suggest that NMN in human milk may be an important nutrient for early childhood development.