Organizational Justice and Physiological Coronary Heart Disease Risk Factors in Japanese Employees: a Cross-Sectional Study.

BACKGROUND: Growing evidence has shown that lack of organizational justice (i.e., procedural justice and interactional justice) is associated with coronary heart disease (CHD) while biological mechanisms underlying this association have not yet been fully clarified. PURPOSE: The purpose of the present study was to investigate the cross-sectional association of organizational justice with physiological CHD risk factors (i.e., blood pressure, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol, and triglyceride) in Japanese employees. METHODS: Overall, 3598 male and 901 female employees from two manufacturing companies in Japan completed self-administered questionnaires measuring organizational justice, demographic characteristics, and lifestyle factors. They completed health checkup, which included blood pressure and serum lipid measurements. Multiple logistic regression analyses and trend tests were conducted. RESULTS: Among male employees, multiple logistic regression analyses and trend tests showed significant associations of low procedural justice and low interactional justice with high triglyceride (defined as 150 mg/dL or greater) after adjusting for demographic characteristics and lifestyle factors. Among female employees, trend tests showed significant dose-response relationship between low interactional justice and high LDL cholesterol (defined as 140 mg/dL or greater) while multiple logistic regression analysis showed only marginally significant or insignificant odds ratio of high LDL cholesterol among the low interactional justice group. Neither procedural justice nor interactional justice was associated with blood pressure or HDL cholesterol. CONCLUSION: Organizational justice may be an important psychosocial factor associated with increased triglyceride at least among Japanese male employees.

Epistasis effects of COMT and MTHFR on inter-individual differences in mental health: under the inverted U-shaped prefrontal dopamine model.

Higher cognitive performance, maintenance of mental health and psychological well-being require adequate prefrontal cortex (PFC) function. "Inverted U-shaped" dopamine model indicates optimal PFC dopamine level is important to attain its function while high or low levels have adverse effects. Catechol-O-methyltransferase (COMT) and methylenetetrahydrofolate reductase (MTHFR) may be involved in this complex non-linear PFC dopamine regulation. We addressed whether genetic variation reflecting COMT and MTHFR activities can explain the inter-individual mental health differences in healthy Japanese men (n=188). The mental health was measured by Mental Health Inventory (MHI)-5 score. The rs4633-rs4818-rs4680 haplotypes were used to represent the multilevel COMT activities, while for MTHFR, the functional single polymorphism, rs1801133 (C677T), was used. We examined the effectiveness of haplotype-based association analysis of COMT on mental health together with studying its interaction with MTHFR-C677T. As a result, the relation between activity-ranked COMT genotype and MHI-5 score showed a tendency to fit into an "inverted U-shaped" quadratic curve (P=0.054). This curvilinear correlation was significant in the subjects with MTHFR-CC (P<0.001), but not with MTHFR T-allele carriers (P=0.793). Our pilot study implies a potential influence of COMT and MTHFR genotypic combination on normal variation of mental health.

Altered DNA methylation status of human brain derived neurotrophis factor gene could be useful as biomarker of depression.

Brain-derived neurotrophic factor (BDNF) is involved in the survival, development, and synaptic plasticity of neurons. BDNF is believed to be associated with the pathophysiology of psychiatric disorders. Several studies have suggested the relevance of DNA methylation in its promoter region with depression. Here, we report different methylation statuses in groups with different depressive scores or undergoing different levels of job-stress. DNA samples were extracted from the saliva of 774 Japanese workers, and the methylation status was determined using the Illumina HumanMethylation 450 K Microarray. Depressive symptoms were measured using the Kessler's K6 questionnaire. Job-stress scales were assessed via a self-administered questionnaire. Independent DNA pools were formed based on K6 and job-strain scores, and the methylation levels were compared among these pools. The average DNA methylation rate was significantly decreased in the highest K6 score group compared to the lowest group (methylated signals, 14.2% vs. 16.5%, P = 2 · 16 × 10(-198)). This difference remained for the CpG island in the promoter region (10.4% vs. 5.8%, P = 3 · 67 × 10(-133)). Regarding the job-strain score, there was a slight increase in the methylation level of the whole gene in the group with the highest score compared to that with the lowest score; however, these groups showed no difference in the promoter region. Our results revealed significant changes in the DNA methylation status of the complete human BDNF gene in persons with depression compared to normal individuals, especially in the promoter region of exon 1. This indicates that DNA methylation in this gene is a promising biomarker for diagnosing depression.

