New data demonstrates that relationship of salivary to serum progesterone in Bolivian women is comparable to that in other populations
Date
2011-04-13Author
Thornburg, Jonathan
Bellido, Diva
Stewart, Rose
Spielvogel, Hilde
Echalar, Lourdes
Burch, Jennifer
Vitzthum, Virginia J
Metadata
Show full item recordAbstract
Abstract.
Salivary progesterone (P) concentration is widely
used in field studies as a relatively easy-to-measure
proxy for serum P. Chatterton et al. [Fertility & Sterility 86:723 (2006)] compared sample means of salivary
and serum P in concurrent samples taken during the
putative luteal phase from women in La Paz, Bolivia
(n526) and Chicago, USA (n520). They concluded that
salivary/serum P ratios (hereinafter ‘‘uptake fractions’’)
vary significantly among populations (precluding crosspopulational comparisons of salivary P), and that salivary
P may not be a reliable proxy for serum P in Bolivian
and other non-industrialized populations. We have previously disputed this claim [AJHB 21:271 (2008)], arguing
that sample contamination and/or assay errors are
more plausible explanations for Chatterton et al.’s
data. Here we report analyses of new data collected
specifically to investigate the relationship of salivary P
280 ABSTRACTS
to serum P in Bolivian women. Simultaneous saliva/serum samples (n572) from 36 women were collected
approximately one and three weeks following the preceding menses; samples were subsequently assigned to
an ovarian-cycle phase based on the date of the subsequent menses. As did Chatterton et al., here we focus
on the luteal-phase data. We find an excellent correlation (r50.78) between salivary and serum P in these
samples, with uptake fractions typically around 3%,
similar to published reports of this ratio in other populations. We conclude that salivary P is a reliable proxy
for serum P in Bolivian women and (assuming comparable assays) that comparisons of salivary P are valid
across populations.