Different effects of cabergoline and bromocriptine on metabolic and cardiovascular risk factors in patients with elevated prolactin levels.

Hyperprolactinaemia is suggested to be associated with metabolic and hormonal complications. No previous study has compared the effect of different dopamine agonists on plasma lipids, carbohydrate metabolism markers and cardiovascular risk factors in patients with elevated prolactin levels. The study included eight bromocriptine-resistant women with prolactinoma (group 1) and twelve matched women with hyperprolactinaemia unrelated to prolactinoma (group 2). Group 1 was then treated with cabergoline, while group 2 with bromocriptine. Plasma lipids, glucose homeostasis markers and plasma levels of prolactin, insulin-like growth factor-1 (IGF-1) and cardiovascular risk factors were assessed before and after 6 months of therapy. Both treatments normalized plasma prolactin levels. Cabergoline reduced triglycerides, 2-hr post-challenge plasma glucose, the homeostatic model assessment of insulin resistance (HOMA-IR), and circulating levels of IGF-1, free fatty acids (FFA), uric acid, high-sensitivity C-reactive protein (hsCRP), homocysteine and fibrinogen, as well as increased HDL cholesterol and 25-hydroxyvitamin D. With the exception of a reduction in HOMA-IR, bromocriptine treatment produced no significant effect on the investigated biomarkers. Cabergoline was superior to bromocriptine in affecting 2-hr post-challenge plasma glucose levels, HOMA-IR, as well as circulating levels of IGF-1, FFA, uric acid, hsCRP, homocysteine, fibrinogen and 25-hydroxyvitamin D. Our results may suggest that cabergoline is superior to bromocriptine when it comes to affecting atherogenic dyslipidaemia, insulin sensitivity and circulating levels of cardiovascular risk factors in hyperprolactinaemic patients. These findings seem to support previous observations that cabergoline may be a better treatment for patients with elevated prolactin levels than bromocriptine.