Folate intake and depressive symptoms in Japanese workers considering SES and job stress factors: J-HOPE study.

BACKGROUND: Recently socioeconomic status (SES) and job stress index received more attention to affect mental health. Folate intake has been implicated to have negative association with depression. However, few studies were published for the evidence association together with the consideration of SES and job stress factors. The current study is a part of the Japanese study of Health, Occupation and Psychosocial factors related Equity (J-HOPE study) that focused on the association of social stratification and health and our objective was to clarify the association between folate intake and depressive symptoms in Japanese general workers. METHODS: Subjects were 2266 workers in a Japanese nationwide company. SES and job stress factors were assessed by self-administered questionnaire. Folate intake was estimated by a validated, brief, self-administered diet history questionnaire. Depressive symptoms were measured by Kessler's K6 questionnaire. "Individuals with depressive symptoms" was defined as K6≥9 (in K6 score of 0-24 scoring system). Multiple logistic regression and linear regression model were used to evaluate the association between folate and depressive symptoms. RESULTS: Several SES factors (proportion of management positions, years of continuous employment, and annual household income) and folate intake were found to be significantly lower in the subjects with depressive symptom (SES factors: p < 0.001; folate intake: P = 0.001). There was an inverse, independent linear association between K6 score and folate intake after adjusting for age, sex, job stress scores (job strains, worksite supports), and SES factors (p = 0.010). The impact of folate intake on the prevalence of depressive symptom by a multiple logistic model was (ORs[95% CI]: 0.813 [0.664-0.994]; P =0.044). CONCLUSIONS: Our cross-sectional study suggested an inverse, independent relation of energy-adjusted folate intake with depression score and prevalence of depressive symptoms in Japanese workers, together with the consideration of SES and job stress factors.

Association of GLUT4 gene variants with HbA1c level in Japanese men.

GLUT4 is a major mediator of glucose removal from the circulation and a key regulator of whole-body glucose homeostasis. Recent studies in south Indian populations revealed that haplotypes of the GLUT4 gene associated with type 2 diabetes. A total of 734 middle aged apparently healthy Japanese men were recruited from two separate occupational cohorts from Kanagawa and Kyoto. Participants were genotyped for GLUT4 variants, rs5418 (A/G) and rs2654185 (C/A), and association with HbA1c level was analyzed. The HbA1c value was determined by JDS method which is 0.4% lower than NGSP value. The G allele carrier of rs5418 and A allele carrier of rs2654185 associated with significantly higher HbA1c level (AG + GG vs. AA carriers; 5.2 ± 0.8 vs. 4.9 ± 0.4, P < 0.002, and AA + AC vs. CC; 5.2 ± 0.9, vs. 4.9 ± 0.4, P < 0.002, respectively). G allele, AG + GG genotype of rs5418 and A allele, AA + AC genotype of rs2654185 showed a significant association with higher HbA1c (ß = 0.215, P = 0.026; ß = 0.215, P = 0.026; ß = 0.190, P = 0.042; ß = 0.190, P = 0.042, respectively). These two SNPs are in high linkage disequilibrium (LD) of r(2) = 0.67. In haplotype analysis, four haplotypes were estimated. HbA1c is significantly higher in the most frequent GA haplotype compared with the second frequent AC haplotype (5.2% vs. 5.1%, P = 0.004). Genetic variations, rs5418 and rs2654185 in GLUT4 gene are associated with HbA1c level in Japanese men.

Clinical features and neurologic severity in stroke patients with mild to moderate renal dysfunction.

BACKGROUND: To evaluate the independent effect of moderate renal dysfunction on stroke severity and to disclose the clinical features of stroke patients with moderate renal dysfunction. METHODS: We studied consecutive stroke patients presenting within 48 hours of onset. The National Institutes of Health Stroke Scale (NIHSS) score at the time of presentation was used as an index of stroke severity. Patients were categorized into 2 groups based on their estimated glomerular filtration rates (eGFRs). RESULTS: Of the 475 patients with an eGFR >15 mL per minute per 1.73 m(2), 158 patients (33.3%) had an eGFR <60 mL per minute per 1.73 m(2). These patients were older and included significantly more cases with hypertension and atrial fibrillation. The NIHSS score at the time of admission was higher among the patients with renal dysfunction. In a multivariable model with adjustments for other clinical background factors, moderate renal dysfunction was an independent predictor of the neurologic severity of stroke at the time of admission (odds ratio, 1.261; 95% confidence interval, 1.032-1.545; P = .0244). CONCLUSIONS: Stroke patients with moderate renal dysfunction had a higher prevalence of hypertension and atrial fibrillation. Moderate renal dysfunction was associated with a higher severity of stroke on admission.

