Physical activity and incident dementia in older Japanese adults: The Okayama study

OBJECTIVE

To evaluate the association between regular physical activity and the risk of incident dementia in older Japanese adults.

METHODS

This was a retrospective cohort study performed in Okayama City, Japan. Overall, 51 477 older Japanese adults were followed from 2008 to 2014. A health checkup questionnaire was used to assess regular physical activity. The Dementia Scale of long-term care insurance was used as a measure of incident dementia. Cox proportional hazard models were used to calculate adjusted hazard ratios, with their 95% confidence intervals, for the incidence of dementia across the categories of physical activity.

RESULTS

During a 7-year follow-up, 13 816 subjects were considered as having incident dementia. Compared with participants who performed physical activity less than or equal to one time per week, the multivariate adjusted hazard ratio values (95% confidence intervals) for participants who performed physical activity greater than or equal to two times per week but not every day and those who performed physical activity every day were 0.79 (0.75-0.84) and 0.94 (0.89-0.98), respectively. The interaction of physical activity and sex was statistically significant (P < .01). In subgroup analysis, the multivariate-adjusted hazard ratio values (95% confidence intervals) remained low, at 0.76 (0.70-0.84) in males and 0.81 (0.76-0.87) in females who performed physical activity greater than or equal to two times per week but not every day; they were 0.82 (0.76-0.89) in males and 1.01 (0.95-1.07) in females who performed physical activity every day.

CONCLUSIONS

Regular physical activity could reduce the risk of incident dementia in older Japanese adults, except females who performed physical activity every day.

Associations of Cell Phone Use and Screen Viewing with Overweight in Children

Background: Effects of using mobile devices on childhood obesity have not been well studied. We aimed to ascertain whether cell phone use and screen viewing are associated with excess body weight in a cross-sectional study of Japanese school children. Methods: Subjects were 3141 students, ages 6 to 7 years, who participated in the Hekinan Children's Study conducted during 2011-2015. Participants were asked to submit a parent-administered questionnaire on child and parent demographics, health status, and lifestyles, including cell phone use and screen time. Heights and weights were measured at the schools. Being overweight was defined according to the cutoff point for children specified by the Extended International Obesity Task Force. Among 2596 analytic children, the odds ratios (ORs) for being overweight were estimated according to cell phone use, time spent watching television, and time spent on games and computers using the logistic regression models. Analyses were conducted after adjustments for potential confounders, including dietary intake, physical activities, sleep duration, and quality of sleep. Results: After multivariate adjustments, cell phone users were found to have an OR of 1.74 for being overweight compared with nonusers. Cell phone use of longer duration was associated with higher risk of being overweight (trend p = 0.018). Time spent watching television was positively associated with the risk of being overweight (trend p = 0.003). Conclusions: Just as earlier studies have shown for television viewing, cell phone use might be a risk factor related to being overweight among children.

The Hekinan Children's Study: Design and Profile of Participants at Baseline

BACKGROUND

The early life environment is now recognized as a key factor contributing to susceptibility to certain diseases in later life.

METHODS

We initiated a cohort study among school children in 2011 to primarily investigate the associations between lifestyle and environmental factors and some surrogate markers of chronic diseases, such as cardiometabolic risk factors (ie, obesity, high blood pressure, high blood glucose, insulin, or lipids) and cancer risk factors (ie, height and age at menarche). A baseline questionnaire asked for information, including demographic variables, medical history and use of medication, dietary habits, physical activity, sleep habits, and behavioral and emotional problems of children. Follow-up surveys are planned for the fourth grade of elementary school and the first grade of junior high school. At these follow-up surveys, fasting blood samples will be obtained to measure cardiometabolic markers. We also checked the validity of a food frequency questionnaire, which was originally created for 6-year-olds but was modified for use in older children.

RESULTS

A total of 3,141 first-year students at elementary schools in Hekinan City, Aichi Prefecture, participated in the study. The response rate was 87.4%. The means of age and body mass index were 6.99 (standard deviation, 0.28) years and 15.3 (standard deviation, 1.7) kg/m2, respectively, in the 3,067 Japanese children (1,639 boys and 1,428 girls).

CONCLUSIONS

This cohort will reveal determinants of cardiometabolic risk factors and cancer risk factors during childhood.

