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Elevated sperm mitochondrial DNA copy number (mtDNAcn) is associated with damage to sperm and poorer measures of semen quality. Exposure to cadmium (Cd) can increase oxidative stress and damage sperm mitochondria. The adverse effects of Cd can potentially be reduced by sufficient selenium (Se). The objective of this study was to examine the associations between sperm mtDNAcn and urinary concentrations of Cd, Se, and the Cd/Se molar ratio. Participants were recruited from patients who sought infertility treatment at two hospitals in Japan. Urine and semen specimens and self-administered questionnaires were collected on the day of recruitment. Sperm mtDNAcn was measured in extracted sperm DNA by multiplex real-time qPCR. Urinary Cd and Se concentrations were measured using inductively coupled plasma mass spectrometry. Cd/Se molar weights were calculated to obtain the molar ratio. Linear regression was used to predict associations after adjusting for age, BMI, smoking, drinking, exercise, varicocele, and hospital of recruitment. Sperm mtDNAcn showed statistically insignificant associations with urinary Cd (β = 0.13, 95% CI -0.18, 0.44), urinary Se concentration (β = -0.09, 95% CI -0.54, 0.35), and Cd/Se molar ratio (β = 0.12, 95% -0.13, 0.37). The current study did not find evidence of urinary Cd or Se concentrations or Cd/Se molar ratio being related to mtDNAcn.

The microbiome is believed to be established during the birthing process through exposure to the maternal microbiome and immediate external environment. The absence of a microbiome prior to birth is based on the sterile womb hypothesis, which was formulated at the beginning of the 20th century and is supported primarily by the culture-based approach in microbiological studies.Findings of bacterial presence in products of fertilization such as the placenta, amniotic fluid, foetal membranes, and umbilical cord blood in studies using next-generation DNA sequencing technologies began to challenge the sterile nature of the intrauterine environment during gestation. These studies have been mainly criticized by their approach to contamination and inconclusive evidence of viability. The implications of bacterial presence in utero are far reaching in medicine and basic sciences. If commensal bacteria exist in the foetus, antibiotic therapies in pregnancy particularly for asymptomatic cases will need to be re-evaluated. Experimental studies utilizing gnotobiology may also be impacted by a realignment of theory.This review of existing literature aims to provide insight into the existence of bacteria in utero, specifically the foetal microbiome through analysis of experimental evidence and theoretical concepts, and to suggest approaches that may further provide clarity into this inquiry.

Telomere length is thought to be a biomarker of biological aging. This study examined whether telomere length was associated with urinary concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative stress, and antioxidative trace elements in 73 female Japanese university students (age: 19.2 ± 0.7 years). We quantified 8-OHdG and selenium in urine by liquid chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry, respectively. Telomere length and urinary concentrations of other essential trace elements (molybdenum, cobalt, and chromium) that were previously measured in the same study participants, were used in this study. We used multiple linear regression analysis to examine the associations of telomere length with urinary 8-OHdG and essential trace element concentrations (covariates: urinary cotinine concentration, age, BMI, and drinking status). The geometric means (geometric standard deviation) of 8-OHdG and selenium were 3.4 (1.5) and 31 (1.3) µg/g creatinine, respectively. Telomere length was not associated with urinary 8-OHdG concentration, but was negatively associated with urinary selenium concentration. In conclusion, telomere length was not associated with urinary 8-OHdG concentration in the young women in this study. Longitudinal studies should be conducted to clarify the association between telomere shortening rate and oxidative stress level.