Prestroke anticoagulation and paroxysmal type are correlated with favorable outcome in ischemic stroke patients with atrial fibrillation.

Paroxysmal atrial fibrillation (AF), which often precedes permanent AF, is reported to be a risk factor for milder ischemic stroke. We assessed whether the type of AF and prestroke treatment with an anticoagulant were associated with physical disabilities in patients with AF-related acute ischemic stroke. We identified 162 consecutive acute ischemic stroke patients with AF who were admitted to our hospital over a 3-year period. Disability was measured using the modified Rankin Scale (mRS) at the time of discharge and was categorized according to favorable clinical outcome (mRS score 0-2). Of the 162 patients, 71 (43.8%) had paroxysmal AF and 91 had permanent AF. Fifty-six patients (34.6%) had been treated with a prophylactic anticoagulant. A total of 103 patients (63.6%) had a favorable outcome. Multivariate logistic analysis revealed that paroxysmal AF (odds ratio [OR], 1.58; P = .0187), prestroke anticoagulation treatment (OR, 1.95; P = .0019), and noncardiogenic embolism (OR, 2.20; P = .0073) were independent factors associated with a favorable clinical outcome. Our data indicate that paroxysmal AF and prestroke anticoagulation treatment are independently associated with favorable clinical outcome at the time of hospital discharge in patients with AF.

Internet use for health-related information via personal computers and cell phones in Japan: a cross-sectional population-based survey.

BACKGROUND: The Internet is known to be used for health purposes by the general public all over the world. However, little is known about the use of, attitudes toward, and activities regarding eHealth among the Japanese population. OBJECTIVES: This study aimed to measure the prevalence of Internet use for health-related information compared with other sources, and to examine the effects on user knowledge, attitudes, and activities with regard to Internet use for health-related information in Japan. We examined the extent of use via personal computers and cell phones. METHODS: We conducted a cross-sectional survey of a quasi-representative sample (N = 1200) of the Japanese general population aged 15-79 years in September 2007. The main outcome measures were (1) self-reported rates of Internet use in the past year to acquire health-related information and to contact health professionals, family, friends, and peers specifically for health-related purposes, and (2) perceived effects of Internet use on health care. RESULTS: The prevalence of Internet use via personal computer for acquiring health-related information was 23.8% (286/1200) among those surveyed, whereas the prevalence via cell phone was 6% (77). Internet use via both personal computer and cell phone for communicating with health professionals, family, friends, or peers was not common. The Internet was used via personal computer for acquiring health-related information primarily by younger people, people with higher education levels, and people with higher household incomes. The majority of those who used the Internet for health care purposes responded that the Internet improved their knowledge or affected their lifestyle attitude, and that they felt confident in the health-related information they obtained from the Internet. However, less than one-quarter thought it improved their ability to manage their health or affected their health-related activities. CONCLUSIONS: Japanese moderately used the Internet via personal computers for health purposes, and rarely used the Internet via cell phones. Older people, people with lower education levels, and people with lower household incomes were less likely to access the Internet via cell phone. The Internet moderately improved users' health-related knowledge and attitudes but seldom changed their health-related abilities and activities. To encourage communication between health providers and consumers, it is important to improve eHealth literacy, especially in middle-aged people. It is also important to make adequate amendments to the reimbursement payment system and nationwide eHealth privacy and security framework, and to develop a collaborative relationship among industry, government, and academia.

Association of a cyclin-dependent kinase 5 regulatory subunit-associated protein 1-like 1 (CDKAL1) polymorphism with elevated hemoglobin A1(c) levels and the prevalence of metabolic syndrome in Japanese men: interaction with dietary energy intake.

