Impact of cabergoline therapy on the metabolic and cardiovascular profile in patients with prolactinoma

Objective: Although the effects of hyperprolactinemia on the reproductive system are well established, increasing evidence suggests that it may also be associated with cardiometabolic abnormalities, including insulin resistance, obesity, dyslipidemia, hepatic steatosis, hypertension, atherosclerosis, and endothelial dysfunction. This study aimed to evaluate the effects of long-term cabergoline treatment on metabolic parameters, non-alcoholic fatty liver disease, and cardiovascular risk markers in patients with prolactinoma. Materials and Methods: This single-center, retrospective observational study included 243 patients aged 18–65 years who were diagnosed with prolactinoma at the Endocrinology and Metabolism Outpatient Clinic of Başkent University Ankara Hospital between 2011 and 2023 and received cabergoline treatment for at least one year. Sociodemographic and clinical characteristics, data regarding prolactinoma and cabergoline treatment, hormone levels, anthropometric measurements, glycemic and lipid parameters, markers associated with hepatic steatosis, and cardiovascular risk measurements were retrospectively reviewed. Data obtained at the initiation of cabergoline treatment and at months 6 and 12 were compared. Results: The mean age of the patients was 33.20±9.76 years, 82.7% were female, and 81% had microprolactinoma. The response rate to cabergoline treatment was 88.9%, and the mean baseline prolactin concentration was 237.71 µg/L. Prolactin concentrations decreased significantly at months 6 and 12 (p<0.001). Significant improvements were observed in body mass index, waist circumference, fasting plasma glucose, HOMA-IR, and other glycemic indices, as well as in total cholesterol, LDL cholesterol, and triglyceride concentrations. The fatty liver index and ultrasonographic grade of hepatic steatosis decreased during treatment. Long-term therapy was associated with significant reductions in systolic and diastolic blood pressure. C-reactive protein, Framingham risk score, epicardial adipose tissue thickness, and carotid intima-media thickness decreased, whereas flow-mediated dilation increased, indicating improvements in cardiovascular risk, atherosclerosis, and endothelial dysfunction. No significant correlation was identified between the reduction in prolactin concentration and most changes in metabolic or cardiovascular parameters. Among the 29 patients with echocardiographic data at month 12, four patients (13.8%) had cardiac or echocardiographic findings potentially associated with cabergoline treatment. Conclusion: Hyperprolactinemia appears to be associated with an unfavorable metabolic and cardiovascular profile in patients with prolactinoma. Cabergoline treatment was associated with significant improvements in body weight, glycemic control, insulin resistance, lipid profile, hepatic steatosis, blood pressure, atherosclerosis-related markers, and endothelial function. The absence of a strong correlation between these improvements and the reduction in prolactin concentrations suggests that cabergoline may have direct cardiometabolic effects. Nevertheless, clinical and echocardiographic monitoring may be appropriate, particularly in patients receiving long-term treatment, because of the potential risk of cardiac adverse effects.