Thyroid functioning is an integral part of the endocrine system that supports conception and pregnancy. Frequent consumption of seafood and iodine by Japanese people may adversely affect their thyroid function. Thus, in this study, we aimed to analyze the associations between iodine intake, thyroid hormones, autoimmunity, and natural conception rates in Japanese women trying to conceive their first child. A prospective study of 24 weeks targeted 80 women with no history of infertility, who did not plan to undergo fertility treatment. Concentrations of urinary iodine concentration and thyroid biomarkers in the serum at enrollment were measured. Thirty-five women naturally conceived during the follow-up. The median (inter-quartile range) urinary concentration of iodine was 297 (165, 500) μg/L. Free triiodothyronine (T3) and free thyroxin (T4) negatively correlated with urinary iodine concentrations. Women with anti-thyroid peroxidase (anti-TPO) ≥ 16 IU/mL had lower conception rates (hazard ratio: 0.28, 95% confidence interval, 0.08–0.92) compared with those with anti-TPO < 16 IU/mL, after adjusting for age and coital frequency. None of anti-thyroglobulin antibody, free T3, free T4, or thyroid-stimulating hormone showed significant associations with conception rate after adjusting for age and coital frequency. The negative association between thyroid autoimmunity and natural conception rates warrants further investigation.

Arsenic exposure in postnatal life impacts the growth of children, but little is known about the effect of in-utero arsenic exposure on growth very early in childhood. The aim of this study was to ...

Fecundability, the probability of conception in a month or in a menstrual cycle, varies across and within age groups for both women and men. Fertility treatment has become common in a number of countries including Japan, but its impact on the age pattern of fecundability is unknown. By utilizing the previously collected data on time to pregnancy (TTP) of Japanese couples trying to conceive their first child, the present study aimed to estimate fecundability and sterility by women’s age and to assess how the estimates may differ by including or excluding assisted conceptions. Duration between discontinuing contraception and conception (including both natural and assisted) resulted in a live birth was called TTP-all, and the duration ending with natural conception was called TTP-natural. TTP-natural was censored when a participant received fertility consultation or treatment. A zero-inflated beta distribution model was used to estimate a proportion of sterile (zero probability of conception) and a distribution of fecundability for each age group. Parameters of the distribution were estimated using the maximum likelihood method. When TTP-all and TTP-natural were used, the sterile proportion of the whole sample was, respectively, 2% and 14%, and the median (interquartile range) of fecundability was, respectively, 0.10 (0.04, 0.19) and 0.11 (0.05, 0.19). The median (interquartile range) of fecundability was 0.18 (0.10, 0.29) for women aged 24 years or younger and 0.05 (0.02, 0.13) for 35–39 years old when TTP-all was used, and the estimates were quite similar with those based on TTP-natural: it was 0.18 (0.10, 0.29) for women aged 24 years or younger and 0.06 (0.00, 0.15) for 35–39 years old. Exclusion of assisted conceptions resulted in larger proportions of sterility, but it had little impact on median or interquartile ranges of fecundability estimates. Fecundability is overall lower at higher ages, while interquartile ranges are overlapping, suggesting that inter-individual variability of fecundability within an age group is as large as the variability across age groups.

Telomere length can be a biomarker of cumulative oxidative stress and inflammation indicating biological aging. Previous studies examined association of nutrient intake with telomere length targeting middle-aged and elderly individuals. This study examined whether dietary macro- and micronutrient intake was associated with telomere length in young females.Seventy-four Japanese young females (median (interquartile range) age was 19 (19 - 20) years) participated. We estimated their intake of nutrients (energy, protein, fat, carbohydrate, essential elements, vitamins, fatty acids, and dietary fibre) using a semi-quantitative food frequency questionnaire and measured telomere length (T/S ratio, the ratio of telomere repeat copy number (T) to single-copy gene number (S)) of DNA extracted from blood by qPCR. The association between telomere length and tertiles of nutrient intake were analysed.The median (interquartile range) of telomere length was 0.70 (0.52 - 0.98). Vitamin A intake was positively associated with telomere length (tertile 1 vs. 2, coefficient [95% confidence interval] = 0.42 [0.12, 0.71]; tertile 1 vs. 3, coefficient [95% confidence interval] = 0.33 [0.04, 0.62]) after adjusting for covariates (age, BMI, passive smoking, and drinking).Our findings suggest that variation in vitamin A intake might influence telomere attrition in healthy individuals.

