Low-dose testosterone administration and oestrogen synthase availability in the female brain: A pilot study

Area of Science:

• Neuroendocrinology
• Pharmacology
• Women's Health

Background:

• Testosterone and oestrogens are crucial for female physiology, impacting brain health, mood, and behavior.
• Low-dose testosterone therapy is explored for postmenopausal sexual dysfunction and depression, but its brain effects and safety are unclear.
• The impact of testosterone on brain aromatase, key for androgen-oestrogen balance, is unknown.

Purpose of the Study:

• To investigate the effects of short-term, low-dose testosterone administration on brain aromatase availability in healthy women.
• To assess associated changes in mood and behavior during testosterone treatment.

Main Methods:

• Healthy women received 1 week of low-dose testosterone (10 mg/day).
• Brain aromatase binding was measured using [11C]cetrozole positron emission tomography (PET) before and during treatment.
• Psychometric assessments evaluated depression, anxiety, and aggression.

Main Results:

• Peripheral testosterone levels increased significantly (up to 33-fold) with treatment.
• No significant effect of testosterone was observed on brain aromatase binding in the thalamus, hypothalamus, or amygdala.
• Mood and behavioral measures (depression, anxiety, aggression) remained unchanged.

Conclusions:

• Short-term, clinically relevant testosterone administration does not significantly alter brain aromatase availability in healthy women.
• These findings may offer reassurance to patients considering testosterone for hypoactive sexual desire disorder.
• Larger, long-term studies are necessary to confirm these effects, especially in patient populations with clinical needs.