Neurodevelopmental Disorder Traits in Taijin-Kyofu-sho and Social Anxiety Disorder: A Cross-Sectional Study among University Students.

Taijin-Kyofu-sho is an East Asian culture-bound anxiety disorder with similarities to social anxiety disorder. However, few studies have examined these two disorders from the perspective of neurodevelopmental disorders. This study is aimed at examining the association of Taijin-Kyofu-sho and social anxiety disorder with the attention-deficit/hyperactivity disorder (ADHD) trait and autism spectrum disorder (ASD) trait. The Liebowitz Social Anxiety, Taijin-Kyofu-sho, and Adult Attention-Deficit/Hyperactivity Disorder Self-Report scales and the 16-item Autism-Spectrum Quotient were administered to 818 university students. Participants were divided into four groups: control (neither Taijin-Kyofu-sho nor social anxiety disorder), pure Taijin-Kyofu-sho (Taijin-Kyofu-sho alone), pure social anxiety disorder (social anxiety disorder alone), and mixed Taijin-Kyofu-sho-social anxiety disorder (both Taijin-Kyofu-sho and social anxiety disorder). We used logistic regression analysis to examine whether the ADHD trait and ASD trait were associated with Taijin-Kyofu-sho and social anxiety disorder. ASD trait was significantly associated with pure Taijin-Kyofu-sho (p = 0.006, odds ratio: 3.99). Female sex and ADHD trait were significantly associated with pure social anxiety disorder (sex: p = 0.013, odds ratio: 2.61; ADHD trait: p = 0.012, odds ratio: 2.46). Female sex, ADHD trait, and ASD trait were significantly associated with mixed Taijin-Kyofu-sho-social anxiety disorder (sex: p = 0.043, odds ratio: 2.16; ADHD trait: p = 0.003, odds ratio: 2.75; ASD trait: p < 0.001, odds ratio: 16.93). Neurodevelopmental disorder traits differed between individuals with Taijin-Kyofu-sho and those with social anxiety disorder. Overall, our study reveals that Japanese individuals with the ADHD or ASD traits are at a heightened risk of developing Taijin-Kyofu-sho or social anxiety disorder.

Maternal prenatal stress and infantile wheeze and asthma: The Osaka Maternal and Child Health Study.

OBJECTIVE: Some recent studies suggest that maternal prenatal stress (MPS) increases allergic diseases in the children. However, knowledge on this issue in Asian children are lacking. We investigated the association between MPS and the risks of wheeze and asthma in Japanese infants aged 16-24 months. METHODS: The present subjects were 763 Japanese mother-child pairs. The first, second, and third surveys based on self-administered questionnaires were performed during pregnancy, between 2 and 9 months postpartum, and from 16 to 24 months postpartum, respectively. Data on MPS was obtained in the first survey, using the Stress Inventory (SI), which constructs 12 specific behavioral patterns as response styles to stressors. Data on wheeze and asthma was obtained in the third survey, where wheeze was based on the International Study of Asthma and Allergies in Childhood criteria and asthma was based on doctors' diagnosis. RESULTS: There were 169 infants with wheeze (22.1%) and 33 infants with asthma (4.3%), at the time of the third survey. Multiple logistic regression analyses found that a maternal behavioral pattern characterized by chronic irritation and anger was associated with the risk of childhood asthma (adjusted odds ratio [OR] = 1.56, 95% confidence interval [CI]: 1.11 to 2.22), but not wheeze (adjusted OR = 1.02, 95%CI: 0.88 to 1.19), while there was no appreciable association between the other SI scales and the risk of childhood wheeze or asthma. CONCLUSIONS: The results partly supported the hypothesis that MPS might increase the risk of asthma in their infants in Japanese.

Contributions of Anthropometrics and Lifestyle to Blood Pressure in Japanese University Students†:†Investigation by Annual Health Screening.

