The metabolic role of prolactin: systematic review, meta-analysis and preclinical considerations

ABSTRACT

Introduction

Hyperprolactinemia has been proven to induce hypogonadism and metabolic derangements in both genders, while the consequences of prolactin (PRL) deficiency have been poorly investigated.

Areas covered

To systematically review and analyze data from clinical studies focusing on the metabolic consequences of abnormally high prolactin levels (HPRL) and low prolactin levels (LPRL). In addition, data from preclinical studies about underlying pathophysiological mechanisms were summarized and discussed.

Expert opinion

PRL contributes to providing the correct amount of energy to support the mother and the fetus/offspring during pregnancy and lactation, but it also has a homeostatic role. Pathological PRL elevation beyond these physiological conditions, but also its reduction, impairs metabolism and body composition in both genders, increasing the risk of diabetes and cardiovascular events. Hence, hypoprolactinemia should be avoided as much as possible during treatment with dopamine agonists for prolactinomas. Patients with hypoprolactinemia, because of endogenous or iatrogenic conditions, deserve, as those with hyperprolactinemia, careful metabolic assessment.

KEYWORDS:

• Diabetes mellitus
• hyperprolactinemia
• hypoprolactinemia
• obesity
• prolactin
• testosterone

Article highlights

• High prolactin levels are associated with worse body composition and glycometabolic profile

• Restoring normal prolactin levels in patients with hypoprolactinemia ameliorates body composition and glycometabolic profile

• Gender differences can interfere with elevated prolactin metabolic-related disturbances.

• Low prolactin levels are characterized by worse lipid profiles, higher fasting glucose and higher risk of diabetes when compared to controls.

• The clinical syndrome hypoprolactinemia is a new condition that needs further studies to define its pathological burden.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/17446651.2022.2144829

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funding.