Genome-wide association studies have identified the cyclin-dependent kinase 5 regulatory subunit-associated protein 1-like 1 (CDKAL1) gene as a novel risk factor for type 2 diabetes mellitus. Application of this genetic marker for prevention of type 2 diabetes and metabolic syndrome (MetS) in healthy populations has not yet been evaluated. The authors examined the effects of a CDKAL1 polymorphism (rs9465871) on metabolic phenotype and of gene-lifestyle (CDKAL1-energy intake) interaction on MetS in a cohort of apparently healthy Japanese men examined in 2003. The CC genotype of the CDKAL1 variant was associated with elevated glycosylated hemoglobin A1(c) (HbA1c) levels. The prevalence of MetS was 25.6% for CC and 16.3% for TT + CT (odds ratio = 2.18, 95% confidence interval: 1.06, 4.48; P = 0.035). When dietary energy intake was accounted for, the variant's effect on HbA1c was observed in the highest energy-intake group (mean: CC, 5.6% (standard deviation, 1.7); TT + CT, 5.0% (standard deviation, 0.5); P = 0.025). In addition, the positive association between HbA1c and energy intake was stronger in subjects with the CC genotype than in subjects with TT + CT. These results suggest that the interaction between the CDKAL1 polymorphism and dietary energy intake influences the dysglycemic phenotype leading to MetS, possibly through impaired insulin secretion. The CDKAL1 polymorphism may be a marker for MetS in the Japanese population.

Genetic polymorphisms in homocysteine metabolism and response to folate intake: a comprehensive strategy to elucidate useful genetic information.

Homocysteine is a risk factor for atherosclerosis, and the level of homocysteine in plasma is known to be strongly influenced by genetic factors-not only rare variants, but also common polymorphisms. This report describes a comprehensive postgenomic strategy for elucidating useful genetic information about homocysteine metabolism. The standard method for gathering such information is the candidate gene approach, which is an effective method based on known biological information. After collecting evidence from independent research projects, a critical epidemiological review permits a determination as to whether a putative association is true or not. A genome-wide association study (GWAS), which requires no biological information, can identify new candidates and confirm associations suggested by the candidate gene approach. The importance of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which was shown in a randomized controlled trial conducted by the present author, and in other studies, was independently confirmed by a large-scale GWAS. GWASs have also identified new candidate genes, but these must be confirmed by independent studies. In homocysteine metabolism, the classical candidate gene approach was sufficiently robust to detect the true association. However, candidate markers newly discovered by GWAS need to be confirmed by well-designed epidemiological studies to determine their significance. International statements, such as CONSORT and STREGA, provide useful principles for conducting such research.

Which autistic traits are related to depressive symptoms in Japanese workers?

Individuals with autism spectrum disorders are at a high risk of experiencing depressive symptoms. However, the relationship between autistic traits and depressive symptoms is unclear. This study aimed to identify which autistic traits are related to depressive symptoms in Japanese workers. The study participants included 2,049 workers from all areas of Japan. Autistic traits and depressive symptoms were measured using an abridged Japanese version of the Autism-Spectrum Quotient (AQ-Short) and the Japanese version of the K6 scale, respectively. The AQ-Short comprises five autistic trait subcomponents that assess fascination for numbers/patterns, difficulties with imagination, preference for routine, difficulties with social skills, and attention-switching difficulties. Linear regression analyses were performed to estimate the association between total and subcomponent autistic trait scores and depressive symptoms. Participants with higher total autistic trait scores were significantly more likely to have depressive symptoms (p<0.001). When scores on the five autistic trait subcomponents were entered simultaneously into the model, participants with higher scores on all subcomponents other than 'difficulties with imagination' were significantly more likely to report depressive symptoms. Total autistic traits and autistic trait subcomponents could be used for early detection of the risk of depressive symptoms.

Work Engagement and Work Performance Among Japanese Workers: A 1-Year Prospective Cohort Study.

OBJECTIVE: We carried out a prospective study to investigate the association between work engagement and work performance in a group of Japanese workers. METHODS: Our cohort included 1632 men and 192 women aged 65 years or younger who worked at a manufacturing company in Japan. Multiple regression analysis was conducted. RESULTS: Higher work engagement at baseline was significantly associated with better work performance at follow-up (ß = 0.159, P < 0.001). A sex-stratified analysis showed that the impact of work engagement at baseline on work performance at follow-up was stronger among women than among men (ß = 0.242, P < 0.001 and ß = 0.153, P < 0.001, respectively). CONCLUSIONS: Higher work engagement may have beneficial effects on work performance. The impact of work engagement on work performance may be greater among women than among men.