Background : High blood pressure (BP) is a healthcare problem in young persons. There are racial differences in anthropometrics, dietary habit and lifestyle relating to BP. Therefore, this study investigated the relationship between anthropometrics, lifestyle and BP obtained in the Japanese university students. Materials and Methods : Participants were recruited in annual health screening including questionnaire, measurements of BP and anthropometrics calculating body mass index (BMI). Totally, 14,280 students (10,273 males and 4,007 females) were eligible. Multiple regression analyses were applied to predict contributors to high BP. Results : BMI was the most powerful contributor to high BP in many subgroups divided by gender and graduation (p < 0.001). In lifestyle, contribution of lack of exercise to high BPs was observed in the undergraduates. Smoking, drinking and breakfast skipping had no significant impact on high BP. However, smoking and drinking permeated and exercise habit declined after graduation. Prevalence of obesity (BMI ≥ 25 kg / m2) and hypertension ( ≥ 140 / 90 mmHg) increased in subgroups with advanced age (p < 0.001). Conclusion: BMI was found to be the most powerful contributor to high BPs. Health literacy to modify lifestyle is important to prevent hypertension for university students who are exposed to social trends of unhealthy lifestyle. J. Med. Invest. 67 : 174-181, February, 2020.

Relevance of hoarding behavior and the traits of developmental disorders among university students: a self-reported assessment study.

BACKGROUND: Previous studies have shown that hoarding behavior usually starts at a subclinical level in early adolescence and gradually worsens; however, a limited number of studies have examined the prevalence of hoarding behavior and its association with developmental disorders in young adults. The aims of this study were to estimate the prevalence of hoarding behavior and to identify correlations between hoarding behavior and developmental disorder traits in university students. METHODS: The study participants included 801 university students (616 men, 185 women) who completed questionnaires (ASRS: Adult ADHD Self-Report Scale version 1.1, AQ16: Autism-Spectrum Quotient with 16 items, and CIR: Clutter Image Rating). RESULTS: Among 801 participants, 27 (3.4%) exceeded the CIR cut-off score. Moreover, the participants with hoarding behavior had a significantly higher percentage of ADHD traits compared to participants without hoarding behavior (HB(+) vs HB(-), 40.7% vs 21.7%). In addition, 7.4% of HB(+) participants had autism spectrum disorder (ASD) traits, compared to 4.1% of HB(-) participants. A correlation analysis revealed that the CIR composite score had a stronger correlation with the ASRS inattentive score than with the hyperactivity/impulsivity score (CIR composite vs ASRS IA, r = 0.283; CIR composite vs ASRS H/I, r = 0.147). CONCLUSIONS: The results showed a high prevalence of ADHD traits in the university students with hoarding behavior. Moreover, we found that the hoarding behavior was more strongly correlated with inattentive symptoms rather than with hyperactivity/impulsivity symptoms. Our results support the concept of a common pathophysiology behind hoarding behavior and ADHD in young adults.

Medical Radiation Exposure among Atomic Bomb Survivors: Understanding its Impact on Risk Estimates of Atomic Bomb Radiation.

There have been some concerns about the influence of medical X rays in dose-response analysis of atomic bomb radiation on health outcomes. Among atomic bomb survivors in the Life Span Study, the association between atomic bomb radiation dose and exposures to medical X rays was investigated using questionnaire data collected by a mail survey conducted between 2007-2011, soliciting information on the history of computed tomography (CT) scans, gastrointestinal fluoroscopy, angiography and radiotherapy. Among 12,670 participants, 76% received at least one CT scan; 77%, a fluoroscopic examination; 23%, an angiographic examination; and 8%, radiotherapy. Descriptive and multivariable-adjusted analyses showed that medical X rays were administered in greater frequencies among those who were exposed to an atomic bomb radiation dose of 1.0 Gy or higher, compared to those exposed to lower doses. This is possibly explained by a greater frequency in major chronic diseases such as cancer in the ≥1.0 Gy group. The frequency of medical X rays in the groups exposed to 0.005-0.1 Gy or 0.1-1.0 Gy did not differ significantly from those exposed to <0.005 Gy. An analysis of finer dose groups under 1 Gy likewise showed no differences in frequencies of medical X rays. Thus, no evidence of material confounding of atomic bomb effects was found. Among those exposed to atomic bomb doses <1 Gy, doses were not associated with medical radiation exposures. The significant association of doses ≥1 Gy with medical radiation exposures likely produces no substantive bias in radiation effect estimates because diagnostic medical X-ray doses are much lower than the atomic bomb doses. Further information on actual medical X-ray doses and on the validity of self-reports of X-ray procedures would strengthen this conclusion.

