Ethnic variation in correlations of salivary and serum reproductive steroid hormones: a comparison of Bangladeshi and British women

Abstract

Matched samples of saliva and blood have yielded significantly correlated hormone concentrations. However, these verified correlations are restricted to healthy women of European descent in more developed countries. This relationship does not appear to have been extensively explored for non-White women. This study examined the correlation between progesterone and oestradiol concentrations in matched saliva and serum samples among sedentee women living in Sylhet, Bangladesh, and migrant Bangladeshi and British women of European descent in London, England. Participants were aged 19-42, regularly menstruating, free from exogenous steroids with no history of thyroid or fertility problems. Thirty-nine women provided matched blood and saliva samples during the luteal phase of their menstrual cycle at least one hour after consuming food or drink. Concentrations of progesterone and oestradiol were measured by direct radioimmunoassay and examined in relation to demographic groups. The study subjects were also examined in relation to age. Bangladeshi migrant women matched British women of European descent in age (mean= 33), but sedentee women were significantly younger than both groups. Serum and salivary progesterone concentrations were highly and significantly correlated in the British group of European descent (rho=0.879, n=10, p<. 0005) and the Bangladeshi sedentees (rho=0.700, n=ll, p<. 0005), but not in the Bangladeshi migrants (rho= 0.191, n-18, p= 0.448/ Serum and salivary oestradiol were significantly positively correlated in the Bangladeshi sedentee group (r=0.678, n=l 1, p<. 0005) but not in either the British group (r= 0.431, n=10, p= 0.214) or the migrant Bangladeshi women (r=-O.I78, n=18, p= 0.479). With inconsistent correlations across the three study groups, these findings do not clarify whether hormone measurements in saliva or serum best reflects ovarian function. The current study prompts further research with a larger sample size and refined assay procedures.