Dehydroepiandrosterone (DHEA) Serum Levels Sufficiently Predict Cerebrospinal Fluid Levels of DHEA and Estradiol (E2) in Women at Term Pregnancy

Abstract Background and objectives:Neuroactive steroids such as dehydroepiandrosterone (DHEA), estradiol (E2), and progesterone (P4) are associated with structural and functional changes in the central nervous system (CNS). Measurement of steroid levels in the CNS compartments, though restricted in accessibility, is essential for clinical evaluation. Consequently, there is only limited human data on the correlation and equilibrium for steroid levels between peripheral and central compartments. While some neuroactive steroids including DHEA and E2 have been reported to convey excitatory and proconvulsant properties, the opposite was demonstrated for progesterone. We aimed to elucidate the correlation between peripheral and central DHEA, E2, and P4 levels in women at term pregnancy.Subjects and Methods:CSF and serum samples of 27 healthy pregnant women (22-39 years) at term pregnancy were collected simultaneously under combined spinal and epidural anesthesia and used for DHEA, E2, and P4 ELISA.Results:All three neuroactive steroids were detected at markedly lower levels in CSF compared to their corresponding serum concentrations (decrease, mean ± SD, 97.66 ± 0.83 %).We found a strong correlation for DHEA between its serum and the corresponding CSF levels (r=0.65, p=0.003). While a significant but weak correlation (r=0.39, p=0.046) was detected for P4, serum and CSF levels of E2 (r=0.31, p=0.12) appeared not to correlate in the investigated cohort. DHEA serum concentration correlated significantly with both E2 (r=0.58, p=0.0016) and P4 in CSF (r=0.39, p=0.046). A strong correlation between the steroids DHEA and E2 measured in CSF was found (r=0.65, p=0.0002), while no substantial correlation between DHEA and P4 was evident in this compartment (r=0.34, p=0.085). Conclusions: Peripheral DHEA levels might serve as a valid predictor for central nervous levels of the neuroactive steroids DHEA and E2 in pregnant women.