A peptide inhibitor of antibody-dependent cell-mediated cytotoxicity against EGFR/folate receptor-α double positive cells.

Antibody-dependent cell-mediated cytotoxicity (ADCC) is caused by natural killer (NK) cells upon recognition of antigen-bound IgG via FcγRIIIa. This mechanism is crucial for cytolysis of pathogen-infected cells and monoclonal antibody (mAb)-mediated elimination of cancer cells. However, there is concern that mAb-based cancer therapy induces ADCC against non-target cells expressing antigens. To date, no strategy has been reported to enhance the selectivity of ADCC to protect non-target cells expressing antigens. Here, we introduce a model inhibitor which specifically blocks ADCC of anti-EGFR mAbs towards EGFR/folate receptor α (FRα) double positive cells. This inhibitor recruits mAbs on the FRα of the cell surface independent of Fab antigen recognition. The resulting ternary and/or quaternary complexes formed on the cell surface suppress signal transduction of FcγRIIIa in NK cells, consequently leading to more specific ADCC.

Inhibition of emotional needs and emotional wellbeing predict disease progression of chronic hepatitis C patients: an 8-year prospective study.

BACKGROUND: The role of psycosocial factors in the disease progression of chronic hepatitis C (CHC) patients remains unclear. The aim of the present study was to prospectively evaluate the prognostic value of behavioral patterns and the quality of life (QOL) of patients with CHC. METHODS: Two hundred and forty Japanese CHC patients (mean age 62.4 years) were assessed for behavioral patterns (Stress Inventory), QOL (Functional Assessment of Chronic Illness Therapy-Spiritual), and known prognostic factors at baseline then followed for a maximum of 8 years for disease progression, defined as either the first diagnosis of hepatocellular carcinoma (HCC) or hepatitis-related death. RESULTS: Forty-nine events occurred during the study period (46 newly diagnosed HCC cases, three hepatitis-related deaths). In a Cox proportional hazard model including known prognostic factors and treatment-related factors as time-dependent variables, behavioral patterns associated with inhibition of emotional needs (hazard ratio (HR): 1.35; 95 % confidence interval (CI): 1.02-1.77; p = 0.036) and QOL, representing emotional wellbeing (HR 0.60; 95 % CI 0.37-0.98; p = 0.041), were each associated with the risk of disease progression. CONCLUSION: Psychosocial factors such as behavioral patterns relevant to the inhibition of emotional needs and emotional wellbeing independently affect the clinical course of patients with CHC.

Age-associated effect of kestose on Faecalibacterium prausnitzii and symptoms in the atopic dermatitis infants.

BACKGROUND: Although Faecalibacterium prausnitzii is a major bacterium in the intestine of adults, which is known to have anti-inflammatory effects, the development in infants or the response to prebiotics remains unclear. METHODS: The counts of F. prausnitzii in the feces were examined by real-time polymerase chain reaction (PCR). Fecal samples were obtained from 65 atopic dermatitis (AD) infants who participated in a randomized controlled clinical trial to investigate the therapeutic effect of kestose, the smallest fructooligosaccharide. RESULTS: Although the F. prausnitzii count was undetectable level in most 0- to 1-y-old infants, the count reached a level comparable to that in adults in 2- to 5-y-old infants. The bacterial number increased about 10-fold by oral administration of kestose every day for 12 wk in the younger infants, but not so much in the older infants. This bacterial increase was significantly correlated with an improvement in the AD symptoms in the older infants. CONCLUSION: The F. prausnitzii population in the intestine reaches a level comparable to that in adult at approximately 2 y of age. Kestose efficiently stimulates the growth of this bacterium in the intestine, which might lead to an improvement in AD symptoms in infants.

Life events, emotional responsiveness, and the functional prognosis of patients with rheumatoid arthritis.

