Total estradiol levels in migrant and British‐born British Pakistani women: Investigating early life influences on ovarian function

Abstract

The purpose of this study was to test the hypothesis that women who grow up in energetically stressed environments have later menarche and lower total estradiol levels during their reproductive years than do women who grow up in less energetically stressed environments. We assessed total estradiol in a serum sample taken 9-11 days after the start of the menstrual cycle in 26 women who grew up in Pakistan and migrated to the UK as adults, in 28 British-born British Pakistani women, and in 25 British-born women of European origin. Women who grew up in Pakistan reported a later menarche than women who grew up in the UK. However, we found no significant differences between the groups in total estradiol level. Thus our findings do not support the hypothesis that estradiol levels are partially determined during early life. However, having considered our findings in relation to those of other studies, we conclude that new methodological approaches are needed to provide a more definitive test of the hypothesis.

The ecology and evolutionary endocrinology of reproduction in the human female

“…Small sample sizes and only one blood sample to characterize an entire cycle's hormone levels may have obscured genuine differences among the migrant samples. Pollard et al (2009) reported no differences in serum estradiol levels (estimated from a single sample drawn some time during Days 9-11 of the cycle) between adult migrants from Pakistan, British-born British Pakistani women, and British-born women of European ancestry.…”

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

“…For example, while we previously found differences in salivary P4 levels between Bangladeshi sedentees, immigrants from Bangladesh to the UK, second generation British-Bangladeshis, and UK white women who were of prime reproductive age (19-39) (Núñez-de la Mora et al, 2007), we observed no significant differences in salivary E2 levels by migrant status in this same sample (Núñez-de la Mora et al, 2008). Additionally, a similar migrant study comparing serum E2 levels among Pakistani women in Pakistan, adult Pakistani migrants to the UK, Pakistani women born in the UK, and UK white women also found no significant differences in E2 across these groups (Pollard et al, 2009). While E2 variation among post-reproductive women is not well-studied, serum E2 levels do not appear to vary by population or ethnicity among women during the peri-or postmenopause (Golden et al, 2007;McTiernan et al, 2008;Randolph et al, 2003; although see Setiawan et al, 2006).…”