Workplace social capital and refraining from seeking medical care in Japanese employees: a 1-year prospective cohort study.

OBJECTIVES: We examined the association of workplace social capital (WSC), including structural and cognitive dimensions, with refraining from seeking medical care (RSMC) among Japanese employees. DESIGN: One-year prospective cohort study. SETTING AND PARTICIPANTS: We surveyed 8770 employees (6881 men and 1889 women) aged 18-70 years from 12 firms in Japan using a self-administered questionnaire comprising the WSC scale and the items on potential confounders (ie, age, educational attainment and equivalent annual household income) at baseline (from April 2011 to March 2013). OUTCOME MEASURES: At a 1-year follow-up, we measured RSMC using a single-item question 'In the past year, have you ever refrained from visiting a hospital, clinic, acupuncturist or dentist despite your sickness (including a slight cold or cavity) or injury?' RESULTS: The results of Cox regression with robust variance showed that, after adjusting for potential confounders, the low WSC group (ie, the lowest tertile group) had a significantly higher relative risk (RR) of RSMC compared with the high WSC group (ie, the highest tertile group) among both men and women (overall WSC: RR 1.09 (95% CI 1.01 to 1.17) and 1.20 (95% CI 1.06 to 1.37); structural dimension: RR 1.13 (95% CI 1.04 to 1.22) and 1.25 (95% CI 1.07 to 1.45); and cognitive dimension: RR 1.11 (95% CI 1.03 to 1.20) and 1.21 (95% CI 1.06 to 1.38), respectively). Trend analysis using a continuous score of the WSC scale also showed a significant association of low WSC with a higher risk of RSMC among both men and women. CONCLUSIONS: Our findings suggest that the lack of social capital in the workplace is associated with RSMC among Japanese employees.

Potential benefits and harms of a peer support social network service on the internet for people with depressive tendencies: qualitative content analysis and social network analysis.

BACKGROUND: Internet peer support groups for depression are becoming popular and could be affected by an increasing number of social network services (SNSs). However, little is known about participant characteristics, social relationships in SNSs, and the reasons for usage. In addition, the effects of SNS participation on people with depression are rather unknown. OBJECTIVE: The aim was to explore the potential benefits and harms of an SNS for depression based on a concurrent triangulation design of mixed methods strategy, including qualitative content analysis and social network analysis. METHODS: A cross-sectional Internet survey of participants, which involved the collection of SNS log files and a questionnaire, was conducted in an SNS for people with self-reported depressive tendencies in Japan in 2007. Quantitative data, which included user demographics, depressive state, and assessment of the SNS (positive vs not positive), were statistically analyzed. Descriptive contents of responses to open-ended questions concerning advantages and disadvantages of SNS participation were analyzed using the inductive approach of qualitative content analysis. Contents were organized into codes, concepts, categories, and a storyline based on the grounded theory approach. Social relationships, derived from data of "friends," were analyzed using social network analysis, in which network measures and the extent of interpersonal association were calculated based on the social network theory. Each analysis and integration of results were performed through a concurrent triangulation design of mixed methods strategy. RESULTS: There were 105 participants. Median age was 36 years, and 51% (36/71) were male. There were 37 valid respondents; their number of friends and frequency of accessing the SNS were significantly higher than for invalid/nonrespondents (P = .008 and P = .003). Among respondents, 90% (28/31) were mildly, moderately, or severely depressed. Assessment of the SNS was performed by determining the access frequency of the SNS and the number of friends. Qualitative content analysis indicated that user-selectable peer support could be passive, active, and/or interactive based on anonymity or ease of use, and there was the potential harm of a downward depressive spiral triggered by aggravated psychological burden. Social network analysis revealed that users communicated one-on-one with each other or in small groups (five people or less). A downward depressive spiral was related to friends who were moderately or severely depressed and friends with negative assessment of the SNS. CONCLUSIONS: An SNS for people with depressive tendencies provides various opportunities to obtain support that meets users' needs. To avoid a downward depressive spiral, we recommend that participants do not use SNSs when they feel that the SNS is not user-selectable, when they get egocentric comments, when friends have a negative assessment of the SNS, or when they have additional psychological burden.