BACKGROUND: Stressors may differently affect human physiological systems according to the host properties relevant to psycho-behavioral processes that the stressors invoke. In a Japanese multicenter cohort study of patients with rheumatoid arthritis (RA), we examined if major life events differently contribute to the patients' functional prognosis according to their ability to identify emotions as manifest feelings when encountering the events (emotional responsiveness). METHODS: 460 patients with RA completed a self-administered baseline questionnaire about psychosocial factors including emotional responsiveness. Two years later, they checked on a list of positive/negative personal events that happened during the two-year study period. Rheumatologists evaluated their functional status at baseline and follow-up using the ACR classification system. RESULTS: In a multiple logistic regression model that included baseline demographic, disease activity/severity-related, therapeutic, and socioeconomic factors as covariates, none of the counts of positive, negative, or all life events was associated with the functional status at follow-up. In the subgroup with poor emotional responsiveness, however, these life event counts were all associated with a poorer functional prognosis (odds ratio of ACR class 3-4 vs. 1-2 associated with one increment in the all life-event count = 2.39, 95 % confidence interval = 1.27-4.48, p = .007), while no such relationship was evident for the rest of the patients. CONCLUSIONS: Major life events, whether positive or negative in nature, may have an impact on the disease course of patients with RA when the patient has poor emotional responsiveness to the event(s).

Parental stress and the onset and course of childhood asthma.

The influence of a caregiver's stress on the development of childhood asthma is an important aspect of the treatment and prevention of illness. Many cross-sectional studies have investigated the association between parenting attitude and/or caregiver's stress and childhood asthma morbidity, but prospective studies are more advantageous than cross-sectional studies in interpreting a causal relationship from the results. We here present an overview of prospective studies that have reported a relationship between parental stress and the morbidity or course of childhood asthma and discuss the role of parental mental health in its prevention and treatment. Almost all of the studies referred to in this paper show that caregiver (mostly mothers) stress contributed to the onset and to a poor prognosis, while only a few studies have examined the adverse effect of paternal stress on childhood asthma. Their results are inconsistent, and there is insufficient data examining specific stress-related properties that can be targeted in intervention studies. Not only maternal but also paternal influence should be considered in future studies, and it will be important to assess specific stress-related properties that can be the foundation of specific intervention methods.

Correlation between the Serum Pepsinogen I Level and the Symptom Degree in Proton Pump Inhibitor-Users Administered with a Probiotic.

In patients with functional upper gastrointestinal disorders such as gastroesophageal reflux disease and functional dyspepsia, the presence of symptoms is thought to occur in the absence of any organic diseases and the mechanisms behind this remain unclear. We therefore examined the relationship between stomach-related biomarker levels and symptoms. Twenty-four outpatients who had taken proton-pump inhibitors every day were enrolled in this study. The subjects consumed yogurt containing 109 colony-forming units of Lactobacillus gasseri OLL2716 (LG21) every day for three months. They underwent four clinical examinations in total. Each examination consisted of answering a questionnaire with a frequency scale for the symptoms of GERD (FSSG), and included measurements of the serum gastrin, ghrelin, and pepsinogens I and II levels. As a result, the FSSG score and the PGI value showed a decrease and an increase, respectively, after LG21 treatment when analyzed without age adjustment. A multiple regression analysis with additional adjustments for gender and age revealed a strong association between the PGI value and the FSSG symptom scores. Therefore either the PGI level itself or the factors regulating the PGI level might be involved in the etiology of these symptoms.

Rational/antiemotional behaviors in interpersonal relationships and the functional prognosis of patients with rheumatoid arthritis: a Japanese multicenter, longitudinal study.

