GWAS of Folate Metabolism With Gene-environment Interaction Analysis Revealed the Possible Role of Lifestyles in the Control of Blood Folate Metabolites in Japanese: The J-MICC Study

BACKGROUND

The present genome-wide association study (GWAS) aimed to reveal the genetic loci associated with folate metabolites, as well as to detect related gene-environment interactions in Japanese.

METHODS

We conducted the GWAS of plasma homocysteine (Hcy), folic acid (FA), and vitamin B12 (VB12) levels in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study participants who joined from 2005 to 2012, and also estimated gene-environment interactions. In the replication phase, we used data from the Yakumo Study conducted in 2009. In the discovery phase, data of 2,263 participants from four independent study sites of the J-MICC Study were analyzed. In the replication phase, data of 573 participants from the Yakumo Study were analyzed.

RESULTS

For Hcy, MTHFR locus on chr 1, NOX4 on chr 11, CHMP1A on chr 16, and DPEP1 on chr 16 reached genome-wide significance (P < 5 × 10-8). MTHFR also associated with FA, and FUT2 on chr 19 associated with VB12. We investigated gene-environment interactions in both studies and found significant interactions between MTHFR C677T and ever drinking, current drinking, and physical activity >33% on Hcy (β = 0.039, 0.038 and -0.054, P = 0.018, 0.021 and <0.001, respectively) and the interaction of MTHFR C677T with ever drinking on FA (β = 0.033, P = 0.048).

CONCLUSION

The present GWAS revealed the folate metabolism-associated genetic loci and gene-environment interactions with drinking and physical activity in Japanese, suggesting the possibility of future personalized cardiovascular disease prevention.

Psychometrics of rating scales for externalizing disorders in Japanese outpatients: The ADHD-Rating Scale-5 and the Disruptive Behavior Disorders Rating Scale

OBJECTIVES

This study validated the Japanese version of the Attention-Deficit/Hyperactivity Disorder-Rating Scale-5 (ADHD-RS-5) and the Disruptive Behavior Disorders Rating Scale. We extended the ADHD-RS-5 by adding the oppositional defiant disorder and conduct disorder subscales to compare the two rating scales psychometrically.

METHODS

We examined the internal consistency, test-retest reliability, construct validity and criterion validity of the two rating scales in 135 Japanese outpatients aged 6-18 years.

RESULTS

The internal consistency and test-retest reliability were good for all the subscales of the two rating scales except for the conduct disorder subscale of the ADHD-RS-5 extended. Good construct validity was revealed by expected correlational patterns between subscales from the two rating scales and the Children Behavior Checklist. The criterion validity was good for all the subscales of the two rating scales rated by parents, while teacher-ratings revealed substantially lower predictive ability for all the subscales. Agreement between parent- and teacher-ratings of the two rating scales was generally moderate and using predictive ratings alone of both ratings showed the best predictive ability among the integration methods examined.

CONCLUSION

The two rating scales have sound psychometric properties and will aid in screening and severity assessment of externalizing disorders in Japanese clinical settings.

BMI and Cardiometabolic Traits in Japanese: A Mendelian Randomization Study

BACKGROUND

Although many observational studies have demonstrated significant relationships between obesity and cardiometabolic traits, the causality of these relationships in East Asians remains to be elucidated.

METHODS

We conducted individual-level Mendelian randomization (MR) analyses targeting 14,083 participants in the Japan Multi-Institutional Collaborative Cohort Study and two-sample MR analyses using summary statistics based on genome-wide association study data from 173,430 Japanese. Using 83 body mass index (BMI)-related loci, genetic risk scores (GRS) for BMI were calculated, and the effects of BMI on cardiometabolic traits were examined for individual-level MR analyses using the two-stage least squares estimator method. The β-coefficients and standard errors for the per-allele association of each single-nucleotide polymorphism as well as all outcomes, or odds ratios with 95% confidence intervals were calculated in the two-sample MR analyses.

RESULTS

In individual-level MR analyses, the GRS of BMI was not significantly associated with any cardiometabolic traits. In two-sample MR analyses, higher BMI was associated with increased risks of higher blood pressure, triglycerides, and uric acid, as well as lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent using different methods, including the directions.

CONCLUSION

The results of this study suggest that, even among the Japanese, an East Asian population with low levels of obesity, higher BMI could be causally associated with the development of a variety of cardiometabolic traits. Causality in those associations should be clarified in future studies with larger populations, especially those of BMI with type 2 diabetes.

Positive association between blood glucose in physical examinations and self-reported fractures among middle-aged and elderly Japanese men: a prospective cohort study

The association between blood glucose and fractures is not consistent across populations. Blood glucose was associated with fractures five years later in middle-aged and elderly men who underwent health examinations in Japan, respectively. Blood glucose-targeted fracture alerts are crucial for middle-aged and elderly individuals.

OBJECTIVES

The evidence on blood glucose as a fracture risk marker has not been adequately examined in various populations, and there are no studies in middle-aged Japanese. We aimed to determine the association between blood glucose status and self-report fractures among middle-aged and elderly Japanese men.

METHODS

The data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Okazaki Study were used. Hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) measured at baseline physical examinations were examined for association with fractures questioned five years later. Analyses were performed for the middle-aged and elderly respondents.

RESULTS

The HbA1c was dichotomized into 290 (11.8%) with HbA1c ≥ 6.5% and 2165 (88.2%) with HbA1c < 6.5%. Compared to the group with an HbA1c < 6.5, the odds ratio for the risks of fracture among the group with an HbA1c ≥ 6.5% were 3.46 (95% confidence interval (CI), 1.75-6.84) in Model 1 (adjusted for age) and 3.60 (95% CI, 1.77-7.34) in Model 2 (adjusted for various confounding factors). These associations were also observed in both middle-aged and elderly generations, whereas no association was observed for FPG.

CONCLUSIONS

Among Japanese men who have undergone physical examinations, those with an HbA1c of 6.5% or higher are at higher risk for fractures, and HbA1c-targeted fracture alerts are crucial for middle-aged and elderly individuals.

Psychometrics of the kiddie schedule for affective disorders and schizophrenia present and lifetime version for DSM-5 in Japanese outpatients

OBJECTIVE

The Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL) is a widely used semi-structured diagnostic interview in child and adolescent psychiatry. However, the psychometric properties of its updated version, the K-SADS-PL for DSM-5, have scarcely been examined, especially for criterion validity. This study was designed to examine the inter-rater reliability, criterion validity and construct validity of the K-SADS-PL for DSM-5 in 137 Japanese outpatients.

METHODS

Two of 12 experienced clinicians independently performed the K-SADS interview for each patient in a conjoint session, and the resulting consensus diagnosis was compared with a "best-estimate" diagnosis made by two of eight experienced clinicians using all available information for the patient.

RESULTS

The inter-rater reliability was excellent, as shown by κ > 0.75 for all disorders, with the exception of current separation anxiety disorder. The criterion validity was fair to good, as shown by κ > 0.40 for all disorders, with the exception of current and lifetime agoraphobia. The construct validity was also good, as shown by theoretically expected associations between the K-SADS-PL diagnoses and subscales of the child behavior checklist.

CONCLUSION

The K-SADS-PL for DSM-5, now available in Japanese, generates valid diagnoses in child and adolescent psychiatry.

Association between awareness of limiting food intake and all-cause mortality: A cohort study in Japan

BACKGROUND

Improving diets requires an awareness of the need to limit foods for which excessive consumption is a health problem. Since there are limited reports on the link between this awareness and mortality risk, we examined the association between awareness of limiting food intake (energy, fat, and sweets) and all-cause mortality in a Japanese cohort study.

