Diagnosis of hypoprolactinemia

Area of Science:

• Endocrinology
• Metabolic Health

Background:

• Prolactin, a hormone from lactotroph cells, impacts mammary glands, gonadal axes, and metabolic functions.
• Clinical focus has been on hyperprolactinemia, with limited attention to hypoprolactinemia due to lack of effective treatments and diagnostic data.
• Hypoprolactinemia is associated with metabolic disorders including type 2 diabetes, fatty liver, dyslipidemia, infertility, sexual dysfunction, and cardiovascular disease.

Purpose of the Study:

• To review the limited data on hypoprolactinemia diagnosis and its association with metabolic dysfunctions.
• To highlight the diagnostic criteria and challenges for hypoprolactinemia.
• To emphasize the potential role of hypoprolactinemia as a marker for pituitary dysfunction.

Main Methods:

• Review of existing literature on hypoprolactinemia diagnosis and its clinical associations.
• Analysis of diagnostic criteria including serum prolactin levels and thyrotropin-releasing hormone (TRH) stimulation tests.
• Examination of gender-specific differences in prolactin levels and responses.

Main Results:

• Hypoprolactinemia diagnosis relies on low serum prolactin and insufficient prolactin peak post-TRH stimulation.
• Gender influences basal prolactin levels and TRH test responses, with proposed cut-off levels for normal reserve and peak response.
• Isolated prolactin deficiency is rare, often indicating broader pituitary damage.

Conclusions:

• Hypoprolactinemia, though under-recognized, is linked to significant metabolic and reproductive health issues.
• Established diagnostic criteria for hypoprolactinemia involve serum prolactin assessment and TRH stimulation testing.
• Further large-scale studies are required to refine normal prolactin levels and TRH test responses across diverse populations.