Urhan Emre, Karaca Zuleyha
Department of Endocrinology, Erciyes University Medical School, Kayseri, Turkey.
Rev Endocr Metab Disord. 2024 Dec;25(6):985-993. doi: 10.1007/s11154-024-09896-8. Epub 2024 Jul 22.
Prolactin is a polypeptide hormone composed of 199 amino acids, synthesized by lactotroph cells. Its primary effects are on the mammary gland and gonadal axes, but it also influences different organs and systems, particularly metabolic functions. Current literature has mainly focused on the diagnosis, monitoring, and treatment of hyperprolactinemia. Due to the lack of a well-established effective treatment for hypoprolactinemia, it is not clinically emphasized. Therefore, data on its diagnosis is limited. Hypoprolactinemia has been associated with metabolic dysfunctions such as type 2 diabetes mellitus, fatty liver, dyslipidemia, fertility problems, sexual dysfunction, and increased cardiovascular disease. While often seen as a part of combined hormone deficiencies due to pituitary damage, isolated prolactin deficiency is rare. Hypoprolactinemia can serve as a marker for extensive pituitary gland damage and dysfunction.Low or undetectable serum prolactin levels and the absence of a sufficient prolactin peak in the thyrotropin-releasing hormone (TRH) stimulation test are considered diagnostic for hypoprolactinemia. Gender appears to influence both basal prolactin levels and TRH stimulation test responses. Basal prolactin levels of, at least, 5 ng/mL for males and 7 ng/mL for females can be used as cut-off levels for normal prolactin reserve. Minimum peak prolactin responses of 18 ng/mL for males and 41 ng/mL for females to TRH stimulation can exclude hypoprolactinemia. However, larger population studies across different age groups and sexes are needed to better define normal basal prolactin levels and prolactin responses to the TRH stimulation test.
催乳素是一种由199个氨基酸组成的多肽激素，由催乳细胞合成。其主要作用于乳腺和性腺轴，但也会影响不同的器官和系统，尤其是代谢功能。目前的文献主要集中在高催乳素血症的诊断、监测和治疗上。由于缺乏针对低催乳素血症的成熟有效治疗方法，临床上对此并未给予足够重视。因此，关于其诊断的数据有限。低催乳素血症与2型糖尿病、脂肪肝、血脂异常、生育问题、性功能障碍和心血管疾病增加等代谢功能障碍有关。虽然低催乳素血症常被视为垂体损伤导致的联合激素缺乏的一部分，但孤立性催乳素缺乏很少见。低催乳素血症可作为广泛垂体损伤和功能障碍的标志物。血清催乳素水平低或检测不到，以及促甲状腺激素释放激素（TRH）刺激试验中催乳素峰值不足，被认为是低催乳素血症的诊断依据。性别似乎会影响基础催乳素水平和TRH刺激试验反应。男性基础催乳素水平至少为5 ng/mL，女性为7 ng/mL，可作为正常催乳素储备的临界值。男性对TRH刺激的最小催乳素峰值反应为18 ng/mL，女性为41 ng/mL，可排除低催乳素血症。然而，需要对不同年龄组和性别的更大规模人群进行研究，以更好地确定正常基础催乳素水平以及催乳素对TRH刺激试验的反应。