METHODS

Participants comprised 58,772 residents (27,294 men; 31,478 women) aged 35-69 years who completed baseline surveys of the Japan Multi-Institutional Collaborative Cohort Study from 2004 to 2014. Hazard ratios (HRs) for all-cause mortality and 95% confidence intervals (CIs) were estimated by sex using a Cox proportional hazard model, with adjustment for related factors. Mediation analysis with fat intake as a mediator was also conducted.

RESULTS

The mean follow-up period was 11 years and 2,516 people died. Estimated energy and fat intakes according to the Food Frequency Questionnaire were lower in those with awareness of limiting food intake than in those without this awareness. Women with awareness of limiting fat intake showed a significant decrease in mortality risk (HR=0.73; 95% CI, 0.55 to 0.94). Mediation analysis revealed that this association was due to the direct effect of the awareness of limiting fat intake and that the total effect was not mediated by actual fat intake. Awareness of limiting energy or sweets intake was not related to mortality risk reduction.

CONCLUSION

Awareness of limiting food intake had a limited effect on reducing all-cause mortality risk.

Association between Dietary Patterns and Serum Low Density Lipoprotein Cholesterol in Japanese Women and Men: The Japan Multi-Institutional Collaborative Cohort (J-MICC) Study

AIMS

The association between dietary patterns and serum low density lipoprotein (LDL) cholesterol would be changing in recent dietary habits in Japan. We investigated the relationship between dietary patterns and serum LDL cholesterol in a large general population.

METHODS

From the baseline survey of Japan Multi-Institutional Collaborative Cohort Study between 2005 and 2013, 27,237 participants (13,994 were women) aged 35-69 years were cross-sectionally analyzed. Using a semi-quantitative food frequency questionnaire, five major sex-specific dietary patterns were identified using factor analysis. We assessed serum LDL cholesterol by quintiles of dietary pattern factor score.

RESULTS

We identified dietary patterns; "vegetable rich pattern" , "meat and fried food rich pattern" and "high bread and low rice pattern" in women and men; "fish and shellfish rich pattern" and "high confectioneries and low alcohol pattern" in men; "healthy Japanese diet pattern" and "high alcohol and low rice pattern" in women. Serum LDL cholesterol in men was associated with "high bread and low rice pattern" score (Q5 was 4.2 mg/dL higher than Q1, p for trend ＜0.001) and "high confectioneries and low alcohol pattern" scores (Q5 was 9.5 mg/dL higher than Q1, p for trend ＜0.001). In women, serum LDL cholesterol was associated with "high bread and low rice pattern" score (Q5 was 7.1 mg/dL higher than Q1, p for trend ＜0.001).

CONCLUSION

Some recent dietary patterns in Japan were associated with serum LDL cholesterol. Serum LDL cholesterol was associated with high bread and low rice pattern in both sex, and high confectioneries and low alcohol pattern in men.

Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Possible contribution of phosphate to the pathogenesis of chronic kidney disease in dolphins

This study aimed to investigate whether phosphate contributes to the pathogenesis of chronic kidney disease (CKD) in dolphins. Renal necropsy tissue of an aged captive dolphin was analyzed and in vitro experiments using cultured immortalized dolphin proximal tubular (DolKT-1) cells were performed. An older dolphin in captivity died of myocarditis, but its renal function was within the normal range until shortly before death. In renal necropsy tissue, obvious glomerular and tubulointerstitial changes were not observed except for renal infarction resulting from myocarditis. However, a computed tomography scan showed medullary calcification in reniculi. Micro area X-ray diffractometry and infrared absorption spectrometry showed that the calcified areas were primarily composed of hydroxyapatite. In vitro experiments showed that treatment with both phosphate and calciprotein particles (CPPs) resulted in cell viability loss and lactate dehydrogenase release in DolKT-1 cells. However, treatment with magnesium markedly attenuated this cellular injury induced by phosphate, but not by CPPs. Magnesium dose-dependently decreased CPP formation. These data support the hypothesis that continuous exposure to high phosphate contributes to the progression of CKD in captive-aged dolphins. Our data also suggest that phosphate-induced renal injury is mediated by CPP formation in dolphins, and it is attenuated by magnesium administration.

Novel WNT10A variant in a Japanese case of nonsyndromic oligodontia

Congenital tooth agenesis is one of the most common anomalies in humans. Many genetic factors are involved in tooth development, including MSX1, PAX9, WNT10A, and LRP6. Thus, mutations in these genes can cause congenital tooth agenesis in humans. In this study, we identified a novel nonsense WNT10A variant, NM_025216.3(WNT10A_v001):c.1090A > T, which produces a C-terminal truncated gene product, p.(Lys364*), in a sporadic form of congenital tooth agenesis. The variant was not found in the healthy parents and thus was considered to cause congenital tooth agenesis in the case.

A nationwide survey of Schaaf-Yang syndrome in Japan

Schaaf-Yang syndrome (SYS) is a congenital disorder characterized by developmental delay, autism spectrum disorder and congenital joint contractures. In this study, a nationwide epidemiological questionnaire-based survey of SYS in the Japanese population was conducted to establish patient numbers, clinical features and genetic information. In the primary survey, we investigated the number of SYS patients. In the secondary survey, we obtained and analyzed detailed clinical and genetic information of SYS patients. This survey collected information on 25 genetically-confirmed patients. The major clinical symptoms included neonatal hypotonia (96% of the patients), poor suck in infancy (82%), developmental delay (100%) and joint contractures (83%). Other main symptoms and findings included characteristic facial features (100%), small hands (92%), eye abnormalities (92%) and short stature (79%). Based on the information collected on activities of daily living, 71% of patients were unable to walk, while 67%, 71%, and 81% of patients required full assistance with eating, toileting and bathing, respectively. Regarding inheritability, the genetic analysis of 21 patients revealed that 14 (67%) carried de novo truncating variants in the melanoma antigen L2 (MAGEL2) gene and seven (33%) had inherited truncating variants from their fathers who were carriers. This survey revealed the clinical and genetic features in Japanese SYS patients. The majority of SYS patients required assistance in many aspects of daily living, and there were a certain number of carriers of the imprinting disorder.

Associations between Work-Related Factors and Happiness among Working Older Adults: A Cross-Sectional Study

Background

As the global population ages, the number of older adults working after retirement is increasing. However, knowledge regarding working conditions for health and happiness among this population is insufficient. Therefore, we examined the association between work-related factors (e.g., employment status, daily working time, work-related stress) and happiness among working older adults.

Methods

This cross-sectional study recruited Japanese older adults, aged 65 years and older, who were engaged in paid work, during their annual health checkups. Self-administered questionnaires were used to assess happiness, employment status, daily working time, and work-related stress (i.e., job strain, job control, job suitability, and relationships at work).

Results

The data of 520 men and 168 women were analyzed (mean ages, 68.5 years and 68.0 years, respectively). The results of the multivariable ordinal logistic regression analysis indicated that low job suitability was negatively associated with happiness in men (odds ratio [OR]=0.46; 95% confidence interval [CI], 0.28–0.78; p=0.004). In women, long working hours and low job control were negatively associated with happiness—working >8 hours daily (OR=0.29; 95% CI, 0.12–0.71; p=0.008) and low job control (OR=0.29; 95% CI, 0.12–0.72; p=0.009).

Conclusion

The results showed that low job suitability for men and long daily working time and low job control for women were negatively associated with happiness. These findings suggest the need to improve working conditions to enhance the well-being of working older adults.

