Childhood Conditions Influence Adult Progesterone Levels

Abstract

BackgroundAverage profiles of salivary progesterone in women vary significantly at the inter- and intrapopulation level as a function of age and acute energetic conditions related to energy intake, energy expenditure, or a combination of both. In addition to acute stressors, baseline progesterone levels differ among populations. The causes of such chronic differences are not well understood, but it has been hypothesised that they may result from varying tempos of growth and maturation and, by implication, from diverse environmental conditions encountered during childhood and adolescence.Methods and FindingsTo test this hypothesis, we conducted a migrant study among first- and second-generation Bangladeshi women aged 19–39 who migrated to London, UK at different points in the life-course, women still resident in Bangladesh, and women of European descent living in neighbourhoods similar to those of the migrants in London (total n = 227). Data collected included saliva samples for radioimmunoassay of progesterone, anthropometrics, and information from questionnaires on diet, lifestyle, and health. Results from multiple linear regression, controlled for anthropometric and reproductive variables, show that women who spend their childhood in conditions of low energy expenditure, stable energy intake, good sanitation, low immune challenges, and good health care in the UK have up to 103% higher levels of salivary progesterone and an earlier maturation than women who develop in less optimal conditions in Sylhet, Bangladesh (F 9,178 = 5.05, p < 0.001, standard error of the mean = 0.32; adjusted R 2 = 0.16). Our results point to the period prior to puberty as a sensitive phase when changes in environmental conditions positively impact developmental tempos such as menarcheal age (F 2,81 = 3.21, p = 0.03) and patterns of ovarian function as measured using salivary progesterone (F 2,81 = 3.14, p = 0.04).ConclusionsThis research demonstrates that human females use an extended period of the life cycle prior to reproductive maturation to monitor their environment and to modulate reproductive steroid levels in accordance with projected conditions they might encounter as adults. Given the prolonged investment of human pregnancy and lactation, such plasticity (extending beyond any intrauterine programming) enables a more flexible and finely tuned adjustment to the potential constraints or opportunities of the later adult environment. This research is the first, to our knowledge, to demonstrate a postuterine developmental component to variation in reproductive steroid levels in women.

Ethnicity or environment: effects of migration on ovarian reserve among Bangladeshi women in the United Kingdom

“…In an earlier paper, we found that infectious disease load was a significant predictor of age at menopause among a larger sample of Bangladeshi women, but this variable was not significant in the analyses here of a smaller group of women sampled for hormone levels (60). We have similarly suggested, however, in past papers that life history trade-offs could explain differences in other reproductive and developmental parameters between Bangladeshis who grow up in contrasting UK and Bangladeshi environments, including ages at adrenarche and menarche, levels of salivary progesterone and rates of ovulation (41)(42)(43)84).…”

“…More recently, effects of the developmental environment on adult ovarian function have also been assessed (41)(42)(43). In our earlier work, for example, we found significant differences in levels of reproductive steroids, length of the reproductive lifespan, and rates of ovulation among age-and socioeconomically matched Bangladeshi women depending on whether they had grown up in Bangladesh or the UK (32,(41)(42)(43).…”

Apolipoprotein E ( ApoE ) polymorphism is related to differences in potential fertility in women: a case of antagonistic pleiotropy?

“…Several lifestyle and reproductive factors are known to influence levels of ovarian steroid hormones and fertility in healthy women [27,[34][35][36][37][38][39]. Therefore, we analysed differences between genotypes with at least one ApoE4 allele and without ApoE4 alleles in age, reproductive characteristics (menarcheal age, number of children, age at first reproduction, length of menstrual cycle), body size (at birth and in adulthood), levels of daily physical activity and of education.…”

Visceral adiposity would be expected to predict incident diabetes better in women than men

“…However, this negates neither the importance of the potential mechanism, nor its implications for the rest of the world and the changing disease patterns it is experiencing. Economic development over generations may increase levels of sex steroids [6]. One key exposure (pubertal sex steroids) could provide a simple sociobiological explanation for the secular trends in diabetes and ischaemic heart disease that occur with economic development.…”