Background: Low fertility persists but remains unexplained in Japan. We examined whether the probability of pregnancy was influenced by coital frequency, age, reproductive age (assessed by antim&uuml, llerian hormone, AMH), and BMI. Methods: We established a two-year prospective study with a sample of hormonally monitored Japanese women aged 23&ndash, 34 years wanting to conceive their first child. For a maximum of 24 weeks participants recorded menstrual bleeding, sexual intercourse, ovulation, and pregnancy. Additional information on pregnancy and infertility treatment was collected one and two years after intake. Results: The natural conception rate and coital frequency were both low in this sample. Among 80 participants, 44% (35) naturally conceived in 24 weeks. After two years, 74% (59) of women had delivered or were currently pregnant, 50% (40) due to natural and 24% (19) due to assisted conception, and 5% (4) were lost to follow-up. By two years, 56% (45) of women had sought fertility treatment. In 18% (58/319) of the observed ovarian cycles across 24 weeks there was no intercourse in a fertile period. Higher coital frequency at intake was associated with increased probability of conception by 24 weeks of follow-up (OR 1.23, 95%CI 1.02, 1.47). Chronological age, reproductive age, and BMI were not associated with the probability of pregnancy at 24 weeks. Conclusions: Our results suggest that first, natural conception rates could potentially increase with more frequent and well timed intercourse, and second that further work is needed to understand why even in a motivated sample of women monitoring their fertile periods, both the conception and coitus rates were low.

Cadmium is a toxic metal found ubiquitously throughout the world. Our study evaluated whether cadmium exposure was associated with telomere length in 73 female university students. Determination of telomere length was performed by quantitative polymerase chain reaction using DNA in blood. Urinary cadmium concentration was measured by inductively coupled plasma mass spectrometry. The students' physiological attributes and lifestyle were surveyed by means of a self-administered questionnaire. The geometric mean of urinary cadmium concentration was 0.312 μg/g creatinine, which was lower than the levels previously reported for Japan. Urinary cadmium concentration was not significantly associated with telomere length, though the exposure level of the present subjects was similar to that of previous study subjects which found significantly negative associations. It is possible that other factors affected telomere length in this study population.

AimsDeath ideation (thinking about/wishing for one's own death, thinking that one would be better off dead) is linked to an increased mortality risk. However, comparatively little is known about more general thoughts of death (GTOD) where no wish to die or life value is expressed. This study examined whether GTOD predicted mortality in a community-based cohort of older adults.MethodsData came from the Komo-Ise cohort study in Gunma prefecture, Japan. The analytic sample comprised 8208 individuals (average age 61.3 (range 47–77)) who were asked in wave 2 of the study in 2000 if they had ‘Thought about death more than usual, either your own, someone else's or death in general?’ in the past 2 weeks. Death data were obtained from the municipal resident registration file. Cox proportional hazards regression analysis was used to examine associations.ResultsDuring the follow-up period (2000–2008), there were 672 deaths. In a model adjusted for baseline covariates, GTOD were significantly associated with all-cause mortality (hazards ratio 1.66, 95% confidence interval 1.20–2.29). Stratified analyses showed an association between GTOD and mortality in men, older subjects (⩾70 years), married individuals and those with higher social support.ConclusionsGTOD are associated with an increased mortality risk among older citizens in Japan. Research is now needed to determine the factors underlying this association and assess the clinical relevance of screening for GTOD in older individuals.

We evaluated the representativeness of concentrations of parabens in a spot urine sample for the assessment of long-term exposure levels. Urine sample was taken monthly from 10 male Japanese subjects (35.9 ± 6.8 years) and 12 female Japanese university students (21.1 ± 0.4 years) for 5 months and measured for methyl (MP), ethyl (EP), propyl (PP) and butyl (BP) parabens by liquid chromatography–tandem mass spectrometry. Median (min–max) specific-gravity-adjusted urinary concentrations of the male group (n = 10) were 39.7 (2.99–268), 1.69 (< 0.045–75.2), 0.569 (< 0.11–123) and 0.0264 (< 0.020–24.4) ng mL−1 for MP, EP, PP and BP, respectively. Those of the female group (n = 12) were 283 (5.49–1687), 9.30 (0.290–487), 22.9 (< 0.11–307) and 3.76 (< 0.020–135) ng mL−1, respectively, which were significantly higher than those of the male group. Intra-class correlation coefficients (ICCs) were calculated for the four parabens to find 0.56, 0.58, 0.39 and 0.28 for MP, EP, PP and BP, respectively, in the ma...

