Effects of chronic retinoid administration on pituitary function

Area of Science:

• Endocrinology
• Dermatology
• Pharmacology

Background:

• Retinoids, such as acitretin, are known to potentially impact the hypothalamic-pituitary-thyroid axis.
• Central hypothyroidism has been a reported concern with retinoid use.

Purpose of the Study:

• To evaluate the effects of acitretin on pituitary function in male psoriatic patients.
• To assess hormonal changes, specifically thyroid and pituitary hormones, during acitretin treatment.

Main Methods:

• 11 male psoriatic patients were treated with acitretin (35 mg/day).
• Hormone levels (LH, FSH, testosterone, cortisol, GH, IGF-I, TSH, FT4, FT3, PRL) were measured at baseline, 1 month, and 3 months.
• Pituitary response to TRH and dopamine was assessed during treatment.

Main Results:

• Acitretin did not affect LH, FSH, testosterone, cortisol, GH, or IGF-I levels.
• A transient decrease in TSH was observed at 1 month, reverting by 3 months.
• Free T3 levels significantly decreased at 1 and 3 months, while FT4 remained unchanged.
• Prolactin levels showed a significant reduction after 3 months of treatment.
• No changes in TSH or PRL response to TRH or dopamine infusion were noted.

Conclusions:

• Low-dose acitretin treatment induces hormonal modifications in psoriatic patients.
• These include transient TSH reduction, persistent FT3 decrease possibly due to altered thyroid hormone metabolism, and reduced PRL levels.
• Pituitary function, assessed by TRH and dopamine response, remained unaffected.