Androsterone glucuronide (ADG) is a major metabolite of the androgen dihydrotestosterone and has also been shown to arise from the intracrine conversion of other adrenal androgens such as androstenedione and androsterone. ADG has been shown to be raised in some women with clinical signs of hyperandrogenism such as acne and hirsutism, even when levels of androgens, e.g. testosterone or DHEA-S are normal. This indicates that raised ADG levels may be an early indication of hyperandrogenism therefore measurement could be helpful in patients with clinical symptoms. Reference range data is essential before an assay can be used clinically, in order to distinguish between normal and abnormal levels.
In order to produce this data, serum samples from 104 healthy female and 105 healthy male volunteers aged between 16 and 74 were analysed for ADG by liquid chromatographytandem mass spectrometry. The data was found not to be normally distributed, with a skewness of 1.90 for the female data and 1.63 for the male data. The reference ranges were therefore determined non-parametrically. The reference range for the female population was 15322 nmol/l. The lower limit of quantitation of the assay is 20 nmol/l, but as low levels of ADG have not been shown to be of clinical significance, this means that the female reference range can be given as <20 to 322 nmol/l. The male reference range was 56377 nmol/l.
This reference range data will enable the ADG assay to be used to aid in the identification of androgen disorders such as hyperandrogenism in women. It may allow earlier diagnosis as ADG is produced from the intracrine metabolism of androgens therefore may better reflect tissue concentrations of androgens than traditional markers. Further work could be carried out to determine whether the assay is of use in other situations, e.g. detection of hypogonadism.