Testosterone or dihydrotestosterone: what should be evaluated in hirsutism?

Dihydrotestosterone is a more potent androgen derived from testosterone and androstenediones, but its measurement has not been routinely recommended in women with hirsutism, and there is limited information in this regard with equivocal findings. This study aimed to evaluate serum dihydrotestosterone level in patients with hirsutism compared to women without hirsutism.

In this case-control study (during 2021-2022), serum levels of total testosterone, free testosterone, and dihydrotestosterone were evaluated in 101 women with hirsutism and 101 healthy women. Hormonal levels were measured with chemiluminescent immunoassay method. Age and hormonal levels in each group, body mass index, menstrual status, complaint of decreased scalp hair density, and ovarian ultrasound findings in hirsutism group were collected and analyzed.

There was significant difference in free testosterone and dihydrotestosterone levels (P < 0.001) and no significant difference in total testosterone level between two groups (P = 0.628). Dihydrotestosterone level was significantly higher in women with hirsutism with menses irregularity, complaint of decreased scalp hair density, and presence of polycystic ovary on ultrasound (P < 0.05).

Measuring dihydrotestosterone level is not considered in routine evaluation of hirsutism, but we think that this significant difference shows that elevated level of dihydrotestosterone hormone in women with hirsutism is an important factor.