No impact of developmental conditions on serum estradiol levels among Bangladeshi women in the UK and Bangladesh.

INTRODUCTION: While many aspects of female ovarian function respond to environmental stressors, estradiol (E2) appears less sensitive to stressors than progesterone, except under extreme ecological conditions. However, earlier studies relied on saliva samples, considered less sensitive than blood. Here, we investigated E2 variation among 177 Bangladeshi and UK white women, aged 35-59, using single serum samples. Bangladeshi women either grew up in Sylhet, Bangladesh (exposed to poor sanitation, limited health care, and higher pathogen loads but not poor energy availability), or in the UK. METHODS: We collected samples on days 4-6 of the menstrual cycle in menstruating women and on any day for post-menopausal women. Participants included: (i) Bangladeshi sedentees (n = 36), (ii) Bangladeshis who migrated to the UK as adults (n = 52), (iii) Bangladeshis who migrated as children (n = 40), and (iv) UK white women matched for neighborhood residence to the migrants (n = 49). Serum was obtained by venipuncture and analyzed using electrochemiluminescence. We collected anthropometrics and supplementary sociodemographic and reproductive data through questionnaires. We analyzed the data using multivariate regression. RESULTS: E2 levels did not differ between migrant groups after controlling for age, BMI, physical activity, psychosocial stress, parity, and time since last birth (parous women). Paralleling results from salivary E2, serum E2 did not differ among women who experienced varying developmental conditions. CONCLUSION: Our results reinforce the hypothesis that E2 levels are stable under challenging environmental conditions. Interpopulation variation may only arise under chronic conditions of extreme nutritional scarcity, energy expenditure, and/or high disease burdens.

Comparison of two human infant urine collection methods for measuring estrone-3-glucuronide.

OBJECTIVES: Current human infant urine collection methods for the field are problematic for the researcher and potentially uncomfortable for the infant. In this study, we compared two minimally invasive methods for collecting infant urine: organic cotton balls and filter paper. MATERIALS AND METHODS: We first collected urine from infants using the clean catch method. We then used those samples to compare the performance of filter paper and cotton ball collection protocols. We analyzed the clean catch and cotton samples using commercial estrone-3-glucuronide (E1G) kits and tried two different extraction methods for the filter paper. Using a paired t-test (n = 10), we compared clean catch and cotton samples. We also compared effect sizes within and between methods. RESULTS: We were unable to extract enough urine from the filter paper to successfully assay the samples for E1G. The paired t-test revealed a statistically significant difference between the clean catch and cotton methods (t = 2.63, p-value = 0.03). However, the effect size was small (5.91 µg/ml, n = 10, 95% CI = 3.80, 8.02) and similar to or larger than the difference seen between duplicate wells for clean catch and cotton values. DISCUSSION: While this study is limited by sample size, our results indicate that filter paper is not a field-friendly method for collecting infant urine. However, we found that organic cotton balls showed similar values to the clean catch method, and we propose this method as an alternative, minimally invasive method for study of E1G in human infant urine.

Salivary secretory immunoglobulin A variation between female varsity athletes and nonathletes.

OBJECTIVES: Exercise can lead to changes in immune function. To further investigate this relationship, we examined possible differences in salivary secretory immunoglobulin A (sIgA) secretion rates among female college athletes and nonathlete students. We predicted that athletes would have higher sIgA secretion rates than nonathletes and show greater declines in sIgA during the study period as intensive exercise training continued. METHODS: We recruited 52 female participants aged 18-22 years (13 swimmers, 20 runners, and 19 nonathletes). We collected two saliva samples from each participant: baseline and a second sample 2 weeks later. Additionally, participants reported minutes of cardiovascular activity performed per week and completed a survey that included a modified Profile of Mood States and the Undergraduate Stress Questionnaire. RESULTS: We found no significant differences in mean salivary sIgA secretion rates between athletes and nonathletes. Salivary sIgA significantly increased between sample collections for both groups, with nonathletes exhibiting a greater increase in sIgA than athletes. Cardiovascular activity was not associated with sIgA secretion rates. Illness status was a significant positive predictor of sIgA secretion rates. CONCLUSIONS: Cardiovascular activity did not predict salivary sIgA secretion rates in this sample of female college students, and athletes did not show significantly different sIgA secretion rates than nonathletes. Together, these findings suggest that exercise may not be associated with altered immune function in well-nourished college-aged women. The increase in secretion rates among both athletes and nonathletes suggests that additional factors shared by both groups may have led to increases.

Systematic Review of Chronic Discrimination and Changes in Biology During Pregnancy Among African American Women.

Profound racial health disparities in maternal and infant health exist in the USA. Discrimination based on race may contribute to these disparities, but the biological pathways through which racial discrimination acts on health are not fully known. Even less is known about these pathways during development. Examining how racial discrimination becomes biology is paramount because it may shed light on how and when such social forces result in lasting biological consequences for health and wellbeing. To begin exploring this issue, we performed a systematic review of the relationships between experiences of chronic racial discrimination and relevant biomarkers measured during pregnancy among African American women. The literature search included studies published prior to August 2018 in the MEDLINE, Embase, and PsycINFO databases, and 11 studies met our inclusion criteria. We evaluated the articles based on the biological system that the authors investigated, which included the immune, neuroendocrine, and cardiovascular systems. We found that the current literature provides preliminary evidence that experiences of chronic racial discrimination are associated with changes in maternal biology during pregnancy. However, the literature was limited in both quantity and quality. We found only 11 studies that addressed this subject, four of which only provided indirect evidence, and many studies had small sample sizes. Future work in this area should develop more informative methods that consider the interaction between interpersonal and structural racial discrimination, individual variation, and sociocultural factors. We conclude researchers should continue to work in this area and focus on developing more effective study designs and larger sample sizes.

A time to be born: Variation in the hour of birth in a rural population of Northern Argentina.

OBJECTIVES: The present study aimed at investigating the timing of birth across the day in a rural population of indigenous and nonindigenous women in the province of Formosa, Argentina in order to explore the variation in patterns in a non-Western setting. MATERIALS AND METHODS: This study utilized birth record data transcribed from delivery room records at a rural hospital in the province of Formosa, northern Argentina. The sample included data for Criollo, Wichí, and Toba/Qom women (n = 2421). Statistical analysis was conducted using directional statistics to identify a mean sample direction. Chi-square tests for homogeneity were also used to test for statistical significant differences between hours of the day. RESULTS: The mean sample direction was 81.04°, which equates to 5:24 AM when calculated as time on a 24-hr clock. Chi-squared analyses showed a statistically significant peak in births between 12:00 and 4:00 AM. Birth counts generally declined throughout the day until a statistically significant trough around 5:00 PM. DISCUSSION: This pattern may be associated with the circadian rhythms of hormone release, particularly melatonin, on a proximate level. At the ultimate level, giving birth in the early hours of the morning may have been selected to time births when the mother could benefit from the predator protection and support provided by her social group as well as increased mother-infant bonding from a more peaceful environment.