Sex hormone-binding globulin and androgen levels in immigrant and British-born premenopausal British Pakistani women: Evidence of early life influences?

Human reproduction and health: an evolutionary perspective

According to life history theory, increased investment in reproductive function (physiology and behaviour) at different times throughout the life course affects the risk of many diseases and, ultimately, longevity. Although genetic factors contribute to interindividual and interpopulation variation in reproductive traits, the dominant source of variability is phenotypic plasticity during development and adult life. Reproductive traits in both sexes evolved sensitivity to ecological conditions, as reflected in contemporary associations of hormone concentrations with geographical setting, nutritional status, and physical activity level. Lifetime exposure to increased concentrations of sex hormones is associated with the risk of some cancers, hence decreasing fertility patterns contribute to secular increases in their incidence. Conversely, increased investment in reproductive function might compromise somatic investment in health, such that faster sexual maturation and higher parity increases risk of diabetes and cardiovascular disease. An evolutionary perspective on reproductive biology could improve the efficacy of public health efforts to reduce the risk of hormone-sensitive cancers and other non-communicable diseases.

Endogenous sex steroid hormones and glucose in a South-Asian population without diabetes: the Metabolic Syndrome and Atherosclerosis in South-Asians Living in America pilot study

AIMS

To examine the associations between endogenous sex steroid hormones (oestradiol, testosterone and sex hormone-binding globulin) with diabetes risk in a South-Asian population living in the USA.

METHODS

We used data from the Metabolic Syndrome and Atherosclerosis in South-Asians Living in America pilot study. The analytical sample included 60 women and 45 men of Asian Indian origin living in the San Francisco Bay Area, who were free from diabetes and cardiovascular disease and did not use exogenous sex steroids. Sex steroid hormone levels were assessed by validated conventional radioimmunoassays, and visceral and hepatic adiposity were assessed by computed tomography. We used multivariable regression to examine the association between endogenous sex steroid hormone levels (log-transformed) and fasting glucose and 2-h glucose levels in a series of sex-stratified models adjusted for age, waist circumference, visceral and hepatic adiposity, and insulin resistance.

RESULTS

In age-adjusted models, lower levels of sex hormone-binding globulin (β = -0.18, 95% CI -0.30, -0.06) and higher levels of free testosterone (β = 0.14, 95% CI 0.02, 0.26) were associated with elevated fasting glucose levels in South-Asian women, whereas lower levels of sex hormone-binding globulin (β = -0.14, 95% CI -0.26, -0.02) and lower levels of total testosterone (β = -0.12, 95% CI -0.24, 0.00) were associated with elevated fasting glucose levels in South-Asian men. Adjustment for waist circumference, visceral adiposity and insulin resistance attenuated most of these associations, while adjustment for hepatic adiposity strengthened some of the observed associations. Similar results were found for 2-h glucose levels.

CONCLUSIONS

Results were consistent with previous research, which suggests that endogenous sex steroid hormones are a risk factor for diabetes across multiple race/ethnic groups. Additional studies are needed to determine whether visceral fat is a mediator or confounder of associations between sex steroid hormone and glucose levels.

Testosterone levels are negatively associated with fatherhood [corrected] in males, but positively related to offspring count in fathers

Variation in testosterone (T) is thought to affect the allocation of effort between reproductive and parenting strategies. Here, using a large sample of elderly American men (n = 754) and women (n = 669) we examined the relationship between T and self-reported parenthood, as well as the relationship between T and number of reported children. Results supported previous findings from the literature, showing that fathers had lower T levels than men who report no children. Furthermore, we found that among fathers T levels were positively associated with the number of children a man reports close to the end of his lifespan. Results were maintained when controlling for a number of relevant factors such as time of T sampling, participant age, educational attainment, BMI, marital status and reported number of sex partners. In contrast, T was not associated with either motherhood or the number of children women had, suggesting that, at least in this sample, T does not influence the allocation of effort between reproductive and parenting strategies among women. Findings from this study contribute to the growing body of literature suggesting that, among men, pair bonding and paternal care are associated with lower T levels, while searching and acquiring sex partners is associated with higher T levels.

Phenotypic comparison of Caucasian and Asian women with polycystic ovary syndrome: a cross-sectional study

OBJECTIVE

To determine whether manifestations of polycystic ovary syndrome (PCOS), particularly androgen excess, differ between Caucasian and Asian women in the San Francisco Bay Area.

DESIGN

Cross-sectional study.

SETTING

Multidisciplinary PCOS clinic at a tertiary academic center.

PATIENT(S)

121 Caucasian and 28 Asian women, aged 18-44, examined between 2006 and 2011 with PCOS verified by a reproductive endocrinologist and dermatologist according to the Rotterdam criteria.

INTERVENTION(S)

Transvaginal ultrasounds, comprehensive dermatologic exams, and serum testing.

MAIN OUTCOME MEASURE(S)

Hirsutism defined as a modified Ferriman-Gallwey (mFG) score ≥ 8, acne, androgenic alopecia, and biochemical hyperandrogenism.

RESULT(S)

Caucasian and Asian women had a similar prevalence of all measures of androgen excess. Both groups had similar total mFG scores and site-specific mFG scores, except Asian women had a lower site-specific mFG score for the chest. Although Asian women were more likely to use laser hair removal, the results were unchanged when the women with a history of laser hair removal were excluded.

CONCLUSION(S)

Caucasian and Asian women with PCOS living in the same geographic region had a similar prevalence of hirsutism as well as other markers for androgen excess. Further studies are necessary to evaluate the need for ethnic-specific mFG scores in women with PCOS.

'Everybody is moving on': infertility, relationality and the aesthetics of family among British-Pakistani Muslims

It is now widely recognised that experiences of infertility are socially and culturally contingent. Drawing on reproductive narratives of 108 British-Pakistani Muslims living in Northeast England (collected from 2007 to 2010), we show that subjective experiences of infertility in this population can take many forms, from 'straightforward' childlessness to concerns about inability to fulfil a range of reproductive expectations, desires and obligations, regarding timing, gender balance and number of offspring. Extended family relations are pivotal in the processes through which reproduction (or lack thereof) becomes defined as problematic. Changing family aesthetics can thus shape individuals' experiences of infertility in important ways. A growing emphasis on conjugal relationships for some couples offers a greater range of reproductive possibilities (enabling, for example, a period of voluntary childlessness). For others, increasing nuclearisation of family life reduces the possibilities for extended families to 'plug the gap' by providing proxy-children and a normalised social role for infertile couples. Moreover, such social roles may be time-limited, creating serious challenges for the long-term childless, who find themselves caught 'betwixt and between' two disparate sets of values.