BACKGROUND: The repression of negative emotions is a personality factor that received considerable attention in the 1950-60s as being relevant to the onset and course of rheumatoid arthritis (RA). Despite subsequent, repeated criticisms of the cross-sectional nature of the earlier studies, even to date few prospective studies have been reported on this issue. This multicenter study prospectively examined if "rational and antiemotional" behavior (antiemotionality), characterized by an extreme tendency to suppress emotional behaviors and to rationalize negative experiences in conflicting interpersonal situations, is associated with the functional prognosis of patients with RA. METHODS: 532 patients with RA who regularly visited one of eight hospitals/clinics in Japan in 2000 were recruited for study. All completed a self-administered baseline questionnaire about lifestyle and psychosocial factors including antiemotionality. Two years after, 460 (mean age, 56.1 years; 54 men and 406 women) of 471 patients who continued to visit the clinics agreed to take the follow-up questionnaire. The functional status of the patients was evaluated by rheumatologists based on the ACR classification system. RESULTS: A multiple logistic regression model that included baseline demographic, disease activity/severity-related, therapeutic, and socioeconomic factors as covariates found a tendency toward higher antiemotionality to be related to poorer functional status at follow-up. This relationship was not explained by lifestyle factors. CONCLUSIONS: Antiemotionality may be a prognostic factor for the functional status of patients with RA. This finding sheds light on a seemingly forgotten issue in the care of patients with RA.

Microsomal epoxide hydrolase polymorphisms, cigarette smoking, and risk of colorectal cancer: the Fukuoka Colorectal Cancer Study.

Microsomal epoxide hydrolase (EPHX1) plays an important role in the activation and detoxification of polycyclic aromatic hydrocarbons, carcinogens found in cigarette smoke. Polymorphisms in exon 3 (Y113H) and exon 4 (H139R) of the EPHX1 have been associated with enzyme activity. We investigated the risk of colorectal cancer in relation to the EPHX1 Y113H and H139R polymorphisms and assessed effect modifications of cigarette smoking and the other covariates. The interaction between the EPHX1 polymorphisms and selected genetic polymorphisms was also examined. We used data from Fukuoka Colorectal Cancer Study, a community-based case-control study, including 685 cases and 778 controls. In-person interviews were conducted to assess lifestyle factors. The EPHX1 Y113H and H139R polymorphisms were determined by the TaqMan assay and the polymerase chain reaction-restriction fragment length polymorphism, respectively. Neither of the two polymorphisms nor the imputed EPHX1 phenotype was associated with colorectal cancer risk. Cigarette smoking and alcohol intake showed no effect modification on the association with the EPHX1 polymorphisms or the imputed EPHX1 phenotype. Increased risks of colorectal cancer associated with the 113Y allele and imputed EPHX1 phenotype were observed among individuals with high body mass index (BMI; ≥25.0 kg/m(2)), but not among those with low BMI (<25.0 kg/m(2)). The risk decreased with an increasing number of the 139R allele in the null genotypes of GSTM1/GSTT1. It is unlikely that the EPHX1 polymorphisms play an important role in colorectal carcinogenesis. The observed interactions of the EPHX1 polymorphisms with BMI and the GSTM1/GSTT1 genotypes warrant further investigation.

Volatiles emitted from the roots of Vetiveria zizanioides suppress the decline in attention during a visual display terminal task.

The perennial grass Vetiveria zizanioides (vetiver) is mainly cultivated for its fragrant essential oil. Although the components of the oil and their biological activities have been studied extensively, the effect of the volatiles emitted from the roots of V. zizanioides on humans has so far remained unexplored. We investigated the effects of volatile compounds emitted from the cut roots of V. zizanioides (1.0 g, low-dose conditions; 30 g, high-dose conditions) on individuals during a visual display terminal task. Participants who breathed the volatile compounds emitted under low-dose conditions showed faster reaction times and stimulation of sympathetic nerve activity as measured by electrocardiography. These effects were not observed under high-dose conditions. The total amounnt of volatiles emitted during the experiment was 0.25 µg under low-dose conditions and 1.35 µg under high-dose conditions. These findings indicate that volatile compounds emitted from the roots of V. zizanioides under low-dose conditions may have helped subjects to maintain performance in visual discrimination tasks while maintaining high sympathetic nerve system activity.

Neuroticism and extraversion personality traits, health behaviours, and subjective well-being: the Fukuoka Study (Japan).

