Metabolic parameters in patients with prolactinomas: a case-control study

Abstract

Introduction: Prolactinomas are benign tumours of the pituitary gland causing hyperprolactinaemia. They occur most often in women between the second and fifth decade. Presenting symptoms are mostly due to hypogonadism or mass effect. The first line therapy is treatment with cabergoline, a dopamine agonist, inhibiting the anterior pituitary function. Only in resistant prolactinomas surgery or radiotherapy should be carried out. Other than symptoms associated with hyperprolactinemia or hypogonadism, an adverse metabolic profile has been described in prolactinoma patients, seemingly improving during cabergoline therapy. The available studies are, however, inconclusive. The aim of this study is to compare lipid and glucose parameters in treatment-naϊve prolactinoma patients to healthy controls and to examine whether an improvement in these parameters can be observed after dopamine agonist therapy. Methods: In this case control study 21 patients with micro- and macroprolactinomas and 30 healthy controls were included. They were recruited between 2014 and 2019 at the outpatient clinic of the Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Austria. At baseline and at follow-up metabolic parameters including low density lipoprotein LDL, high density lipoprotein HDL, total cholesterol, triglycerides, glycated haemoglobin HbA1c and fasting glucose as well as the BMI were collected. Additionally, pituitary hormone levels and bone mineral density were investigated. Results: The LDL cholesterol was significantly higher in untreated prolactinoma patients with 130 mg/dl (107 – 147,5) compared to 94,5 mg/dl (80 – 127,5) in controls (p=0,030). After adjustment for bodyweight, none of the other metabolic parameters showed a significant difference. Furthermore, no difference in bone mineral density could be found. At follow-up, total cholesterol decreased significantly from 214,50 mg/dl (±38,32) to 196,89 mg/dl (±40,62). There was also a significant decrease in LDL cholesterol levels from 135,72 mg/dl (±35,65) initially to 119,56 mg/dl (±35,61) after treatment with cabergoline (different to initially reported LDL, due to the fact that one patient had to be excluded for follow-up analysis). Furthermore, a significant increase in total testosterone from 1,28 ng/ml (±0,63) to 2,44 ng/ml (±1,03) (p

Date of Award	2021
Original language	English
Awarding Institution	Medical University Graz
Supervisor	Verena Theiler-Schwetz (Supervisor) & Barbara Obermayer-Pietsch (Co-supervisor)