Dietary Soy Intake Is Inversely Associated with Risk of Type 2 Diabetes in Japanese Women but Not in Men

BACKGROUND

Whole soy foods, as well as their components, including protein and isoflavones, have garnered attention because they may have beneficial effects against diabetes.

OBJECTIVES

We examined associations between the intake of soy foods, soy protein, and soy isoflavones and the risk of diabetes in the Japanese population.

METHODS

This prospective cohort study included 13,521 residents (5883 men and 7638 women; 35-69 y old) of Takayama City, Japan. The subjects responded to a self-administered baseline questionnaire in 1992 and to a follow-up questionnaire seeking information about diabetes in 2002. Their mean ± SD body mass index was 22.6 ± 2.6 kg/m2 (men) and 22.1 ± 2.7 (women). The intakes of total soy foods, fried soy foods, nonfried soy foods, soy protein, and soy isoflavones were estimated through the use of a validated food-frequency questionnaire administered in 1992. Associations between soy intake and the risk of diabetes were evaluated through the use of Cox proportional hazards models incorporating age, education level, physical activity, smoking status, alcohol consumption, history of hypertension, use of vitamin supplements, menopausal status, and dietary factors including glycemic load, total energy, total fat, meat, fruit, vegetables, and coffee.

RESULTS

During a 10-y follow-up, 438 participants reported physician-diagnosed diabetes. Women in the highest tertile of intakes of total soy foods, fried soy foods, nonfried soy foods, soy protein, and soy isoflavone had significantly lower HRs, after controlling for covariates, than those with the lowest intakes. For example, HRs were 0.45 (95% CI: 0.30, 0.68; P-trend <0.001) for total soy food intake. In men, there were no significant associations between soy intake and the risk of diabetes.

CONCLUSIONS

These results suggest that a high soy intake may be associated with a lower risk of diabetes in Japanese women.

Alcohol consumption and incident dementia in older Japanese adults: The Okayama Study

AIM

To evaluate the association between the amount and frequency of alcohol consumption and incident dementia in older Japanese adults using large sample size data over a long follow-up period.

METHODS

This was a retrospective cohort study carried out in Japan. A total of 53 311 older adults were followed from 2008 to 2014. A health checkup questionnaire was used to assess the amount and frequency of alcohol consumption. The Dementia Scale of long-term care insurance was used as a measure of incident dementia. Cox proportional hazards models were used to calculate adjusted hazard ratios, with their 95% confidence intervals, for the incidence of dementia across the categories of alcohol consumption by sex.

RESULTS

During a 7-year follow-up period, 14 479 participants were regarded as having incident dementia. Compared with non-drinkers, the multivariate adjusted hazard ratios for participants with alcohol consumption ≤2 units per day, occasionally (0.88, 95% CI 0.81-0.96 in men and 0.84, 95% 0.79-0.90 in women) and daily (0.79, 95% 0.73-0.85 in men and 0.87, 95% 0.78-0.97 in women) were statistically significant, and the difference between occasional and daily consumption was only statistically significant in men; however, for participants with alcohol consumption >2 units per day, occasionally (0.91, 95% 0.71-1.16 in men and 1.09, 95% 0.72-1.67 in women) and daily (0.89, 95% 0.81-1.00 in men and 1.16, 95% 0.84-1.81 in women) were not significant.

CONCLUSIONS

Alcohol consumption of ≤2 units per day, occasionally or daily, could reduce the risk of incident dementia, with greater benefit for men with such daily consumption. Geriatr Gerontol Int 2019; 19: 740-746.

Health risk management behaviors and related factors among Japanese university students participating in short-term study abroad programs

BACKGROUND

Overseas travelers should prepare for health problems at their destinations prior to travel. No prospective studies have evaluated factors related to health risk management behaviors among overseas travelers, specifically young travelers.

METHODS

We prospectively collected data from pre- and post-travel questionnaire surveys, targeting students of a university in Japan who participated in short-term study abroad programs (n = 532, 6 to 38 travel days and 11 countries). We examined health information collection, receipt of travel vaccinations for the programs and medical kit preparation as health risk management behavior outcomes and their related factors among the participants (82.7% follow-up rate).

