Shoko Konishi

Particulate matter modifies the association between airborne pollen and daily medical consultations for pollinosis in Tokyo

Pollen from Japanese cedar (sugi) and cypress (hinoki) trees is responsible for the growing prevalence of allergic rhinitis, especially pollinosis in Japan. Previous studies have suggested that air pollutants enhance the allergic response to pollen in susceptible individuals. We conducted a time-stratified case-crossover study to examine the potential modifying effects of PM2.5 and suspended particulate matter (SPM) on the association between pollen concentration and daily consultations for pollinosis. A total of 11,713 daily pollinosis cases (International Classification of Diseases, ICD-10, J30.1) from January to May, 2001-2011, were obtained from a clinic in Chiyoda, Tokyo. Daily pollen counts and the daily mean values of air pollutants (PM2.5, SPM, SO2, NO2, CO, and O3) were collected from monitoring stations across Tokyo. The effects of pollen were stratified by the level of PM2.5 and SPM to examine the interaction effect of pollen and particulate pollutants. We found a statistically significant interaction between pollen concentration and PM2.5/SPM. On days with a high level of PM2.5 (>95th percentile), an interquartile increase in the mean cumulative pollen count (an average of 28 pollen grains per cm(2) during lag-days 0 to 5) corresponded to a 10.30% (95%CI: 8.48%-12.16%) increase in daily new pollinosis cases, compared to 8.04% (95%CI: 7.28%-8.81%) on days with a moderate level of PM2.5 (5th-95th percentile). This interaction persisted when different percentile cut-offs were used and was robust to the inclusion of other air pollutants. A similar interaction pattern was observed between SPM and pollen when a less extreme cut-off for SPM was used to stratify the effect of pollen. Our study showed the acute effect of pollen was greater when the concentration of air particulate pollutant, specifically PM2.5 and SPM, was higher. These findings are consistent with the notion that particulate air pollution may act as an adjuvant that promotes allergic disease (i.e. pollinosis).

Ambient air pollution and suicide in Tokyo, 2001–2011

BACKGROUND Some evidence suggests an association may exist between the level of air pollution and suicide mortality. However, this relation has been little studied to date. The current study examined the association in Tokyo, Japan. METHODS Suicide mortality data for Tokyo for the 11-year period 2001-2011 were obtained together with data on four air pollutants: fine particulate matter (PM2.5), suspended particulate matter (SPM), sulphur dioxide (SO2) and nitrogen dioxide (NO2). A time-stratified case-crossover study design was used to examine the daily association between the level of air pollution and suicide mortality. RESULTS During the study period there were 29,939 suicide deaths. In stratified analyses an interquartile range (IQR) increase in the same-day concentration of NO2 was linked to increased suicide mortality among those aged under 30 (percentage change: 6.73%, 95% CI: 0.69-13.12%). An IQR increase in PM2.5 and SO2 was associated with a 10.55% (95% CI: 2.05-19.75%) and 11.47% (95% CI: 3.60-19.93%) increase, respectively, in suicide mortality among widowed individuals for mean exposure on the first four days (average lags 0-3). Positive associations were observed for the air pollutants in the summer although associations were reversed in autumn. LIMITATIONS We relied on monitoring data to approximate individual exposure to air pollutants. CONCLUSIONS Higher levels of air pollution are associated with increased suicide mortality in some population subgroups in Tokyo. Further research is needed to elucidate the mechanisms linking air pollutants and suicide in this setting.

Association between paraben exposure and menstrual cycle in female university students in Japan.

Parabens have been known to have estrogenic activity in many in vivo and in vitro studies and biomonitoring data indicated ubiquitous exposure in general populations. However, there are few human studies on reproductive effects of parabens. In this study, menstrual cycle length and its intra-individual variation were investigated by bleeding record over the period of 5 months and urinary concentrations of parabens were measured for 128 female Japanese university students. We found significantly negative relationships between menstrual cycle length and urinary estrogen-equivalent total paraben (odds=0.73, 95% CI 0.56-0.96) and butyl paraben concentrations (odds=0.83, 0.70-0.99), which indicated shortened cycle length in women with high urinary paraben concentrations. This study indicated that paraben exposure at not excessive levels is associated with menstrual cycle length or its variability among general female subjects. These results suggest a possibility that parabens exposure is one of the environmental causes of human reproductive problem.

Differences in the responses of three plasma selenium-containing proteins in relation to methylmercury-exposure through consumption of fish/whales.