Performance Status Modifies the Association Between Vitamin D Receptor Activator and Mortality or Fracture: A Prospective Cohort Study on the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry

Immobilization osteoporosis is characterized by excess bone resorption. Vitamin D receptor activators (VDRA) might have adverse effects in immobilized patients. The objective of this study was to elucidate the impact of performance status (PS) on the associations between VDRA use and outcomes among hemodialysis patients. This is a prospective cohort study. Adults on hemodialysis in the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry were included. Exposure of interest was the use of VDRA. Outcomes were all-cause mortality and hip fracture. Associations between VDRA use and mortality or hip fractures were examined by Cox and Poisson regression analyses, respectively. Among 208,512 subjects, 128,535 were on VDRA. Poor PS was associated with higher calcium (Ca), lower parathyroid hormone, and higher alkaline phosphatase levels. The association between higher Ca levels and VDRA use was stronger among those with poor PS (p interaction 0.007). Adjusted hazard ratio (HR) (95% confidence interval [CI]) for mortality and incidence rate ratio (IRR) for hip fracture was 1.02 (95% CI, 0.99-1.05) and 0.93 (0.86-1.00) among users of VDRA, respectively. The VDRA use was associated with lower mortality and incidence of hip fractures among subjects with good PS but not among subjects with poor PS (p interaction 0.03 and 0.05). Effect modification by PS was observed for cardiovascular (CV) mortality but not for non-CV mortality. In conclusion, VDRA use was associated with better outcomes only among those with good PS. These results suggest that bone and mineral disorders among hemodialysis patients should be treated differently, depending on their performance status. © 2022 American Society for Bone and Mineral Research (ASBMR).

Associations of metabolic syndrome and metabolically unhealthy obesity with cancer mortality: The Japan Multi-Institutional Collaborative Cohort (J-MICC) study

Purpose

The association between metabolic syndrome (MetS) and the risk of death from cancer is still a controversial issue. The purpose of this study was to examine the associations of MetS and metabolically unhealthy obesity (MUHO) with cancer mortality in a Japanese population.

Methods

We used data from the Japan Multi-Institutional Collaborative Cohort Study. The study population consisted of 28,554 eligible subjects (14,103 men and 14,451 women) aged 35–69 years. MetS was diagnosed based on the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) and the Japan Society for the Study of Obesity (JASSO), using the body mass index instead of waist circumference. The Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for total cancer mortality in relation to MetS and its components. Additionally, the associations of obesity and the metabolic health status with cancer mortality were examined.

Results

During an average 6.9-year follow-up, there were 192 deaths from cancer. The presence of MetS was significantly correlated with increased total cancer mortality when the JASSO criteria were used (HR = 1.51, 95% CI 1.04–2.21), but not when the NCEP-ATP III criteria were used (HR = 1.09, 95% CI 0.78–1.53). Metabolic risk factors, elevated fasting blood glucose, and MUHO were positively associated with cancer mortality (P <0.05).

Conclusion

MetS diagnosed using the JASSO criteria and MUHO were associated with an increased risk of total cancer mortality in the Japanese population.

O-301 Genome-wide association study identified meiotic variant associated with aneuploid pregnancy loss

Study question

Which single nucleotide variant (SNVs) are associated with aneuploid pregnancy loss?

Summary answer

We identified a SNV on MEIG1 gene, which are associated with meiosis/spermiogenesis.

What is known already

Recurrent pregnancy loss (RPL) refers to the loss of two or more pregnancies, with a frequency of 5%. Chromosomal abnormalities in embryos are found in 80% of first trimester miscarriages, 86% of which are aneuploid. Recently, embryonic aneuploidy was found to be the most common cause of RPL, with a frequency of 40-50%. Most trisomy miscarriages are of maternal origin, with errors occurring during meiosis of the oocyte. Chromosome segregation abnormalities in oocytes are thought to be an event associated with increasing maternal age, but in addition, maternal genetic causes are thought to contribute.

Study design, size, duration

A Genome wide association study (GWAS) was performed on a clinically well characterized cohort of 189 women with RPL whose previous aborted conceptus was ascertained to be an aneuploid embryo. Samples were mainly collected from 2007 to 2018 mainly at Nagoya City University Hospital. For control samples, we used 1157 samples from the population-based prospective cohorts that included fertile women.

Participants/materials, setting, methods

All patients underwent a systematic examination. Patients with antiphospholipid syndrome, an abnormal chromosome in either partner, or uterine anomaly were excluded. Patients whose previously miscarried POC exhibited triploidy or 45, X were excluded. DNA was isolated from stored EDTA-blood samples and genotyped by Axiom Japonica-array v2659,503 SNVs). For the GWAS, a chi-squared test was applied to a two-by-two contingency table in allele frequency model.

Main results and the role of chance

The mean (SD) ages and number of previous miscarriages of the patients were 36.8 (4.3) and 3.09 (1.13). GWAS data revealed 5 SNVs with suggestive significance (p &lt; 9.46e-06). The SNVs that showed the most significant associations (P = 1.06E-06, OR = 1.72) was located on meiosis/spermiogenesis associated 1 (MEIG1) gene under an allelic model after Bonferroni correction considering the number of analyzed SNVs. The SNV rs7908491 was reported as a splicing QTL in the MEIG1 gene, which is a meiosis/meiosis-associated factor and is plausibly associated with chromosome aneuploidy. This is the first GWAS in patients with RPL caused by aneuploidy.

Limitations, reasons for caution

Since this study was conducted in a single center and had a small sample size, it needs to be replicated in different centers with more subjects and on an international scale. Whole genome imputation analysis will be performed to detect SNVs with more significant associations.

Wider implications of the findings

Our findings demonstrate that a specific genotype of MEIG1 gene can be a risk factor for aneuploid pregnancy loss. The establishment of clinically applicable maternal germ cell markers could identify groups for whom PGT would be more useful or provide patients with counseling that provides prognostic information about pregnancy.

Trial registration number

not applicable

Application of the RNA interference technique to Xenopus embryos: Specific reduction of the β-catenin gene products by short double-stranded RNA produced by recombinant human Dicer

RNA interference (RNAi) is a technique for suppressing the function of specific genes and is widely used in many organisms, including yeast, nematodes, flies, plants, mice, and cultured mammalian cells. As of date, this technique has not been successfully applied to Xenopus laevis embryos. In this study, we applied RNAi to Xenopus embryos using β-catenin as a model gene. Injection of long double-stranded RNA (dsRNA) corresponding to the 3'-untranslated region of β-catenin mRNA into embryos induced embryonic lethality without any specific phenotype. However, injection of short dsRNA, generated from long dsRNA by treatment with recombinant human Dicer, into embryos resulted in decreased expression of endogenous β-catenin mRNA and protein, as well as decreased Wnt signaling activity in the embryos. The decrease in β-catenin mRNA and protein levels was observed only after mid-blastula transition. Embryos injected with short dsRNA showed a characteristic phenotype of enlarged anterior structures and loss of posterior structures. These phenotypes, as well as the increased expression of the anterior gene and decreased expression of the posterior gene, suggest that RNAi against the β-catenin gene suppresses the "late Wnt signaling" involved in proper anterior-posterior patterning of Xenopus embryos. The effect of RNAi on Xenopus embryos was also found to be sensitive to temperature. These results strongly suggest that the RNAi technique can be applied to Xenopus embryos using short dsRNAs, appropriate temperature control, and proper selection of target genes.

Sex-specific Relationship between Stress Coping Strategies and All-Cause Mortality: Japan Multi-Institutional Collaborative Cohort Study

BACKGROUND

Stress coping strategies are related to health outcomes. However, there is no clear evidence for sex differences between stress-coping strategies and mortality. We investigated the relationship between all-cause mortality and stress-coping strategies, focusing on sex differences among Japanese adults.