RESULTS

In total, 17.5%, 8.0% (28.6% in Southeast Asia) and 68.9% of participants, respectively, collected travel health information via the Japanese or foreign official websites, received travel vaccinations and carried commonly used medicines. Female, travel experience to study destination, parental medical occupation and presence of illness in treatment were positively associated with the health risk management behaviors after adjusting for the covariates including study destination. For example, the adjusted odds ratio (OR) (95% confidence interval [CI]) of receiving travel vaccinations was 4.16 (1.70-10.2) for parental medical occupation relative to non-medical occupation. The adjusted OR (95% CI) of collecting travel health information was 2.54 (1.04-6.21) for travel experience to study destination relative to no overseas travel experience.

CONCLUSIONS

Personal characteristics including overseas travel experience and parental occupation provide a useful insight into approaches to promoting health risk management among university students traveling abroad.

Number of Teeth and All-Cause and Cancer Mortality in a Japanese Community: The Takayama Study

BACKGROUND

The association between the number of teeth and mortality among community-dwelling people has been examined in many epidemiological studies. However, few Japanese studies have included cancer mortality as an endpoint. We prospectively investigated the association between number of remaining teeth and all-cause and cancer mortality in a Japanese community.

METHODS

This study included participants in the Takayama Study who were aged 35-70 years old at baseline in 1992. Information on the number of remaining teeth was obtained from 11,273 participants via questionnaire at the second survey in 2002. The response rate was 66.9%. Deaths and their causes were ascertained during 11.8 years of follow-up.

RESULTS

A total of 1,098 deaths (435 cancer-related and 235 cardiovascular-related) were identified during the follow-up period. After adjusting for covariates, participants with 0 to 9 teeth were at moderate but significantly increased risk of all-cause mortality (hazard ratio [HR] 1.19; 95% confidence interval [CI], 1.03-1.39) and cancer mortality (HR 1.31; 95% CI, 1.03-1.67) compared to those with 20 or more teeth. With regard to cancer site, a significant association was observed for lung cancer (HR for 0-9 teeth vs. 20 or more teeth, 1.75; 95% CI, 1.08-2.83). This association was somewhat strengthened among never-smokers (HR 3.56; 95% CI, 1.02-12.45).

CONCLUSIONS

We observed that a lower number of remaining teeth was significantly associated with increased risk from all-cause and lung cancer mortality. Further studies on the number of teeth and lung and other types of cancer are needed.

Association between exposure to household smoking and dental caries in preschool children: a cross-sectional study

BACKGROUND

We aimed to examine the association of exposure to environmental tobacco smoke with dental caries among preschool children. Exposure to environmental tobacco smoke was assessed in terms of urinary cotinine concentrations and pack-years of exposure to smoking by parents and other family members at home.

METHODS

This cross-sectional study included 405 preschool children aged 3-6 years from two preschools in Japan in 2006. Information on the smoking habits of family members living with the child was obtained from parent-administered questionnaires. Dental examination was conducted to assess dental caries, that is, decayed and/or filled teeth. Urinary cotinine levels were measured using first-void morning urine samples.

RESULTS

Overall, 31.1% of the children had dental caries, and 29.5% had decayed teeth. Exposure to current maternal and paternal smoking was positively associated with the presence of dental caries after controlling for covariates. More than three pack-years of exposure to maternal smoking and more than five pack-years of exposure to smoking by all family members were significantly associated with the presence of dental caries as compared with no exposure (odds ratio [OR] = 5.55, 95% confidence interval [CI] = 2.17-14.22, P for trend < 0.001 and OR = 2.00, 95% CI = 1.12-3.58, P for trend = 0.004, respectively). These exposure variables were similarly associated with the presence of decayed teeth (OR = 2.92, 95% CI = 1.23-6.96, P for trend = 0.01 and OR = 1.75, 95% CI = 0.96-3.20, P for trend = 0.03, respectively). As compared with lowest tertile of the urinary cotinine level, the highest tertile of the urinary cotinine level was significantly associated with the presence of dental caries as well as decayed teeth; the ORs for the highest vs. lowest tertile of urinary cotinine levels were 3.10 (95% CI = 1.71-5.63, P for trend = 0.012) and 2.02 (95% CI = 1.10-3.70, P for trend = 0.10), respectively.