Aim Secular trends of preterm birth in Japan between 1979 and 2014 were examined to determine whether changes could be explained by a shift in the distribution of maternal age at delivery and parity and/or by changes in age-specific preterm birth rates. Methods Live birth data for 1979 to 2014 were obtained from the Japanese Ministry of Health, Labour and Welfare. Analyses were limited to singleton children born in Japan (n = 43 632 786). Preterm birth was defined using two cut-offs at < 37 or < 34 weeks of gestation. Crude and standardized rates of preterm birth were calculated for firstborn and later-born singletons by maternal age at delivery for specific time periods. Results Throughout the study period, the rates of preterm birth (both at < 37 and < 34 weeks of gestation) were higher among mothers aged 20 and younger, and mid-30s and older, compared to mothers in their 20s or early 30s. The rates of preterm birth at < 37 (but not at < 34) weeks decreased for mothers aged in their late 30s and 40s, and increased for mothers in their 20s and early 30s. Standardized rates of preterm birth showed a secular increase for preterm births at < 37 but not < 34 weeks of gestation. Conclusion The rates of preterm birth among mothers aged in their 20s and early 30s increased between 1979 and 2014, which contributed to the secular increase in rates of preterm birth at < 37 weeks.

Background Previous studies have revealed the interactive effects of airborne pollen and particulate matter on the daily consultations for pollinosis, but it is uncertain which compositions are responsible. This study aimed to investigate the interactive effects of specific PM2.5 compositions and airborne pollen on the daily number of clinic visits for pollinosis in Fukuoka. Methods We obtained daily data on pollen concentrations, PM2.5 compositions, PM2.5 mass, gaseous pollutants (SO2, NO2, CO, and O3), and weather variables monitored in Fukuoka between February and April, 2002–2012. In total, 73,995 clinic visits for pollinosis were made at 10 clinics in Fukuoka Prefecture during the study period. A time-stratified case-crossover design was applied to examine the interactive effects. The concentrations of PM2.5 and its compositions were stratified into low ( 85th percentile) levels, and the association between airborne pollen and daily clinic visits for pollinosis was analyzed within each level. Results We found a significant interaction between specific PM2.5 compositions and airborne pollen. Specifically, the odds ratio of daily clinic visits for pollinosis per interquartile increase in pollen concentration (39.8 grains/cm2) at the average cumulative lag of 0 and 2 days during high levels of non-sea-salt Ca2+ was 1.446 (95% CI: 1.323–1.581), compared to 1.075 (95% CI: 1.067–1.083) when only moderate levels were observed. This result remained significant when other air pollutants were incorporated into the model and was fairly persistent even when different percentile cut-off points were used. A similar interaction was found when we stratified the data according to non-sea-salt SO42- levels. This finding differed from estimates made according to PM2.5 and NO3- levels, which predicted that the effects of pollen were strongest in the lower levels. Conclusions Associations between airborne pollen and daily clinic visits for pollinosis could be enhanced by high levels of specific PM2.5 compositions, especially non-sea-salt Ca2+.

Higher concentrations of oxidative stress biomarkers are found in women with polycystic ovary syndrome (PCOS) and endometriosis, conditions linked to irregular menstrual cycles and menstrual pain. The aim of the present study was to test whether women with higher oxidative stress are more likely to show irregular menstrual cycles and severe menstrual pain compared with women with lower oxidative stress. A cross-sectional study was conducted targeting female university students with a mean (SD) age of 20.5 (1.8) years (n = 188). Participants completed a questionnaire on reproductive characteristics and anthropometry and kept a menstrual cycle diary for 5 consecutive months. Urinary 8-hydroxy-2&prime, deoxyguanosine (8-OHdG), cotinine, and creatinine concentrations were measured once during the study period. The mean (SD) value of the urinary 8-OHdG concentration was 4.7 (2.0) &mu, g/g of creatinine. A total of 1021 menstrual cycles were recorded. The participants were categorized as either having regular (68%) or irregular (18%) cycles or oligomenorrhea (13%) or polymenorrhea (1%). The urinary 8-OHdG concentration did not significantly differ across menstrual cycle regularity or pain categories. Even after adjusting for age, body mass index (BMI), and urinary cotinine concentrations, having irregular cycles or more severe menstrual pain was not associated with urinary 8-OHdG concentration.