Putative protective effects of selenium (Se) against methylmercury (MeHg) toxicity have been examined but no conclusion has been reached. We recently reported the lack of serious neurological symptoms in a Japanese fish-eating population with high intakes of MeHg and suggested a potential protective role for Se. Here, relationships between levels of Hg and Se in the blood and plasma samples, with a quantitative evaluation of Se-containing proteins, obtained from this population were examined. While levels of the whole-blood Hg (WB-Hg) and plasma Se (P-Se) showed a positive correlation, stratified analysis revealed that they correlated only in samples with higher (greater than the median) levels of MeHg. A food frequency questionnaire showed that consumption of fish/whales correlated with WB-Hg, but not with P-Se, suggesting that the positive correlation between WB-Hg and P-Se might not be the result of co-intake of these elements from seafood. Speciation of plasma Se revealed the differences in the responses of two plasma selenoproteins, glutathione peroxidase (GPx) and selenoprotein P (SePP), in relation to Hg exposure. In the high-Hg group, SePP showed a positive correlation with WB-Hg, but GPx did not. In the low-Hg group, neither SePP nor GPx showed any correlation with WB-Hg. These observations suggest that the increase in P-Se in the high-Hg group might be associated with an increase in SePP, which may, in turn, suggest an increased demand for one or more selenoproteins in various organs, for which SePP supplies the element.

Salivary Concentration of Progesterone and Cortisol Significantly Differs Across Individuals After Correcting for Blood Hormone Values

Between-individual variation of salivary progesterone (P4) and cortisol levels does not always closely reflect blood hormone concentrations. This may be partly a function of individual differences in salivary hormone excretion. We tested whether time of day at sampling and ethnicity contributed to individual variation in salivary hormones after adjusting for blood hormone levels. Forty-three Caucasian and 15 Japanese women (18-34 years) collected four sets of matched dried blood spot (DBS) and saliva specimens across a menstrual cycle (N = 232 specimen sets). Linear fixed-effects (LFE) models were used to estimate the effects of diurnal variation and ethnicity on salivary P4 and cortisol while adjusting for DBS levels. For each hormone, women with exclusively positive or negative residuals (unexplained variance) from the LFE models were categorized as high- or low-saliva-to-DBS hormone ratio (SDR; high or low salivary secretors), respectively. We found that salivary P4 (P < 0.05) was significantly higher in early morning compared to the afternoon, after controlling for DBS levels, ethnicity, and BMI. After further adjusting for this diurnal effect, significant individual variation in salivary P4 and cortisol remained: sixteen and nine women, respectively were categorized as low or high salivary secretors for both hormones (P < 0.001), suggesting systematic individual-specific variation of salivary hormonal concentration. We conclude that when saliva is used to quantify P4 or cortisol levels, time of day at sampling should be controlled. Even with this adjustment, salivary P4 and cortisol do not closely mirror between- individual variation of serum P4 and cortisol in a substantial proportion of individuals.

Significant sex difference in the association between C-reactive protein concentration and anthropometry among 13- to 19-year olds, but not 6- to 12-year olds in Nepal

Life history theory predicts a trade-off between immunostimulation and growth. Using a cross-sectional study design, this study aims to test the hypothesis that C-reactive protein (CRP) is negatively associated with height-for-age z-scores (HAZ scores) and BMI-for-age z-scores (BAZ scores) among 6- to 19-year olds (N = 426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in-house enzyme immunoassay (EIA). Sex- and age-group-specific CRP quartiles were used to examine its association with growth in linear mixed-effects (LME) models. A significant difference was found in the proportion of elevated CRP (>2 mg/L, equivalent to ∼3.2 mg/L serum CRP) between 13- and 19-year-old boys (12%) and girls (4%). Concentrations of CRP were positively associated with HAZ score among adolescent (13-19 years) boys, which may indicate that individuals with greater energy resources have better growth and a better response to infections, thus eliminating the expected trade-off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggesting that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a positive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low-grade inflammation due to body fat rather than infection. The association between CRP and growth was less evident among children (6-12 years) compared with adolescents, indicating that the elevated energy requirement needed for the adolescent growth spurt and puberty may play some role.

airborne pollen and suicide mortality in Tokyo, 2001–2011

&NA; Prior research has indicated that pollen might be linked to suicide mortality although the few studies that have been undertaken to date have produced conflicting findings and been limited to Western settings. This study examined the association between the level of airborne pollen and suicide mortality in Tokyo, Japan in the period from 2001 to 2011. The daily number of suicide deaths was obtained from the Japanese Ministry of Health, Labour and Welfare, with pollen data being obtained from the Tokyo Metropolitan Institute of Public Health. A time‐stratified case‐crossover study was performed to examine the association between different levels of pollen concentration and suicide mortality. During the study period there were 5185 male and 2332 female suicides in the pollen season (February to April). For men there was no association between airborne pollen and suicide mortality. For women, compared to when there was no airborne pollen, the same‐day (lag 0) pollen level of 30 to <100 grains per cm2 was associated with an approximately 50% increase in the odds for suicide (e.g. 30 to <50 grains per cm2: odds ratio 1.574, 95% confidence interval 1.076–2.303, p=0.020). The estimates remained fairly stable after adjusting for air pollutants and after varying the cut‐points that defined the pollen levels. Our results indicate that pollen is associated with female suicide mortality in Tokyo. HighlightsPrior research has indicated that airborne pollen may be associated with suicide.In Tokyo in 2001–2011 the level of airborne pollen was linked to suicide mortality.Only female suicide was associated with the level of airborne pollen.