CONCLUSIONS

These data suggest that exposure to tobacco smoke may have a dose-dependent influence on the development of caries.

Association of early daycare attendance with allergic disorders in children: a longitudinal national survey in Japan

The association between early daycare attendance and risk of allergic diseases remains inconclusive. Therefore, we examined the association among Japanese children on a long-term basis using a nationwide longitudinal survey data. We estimated the association between daycare attendance at age 6 or 18 months and allergy development using information on outpatient visits for atopic dermatitis (AD), food allergy (FA), and asthma and admission for asthma up to 12 years of age as a proxy for developing these diseases, with multilevel logistic regression. Early daycare attendance was associated with increased odds of AD at ages 2.5-3.5 years: the adjusted odds ratio (OR) was 1.34 [95% CI: 1.21, 1.47]. The association with FA was equivocal. The odds of asthma was increased before age 3.5 years and afterwards decreased: the adjusted ORs were 1.60 [1.44, 1.77] for ages 1.5-2.5 years and 0.77 [0.69, 0.87] for ages 5.5-7 years. The effect of early daycare attendance depends on the type of allergies.

National data showed that delayed sleep in six-year-old children was associated with excessive use of electronic devices at 12 years

AIM

Cross-sectional studies have shown associations between adolescent sleep problems and the use of electronic devices, such as mobile phones, but longitudinal studies remain scarce. We explored any association between delayed bedtimes at six years old and the excessive use of electronic devices at 12 years of age. Texting was a prime focus.

METHODS

We analysed 9607 adolescents who owned mobile phones in 2013 using the Japanese Longitudinal Survey of Newborns in the 21st Century, which started in 2001. The outcomes were daily excessive use of a mobile phone, television (TV) and video games.

RESULTS

Delayed bedtime at the age of six years was associated with excessive texting at weekends. The adjusted odds ratios and 95% confidence intervals obtained from logistic regression analyses were 1.88 (1.14-3.10) for the 10-11 pm group and 1.98 (1.08-3.63) for the after 11 pm group, compared with the before 9 pm group. Later bedtimes were also associated with increased risks of excessive TV viewing and video game use.

CONCLUSION

Our study indicated that six-year-olds who regularly stayed up late at night used electronic devices more frequently, or for longer, at the age of 12. Parents need to be more aware of links between sleep issues and electronic devices.

Self-harm and Suicide Attempts in a Japanese Psychiatric Hospital

OBJECTIVE

Self-harm and attempted suicide are risk factors for suicide in psychiatric hospital in-patients. This study aimed to analyse the circumstances of self-harm and suicide attempts in a Japanese psychiatric hospital so as to improve management and care.

METHODS

Incident reports of self-harm and suicide attempts during a 12.4-year period from November 2000 to March 2013 were reviewed. A descriptive analysis was conducted in terms of age, sex, and diagnosis of patients, as well as level, ward, situations, and causes of incidents.

RESULTS

During the study period, 90 cases of self-harm and attempted suicide involving 58 patients were reported. The rate of self-harm and suicide attempts was 0.05 per 1000 patient-days. The types of selfharm and suicide attempts included hanging (n = 25), wrist cutting (n = 19), ingestion of foreign objects (n = 17), and others (n = 29). The single case of completed suicide involved hanging, in a patient with schizophrenia. Among 55 patients with relevant data, the most common clinical diagnosis was mood disorder (41.8%), followed by schizophrenia (36.4%). Mood disorder was 3.5 times as prevalent in females as in males (14 vs. 4). Fourteen patients with mood disorder (n = 8) or schizophrenia (n = 6) were repeatedly involved in 46 of 89 cases of self-harm or attempted suicide; 11 were female. One woman with mood disorder attempted suicide 9 times within the same year. The top 3 management and care factors related to self-harm and suicide attempts were failure to adhere to preventive procedures (28%), insufficient therapeutic communication (28%), and difficulty in predicting suicide (20%).

CONCLUSION

Self-harm and suicide attempts at this psychiatric hospital occurred at a rate of 0.05 per 1000 patient-days between late 2000 and early 2013. Efforts are needed to increase compliance with suicide prevention procedures and therapeutic communication, so as to improve management and care of psychiatric in-patients and prevent them from committing suicide.

