Objectives: Extensive research has demonstrated that marriage and parenting are associated with lower testosterone levels in men, however, very little is known about associations with hormone concentrations in women. Two studies have found lower testosterone in relation to pair-bonding and motherhood in women, with several others suggesting that estradiol levels are lower among parous women than nulliparous women. Here, we examine estradiol and progesterone concentrations in relation to marriage and motherhood in naturally cycling, reproductive age women.
View Article and Find Full Text PDFObjective: To examine associations between environmental exposure to perfluoroalkyl substances (PFASs) and ovarian hormone concentrations in naturally cycling women.
Design: E2 and P were measured in saliva samples collected daily for a single menstrual cycle and concentrations of PFASs (including perfluoroctane sulfonate [PFOS] and perfluoroctanoic acid) were measured in serum samples collected during the same cycle.
Setting: Not applicable.
Human life history contains a series of paradoxes not easily explained by classical life history theory. Although overall reproductive output is higher than in related primates, juvenile growth is slower and age-specific reproductive rates decline faster with age. A simple energetic model would predict that growth and reproductive rates should be positively correlated and that reproductive effort should not decelerate with age.
View Article and Find Full Text PDFHigher exposure to light at night, for example, owing to night shift work or decrease in sleep duration, may suppress melatonin production, 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 estradiol saliva concentrations in healthy, urban women of reproductive age.
View Article and Find Full Text PDFObjective: To investigate possible short-term effects of voluntary weight loss on ovarian steroid profiles in young women, in light of better established long-term effects in older women.
Design: We tested for an association of voluntary weight change over the course of a menstrual cycle with salivary E(2) and P profiles in the same menstrual cycle.
Setting: Students were recruited in a college residence hall, and they provided daily saliva samples to a researcher living nearby.
The relationship between psychological stress and reduced fecundity has been a matter of speculation and investigation for decades. Most previous studies have been compromised, however, by a number of problems including ambiguous direction of causation, poorly operationalized variables, and the confounding of psychological with energetic stress. We present a two-part study of the relationship between moderate anxiety, both acute and chronic, and daily measures of ovarian steroid and corticosteroid levels in saliva.
View Article and Find Full Text PDFWe tested the association between the index-to-ring finger length ratio (2D:4D) and ovarian steroid hormone concentrations measured over the course of a menstrual cycle in the saliva of 38 young women. Estradiol levels were positively associated with right-hand, but not left-hand, 2D:4D, and also with the difference between right- and left-hand 2D:4D. None of these measures predicted progesterone level.
View Article and Find Full Text PDFBackground: Symptom fluctuation in bulimia nervosa (BN) is related to menstrual cycle phase. However, the relationship between bulimic symptoms and ovarian hormones (estrogens and progesterone) has not been examined directly in women with BN.
Method: Regularly menstruating women with DSM-IV BN (n=9) and regularly menstruating controls (n=8) collected hormone samples and recorded mood and bulimic symptoms daily for 35 consecutive days.
Variation in the risk of breast cancer observed among women and among populations may be explained by variation in lifetime exposure to estrogens. The suppressive effect of exercise on estradiol levels in women is well documented, but it is unknown whether habitual (i.e.
View Article and Find Full Text PDFInter-individual variation in levels of sex hormones results from differences in genetic, developmental, and environmental factors. We tested a hypothesis that programming of the fetal neuroendocrine axis may predispose some women to produce higher levels of steroid hormones during their menstrual cycles as adults. One hundred forty-five regularly menstruating 24- to 36- year-old women collected daily saliva samples for one menstrual cycle.
View Article and Find Full Text PDFLow serum high-density lipoprotein cholesterol (HDL-C) is an important component of the metabolic syndrome and has recently been related to increased breast cancer risk in overweight and obese women. We therefore questioned whether serum HDL-C might be a biologically sound marker of breast cancer risk. We obtained cross-sectional data among 206 healthy women ages 25 to 35 years who participated in the Norwegian EBBA study.
View Article and Find Full Text PDFPhysical characteristics, such as breast size and waist-to-hip ratio (WHR), function as important features used by human males to assess female attractiveness. Males supposedly pay attention to these features because they serve as cues to fecundity and health. Here, we document that women with higher breast-to-underbreast ratio (large breasts) and women with relatively low WHR (narrow waists) have higher fecundity as assessed by precise measurements of daily levels of 17-beta-oestradiol (E2) and progesterone.
View Article and Find Full Text PDFPrevious research has shown lower testosterone (T) levels associated with involvement in committed, romantic relationships ("paired" men) and paternal care in eight studies of North American men. An unanswered question is whether differences in male T levels associated with relationship status better reflect state (e.g.
View Article and Find Full Text PDFPrevious research in North America has supported the view that male involvement in committed, romantic relationships is associated with lower testosterone (T) levels. Here, we test the prediction that undergraduate men involved in committed, romantic relationships (paired) will have lower T levels than men not involved in such relationships (unpaired). Further, we also test whether these differences are more apparent in samples collected later, rather than earlier, in the day.
View Article and Find Full Text PDFTo determine if testosterone is negatively related to acute and/or chronic nutritional status among men in a subsistence society, saliva samples and anthropometric measures were compared among nomadic and settled Ariaal pastoralists of northern Kenya. Fifty-six nomadic men and 62 settled men facing drought conditions, estimated ages 22-96 years, were sampled. Measures included height, weight, four skinfolds, and %body fat by bioelectric impedance (BIA).
View Article and Find Full Text PDFAm J Hum Biol
February 2004
We present results from 42 gay men who completed a survey including self-measurement of waist circumference, height, and weight, in addition to providing saliva samples for the assay of testosterone, and a photocopy of the right hand for the measure of second-to-fourth digit length ratio (2D:4D), proposed as a means of approximating androgenic effects during development. The analyses were conducted as a test of the recent hypothesis, proposed by Abbott et al. ([2002] J Endocrinol 174:1-5), that high prenatal androgen exposure causes greater deposition of fat on the abdomen relative to other depots.
View Article and Find Full Text PDFUrinary testosterone and cortisol concentrations were quantified in a large number of samples (>500) collected from wild male chimpanzees (n=11) over the course of 1 year. For both steroids, urinary concentrations were higher and more variable in the morning than in the afternoon. Urinary creatinine levels showed no such diurnal pattern.
View Article and Find Full Text PDFBackground: Age-related declines in free and bioavailable testosterone are frequently reported for Western populations, but interpopulation variation in this pattern has not previously been investigated.
Methods: Salivary testosterone was measured using a consistently applied protocol on morning samples collected from men in four populations (USA, Congo, Nepal, and Paraguay) representing different geographical, ecological, and cultural settings.
Results: Mean testosterone levels varied significantly between the four populations.
The relationship of age to four aspects of ovarian function was investigated: daily progesterone levels, pulsatile progesterone secretion, follicular and luteal estradiol levels, and preovulatory estradiol levels. Daily progesterone levels decrease after age 40. Pulsatile progesterone secretion remains approximately stable with age, though older women have somewhat higher late luteal activity.
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