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 ( 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.

OBJECTIVES Elevated and suppressed concentrations of cortisol have been linked with less favorable metabolic biomarkers, such as elevated lipids and glycosylated hemoglobin (HbA1c). Based on recent work reporting that some individuals secrete more cortisol into saliva (high saliva-to-blood cortisol ratio; high secretors) than others after correcting for blood cortisol concentrations, our objectives were to examine (1) whether lipids and glycosylated hemoglobin varied across cortisol and salivary secretor status; and (2) if blood and saliva provide the same results with respect to metabolic markers. METHODS Matched saliva and dried blood spot (DBS) specimens collected once a week for four weeks (N = 48 healthy women, 192 specimens) were assayed for cortisol. Fasting blood specimens collected once from each woman were quantified for cholesterol (total, HDL, LDL), triglycerides and HbA1c. RESULTS Low salivary cortisol secretors showed significantly higher triglyceride and HbA1c compared to high-secretors (P

OBJECTIVES To acquire fundamental knowledge on menstrual cycle and its intraindividual variation in healthy Japanese female students and their association with biological attributes, lifestyle and food habit. METHODS We asked female students of a nursing school to keep a diary of their menstruation over 5 consecutive months and to fill a questionnaire on their biological attributes, lifestyle and consumption frequency of some food items during the period from November 2012 to January 2014. RESULTS The mean±standard deviation (SD) of cycle lengths of 180 women (20.4±0.9 yrs) was 34.2±10.5 days. Of these 180 women, 141 had a cycle length within the normal range (25-38 days) while 10 had a shorter cycle and 20 had a longer cycle. The intraindividual variations of the cycle, defined as "range" (difference between the longest and shortest cycles of an individual) and "SD" (SD of mean of multiple lengths within an individual), were 11.4±10.3 and 7.9±11.8 days, respectively. Of 177 women, 73 and 109 had normal range and SD (≤6 days), respectively. The mean age of women with long cycles was older than that of women with short cycle (Kruscal-Wallis test, p

In the earlier chapters of this book, we have shown, with limited evidence, that both the duration of lactational infecundability and time to pregnancy (TTP) may be longer among Japanese couples than among Western couples. Longer TTP can be linked to the relatively low coital frequency and prolonged duration of lactation found in couples and mothers in Japan, as well as to other factors such as long work hours, underweight, and overweight. The relatively longer TTP may be linked to the frequent use of ART among couples in Japan. Efficient use of ART, in terms of who should utilize these technologies and at what time, should be investigated in future studies to better meet couples’ needs. We confirm the widely held notions that many Japanese couples continue to rely on unreliable contraception and that induced abortion is common among both married and unmarried women. Conceptions that end in artificial abortions could have a significant impact on fertility trends in Japan if social and other circumstances allowed some of those conceptions to result in live births. It is also important to investigate the biological and sociocultural factors—e.g., exposure to chemical substances, body size, educational level, and working conditions—that may explain variations in TTP and other proximate determinants of fertility. In addition, a model-based approach would enable us to estimate the level of change in each sociocultural factor that would lead to changes in fertility through the modification of proximate determinants. We believe that the accumulation of such data will help us to understand why low levels of fertility persist in Japan.

Proximate determinants link both social and biological factors to fertility. In this section, we will summarize available data related to proximate determinants of fertility in Japan while referring to some of the related literature targeting populations overseas. In addition to data from published studies, we present our original data collected in the biodemography project, an Internet-based cross-sectional survey on reproductive history conducted in 2014 targeting Japanese women between 20 and 44 years of age. Following Wood’s conceptualization, the specific components of the proximate determinants of fertility referred to in this chapter are lactational infecundability, fecund waiting time to conception, and fetal loss (both spontaneous and induced). Additionally, papers on factors that are expected to significantly affect fecund waiting time to conception, i.e., frequency of sexual intercourse, length and regularity of menstrual cycle, and use of contraception and infertility treatment, will be reviewed.