METHODS

A total of 79,580 individuals aged 35-69 years participated in the Japan Multi-Institutional Collaborative Cohort Study between 2004 and 2014 and were followed up for mortality. The frequency of use of the five coping strategies was assessed using a questionnaire. Sex-specific, multivariable-adjusted hazard ratios (HRs) for using each coping strategy "sometimes," and "often/very often" (versus "very few" use) were computed for all-cause mortality. Furthermore, relationships were analyzed in specific follow-up periods when the proportion assumption was violated.

RESULTS

During the follow-up (median: 8.5 years), 1,861 mortalities were recorded. In women, three coping strategies were related to lower total mortality. The HRs (95% confidence intervals) for "sometimes" were 0.81 (0.67-0.97) for emotional expression, 0.79 (0.66-0.95) for emotional support-seeking, and 0.80 (0.66-0.98) for disengagement. Men who "sometimes" used emotional expression and sometimes or often used problem-solving and positive reappraisal had a 15-41% lower HRs for all-cause mortality. However, those relationships were dependent on the follow-up period. There was evidence that sex modified the relationships between emotional support-seeking and all-cause mortality (p for interaction = 0.03).

CONCLUSIONS

In a large Japanese population, selected coping strategies were associated with all-cause mortality. The relationship of emotional support-seeking was different between men and women.

460Social inequalities in second-hand smoking among Japanese adults: A repeated cross-sectional study

Background

We aimed to examine the association between educational history and second-hand smoke (SHS) exposure in Japanese adults.

Methods

We conducted a repeated cross-sectional study using data from the 2007-2011 baseline and the 2013-2016 follow-up survey in a Japanese suburban area. Overall, 5,562 male and 5,381 female non-smokers participated in the study, which evaluated the SHS exposure and educational history of the participants through self-reported questionnaires. We performed a multilevel ordered logistic regression analysis with survey year as the first level and the individual as the second level, SHS exposure as the dependent variable, educational history as the explanatory variable, and age, smoking history, marital status as covariates, stratified by gender and working status.

Results

The prevalence of SHS exposure was 45.4% in males and 41.9% in females in the 2007-2011 survey, and 31.6% in males and 28.7% in females in the 2013-2016 survey. Multilevel analysis indicated that less educational history was associated with higher SHS exposure in both genders (among males, the odds ratio compared with ≥13 years was 1.75 for 10-12 years and 1.64 for ≤9 years; among females, it was 1.79 for 10-12 years and 2.43 for ≤9 years). Stratified analysis by working status showed that for females, education-based inequalities in SHS exposure more strongly impacted for workers than non-workers (p for interaction &lt;0.001).

Conclusions

Education-based inequalities in SHS exposure exist in Japan and might be severe among female workers.

Key messages

Measures against SHS in Japan should be promoted to reduce social and gender inequalities.

Novel MSX1 frameshift mutation in a Japanese family with nonsyndromic oligodontia

Congenital tooth agenesis is a common anomaly in humans. We investigated the etiology of human tooth agenesis by exome analysis in Japanese patients, and found a previously undescribed heterozygous deletion (NM_002448.3(MSX1_v001):c.433_449del) in the first exon of the MSX1 gene. The deletion leads to a frameshift and generates a premature termination codon. The truncated form of MSX1, namely, p.(Trp145Leufs*24) lacks the homeodomain, which is crucial for transcription factor function.

Practical applications of brief screening questionnaires for autism spectrum disorder in a psychiatry outpatient setting

OBJECTIVES

This study was designed to examine the diagnostic performance of the social and communication disorders checklist (SCDC) and strength and difficulties questionnaire (SDQ) to detect autism spectrum conditions (ASC), along with the social responsiveness scale-second edition (SRS-2) as reference, in a psychiatry outpatient setting.

METHODS

We translated the SCDC into Japanese since its Japanese version was unavailable. We examined its test-retest reliability as well as the internal consistency reliability and diagnostic performance of the three questionnaires among 41 Japanese psychiatric outpatients, using the best-estimate diagnosis of ASC based on the diagnostic interview for social and communication disorders, as a gold standard.

RESULTS

The test-retest reliability was high for the SCDC. Although the internal consistency reliability was high for the SCDC and SRS-2, that was low for the prosocial and peer problem subscales of the SDQ. The performance of the SCDC, SDQ, and SRS-2 to detect ASC was moderate: the area under the ROC curve of 0.78, 0.78, and 0.84, respectively.

CONCLUSIONS

Although questionnaires to detect ASC, including the three examined, generally have only moderate performance in this setting, these can be successfully applied to high-risk populations such as psychiatry outpatients, when multi-level rather than dichotomous likelihood ratios are used.

The Impact of Job Conditions on Health-Related Quality of Life among Working Japanese Older Adults: A Five-Year Longitudinal Study Using J-MICC Okazaki Study Data

OBJECTIVES

The number of older adults who continue working after retirement is increasing in Japan. Little is known about how job conditions affect older adults' health. We examined the association between job conditions and health-related quality of life (HRQOL) during a five-year follow-up study.

METHODS

This study included participants aged 65 years or older from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area recruited at baseline between 2007 and 2011 and followed up five years later. Participants completed a self-reported questionnaire on the physical and mental health aspects of HRQOL (SF-8™), employment status, and job conditions (job satisfaction, skill use, and job suitability).

RESULTS

Data of 1,146 men and 522 women were analyzed (mean age: 69.1 and 68.6 years, respectively). Generalized mixed linear regression analysis revealed that, compared to the not-working group, skill use was positively associated with mental health aspects among men (skill use × time: β = 0.16, SE = 0.08, p < 0.05), while poor job satisfaction and job suitability were negatively associated with mental health aspects among women (job satisfaction, not satisfied × time: β = -0.93, SE = 0.47, p < 0.05; job suitability, not suitable × time: β = -1.06, SE = 0.50, p < 0.05).

CONCLUSIONS

Regarding job conditions among older adults, skill use in men was marginally associated with mental health, and poor job satisfaction and suitability in women were negatively associated with mental health. Considering the job conditions of older workers is necessary to protect their mental health.

High phospho-histone H3 expression uniquely predicts favorable survival among four markers of cellular proliferation in colorectal cancer

Colorectal cancer (CRC) is one of the most frequent gastrointestinal cancers worldwide, with high morbidity and mortality rates. Despite numerous attempts to identify prognostic markers for the CRC patients, the significance of the association of cellular proliferation markers with survival is controversial. Here we used immunohistochemistry to detect four markers of cellular proliferation expressed in primary CRC tissue specimens (n = 269) to assess their potential to serve as prognostic factors. CRC cells variably expressed phospho-histone H3 (PHH3) (range, 0-76 per high-powered field (HPF); median, 7 per HPF), cyclin A (CCNA) (range, 11.3-73.7%; median, 32%), geminin (GMNN) (range, 7.8-82.0%; median, 37.1%), and marker of proliferation Ki-67 (MKI67) (range, 4.9-96.6%; median, 49.6%). Among them, patients with PHH3-high (≥7 per HPF) tumors uniquely experienced significantly longer 5-year survival than those with PHH3-low (≤6 per HPF) (81.8% vs. 65.5%; P = 0.0047). Multivariable Cox hazards regression analysis identified PHH3-high (hazard ratio, 0.54; 95% confidence interval, 0.31-0.92; P = 0.025) as potential favorable factors. PHH3 levels inversely associated with pT stage (P < 0.0001) and were significantly and inversely associated with tumor diameter (ρ = -0.314, P < 0.0001). These findings support the use of PHH3 immunohistochemistry for predicting the prognoses of patients with CRC.