Cell death-inducing DNA fragmentation factor alpha-like effector A (CIDEA) gene V115F (G-->T) polymorphism is associated with phenotypes of metabolic syndrome in Japanese men.

Cell death-inducing DNA fragmentation factor alpha-like effector A (CIDEA) regulates energy expenditure in the adipose tissue and is implicated in the development of obesity. A single nucleotide polymorphism in the CIDEA gene that causes an amino acid substitution of valine 115 to c(V115F) has recently been shown to be associated with obesity in the Swedish population. Here, we determined the effects of this polymorphism on phenotypes of metabolic syndrome within the Japanese population. Two hundred seventy unrelated Japanese male workers (mean age, 44.5 years) were analyzed in a cross-sectional study. The clinical features regarding metabolic syndrome, as well as CIDEA V115F polymorphism, were determined for each individual. The V115F polymorphism associated with waist circumference and fasting plasma glucose. These parameters were at higher levels in the VF + FF group than in the VV group (P < .05). The VF + FF group compared with the VV group had a higher prevalence for abdominal obesity (odds ratio [OR] = 1.89; 95% confidence interval [CI], 1.03-3.44), high fasting plasma glucose (OR = 2.81; 95% CI, 1.03-7.67), and metabolic syndrome (OR = 3.15; 95% CI, 1.05-9.48). These results suggest that the F allele of the CIDEA gene may serve as a risk factor for phenotypes related to metabolic syndrome in Japanese men.

Increasing the number of SNP loci does not necessarily improve prediction power at least in the comparison of MTHFR SNP and haplotypes.

BACKGROUND: Rapid advances in genotyping technology have made it possible to easily utilize a large number of genetic markers. According to information theory, an increase in the number of markers provides more information; however, the clinical usefulness does not increase linearly. This study aimed to assess the effect of folic acid supplementation quantitatively in MTHFR haplotypes, and compare its prediction power with that of the C677T single nucleotide polymorphism (SNP) alone. METHODS: The study was a randomized, double-blind, placebo-controlled trial, designed in accordance with the CONSORT statement. The participants were 202 healthy Japanese males who were administered either folic acid at 1 mg/day or a placebo postoperatively for 3 months. The primary endpoint was the total plasma homocysteine levels (tHcy). Stratified analysis by HapMap-based tag SNPs was performed. RESULTS: Of 52 SNPs on the MTHFR gene, 4 SNP loci covering more than 80% of the information were selected, and the haplotypes were estimated. The haplotypes were classified into 3 groups (Hap0, Hap1, and Hap2), on the basis of the number of times the most frequent haplotype was present. The greatest decrease was observed in Hap2 (6.61 micromol/L), compared with the other haplotypes (Hap0, 2.67; Hap1, 2.60) (trend test, P < 0.01). The haplotype information obtained was not more informative than that obtained with grouping by a single SNP, C677T, which strongly influences enzyme activity. CONCLUSIONS: Grouping by the C677T SNP alone was almost as good a predictor of the homocysteine-lowering effects as was grouping by the 4 best SNPs. This shows that increasing the number of typed SNPs does not necessarily provide more information, at least for this gene. A more efficient, cost-informative method for analyzing genomic data is required.

Multimedia presentations on the human genome: Implementation and assessment of a teaching program for the introduction to genome science using a poster and animations.

Genome science, including topics such as gene recombination, cloning, genetic tests, and gene therapy, is now an established part of our daily lives; thus we need to learn genome science to better equip ourselves for the present day. Learning from topics directly related to the human has been suggested to be more effective than learning from Mendel's peas not only because many students do not understand that plants are organisms, but also because human biology contains important social and health issues. Therefore, we have developed a teaching program for the introduction to genome science, whose subjects are focused on the human genome. This program comprises mixed multimedia presentations: a large poster with illustrations and text on the human genome (a human genome map for every home), and animations on the basics of genome science. We implemented and assessed this program at four high schools. Our results indicate that students felt that they learned about the human genome from the program and some increases in students' understanding were observed with longer exposure to the mixed multimedia presentations.

Distribution of autistic traits and their association with sociodemographic characteristics in Japanese workers.