BackgroundProspective cohort studies of contemporary populations in both Western and Asian settings have reported a U-shaped association between fertility and mortality. We examined whether an association exists between fertility and all-cause and cause-specific mortality in a sample of Japanese women.MethodsA prospective cohort study was conducted in one rural and one urban community in Gunma Prefecture, Japan, in 1993. A follow-up survey was conducted in the year 2000 in 4858 women aged 47–77 years, and information on demographic and lifestyle characteristics was collected. Mortality and migration data through December 2008 were obtained. A Cox proportional hazard model was used to examine the relationship between parity and mortality.ResultsCompared with women with 2–4 children (reference group), higher total mortality was observed among women with 0–1 or 5+ children. Low (HR 1.7, 95% CI 1.2 to 2.3) and high (HR 2.1, 95% CI 1.0 to 4.7) parities were both associated with higher all-cause mortality even after adjusting for potential confounders. Mortality due to ischaemic heart disease exhibited a significant association with parity; the HRs were 3.2 (95% CI 1.1 to 9.2) for women with 0–1 child and 8.7 (95% CI 1.7 to 45.5) for women with 5 or more children. No significant association was observed for mortality from malignancies, cancer of the digestive system, cardiovascular disease or cerebrovascular disease.ConclusionsThere exists a U-shaped association between parity and all-cause mortality and cause-specific mortality due to ischaemic heart disease among Japanese women.

Secular trends of preterm birth in Japan between 1979 and 2014 were examined to determine whether changes could be explained by a shift in the distribution of maternal age at delivery and parity and/or by changes in age-specific preterm birth rates.Live birth data for 1979 to 2014 were obtained from the Japanese Ministry of Health, Labour and Welfare. Analyses were limited to singleton children born in Japan (n = 43 632 786). Preterm birth was defined using two cut-offs at37 or34 weeks of gestation. Crude and standardized rates of preterm birth were calculated for firstborn and later-born singletons by maternal age at delivery for specific time periods.Throughout the study period, the rates of preterm birth (both at37 and34 weeks of gestation) were higher among mothers aged 20 and younger, and mid-30s and older, compared to mothers in their 20s or early 30s. The rates of preterm birth at37 (but not at34) weeks decreased for mothers aged in their late 30s and 40s, and increased for mothers in their 20s and early 30s. Standardized rates of preterm birth showed a secular increase for preterm births at37 but not34 weeks of gestation.The rates of preterm birth among mothers aged in their 20s and early 30s increased between 1979 and 2014, which contributed to the secular increase in rates of preterm birth at37 weeks.

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).

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 5426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in-house enzyme immunoas- say (EIA). Sex- and age-group-specific CRP quartiles were used to examine its association with growth in lin- ear 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 elimi- nating the expected trade-off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggest- ing that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a posi- tive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low- grade inflammation due to body fat rather than infec- tion. The association between CRP and growth was less evident among children (6-12 years) compared with ado- lescents, indicating that the elevated energy require- ment needed for the adolescent growth spurt and puberty may play some role. Am J Phys Anthropol

Background: Ambient temperature affects mortality in susceptible populations, but regional differences in thisassociation remain unclear in Japan. We conducted a time-series study to examine the variation in the effects ofambient temperature on daily mortality across Japan.Methods: A total of 731558 all-age non-accidental deaths in 6 cities during 2002–2007 were analyzed. Theassociation between daily mortality and ambient temperature was examined using distributed lag nonlinear modelswith Poisson distribution. City-specific estimates were combined using random-effects meta-analysis. Bivariaterandom-effects meta-regressions were used to examine the moderating effect of city characteristics.Results: The effect of heat generally persisted for 1 to 2 days. In warmer communities, the effect of cold weatherlasted for approximately 1 week. The combined increases in mortality risk due to heat (99th vs 90th percentile of city-specific temperature) and cold (first vs 10th percentile) were 2.21% (95% CI, 1.38%–3.04%) and 3.47%(1.75%–5.21%), respectively. City-specific effects based on absolute temperature changes were more heterogeneousthan estimates based on relative changes, which suggests some degree of acclimatization. Northern populations witha cool climate appeared acclimatized to low temperature but were still vulnerable to extreme cold weather. Populationdensity, average income, cost of property rental, and number of nurses appeared to influence variation in heat effectacross cities.Conclusions: We noted clear regional variation in temperature-related increases in mortality risk, which should beconsidered when planning preventive measures.Key words: heat; cold; mortality; time-series; distributed lag

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

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.