Assessing the relationship between high-sensitivity C-reactive protein and kidney function employing mendelian randomization in a Japanese community based J-MICC Study

Background

Inflammation is thought to be a risk factor for kidney disease. However, whether inflammatory status is either a cause or an outcome of chronic kidney disease remains controversial. We aimed to investigate the causal relationship between high-sensitivity C-reactive protein (hs-CRP) and estimated glomerular filtration rate (eGFR) using Mendelian randomization (MR) approaches.

Methods

A total of 10,521 participants of the Japan Multi-institutional Collaborative Cohort Study was analyzed in this study. We used two-sample MR approaches (the inverse-variance weighted (IVW), the weighted median (WM), and the MR-Egger method) to estimate the effect of genetically determined hs-CRP on kidney function. We selected four and three hs-CRP associated single nucleotide polymorphisms (SNPs) as two instrumental variables (IV): IV_CRP and IV_Asian, based on SNPs previously identified in European and Asian populations. IV_CRP and IV_Asian explained 3.4% and 3.9% of the variation in hs-CRP, respectively.

Results

Using the IV_CRP, genetically determined hs-CRP was not significantly associated with eGFR in the IVW and the WM methods (estimate per 1 unit increase in ln(hs-CRP), 0.000; 95% confidence interval [CI], −0.019 to 0.020 and −0.003; 95% CI, −0.019 to 0.014, respectively). For IV_Asian, we found similar results using the IVW and the WM methods (estimate, 0.005; 95% CI, −0.020 to 0.010 and −0.004; 95% CI, −0.020 to 0.012, respectively). The MR-Egger method also showed no causal relationships between hs-CRP and eGFR (IV_CRP: −0.008; 95% CI, −0.058 to 0.042; IV_Asian: 0.001; 95% CI, −0.036 to 0.036).

Conclusion

Our two-sample MR analyses with different IVs did not support a causal effect of hs-CRP on eGFR.

The impact of marital transitions on vegetable intake in middle-aged and older Japanese adults: a five-year longitudinal study

Background

Marital transitions are associated with adverse health events, such as mortality and cardiovascular disease. Since marital transitions (eg, becoming widowed) are unavoidable life events, it is necessary to identify modifiable intermediate outcomes. Thus, we examined the association between marital transitions and vegetable intake among middle-aged and older Japanese adults.

Methods

This longitudinal study included Japanese adults aged 40–79 years who received an annual health checkup between 2007 and 2011 (baseline) and 5 years later (follow-up). Marital transitions were classified as whether and what type of transition occurred during the 5-year period and comprised five groups: consistently married, married to widowed, married to divorced, not married to married, and remained not married. Changes in total vegetable, green and yellow vegetable, and light-colored vegetable intake from baseline to follow-up were calculated using the Food Frequency Questionnaire.

Results

Data from 4,813 participants were analyzed (mean age, 59.4 years; 44.1% women). Regarding marital transitions, 3,960 participants were classified as “consistently married,” 135 as “married to widowed,” 40 as “married to divorced,” 60 as “not married to married,” and 529 as “remained not married.” Multivariable linear regression analysis revealed that compared to consistently married, married to widowed was inversely associated with the change in total vegetable intake (β = −16.64, SE = 7.68, P = 0.030) and light-colored vegetable intake (β = −11.46, SE = 4.33, P = 0.008).

Conclusion

Our findings suggest that being widowed could result in a reduced intake of vegetables. Hence, dietary counseling according to marital situation is necessary.

Study profile of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study

BACKGROUND

The Japan Multi-institutional Collaborative Cohort (J-MICC) study was launched in 2005 to examine gene-environment interactions in lifestyle-related diseases, including cancers, among the Japanese. This report describes the study design and baseline profile of the study participants.

METHODS

The participants of the J-MICC Study were individuals aged 35 to 69 years enrolled from respondents to study announcements in specified regions, inhabitants attending health checkup examinations provided by local governments, visitors at health checkup centers, and first-visit patients at a cancer hospital in Japan. At the time of the baseline survey, from 2005 to 2014, we obtained comprehensive information regarding demographics, education, alcohol consumption, smoking, sleeping, exercise, food intake frequency, medication and supplement use, personal and family disease history, psychological stress, and female reproductive history, and collected peripheral blood samples.

RESULTS

The baseline survey included 92,610 adults (mean age: 55.2 [9.4] years, 44.1% men) from 14 study regions in 12 prefectures. The participation rate was 33.5%, with participation ranging from 19.7% to 69.8% in different study regions. The largest number of participants was in the age groups of 65-69 years for men and 60-64 years for women. There were differences in body mass index, educational attainment, alcohol consumption, smoking, and sleep duration between men and women.

CONCLUSIONS

The J-MICC Study collected lifestyle and clinical data and biospecimens from over 90,000 participants. This cohort is expected to be a valuable resource for the national and international scientific community in providing evidence to support longer healthy lives.

Association of Dietary Acid Load with the Prevalence of Metabolic Syndrome among Participants in Baseline Survey of the Japan Multi-Institutional Collaborative Cohort Study

The association between dietary acid load and metabolic syndrome (MetS) has not been fully investigated. A cross-sectional study was performed on 14,042 men and 14,105 women (aged 35-69 years) who participated in a baseline survey of the Japan Multi-Institutional Collaborative Cohort study. Dietary acid load was assessed using the net-endogenous-acid-production (NEAP) score that is closely correlated with the rate of renal net acid excretion. MetS was diagnosed according to the Joint Interim Statement Criteria of 2009 using body-mass index instead of waist circumference. After adjusting for potential confounders, higher NEAP scores were associated with a significantly increased odds ratio (OR) of MetS, obesity, high blood pressure, and high fasting blood glucose. These associations remained significant after further adjustment for carbohydrate intake or two nutrient-pattern scores significantly associated with MetS. After adjustment for fiber, iron, potassium, and vitamin pattern scores, the OR of MetS for the highest quartile of NEAP scores, relative to the lowest quartile, was 1.25 (95% confidence interval 1.12-1.39). There was no significant interaction between sex, age, or body-mass index and NEAP. Higher dietary acid load was associated with a higher prevalence of MetS and several of its components, independently of carbohydrate intake or nutrient patterns.

Polo-like kinase 4 and Stromal antigen 3 are not associated with recurrent pregnancy loss caused by embryonic aneuploidy

No genetic association with recurrent pregnancy loss (RPL) caused by embryonic aneuploidy has been found. Recent studies have indicated that the common genetic variant rs2305957, surrounding the PLK4 gene, contributes to mitotic-origin aneuploidy risk during human early embryo development. The decrease in meiosis-specific cohesin causes predivision of sister chromatids in the centromere and chromosome segregation errors. STAG3 is a component of cohesin and is a meiosis-specific gene. Our case-control study included 184 patients with RPL whose previous products of conception (POC) exhibited aneuploidy and 190 fertile control women without a history of miscarriage. We performed a genetic association study to examine the genotype distribution at PLK4 (rs2305957) and STAG3 in patients with RPL caused by aneuploidy compared with controls. Regarding STAG3, SNPs with a minor allele frequency (MAF) threshold > 0.05 that were predicted to be binding sites of transcription factors and that showed significant associations in expression quantitative trait locus (e-QTL) analysis were selected. No significant differences in the MAF or distribution in any model of PLK4 (rs2305957) and 5 selected tag SNPs in STAG3 were found between the patients and controls. A further genome-wide association study is needed since a combination of genetic risk alleles might be useful in predicting future age-dependent RPL caused by aneuploidy.

