Analyses Do Not Support CYP17 Genotype-Estradiol Associations--In Response

In Response: Vitzthum and Thornburg’s comments seem to reflect a basic misunderstanding of our paper and its results. As noted in the title of the article, we document an association between CYP17 genotypes and salivary estradiol levels. Variation in follicular steroidogenesis, up to and including ovulatory failure, is precisely the variation we are studying. To remove anovulatory cycles from the sample would be to remove a principal source of variance in estradiol levels between women, a source of variation with direct implications for breast cancer risk. Vitzthum and Thornburg are also incorrect in their assertion that our statistical methods are flawed. In the repeated-measures ANOVA, the univariate F statistic may be safely used when accompanied by appropriate adjustments (Geisser-Greenhouse and Huynh-Feldt) to the degrees of freedom (even if the sphericity requirement is not met). In the article, we provided P values obtained under both types of adjustment. Our use of the Wilcoxon signed-rank test adhered strictly to the assumptions specified in the principal textbook of biostatistical methods by Sokal and Rohlf (2).AnthropologyHuman Evolutionary Biolog

Digit ratio (2D:4D) and circulating testosterone, oestradiol, and progesterone levels across the menstrual cycle.

BACKGROUND: Digit ratio (2D:4D) is used by researchers as an indicator of prenatal sex hormone exposure. Two previous studies have examined associations between 2D:4D and circulating sex steroid concentrations across the menstrual cycle in adult females. One reported that digit ratio correlated positively with oestradiol levels, whereas the other found no such effect; neither observed significant associations with progesterone. AIMS: To examine associations between 2D:4D, as well as asymmetry (i.e. right minus left 2D:4D), and circulating sex steroids across the menstrual cycle. STUDY DESIGN: Correlational. SUBJECTS: 32 naturally cycling adult females from rural southern Poland. OUTCOME MEASURES: Salivary oestradiol, progesterone, testosterone, and testosterone to oestradiol ratio (T:O) measured during the follicular, peri-ovulatory, and luteal phases. Average levels across the cycle were also examined. RESULTS AND CONCLUSIONS: Asymmetry in digit ratio correlated positively with oestradiol at each phase, as well as with average levels across the cycle. Each association, other than that relating to average levels, remained statistically significant after a range of covariates had been controlled for. No other significant correlations were observed between digit ratio variables and circulating hormone levels. Our results might suggest that low exposure to androgens and/or high exposure to oestrogens during gestation is a predictor of high oestradiol levels in naturally cycling females of reproductive age. However, considering that it was asymmetry in digit ratio, and not either right or left 2D:4D, that was a significant predictor, it is also possible that these effects reflect more general associations between bilateral asymmetry and circulating oestradiol levels

Factors influencing the utilization of health facilities for childbirth in a disadvantaged community of Lalitpur, Nepal

Background: In Nepal, half of deliveries take place at home (HMIS 2014), while institutional birth assisted by skilled birth attendants (SBAs) are still infrequent. Objectives: This study explores factors influencing the utilization of health facilities for childbirth in a disadvantaged community of rural Nepal. Method: A qualitative study with two focus groups: mothers-in-law and husbands, and female community health volunteers. 28 semi-structured in-depth interviews were conducted with selected participants 20 mothers and 8 grass-root and policy level stakeholders. Data were analysed by three delays model of conceptual framework. Results: The main reasons for giving birth at home included cultural tradition, lack of awareness about danger signs during pregnancy and childbirth, about importance of skilled birth attendants and lack of knowledge about availability of free 24-hours delivery sites/birthing centers, inability to afford two way transportation costs despite transport incentives provided by government for institutional delivery, fear of episiotomy/surgery/physical abuse and health service provider’s attitude for home delivery. Health facilities were mostly used by women who experienced complications during childbirth Policy Implications: Significant gaps from policy to grass root levels were identified which -suggests that dissemination of information about free delivery must be more effective. The health workers should convincingly inform families about benefits of institutional delivery, especially in marginalized/disadvantaged communities

Body fat, energy balance and estradiol levels: a study based on hormonal profiles from complete menstrual cycles

BACKGROUND: Female fecundity is regulated by nutritional status. Although widely cited, this hypothesis is not strongly supported by empirical data from non-obese, healthy women of reproductive age. METHODS: Healthy, reproductive aged women (n = 141) from Southern Poland collected daily morning saliva samples for one complete menstrual cycle. Levels of 17-b-estradiol were analyzed by radioimmunoassay. Anthropometric measurements, including body fat percentage, were taken randomly with respect to phase of the menstrual cycle. Energy balance was specified based on changes in body fat percentage from the beginning to the end of the observation period. RESULTS: Women with very low and high body fat had significantly lower levels of E2 compared with women with low and average body fat. In women of very low to average body fat, a 10% increase in body fat was associated with a 5 – 7 pmol/l increase in estradiol levels. The association between fat percentage and E2 was even stronger in women with positive energy balance, who also showed significant differences between body fat groups in estradiol profiles across whole the menstrual cycle. No such relationship was found in women with negative energy balance. CONCLUSIONS: In healthy women, we found a non-linear association between body fat and estradiol levels. Both very low and high body fat was associated with decreased estradiol levels. The relationship between estradiol and body fat was strongly influenced by women’s energy balance.AnthropologyHuman Evolutionary Biolog

High tea consumption diminishes salivary 17beta-estradiol concetration in Polish women

