Previous studies have established that average profiles of salivary progesterone and oestradiol, differ considerably among populations. Diet, age, and energetics appear responsible for acute inter-populational differences, but significant, unexplained differences in chronic levels of reproductive steroids remain. Based on developmental hypotheses advanced by reproductive ecologists, a migration study was initiated to assess whether environmental conditions experienced during development can influence patterns of adult ovarian hormones. Salivary steroid profiles of Bangladeshi women who migrated to the UK at different times (infancy, childhood, adulthood) were compared to those of women in Bangladesh, second-generation Bangladeshi migrants, and white women bom and resident in the UK. Data on socio- demographics, anthropometry, physical activity, diet and reproductive history were also collected. The following hypotheses and predictions were examined: A) Early life conditions influence adult set points of ovarian steroid hormones - women in Bangladesh and adult migrants will have lower ovarian steroids than child migrants, second generation and white women B) improved conditions during childhood can alter levels of ovarian steroids child migrants will have levels of ovarian steroids that are negatively correlated with age at migration and C) alterations in conditions after maturation do not modify set points established during early life - adult migrants will have steroid levels that are comparable to Bangladeshi sedentees. The predictions were upheld for progesterone but not for oestradiol. Results point to infancy and childhood as a sensitive period when changes in environmental conditions determine the tempo of growth and maturation, as well as later adult progesterone levels. In contrast, no evidence was found of a developmental effect on adult levels of oestradiol. The alterations in hormones levels among Bangladeshi migrants, together with a changing diet and reproductive behaviours, may put child migrants and second-generation women at increased risk for breast cancer in later life.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:420135 |
| Date | January 2005 |
| Creators | de la Mora, Alejandra Nunez |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1446321/ |
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