Sedentary Time is Associated with Cardiometabolic Diseases in A Large Japanese Population: A Cross-Sectional Study

Aim: Accumulating evidence reveals that sedentary behavior is associated with mortality and cardiometabolic disease; however, there are potential age and sex differences in sedentary behavior and health outcomes that have not been adequately addressed. This study aimed to determine the association of sedentary behavior with cardiometabolic diseases such as hypertension, dyslipidemia, diabetes mellitus, and its risk factors in a large Japanese population according to age and sex.

Methods: Using data from the Japan Multi-Institutional Collaborative Cohort Study obtained from baseline surveys, data of 62,754 participants (27,930 males, 34,824 females) were analyzed. This study uses a cross-sectional design and self-administered questionnaires to evaluate sedentary time and anamnesis. For the logistic regression analysis, sedentary time < 5 h/day was used as the reference and then adjusted for age, research areas, leisure-time metabolic equivalents, and alcohol and smoking status. From the analysis of anthropometric and blood examinations, 35,973 participants (17,109 males, 18,864 females) were analyzed.

Results: For hypertension and diabetes, sedentary time was associated with a significantly higher proportion of male participants. Both sexes were associated with a significantly higher proportion of participants with dyslipidemia. Participants who had longer sedentary time tended to have increased levels of blood pressure, triglycerides, and non-high-density lipoprotein cholesterol (HDL-C), and decreased levels of HDL-C, especially in the 60–69 years group.

Conclusions: Independent of leisure-time physical activity, sedentary time was associated with cardiometabolic diseases in a large Japanese population classified by age and sex. Our findings indicate that regularly interrupting and replacing sedentary time may contribute to better physical health-related quality of life.

Subtype-specific gout susceptibility loci and enrichment of selection pressure on ABCG2 and ALDH2 identified by subtype genome-wide meta-analyses of clinically defined gout patients

Objectives

Genome-wide meta-analyses of clinically defined gout were performed to identify subtype-specific susceptibility loci. Evaluation using selection pressure analysis with these loci was also conducted to investigate genetic risks characteristic of the Japanese population over the last 2000–3000 years.

Methods

Two genome-wide association studies (GWASs) of 3053 clinically defined gout cases and 4554 controls from Japanese males were performed using the Japonica Array and Illumina Array platforms. About 7.2 million single-nucleotide polymorphisms were meta-analysed after imputation. Patients were then divided into four clinical subtypes (the renal underexcretion type, renal overload type, combined type and normal type), and meta-analyses were conducted in the same manner. Selection pressure analyses using singleton density score were also performed on each subtype.

Results

In addition to the eight loci we reported previously, two novel loci, PIBF1 and ACSM2B, were identified at a genome-wide significance level (p<5.0×10^–8) from a GWAS meta-analysis of all gout patients, and other two novel intergenic loci, CD2-PTGFRN and SLC28A3-NTRK2, from normal type gout patients. Subtype-dependent patterns of Manhattan plots were observed with subtype GWASs of gout patients, indicating that these subtype-specific loci suggest differences in pathophysiology along patients’ gout subtypes. Selection pressure analysis revealed significant enrichment of selection pressure on ABCG2 in addition to ALDH2 loci for all subtypes except for normal type gout.

Conclusions

Our findings on subtype GWAS meta-analyses and selection pressure analysis of gout will assist elucidation of the subtype-dependent molecular targets and evolutionary involvement among genotype, phenotype and subtype-specific tailor-made medicine/prevention of gout and hyperuricaemia.

Five-year follow-up of fundus autofluorescence and retinal sensitivity in the fellow eye in exudative age-related macular degeneration in Japan

PURPOSE

To assess the 5-year change in abnormal fundus autofluorescence (FAF) patterns and retinal sensitivity in the fellow eye of Japanese patients with unilateral exudative age-related macular degeneration (AMD).

METHODS

Patients with unilateral exudative AMD who developed abnormal FAF in the fellow eyes were enrolled. FAF imaging and microperimetry were performed at baseline and follow-ups. FAF findings were classified into 8 patterns based on the International Fundus Autofluorescence Classification Group to assess retinal sensitivity. Forty-five points covering the central 12 degrees on microperimetry were superimposed onto the FAF images. Each point was classified depending on the distance from the abnormal FAF. "Close" was defined as the portion within 1 degree from the border of any abnormal FAF, and "Distant" was defined as the portion over 1 degree from the border of abnormal FAF. To investigate the association between the retinal sensitivity and distance from the abnormal FAF, hierarchical linear mixed-effect models were used with the distance, time and time squared from baseline (months), and angle (degrees) as fixed effects. Differences among patients, eyes, and test point locations were considered successively nested random effects.

RESULTS

We studied 66 fellow eyes with abnormal FAF. Twenty-seven eyes were followed-up during the 5 years. In the 13 of 27 eyes (48%), the abnormal FAF patterns had changed during the 5 years. We found retinal sensitivity was associated significantly with the distance from the abnormal FAF ("Distant": p<0.001, time2 from baseline: p<0.001, angle: p<0.001). The mean retinal sensitivity of the "Close" tended to deteriorate after the third year and eventually showed the similar sensitivity as the portion within the abnormal FAF.

CONCLUSION

FAF patterns can change about half during the 5 years and the retinal sensitivity near abnormal FAF tends to deteriorate after the third year.

Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study

Background

Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample.

Methods

Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as “almost never,” “sometimes,” and “almost every day”. Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms.

Results

Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with “almost never” were 1.25 (95% CI, 1.09–1.42) for “sometimes” and 1.41 (95% CI, 1.09–1.84) for “almost every day” (P for trend <0.001); among smokers, PRs compared with “almost never” were 1.30 (95% CI, 0.82–2.06) for “sometimes” and 1.44 (95% CI, 0.90–2.33) for “almost every day” (P for trend = 0.144).

Conclusions

Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

A primary canine and an impacted permanent canine with infection potentially induced an intracranial abscess

Intracranial abscess is a rare but life-threatening disease. There have been no reports on intracranial abscess induced by the residual primary tooth and the impacted successive permanent tooth with infection. We report on an interesting case of a 29-year-old man suffering from an epidural abscess, potentially caused by an infection of the residual primary maxillary right canine and the impacted permanent maxillary right canine. The patient recovered completely after prolonged antibiotic treatment and extraction of both of the suspected teeth. Fusobacterium sp. was isolated from the culture of a peripheral blood sample. This case alerts us to realize that the lack of suitable and timely intervention in oral conditions might produce a harmful effect on general health.

GWAS analysis reveals a significant contribution of PSCA to the risk of Heliobacter pylori-induced gastric atrophy

Although recent genome-wide association studies (GWASs) have identified genetic variants associated with Helicobacter pylori (HP)-induced gastric cancer, few studies have examined the genetic traits associated with the risk of HP-induced gastric precancerous conditions. This study aimed to elucidate genetic variants associated with these conditions using a genome-wide approach. Data from four sites of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study were used in the discovery phase (Stage I); two datasets from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center 2 (HERPACC2) study were used in the replication phases (Stages II and III) and SKAT (SNP-set Kernel Association Test) and single variant-based GWASs were conducted for the risks of gastric atrophy (GA) and severe GA defined by serum pepsinogen (PG) levels, and PG1 and PG1/2 ratios. In the gene-based SKAT in Stage I, prostate stem cell antigen (PSCA) was significantly associated with the risks of GA and severe GA, and serum PG1/2 level by linear kernel [false discovery rate (FDR) = 0.011, 0.230 and 7.2 × 10−7, respectively]. The single variant-based GWAS revealed that nine PSCA single nucleotide polymorphisms (SNPs) fulfilled the genome-wide significance level (P < 5 × 10−8) for the risks of both GA and severe GA in the combined study, although most of these associations did not reach genome-wide significance in the discovery or validation cohort on their own. GWAS for serum PG1 levels and PG1/2 ratios revealed that the PSCA rs2920283 SNP had a striking P-value of 4.31 × 10−27 for PG1/2 ratios. The present GWAS revealed the genetic locus of PSCA as the most significant locus for the risk of HP-induced GA, which confirmed the recently reported association in Europeans.

