Physiological concentrations of DHEA in human hair

In 1974, steroids were added to the list of doping agents banned by the International Olympic Committee because of their effects on the performance of the athletes. Dehydroepiandrosterone (DHEA) is a steroid hormone naturally produced by the adrenal glands and by the ovaries. DHEA can be converted into other hormones, including estrogen and testosterone. In the United States, DHEA is classified as a nutritional supplement. This is not the case in France, where the drug is listed as a doping agent. As athletes can abuse DHEA to benefit from its conversion to testosterone, there is a need to establish the physiological range of DHEA concentrations in human hair. DHEA was investigated in hair obtained from 27 control subjects, including 15 males and 12 females aged 17-42 years. After decontamination with dichloromethane, 100 mg of hair was incubated in 1 M NaOH in presence of 1 ng of testosterone-d3. After neutralization, the extract was purified using solid-phase extraction with Isolute C18 columns and subsequent liquid-liquid extraction with pentane. After silylation, DHEA was analyzed by gas chromatography-mass spectrometry. Results were linear in the range 1-20 pg/mg. Relative extraction recovery was 91.6% with a limit of detection of 0.5 pg/mg. Concentrations were in the range 1.2-6.7 pg/mg (mean value of 4.3 pg/mg) and 0.5 to 10.6 pg/mg (mean value of 5.3 pg/mg) for the males and females, respectively. Extensive chromatographic procedures (two purification steps by solid-phase and liquid-liquid extraction, combined with injection of 4 microL through the column in pulsed mode) were analytical prerequisites for successful identification of DHEA in hair because of the low target concentrations. This new technology may find useful applications in anabolic abuse control.