Maternal smoking location at home and hospitalization for respiratory tract infections among children in Japan

We examined the effects of maternal smoking location at home on hospitalization for respiratory tract infections among young children in Japan. We used the large nationwide population-based longitudinal survey and restricted study participants to children born after 37 gestational weeks and singleton births (n = 43,851). We evaluated the associations among children between the ages of 6 and 18 months and between the ages of 18 and 30 months, respectively. After adjusting for potential confounders, both maternal outdoor and indoor smoking were associated with the elevated risk. The adjusted odds ratios (95% confidence intervals) of maternal outdoor and indoor smoking (vs nonsmoking mothers) were 1.21 (1.01-1.44) and 1.18 (1.04-1.33), respectively, in children between the ages of 6 and 18 months. We thus encourage a smoke-free home policy to protect children from second- and third-hand smoke exposure.

Association of maternal age with child health: A Japanese longitudinal study

Average maternal age at birth has been rising steadily in Western and some Asian countries. Older maternal age has been associated with adverse pregnancy and birth outcomes; however, studies on the relationship between maternal age and young children’s health remain scarce. Therefore, we sought to investigate the association of maternal age with child health outcomes in the Japanese population. We analyzed data from two birth cohorts of the nationwide Japanese Longitudinal Survey of Babies in 21^st Century (n₂₀₀₁ = 47,715 and n₂₀₁₀ = 38,554). We estimated risks of unintentional injuries and hospital admissions at 18 and 66 months according to maternal age, controlling for the following potential confounders: parental education; maternal parity, smoking status, and employment status; household income; paternal age, and sex of the child. We also included the following as potential mediators: preterm births and birthweight. We observed a decreasing trend in the risks of children’s unintentional injuries and hospital admissions at 18 months according to maternal age in both cohorts. In the 2001 cohort, compared to mothers <25 years, odds ratios of hospital admission at 18 months were 0.97 [95% CI: 0.86, 1.09], 0.92 [0.81, 1.05], 0.76 [0.65, 0.90], and 0.71 [0.51, 0.98] for mothers aged 25.0–29.9, 30.0–34.9, 35.0–39.9, and >40.0 years, respectively, controlling for confounders. Our findings were in line with previous findings from population-based studies conducted in the United Kingdom and Canada suggesting that older maternal age may be beneficial for early child health.

Bombyx mori E26 transformation-specific 2 (BmEts2), an Ets family protein, represses Bombyx mori Rels (BmRels)-mediated promoter activation of antimicrobial peptide genes in the silkworm Bombyx mori

E26 transformation-specific (Ets) family transcription factors are known to play roles in various biological phenomena, including immunity, in vertebrates. However, the mechanisms by which Ets proteins contribute to immunity in invertebrates remain poorly understood. In this study, we identified a cDNA encoding BmEts2, which is a putative orthologue of Drosophila Yan and human translocation-ets-leukemia/Ets-variant gene 6, from the silkworm Bombyx mori. Expression of the BmEts2 gene was significantly increased in the fat bodies of silkworm larvae in response to injection with Escherichia coli and Staphylococcus aureus. BmEts2 overexpression dramatically repressed B. mori Rels (BmRels)-mediated promoter activation of antimicrobial peptide genes in silkworm cells. Conversely, gene knockdown of BmEts2 significantly enhanced BmRels activity. In addition, two κB sites located on the 5' upstream region of cecropin B1 were found to be involved in the repression of BmRels-mediated promoter activation. Protein-competition analysis further demonstrated that BmEts2 competitively inhibited binding of BmRels to κB sites. Overall, BmEts2 acts as a repressor of BmRels-mediated transactivation of antimicrobial protein genes by inhibiting the binding of BmRels to κB sites.