Comparison of the detection of Helicobacter pylori infection by commercially available serological testing kits and the 13C-urea breath test

BACKGROUND

Serum Helicobacter pylori (H. pylori) antibody kits (LZ and LIA) using the latex agglutination immunoassay method are commercially available, but few studies have been performed to determine their diagnostic accuracy or to compare their results with those of enzyme-linked immunosorbent assay (ELISA) kits (EP and EIA).

METHODS

Sera were obtained from 213 hospital outpatients with dyspeptic symptoms. The serological results were compared with the result of the ¹³C-urea breath test (UBT) which seems to be reliable.

RESULTS

Of the 213 subjects, 154 were diagnosed as positive for H. pylori infection according to the UBT. The sensitivities and specificities of these tests were 97.4% and 76.3%, 98.1% and 78.0%, 99.4% and 74.6%, and 98.1% and 71.2% for the EP, LZ, EIA and LIA tests, respectively. When the 13 subjects whose seropositive results of the four kits were completely opposite to the negative results of the UBT were excluded, the specificities of evaluated kits were all higher than 90%. The concordance rate between the EP and EIA tests was 98.1% (Spearman's rank correlation coefficient = 0.83) and that between the LZ and LIA tests was 97.1% (correlation coefficient = 0.91). The LZ gave higher antibody titer value than EP (p < 0.0001, Z = 9.82; Wilcoxon signed-rank test), and EIA gave higher value than LIA (p < 0.0001, Z = 6.43; Wilcoxon signed-rank test).

CONCLUSIONS

The latex immunoassay method provided the same reliability to ELISA in terms of the diagnostic accuracy for current H. pylori infection, although we should take into account the titer value differences by each test method in practical use.

Genome-wide meta-analysis identifies multiple novel loci associated with serum uric acid levels in Japanese individuals

Gout is a common arthritis caused by elevated serum uric acid (SUA) levels. Here we investigated loci influencing SUA in a genome-wide meta-analysis with 121,745 Japanese subjects. We identified 8948 variants at 36 genomic loci (P<5 × 10-8) including eight novel loci. Of these, missense variants of SESN2 and PNPLA3 were predicted to be damaging to the function of these proteins; another five loci-TMEM18, TM4SF4, MXD3-LMAN2, PSORS1C1-PSORS1C2, and HNF4A-are related to cell metabolism, proliferation, or oxidative stress; and the remaining locus, LINC01578, is unknown. We also identified 132 correlated genes whose expression levels are associated with SUA-increasing alleles. These genes are enriched for the UniProt transport term, suggesting the importance of transport-related genes in SUA regulation. Furthermore, trans-ethnic meta-analysis across our own meta-analysis and the Global Urate Genetics Consortium has revealed 15 more novel loci associated with SUA. Our findings provide insight into the pathogenesis, treatment, and prevention of hyperuricemia/gout.

Fundus autofluorescence and retinal sensitivity in fellow eyes of age-related macular degeneration in Japan

Purpose

Abnormal fundus autofluorescence (FAF) potentially precedes onset of late age-related macular degeneration (AMD) in Caucasian patients. Many differences exist between Asian and Caucasian patients regarding AMD types and severity, gender, and genetic backgrounds. We investigated the characteristics of abnormal FAF and retinal sensitivity in the fellow eyes of Japanese patients with unilateral neovascular AMD.

Methods

Sixty-six patients with unilateral neovascular AMD and abnormal FAF in the fellow eye were enrolled in this multicenter, prospective, observational study. The best-corrected visual acuity, fundus photographs, FAF images, and retinal sensitivity on microperimetry were measured periodically for 12 months. The FAF images were classified into eight patterns based on the International Fundus Autofluorescence Classification Group. The points measured by microperimetry were superimposed onto the FAF images and fundus photographs and classified as “within,” “close,” and “distant,” based on the distance from the abnormal FAF and other findings. The relationship between the location of the baseline abnormal FAF and retinal sensitivity was investigated.

Results

In Japanese patients, patchy (33.3%) and focally increased (30.3%) patterns predominated in the abnormal FAF. Intermediate-to-large drusen was associated predominantly with hyperfluorescence and hypofluorescence. Neovascular AMD developed within 1 year in six (9.1%) eyes, the mean baseline retinal sensitivity of which was 12.8 ± 4.7 dB, significantly (p<0.002) lower than the other eyes. In 44 of the other 60 eyes, microperimetry was measurable at baseline and month 12 and the mean retinal sensitivity improved significantly from 13.5 ± 4.4 to 13.9 ± 4.8 dB (p<0.001), possibly associated with lifestyle changes (e.g., smoking cessation, antioxidant and zinc supplementation). The mean retinal sensitivities of points within and close to the abnormal FAF were 9.9 and 11.7 dB, respectively, which were significantly lower than the 14.0 dB of the points distant from the abnormal FAF.

Conclusion

In Japanese patients, patchy and focally increased patterns predominated in the abnormal FAF. The retinal sensitivity was lower close to/within the abnormal FAF. FAF and microperimetry are useful to assess macular function before development of neovascular AMD or geographic atrophy.

Association of exposure level to passive smoking with hypertension among lifetime nonsmokers in Japan: a cross-sectional study

Brief exposure to passive smoking immediately elevates blood pressure. However, little is known about the association between exposure to passive smoking and chronic hypertension. We aimed to examine this association in a cross-sectional study, after controlling multiple potential confounders.Participants included 32,098 lifetime nonsmokers (7,216 men and 24,882 women) enrolled in the Japan Multi-Institutional Collaborative Cohort Study. Passive smoking was assessed using a self-administered questionnaire. The single question about exposure to passive smoking had five response options: "sometimes or almost never," "almost every day, 2 hours/day or less," "almost every day, 2 to 4 hours/day," "almost every day, 4 to 6 hours/day," and "almost every day, 6 hours/day or longer." Hypertension was defined as any of the following: systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medication. Multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for hypertension were estimated by exposure level to passive smoking using unconditional logistic regression models.The multivariate-adjusted OR for hypertension in those exposed almost every day was 1.11 (95% CI: 1.03-1.20) compared with those exposed sometimes or almost never. The OR for a 1-hour per day increase in exposure was 1.03 (95% CI: 1.01-1.06, Pfor trend = .006). This association was stronger in men than in women; the ORs were 1.08 (95% CI: 1.01-1.15, Pfor trend = .036) and 1.03 (95% CI: 1.00-1.05, Pfor trend = .055), respectively.Our findings suggest importance of tobacco smoke control for preventing hypertension.

Towards characterization of photo-excited electron transfer and catalysis in natural and artificial systems using XFELs

The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting X-ray diffraction data and X-ray emission spectra, using an energy dispersive spectrometer, at ambient conditions, and used this approach to study the room temperature structure and intermediate states of the photosynthetic water oxidizing metallo-protein, photosystem II. Moreover, we have also used this setup to simultaneously collect the X-ray emission spectra from multiple metals to follow the ultrafast dynamics of light-induced charge transfer between multiple metal sites. A Mn-Ti containing system was studied at an XFEL to demonstrate the efficacy and potential of this method.