PURPOSE: We evaluated personality dimensions captured by an abbreviated 8-item questionnaire and examined associations of the personality traits with health behaviours and subjective well-being (SWB) measures. METHODS: The subjects were 11,554 participants in the Kyushu University Fukuoka Cohort Study who completed a self-administered questionnaire inquiring health behaviours, morbidity, personality, and SWB. Personality was assessed by using a questionnaire appeared to capture neuroticism and extraversion traits, and SWB-related variables were assessed with 3 single-item questions. RESULTS: Neuroticism was negatively and extraversion was positively associated with BMI. Extraversion, but not neuroticism, was positively associated with smoking and alcohol drinking. After multivariate adjustment, neuroticism was strongly associated with each of 3 SWB measures. The multivariate-adjusted odds ratios for the highest versus lowest quintile of neuroticism were 6.09 (95% confidence interval [CI], 5.05-7.33) for perceived stress; 0.21 (95% CI, 0.18-0.25) for good health condition; and 0.26 (95% CI, 0.22-0.31) for life satisfaction. Extraversion showed no clear association with the SWB measures. CONCLUSIONS: The neuroticism and extraversion scales were associated with health behaviours and BMI differently. The neuroticism scale, but not the extraversion scale, was strongly associated with higher perception of stress, poorer perceived health, and lower satisfaction with life in a Japanese population.

The effect of probiotics on gastric mucosal permeability in humans administered with aspirin.

OBJECTIVE: To examine whether a probiotic strain, Lactobacillus gasseri OLL2716 (LG21), can protect the gastric mucosal integrity from aspirin using urinary sucrose excretion (USE) test. MATERIALS AND METHODS: In the study using high-dose aspirin, the USE tests were carried out in 29 volunteers before and after LG21 treatment for 4 weeks. In the study using patients undergoing low-dose aspirin therapy, USE tests were performed in 37 subjects who took LG21 for 16 weeks. Stool occult blood was examined by the guaiac method. RESULTS: In the former study, the elevation in the USE value after aspirin loading significantly decreased after LG21 treatment (Median ± SD; 0.244 ± 0.237 vs. 0.208 ± 0.112%, p = 0.018). In the latter study, the USE value significantly decreased in the period with LG21 treatment (p = 0.033), while no significant difference was found in the period without LG21 (p = 0.113). The number of positive occult blood tests decreased during LG21 treatment. CONCLUSIONS: The regular ingestion of LG21 may protect the integrity of the gastric mucosal permeability against aspirin.

Do interventions to prevent lifestyle-related diseases reduce healthcare expenditures? A randomized controlled clinical trial.

BACKGROUND: In 2008, the Japanese government implemented a program of health lifestyle interventions to reduce health care expenditure. This study evaluated whether these interventions decreased health care expenditures. METHODS: The study enrolled 99 participants insured by Japanese National Health Insurance, who, in our previous study conducted in 2004, were allocated by random sampling into an intervention group (50 participants) and a control group (49 participants). In the intervention group, we used a health support method that facilitated the attainment of goals established by each participant. The control group received instruction in exercise, as well as health support using publically available media. Although 3 participants in the intervention group and 9 participants in the control group did not participate in a follow-up health examination 1 year after the intervention, the health care expenditures of all initial participants were assessed. Expenditures before and after the intervention were compared within and between groups. Data on health care expenditures were obtained from inpatient, outpatient, pharmacy, and dental health insurance claims. RESULTS: After the intervention, the pharmacy and dental expenditures were significantly higher in the intervention group, while the pharmacy expenditure was significantly higher in the control group. However, there was no significant difference in any medical expenditure item between the intervention and control groups before or after the intervention. CONCLUSIONS: No significant differences were observed in short-term medical expenses for any medical expenditure item after a lifestyle intervention.

The parenting attitudes and the stress of mothers predict the asthmatic severity of their children: a prospective study.