This study aimed to confirm whether autistic traits are normally distributed across a population and to describe their association with the sociodemographic characteristics of Japanese workers. The participants were 2075 workers aged 23-65 years from various parts of Japan. Autistic traits were measured using an abridged Japanese version of the Autism-Spectrum Quotient (AQ-Short). The AQ-Short comprises five subcomponents assessing a fascination for numbers and patterns (numbers/patterns), difficulties with imagination, a preference for routine, difficulties with social skills, and difficulties with switching attention. The five subcomponents of the autistic phenotype as well as the overall autistic phenotype itself were continuously distributed across the sample population of Japanese workers. Men had significantly higher AQ-Short scores than women. AQ-Short scores were not associated with age. Except for the numbers/patterns scores, workers of a lower socioeconomic status had significantly higher AQ-Short scores than their respective counterparts. For the numbers/patterns trait, workers of a higher socioeconomic status scored higher. Workers with low general physical activity had or tended to have higher scores for total and all subcomponent traits, except for the numbers/patterns trait. Generally, the autistic phenotype was more prevalent in workers of a low socioeconomic status, while a particular trait was prevalent among workers of a high socioeconomic status.

The interaction between the interleukin 6 receptor gene genotype and dietary energy intake on abdominal obesity in Japanese men.

Previous reports have shown that the Asp358Ala (T/G) polymorphism of the interleukin 6 receptor (IL6R) gene is associated with obesity and type 2 diabetes mellitus, but few studies have examined this association in the Japanese population. We performed the current study to investigate the relationship between the IL6R Asp358Ala (T/G) polymorphism and obesity in healthy Japanese men. Two hundred eighty-five healthy Japanese men (age, 46.1 +/- 11.5 years [mean +/- SD]; waist circumference [WC], 83.9 +/- 9.3 cm; body mass index, 23.3 +/- 3.3 kg/m(2)) employed by a Japanese company were enrolled in this study. Height, weight, and WC were measured, and daily energy intake levels were assessed by self-reported questionnaires. Genotyping of polymorphisms was performed by using melting curve analysis; no association was found between IL6R genotype and WC or body mass index. However, when the subjects were stratified by IL6R genotype, an association between WC and dietary energy intake level was found in the TT + GT-type subjects (P for linear regression = .048), but not in GG subjects (P for linear regression = .555). In addition, logistic regression analysis revealed that the interaction of IL6R (GG vs TT + GT) genotypes and dietary energy intake levels affected risk for abdominal obesity (P for interaction = .030). We concluded that the IL6R Asp358Ala (T/G) polymorphism appears to interact with energy intake and affect abdominal obesity in Japanese men. The interaction of this genotype and energy intake warrants further study.

Association between vitamin D receptor gene haplotypes and chronic periodontitis among Japanese men.

BACKGROUND: The vitamin D receptor (VDR) is involved in a variety of biological processes, such as bone metabolism and modulation of the immune response. Recent findings suggest that the pathway involving bone mineral density-mediated effects is important for the development of periodontitis, but their effects of combined VDR gene polymorphisms have not been confirmed on periodontitis. We assessed the relationship between ApaI, BsmI, and FokI VDR polymorphisms and the risk of severe chronic periodontitis among Japanese adult men. MATERIALS AND METHODS: In a cross-sectional study, we examined 97 unrelated healthy Japanese men (mean age: 45.6 years, range: 22-59). A clinical examination was performed at a worksite health checkup, and information was obtained using a self-reported questionnaire. DNA was extracted from whole blood, and the VDR ApaI, BsmI, and FokI polymorphisms were genotyped using polymerase chain reaction. RESULTS: F-carriers of FokI VDR polymorphisms were less likely to develop severe chronic periodontitis than non-F-carriers (p = 0.09). The ApaI and BsmI VDR polymorphisms did not show significant differences in the alleles or genotypes between the subjects with or without severe chronic periodontitis. The haplotype analysis of the three combined VDR polymorphisms revealed that the Abf homozygote had a notably higher prevalence of severe chronic periodontitis than the others, and adjustments for age, smoking status, number of teeth present, and prevalence of diabetes did not change this association (OR = 7.5; 95% CI = 1.6-34.4; p = 0.01). CONCLUSION: The VDR haplotype constructed from the ApaI, BsmI, and FokI polymorphisms is related to the risk of severe chronic periodontitis in Japanese men.