Porphyromonas gingivalis infection exacerbates the onset of rheumatoid arthritis in SKG mice

Epidemiological studies have linked periodontitis to rheumatoid arthritis (RA). Porphyromonas gingivalis (Pg) was reported recently to produce citrullinated protein (CP) and increase anti-cyclic CP antibody (ACPA), both of which have been identified as causative factors of RA. In the present study, we determined the effects of Pg infection on the exacerbation of RA in a mouse model. RA model mice (SKG mice) were established by an intraperitoneal (i.p.) injection of laminarin (LA). Mice were divided into six groups, Ctrl (PBS injection), LA (LA injection), Pg/LA (Pg + LA injection), Pg (Pg injection), Ec/LA (Escherichia coli and LA injection) and Ec (E. coli injection). In order to evaluate RA, joint swelling by the arthritis score, bone morphology by microcomputed tomography (microCT), haematoxylin and eosin staining, ACPA, matrix metalloproteinase-3 (MMP-3) and cytokine level in serum by enzyme-linked immunosorbent assay were determined. Osteoclast differentiation from bone marrow mononuclear cells (BMCs) was examined to clarify the underlying mechanisms of RA. The presence of Pg and CP in joint tissue was also investigated. The arthritis score was threefold higher in the Pg/LA group than in the LA group. Severe bone destruction was observed in joint tissue of the Pg/LA group. A microCT analysis of the Pg/LA group revealed a decrease in bone density. ACPA, MMP-3, interleukin (IL)-2, IL-6, CXCL1 and macrophage inflammatory protein (MIP)-1α levels from the Pg/LA group were the highest. The osteoclastogenesis of BMCs was enhanced in the Pg/LA group. Furthermore, large amounts of Pg components and CP were detected in the Pg/LA group. In conclusion, Pg infection has the potential to exacerbate RA.

Risk factors for neutropenia with lenalidomide plus dexamethasone therapy for multiple myeloma

Neutropenia may develop as an adverse event in patients with multiple myeloma receiving lenalidomide (LEN) plus dexamethasone (DEX) therapy. In the present study, we examined the risk factors associated with grade 3/4 neutropenia during the first cycle of LEN plus DEX therapy. We observed that hemoglobin level (≤ 8.5 g/dl) was a significant risk factor for grade 3/4 neutropenia during the first cycle of therapy (odds ratio: 19.40; 95% confidence interval: 2.68-141.00; p < 0.01). thus, our findings suggest that determining the hemoglobin level could be useful in the risk management for neutropenia in patients receiving LEN plus DEX therapy.

Poor toddler-age sleep schedules predict school-age behavioral disorders in a longitudinal survey

OBJECTIVE

Behavioral problems are often associated with poor sleep habits in children. We investigated whether undesirable toddler-age sleep schedules may be related to school-age behavioral problems.

METHODS

We analyzed the data of a nationwide longitudinal survey with available results from 2001 to 2011. The participants were 41,890 children. The predictors were waking time and bedtime at 2years of age, and the outcomes were assessed by determining the presence or absence of three attention problems and four aggressiveness problems at 8years of age. In logistic regression models with adjustments for confounding factors, we estimated odds ratios (ORs) and confidence intervals (CIs) for the association between toddler sleep schedules and behavior during primary-school age years.

RESULTS

The outcomes of attention problems and aggressiveness problems were observed in 1.7% and 1.2% of children, respectively, at 8years of age. The OR of an irregular or late morning waking time at 2years of age with the outcome of aggressiveness problems was 1.52 (95% CI, 1.04-2.22) in comparison to an early waking time. The OR of an irregular or late bedtime with attention problems was 1.62 (95% CI, 1.12-2.36), and the OR of an irregular or late bedtime with aggressiveness problems was 1.81 (95% CI, 1.19-2.77) in comparison to an early bedtime.

CONCLUSION

Poor toddler-age sleep schedules were found to predict behavioral problems during primary-school age years. Thus, good and regular sleep habits appear to be important for young children's healthy development.

Decreased bone mineral density in diabetic patients on hemodialysis

Renal osteodystrophy in hemodialyzed patients with DM-HD shows different features from that in non-DM,HD. Two studies were done. One was a comparison of BMD in 30 non-DM,HD patients and 30 DM-HD patients. The second was a comparison of possible factors affecting calcium metabolism in the higher and lower BMD groups (n = 20/21) in the DM-HD patients. BMD was measured by dual-energy X-ray absorptiometry (DEXA; Hologic QDR 1,000/W) in the third lumbar vertebra (L3), head, pelvis, and whole body. The BMDs of the DM-HD group were lower in these areas and whole body than that in the non-DM,HD group. A significant difference was found in the head BMD (p less than 0.05). In the second study, factors which may contribute to the differences in BMD were compared in the DM-HD patients divided into higher and lower BMD of the head. The group with higher head BMD had a value 110% of the mean value or more. Clinical and biochemical test results (age, the time since the first dialysis, body weight, the degree of obesity, height, serum calcium, serum phosphate, serum aluminum, serum c-PTH level and the dose of 1 alpha-OH-D3) were compared. The degree of obesity of the patients with higher BMD was significantly larger than that with lower BMD (p less than 0.005).