Elevated and suppressed concentrations of cortisol have been linked with less favorable metabolic biomarkers, such as elevated lipids and glycosylated hemoglobin (HbA1c). Based on recent work reporting that some individuals secrete more cortisol into saliva (high saliva-to-blood cortisol ratio; high secretors) than others after correcting for blood cortisol concentrations, our objectives were to examine (1) whether lipids and glycosylated hemoglobin varied across cortisol and salivary secretor status; and (2) if blood and saliva provide the same results with respect to metabolic markers.Matched saliva and dried blood spot (DBS) specimens collected once a week for four weeks (N = 48 healthy women, 192 specimens) were assayed for cortisol. Fasting blood specimens collected once from each woman were quantified for cholesterol (total, HDL, LDL), triglycerides and HbA1c.Low salivary cortisol secretors showed significantly higher triglyceride and HbA1c compared to high-secretors (P0.05; t-test). The only significant correlation with mean blood or salivary cortisol concentration was a negative correlation between salivary cortisol and HbA1c (P = 0.021, r = -0.333).Triglycerides, HDL, and especially HbA1c were associated with salivary cortisol secretor status but not with DBS cortisol concentrations. These results suggest that blood and saliva cortisol measures might provide different health outcome information, and that salivary cortisol secretor status may provide additional information on health status. Am. J. Hum. Biol. 28:539-544, 2016. © 2016 Wiley Periodicals, Inc.

Injury is the leading cause of death among children and adolescents in Japan. Despite this, until now there has been comparatively little research on this phenomenon. The purpose of this study was to examine if there was seasonal variation in child and adolescent injury mortality in Japan in 2000–2010. Vital statistics injury mortality data were obtained from the Ministry of Health, Labour and Welfare of Japan. The seasonality of the major causes of unintentional injury (transport accidents, drowning and suffocation) and intentional injury (suicide and homicide) mortality was examined for children and adolescents aged 0–19. Incidence ratios (IR) with 95 % confidence intervals (CI) were calculated to determine the difference between the numbers of observed and expected seasonal deaths. The annual average injury mortality rate among children and adolescents was 9.0 per 100,000. Deaths from transport accidents, drowning, suffocation and suicide had a significant seasonality. There was a summer peak for transport accidents (IR 1.15, 95 % CI 1.10–1.19) and drowning (IR 2.00, 95 % CI 1.88–2.11), a spring peak for suicide (IR 1.09, 95 % CI 1.04–1.14), while the incidence of suffocation was higher in winter (IR 1.12, 95 % CI 1.03–1.21). Child and adolescent injury mortality from transport accidents, drowning, suffocation and suicide has a pronounced seasonality in Japan. More research is now needed to find the circumstances underpinning different forms of injury mortality in different periods of the year so that effective interventions can be designed and implemented to reduce the burden of injury mortality among Japanese children.

Background: There is debate about whether excess winter deaths (EWD) decline in temperate countries as winters warm. While most populations in the world are now experiencing aging and older people ...

Objective To examine the association between antimullerian 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.

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.

Tongan adults show one of the highest prevalences of obesity in the world. The present study aims to estimate Tongans' energy and nutrient intakes and food sources using a 24-hour recall survey for 14 days targeting 15 men and 19 women. The mean (SD) daily energy intake was 12.2 (2.3) MJ for men and 10.6 (2.2) MJ for women. Imported foods accounted for about half of their energy and macronutrient intakes, but for much less of their micronutrients. Some local food items, specifically pork, kava, and sea hare, contributed significantly to their vitamin, Fe, and Ca intakes, respectively. These findings suggest that heavy reliance on imported foods can lead not only to a high prevalence of obesity, but also to micronutrient deficiencies.