OBJECTIVE: To examine relationships between a mother's stress-related conditions and parenting attitudes and their children's asthmatic status. METHODS: 274 mothers of an asthmatic child 2 to 12 years old completed a questionnaire including questions about their chronic stress/coping behaviors (the "Stress Inventory"), parenting attitudes (the "Ta-ken Diagnostic Test for Parent-Child Relationship, Parent Form"), and their children's disease status. One year later, a follow-up questionnaire was mailed to the mothers that included questions on the child's disease status. RESULTS: 223 mothers (81%) responded to the follow-up survey. After controlling for non-psychosocial factors including disease severity at baseline, multiple linear regression analysis followed by multiple logistic regression analysis found chronic irritation/anger and emotional suppression to be aggravating factors for children aged < 7 years; for children aged 7 and over, the mothers' egocentric behavior was a mitigating factor while interference was an aggravating factor. CONCLUSIONS: Different types of parental stress/coping behaviors and parenting styles may differently predict their children's asthmatic status, and such associations may change as children grow.

Cigarette smoking, genetic polymorphisms and colorectal cancer risk: the Fukuoka Colorectal Cancer Study.

BACKGROUND: It is uncertain whether smoking is related to colorectal cancer risk. Cytochrome P-450 CYP1A1, glutathione-S-transferase (GST) and NAD(P)H:quinone oxidoreductase 1 (NQO1) are important enzymes in the metabolism of tobacco carcinogens, and functional genetic polymorphisms are known for these enzymes. We investigated the relation of cigarette smoking and related genetic polymorphisms to colorectal cancer risk, with special reference to the interaction between smoking and genetic polymorphism. METHODS: We used data from the Fukuoka Colorectal Cancer Study, a population-based case-control study, including 685 cases and 778 controls who gave informed consent to genetic analysis. Interview was conducted to assess lifestyle factors, and DNA was extracted from buffy coat. RESULTS: In comparison with lifelong nonsmokers, the odds ratios (OR) of colorectal cancer for <400, 400-799 and > or = 800 cigarette-years were 0.65 (95% confidence interval [CI], 0.45-0.89), 1.16 (0.83-1.62) and 1.14 (0.73-1.77), respectively. A decreased risk associated with light smoking was observed only for colon cancer, and rectal cancer showed an increased risk among those with > or = 400 cigarette-years (OR 1.60, 95% CI 1.04-2.45). None of the polymorphisms under study was singly associated with colorectal cancer risk. Of the gene-gene interactions studied, the composite genotype of CYP1A1*2A or CYP1A1*2C and GSTT1 polymorphisms was associated with a decreased risk of colorectal cancer, showing a nearly statistically significant (Pinteraction = 0.06) or significant interaction (Pinteraction = 0.02). The composite genotypes of these two polymorphisms, however, showed no measurable interaction with cigarette smoking in relation to colorectal cancer risk. CONCLUSIONS: Cigarette smoking may be associated with increased risk of rectal cancer, but not of colon cancer. The observed interactions between CYP1A1 and GSTT1 polymorphisms warrant further confirmation.

Dietary fiber, source foods and colorectal cancer risk: the Fukuoka Colorectal Cancer Study.

OBJECTIVE: Despite much evidence from laboratory work, epidemiological evidence remains elusive regarding the role of dietary fiber in colorectal carcinogenesis. We investigated associations of dietary fiber and source foods with colorectal cancer risk in the Fukuoka Colorectal Cancer Study, a community-based case-control study. MATERIAL AND METHODS: The study subjects were 816 incident cases of colorectal cancer and 815 community controls. Nutrient and food intakes were estimated on the basis of a computer-assisted interview regarding 148 dietary items. Odds ratios of colorectal cancer according to quintile categories of energy-adjusted intakes of dietary fiber and food groups were obtained with adjustment for non-dietary factors and dietary intakes of calcium and n-3 fatty acids. RESULTS: Total, soluble and insoluble dietary fibers were not measurably associated with overall risk or subsite-specific risk of colorectal cancer. By contrast, rice consumption was associated with a decreased risk of colorectal cancer (trend p = 0.03), particularly of distal colon and rectal cancer (trend p = 0.02), and high intake of non-rice cereals tended to be related to an increased risk of colon cancer (trend p = 0.07). There was no association between vegetable consumption and colorectal cancer, whereas individuals with the lowest intake of fruits tended to have an increased risk of colorectal cancer. CONCLUSIONS: The present study did not corroborate a protective association between dietary fiber and colorectal cancer, but suggested a decreased risk of distal colorectal cancer associated with rice consumption.