Association of breast feeding with early childhood dental caries: Japanese population-based study

OBJECTIVES

We investigated the association between breastfeeding duration during the first half year of life and the risk of early childhood caries from the age of 30 to 66 months in Japan.

DESIGN

Observational study of a longitudinal survey.

SETTING

A secondary data analysis of the Japanese Longitudinal Survey of Babies in the 21st Century.

PARTICIPANTS

43,383 infants at the age of 6 months.

OUTCOME MEASURES

Early childhood caries--defined as a child's visit to a dentist for treatment of dental caries during the past 12 months--was ascertained from the caregiver from the age of 30 months in the survey. We estimated the risk of dental caries each year according to duration of breast feeding using logistic regression analyses. We controlled for a set of biological factors (birth weight, sex, parity and maternal age at delivery) and socioeconomic factors (maternal educational attainment and smoking status, marital status at delivery, family income and region of birth and residence).

RESULTS

We found that infants who had been breast fed for at least 6 or 7 months, both exclusively and partially, were at elevated risk of dental caries at the age of 30 months compared with those who had been exclusively formula fed. Adjusted ORs were 1.78 (95% CI, (1.45 to 2.17)) for the exclusively breastfed group and 1.39 (1.14 to 1.70) for the partially breastfed group. However, the associations became attenuated through the follow-up period and were no longer statistically significant beyond the age of 42 months for the partially breastfed group and beyond the age of 54 months for the exclusively breastfed group.

CONCLUSIONS

We found an association between breast feeding for at least 6 or 7 months and elevated risk of dental caries at age 30 months. However, the association became attenuated as children grew older.

Bovine Arboviruses in Culicoides Biting Midges and Sentinel Cattle in Southern Japan from 2003 to 2013

Epizootic congenital abnormalities, encephalomyelitis and febrile illnesses in cattle caused by arthropod-borne viruses (arboviruses) are prevalent in Japan. Causative viruses including orthobunyaviruses, orbiviruses and rhabdovirus are thought to be transmitted by Culicoides biting midges. Recently, the incursions of several arboviruses, potentially Culicoides-borne, were newly confirmed in Japan. However, their spread pattern and exact vector species are currently uncertain. Attempts to isolate arboviruses from Culicoides biting midges and sentinel cattle were conducted in Kagoshima, located at the southernmost end of the main islands of Japan, a potentially high-risk area for incursion of arboviral diseases and outbreak of endemic ones. Seventy-eight isolates comprising Akabane, Peaton and Sathuperi viruses of the genus Orthobunyavirus of the family Bunyaviridae, bluetongue virus serotype 16, D'Aguilar virus, Bunyip Creek virus and epizootic haemorrhagic disease virus serotype 1 of the genus Orbivirus of the family Reoviridae, a potentially novel rhabdovirus of the genus Ephemerovirus and unidentified orbivirus-like viruses were obtained from Culicoides biting midges and sentinel cattle between 2003 and 2013. Akabane, Sathuperi, D'Aguilar and Bunyip Creek viruses were selectively isolated from Culicoides oxystoma, suggesting this vector's responsibility for these arbovirus outbreaks. The results of virus isolation also implied that C. tainanus, C. jacobsoni and C. punctatus are competent for the transmission of bluetongue virus serotype 16, Peaton virus and epizootic haemorrhagic disease virus serotype 1, respectively. Our monitoring in Culicoides biting midges and sentinel cattle detected the circulation of Akabane virus just prior to the accumulations of bovine congenital abnormalities and encephalomyelitis by it around study sites in 2003, 2006, 2008 and 2013. Silent circulations of the other arboviruses, including potentially new viruses, were also detected during the study period.