Prediction model for pancreatic cancer risk in the general Japanese population

Genome-wide association studies (GWASs) have identified many single nucleotide polymorphisms (SNPs) that are significantly associated with pancreatic cancer susceptibility. We sought to replicate the associations of 61 GWAS-identified SNPs at 42 loci with pancreatic cancer in Japanese and to develop a risk model for the identification of individuals at high risk for pancreatic cancer development in the general Japanese population. The model was based on data including directly determined or imputed SNP genotypes for 664 pancreatic cancer case and 664 age- and sex-matched control subjects. Stepwise logistic regression uncovered five GWAS-identified SNPs at five loci that also showed significant associations in our case-control cohort. These five SNPs were included in the risk model and also applied to calculation of the polygenic risk score (PRS). The area under the curve determined with the leave-one-out cross-validation method was 0.63 (95% confidence interval, 0.60–0.66) or 0.61 (0.58–0.64) for versions of the model that did or did not include cigarette smoking and family history of pancreatic cancer in addition to the five SNPs, respectively. Individuals in the lowest and highest quintiles for the PRS had odds ratios of 0.62 (0.42–0.91) and 1.98 (1.42–2.76), respectively, for pancreatic cancer development compared with those in the middle quintile. We have thus developed a risk model for pancreatic cancer that showed moderately good discriminatory ability with regard to differentiation of pancreatic cancer patients from control individuals. Our findings suggest the potential utility of a risk model that incorporates replicated GWAS-identified SNPs and established demographic or environmental factors for the identification of individuals at increased risk for pancreatic cancer development.

Impact of a 7-Day Field Training on Oral Health Condition in Japan Ground Self-Defense Force Personnel

INTRODUCTION

In the Japan Ground Self-Defense Force (JGSDF), personnel periodically perform intensive training that mimics the conditions seen in battle and during natural disasters. Military training involves intensive, stressful conditions, and changes in immune responses have been found in personnel following training. Good oral condition is important for military personnel to fulfill their duties; however, they have difficulty performing daily oral care under training conditions. In this study, we investigated the impact of a 7-day field training on the oral health status of JGSDF personnel by comparing their oral condition before and just after training.

MATERIALS AND METHODS

The participants were 59 male and 3 female JGSDF personnel undergoing a 7-day field training. All personnel provided informed written consent to participate, and this study was approved by the ethics committee of the Kagoshima University Graduate School of Medical and Dental Sciences. Oral health behaviors before and during the training period were surveyed using a self-administered questionnaire. Dental caries was assessed before training in terms of decayed, missing and filled teeth (DMFT), and periodontal condition was examined before and immediately after training using the community periodontal index (CPI). The presence of eight species of bacteria in dental plaque, including commensal streptococci that are early colonizers on the tooth surface, cariogenic bacteria, and periodontopathic bacteria, was determined using real-time polymerase chain reaction. We also assessed antibacterial factors and a stress marker in saliva samples. Sample collection was performed before and just after training. In addition to difference analysis between groups, logistic regression analysis was performed to examine the association between each health behavior and periodontal deterioration.

RESULTS

The frequency of toothbrushing decreased, and snacking increased during the training period. Thirty-five personnel (56.5%) showed an increase in individual CPI code, and 57 personnel (91.9%) showed deterioration in the CPI code in 1 or more sextants after training (Figure 1). Toothbrushing frequency was significantly associated with CPI deterioration; the odds ratio in subjects who did not brush their teeth was 7.51 compared to those who brushed at least once during the training period. Severe periodontal deterioration was observed in the high-DMFT group (Figure 2), and toothbrushing frequency during the training period decreased more in this group compared to the low-DMFT group. The percentages of Streptococcus sanguinis and Streptococcus gordonii increased significantly after the training period suggesting dental plaque maturation, and an increase in S. sanguinis was associated with toothbrushing frequency. The lactoferrin concentration in saliva increased significantly after training.

CONCLUSIONS

We demonstrated periodontal deterioration in JGSDF personnel after a 7-day training. Behavioral changes, especially discontinuation of regular toothbrushing, fostered dental plaque maturation, resulting in inflammatory changes in participants' periodontal condition. The results indicate the importance of performing toothbrushing at least once over a 7-day training period for prevention of periodontal deterioration. The regimen could be applicable to evacuees from disasters because they are under conditions of stress that may limit oral hygiene activity.

Genome-Wide Association Study of Renal Function Traits: Results from the Japan Multi-Institutional Collaborative Cohort Study

BACKGROUND

Chronic kidney disease (CKD) is a rapidly growing, worldwide public health problem. Recent advances in genome-wide-association studies (GWAS) revealed several genetic loci associated with renal function traits worldwide.

METHODS

We investigated the association of genetic factors with the levels of serum creatinine (SCr) and the estimated glomerular filtration rate (eGFR) in Japanese population-based cohorts analyzing the GWAS imputed data with 11,221 subjects and 12,617,569 variants, and replicated the findings with the 148,829 hospital-based Japanese subjects.

RESULTS

In the discovery phase, 28 variants within 4 loci (chromosome [chr] 2 with 8 variants including rs3770636 in the LDL receptor related protein 2 gene locus, on chr 5 with 2 variants including rs270184, chr 17 with 15 variants including rs3785837 in the BCAS3 gene locus, and chr 18 with 3 variants including rs74183647 in the nuclear factor of -activated T-cells 1 gene locus) reached the suggestive level of p < 1 × 10-6 in association with eGFR and SCr, and 2 variants on chr 4 (including rs78351985 in the microsomal triglyceride transfer protein gene locus) fulfilled the suggestive level in association with the risk of CKD. In the replication phase, 25 variants within 3 loci (chr 2 with 7 variants, chr 17 with 15 variants and chr 18 with 3 variants) in association with eGFR and SCr, and 2 variants on chr 4 associated with the risk of CKD became nominally statistically significant after Bonferroni correction, among which 15 variants on chr 17 and 3 variants on chr 18 reached genome-wide significance of p < 5 × 10-8 in the combined study meta-analysis. The associations of the loci on chr 2 and 18 with eGFR and SCr as well as that on chr 4 with CKD risk have not been previously reported in the Japanese and East Asian populations.

CONCLUSION

Although the present GWAS of renal function traits included the largest sample of Japanese participants to date, we did not identify novel loci for renal traits. However, we identified the novel associations of the genetic loci on chr 2, 4, and 18 with renal function traits in the Japanese population, suggesting these are transethnic loci. Further investigations of these associations are expected to further validate our findings for the potential establishment of personalized prevention of renal disease in the Japanese and East Asian populations.

Association of genetic variants of PD1 with recurrent pregnancy loss

Purpose

Programmed cell death 1 (PD1) and PD ligand 1 (PDL1) are speculated to have an important role in maintaining a normal pregnancy and there are also a few reports of an association between the single-nucleotide polymorphisms (SNPs) of PD1 or PDL1 and diseases in humans. The association was examined between the polymorphisms of PD1,PDL1,CTLA4 and recurrent pregnancy loss (RPL).

Methods

The study group consisted of 243 women with two or more pregnancy losses and 176 parous women. The frequency of three SNPs of PD1, two of PDL1, and four of CTLA4 were compared between the patients and controls. Next, the subsequent live birth rates in the patients with RPL with and without risk alleles were examined.

Results

Two SNPs (rs36084323 and rs3481962) of PD1 were found to occur at significantly higher frequencies in the patient group than in the control group. The subsequent live birth rate of the patients with vs. without the risk alleles of rs36084323 and rs3481962 were 83.3% vs. 83.3% and 81.6% vs. 84.0%, respectively.

Conclusion

Variations of the PD1 gene were identified as risk factors for RPL. However, the presence or absence of the PD1 risk alleles had no predictive effect on the subsequent pregnancy outcome.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.