Prevalence and risk factors of soil-transmitted helminth infection in Nepal.

BACKGROUND The purpose of this study is to evaluate the prevalence and intensity and examine the risk factors of soil transmitted helminth (STH; i.e., roundworm [Ascaris lumbricoides], hookworms [Ancylostoma duodenale and Necator americanus], and whipworm [Trichuris trichiura]) infections in Nepal. METHODS Five hundred and ninety-four adults (256 men and 338 women) were selected via convenience sampling from five communities in Nepal. The Kato-Katz method was used to assess the prevalence and intensity of STH infection in this population. RESULTS Prevalence of STH infection ranged from 3.3% in Birendranagar in Chitwan, 3.5% in Kuleshor in Kathmandu, 11.7% in Kanyam in Ilam, 17.0% in Dhikurpokhari in Kaski and 51.4% in Khokana in Lalitpur District [corrected]. Multivariable regression analysis revealed that not using soap for hand-washing was significantly associated with the prevalence and infection intensity of roundworm, hookworms and whipworm. Similarly, not wearing sandals or shoes outside was significantly associated with the prevalence and infection intensity of roundworm and hookworms, but not with infection intensity of whipworm. Literacy, being underweight or overweight, anemia and occupation were not associated with prevalence and intensity of roundworm and hookworms infection, but there was an association between occupation and the prevalence of whipworm infection. CONCLUSION STH infection was associated with individual hygiene behavior, but not with nutritional status or socio-demographic characteristics. Health policy focusing on changing individual hygiene behaviors might be useful in addressing STH infection in Nepal.

Association of antimüllerian hormone levels with menstrual-cycle type and dysmenorrhea in young asymptomatic women

OBJECTIVE To examine the association between antimüllerian hormone (AMH) levels and menstrual-cycle and lifestyle characteristics among young Japanese women. DESIGN Cross-sectional study. SETTING University. PATIENT(S) Female students aged 20-22 years (n=65) who had never used oral contraceptives. INTERVENTION(S) Participants completed a questionnaire on reproductive and lifestyle characteristics, and kept a menstrual-cycle diary for 5 consecutive months. Serum AMH was measured once during the study period. MAIN OUTCOME MEASURE(S) Serum AMH concentration. RESULT(S) Compared with women with very mild menstrual pain, serum AMH concentration was 49.6% (95% CI 6.5%-72.8%) lower among women with severe menstrual pain. Higher AMH concentration was associated with irregular menstrual cycles. Even after adjusting for menstrual-cycle regularity and its interaction, more-severe menstrual pain was associated with significantly lower AMH concentration. CONCLUSION(S) Circulating AMH concentration was significantly lower among young Japanese women who had more-severe menstrual pain. Underlying physiological mechanisms need to be addressed in future studies.

Association between short-term exposure to fine particulate matter and daily emergency room visits at a cardiovascular hospital in Dhaka, Bangladesh

BACKGROUND It has been suggested that exposure to fine particulate matter (PM2.5) adversely affects cardiovascular health. However, the effect modifications by individual characteristics and season have been less studied in developing countries where PM2.5 levels are high. OBJECTIVES To estimate the risks of cardiovascular emergency room visits in relation to daily concentrations of PM2.5 and to assess how these associations can be modified by age, sex, and nutritional status of patients and by season. METHODS The analytic sample was 6774 adults who visited the emergency room at a cardiovascular disease (CVD) hospital in Dhaka throughout one year (n = 364 days). A time-stratified case-crossover design with conditional Poisson regression analysis was used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) of visits while adjusting for temperature. Stratification was performed by gender, age (<65 and ≥65 years), BMI (underweight, normal weight, overweight), and season (dry summer: February to April; wet summer: May to October; dry winter: November to January). RESULTS The mean concentration of PM2.5 was 86.1 μg/m3. An IQR increase (103 μg/m3) in PM2.5 at lag 3 was significantly associated with a 12% (RR: 1.12; 95% CI: 1.01-1.23) increase in CVD emergency room visits. No evidence of association was found for the other lags. Underweight and overweight patients showed evidence of increased risk at lag 2 (RR: 1.31; 95% CI: 1.02-1.67) and lag 4 (RR: 1.20; 95% CI: 1.04-1.39), respectively. CONCLUSION Increases in the daily concentrations of PM2.5 may lead to more cardiovascular emergency room visits in Dhaka, Bangladesh. Response times from ambient exposure to CVD emergency visits may differ by season and the nutritional status of susceptible individuals, necessitating further research.