Artykuł recenzowany / peer-reviewed articleWe hypothesized that among reproductive-age women consuming large quantities of tea, the production of estradiol would be suppressed. It has been shown that catechins and theaflavines, the major constituents of tea, inhibit aromatase, an enzyme which catalyses the conversion of androgens to estrogens. Our study included Polish women living in urban (N=61) and rural (N=48) areas. Women collected daily saliva samples for one complete menstrual cycle and filled out dietary questionnaires. Saliva samples were analyzed by radioimmunoassay for concentration of 17-β estradiol (E2). Women with high (above the median) average daily consumption of black tea had reduced levels of salivary E2, in comparison with women who drank less black tea (below median). This effect was observed within the whole study group, as well as separately within urban (p = 0.0006) and rural (p = 0.013) groups. High intake of the sum of subclasses of tea catechins and epigallocatechin gallate, assessed using the USDA database [http://www.nal.usda.gov], was also associated with lower concentrations of E2 within all women (p = 0.01 and p = 0.0001, respectively) and within the urban group (p = 0.0001 and p = 0.004, respectively). Similar relationships were observed between the sum of subclasses of theaflavines and thearubigines and E2 levels for the whole group (p = 0.002) and for urban women (p = 0.02). Women with high consumption of tea had lower levels of E2 concentration throughout the entire menstrual cycle. These results may have implications for reducing hormone-related cancer risk by a relatively easy dietary intervention.the State Committee for Scientific Research, Warsaw, Poland, project No. 3 P05E 016 25 and 6 P05D 112 20, the Radcliffe Institute of Advanced Study, Harvard University and the Norwegian Cancer Society

Low estradiol levels in women of reproductive age having low sleep variation

Higher exposure to light at night per se and through decrease in sleep duration and night shift work may suppress serum melatonin levels, which in turn may increase the reproductive hormone levels. High levels of steroid hormones, especially estrogens, may be associated with an increase of the breast cancer risk. This study investigated whether variation in the sleep duration during one entire menstrual cycle corresponds to variation in estradiol levels in healthy, urban women of reproductive age. Ninthy five regularly menstruating women ages 24-36 collected daily saliva samples for one entire menstrual cycle and recorded the number of hours of sleep per night (sleep duration). Saliva samples were analyzed for concentration of 17-ß estradiol (E2). We documented, after adjustments for sleep duration, a positive relationship between the sleep variation (coefficient of variation in sleep duration - sleep CV) and estradiol levels in women of reproductive age. Mean levels of E2 differed significantly in women from the lowest sleep CV quartile in comparison to other quartiles (p<0.001). The low sleep variation group, that is the women who sleep regularly, had mean E2 levels 60% lower than other groups. These results suggest that sleep variation significantly correlates with E2 levels, while sleep duration does not show a statistically significant relationship. According to the breast cancer development hypothesis, increasing the lifetime exposure to endogenous estrogens could result in higher risk of breast cancer.AnthropologyHuman Evolutionary Biolog

From January to June: Birth seasonality across two centuries in a rural Polish community

Seasonality of births is a worldwide phenomenon, but the mechanisms behind it remain insufficiently explored. Birth seasonality is likely to be driven by seasonal changes in women's fecundity (i.e. ability to conceive), which is strongly influenced by their energetic status. We tested whether birth seasonality is driven by high workload and/or low access to food using 200 years of birth data, from 1782 until 2004, in an agricultural rural Polish community. First, we analysed the time series of births and within-annual variance in births, a proxy for the extent of seasonality. Secondly, we tested the hypothesis that a high agricultural workload and/or low access to food decreases number of births. We found seasonality of births throughout more than 200 years of observation in an agricultural Polish population, with a dominant birth seasonality in January and February which gradually shifted towards June in the late twentieth century. The observed pattern does not support the hypothesis that birth seasonality resulted from women's energetic status. We discuss the possible reasons why our results do not support the tested hypothesis and some implications for our understanding of the birth seasonality

Women's preferences for men's beards show no relation to their ovarian cycle phase and sex hormone levels

According to the ovulatory shift hypothesis, women's mate preferences for male morphology indicative of competitive ability, social dominance, and/or underlying health are strongest at the peri-ovulatory phase of the menstrual cycle. However, recent meta-analyses are divided on the robustness of such effects and the validity of the often-used indirect estimates of fertility and ovulation has been called into question in methodological studies. In the current study, we test whether women's preferences for men's beardedness, a cue of male sexual maturity, androgenic development and social dominance, are stronger at the peri-ovulatory phase of the menstrual cycle compared to during the early follicular or the luteal phase. We also tested whether levels of estradiol, progesterone, and the estradiol to progesterone ratio at each phase were associated with facial hair preferences. Fifty-two heterosexual women completed a two-alternative forced choice preference test for clean-shaven and bearded male faces during the follicular, peri-ovulatory (validated by the surge in luteinizing hormone or the drop in estradiol levels) and luteal phases. Participants also provided for one entire menstrual cycle daily saliva samples for subsequent assaying of estradiol and progesterone. Results showed an overall preference for bearded over clean-shaven faces at each phase of the menstrual cycle. However, preferences for facial hair were not significantly different over the phases of menstrual cycle and were not significantly associated with levels of reproductive hormones. We conclude that women's preferences for men's beardedness may not be related to changes in their likelihood of conception