Change in Insulin Sensitivity and Lipid Profile After Dopamine Agonist Therapy in Patients With Prolactinoma

Abstract

Background

Prolactinomas are prolactin(PRL)-secreting neoplastic lesions that can lead to metabolic disturbances and insulin resistance. We aimed to find the change in insulin sensitivity and lipid profile in prolactinoma patients after dopamine therapy. 

Methodology

A prospective observational study was conducted at the Hayatabad Medical Complex, Peshawar between June 2019 to July 2020. All patients with newly diagnosed prolactinoma were eligible to partake in the study. Individuals with multiple hormone-producing pituitary tumors, hyperprolactinemia secondary to other causes than tumors, and those taking medication for hypercholesterolemia were excluded. Diagnosis of prolactinoma was established on the basis of elevated PRL levels on at least two occasions three days apart in addition to an MRI detecting prolactinoma on the hypothalamic-pituitary area. The mean dose for dopamine agonist was 5.8 ± 4.1 mg per day with a range between 1.25 to 15 mg. To assess the change in insulin resistance, the homeostatic model assessment insulin resistance (HOMA-IR) was computed. All data were recorded in a predefined proforma. 

Results 

The difference between pre- and post-treatment values for mean PRL levels was statistically significant (p<0.0001). There was a significant association between dopamine agonist treatment and the BMI (pre- vs. post-treatment; 28.9 ± 4.28 vs. 24.53 ± 2.2, p<0.0001). Both low-density lipoprotein (LDL)-cholesterol and HOMA-IR scores were significantly lower in the post-treatment group as compared to the pre-treatment group (p<0.0001). 

Conclusion

The present study indicated that dopamine agonist therapy was effective not only in lowering the serum PRL levels but also improved insulin sensitivity and decreased lipid metabolism, resulting in improved BMI. Further studies should explore the long-term side effects of dopamine agonists on patients with prolactinoma.