Role of prolactin as a cardiovascular risk in type 2 diabetes mellitus patients: a case-control study in Egypt

Prolactin is a recognized platelet co-stimulator due to enhancement of ADP-induced platelet aggregation, and hence participates in the atherosclerotic process. Studies had shown that human adipose tissue produces PRL as well as expresses the PRL receptor (PRLR), which highlights a previously unappreciated action of PRL as a cytokine involved in adipose tissue function. The aim of our study was to asses whether prolactin level is associated with the presence of cardiovascular risk in patients with acute myocardial infarction (AMI) and patients with type 2 diabetes mellitus (DM). This case-control study was conducted on 89 adult males (ages 40–60 years) divided into four groups: 25 diabetics with AMI patients (group 1), 24 non-diabetics with AMI patients (group 2), 20 diabetics but not known to have AMI (group 3), and 20 healthy controls (group 4), in whom serum prolactin was determined using commercially available ELISA kits. Prolactin levels increased along with increased serum troponin; group 1 had the highest level of serum prolactin (10.6 ± 6 ng/ml) in comparison to groups 2 (8.8 ± 4 ng/ml), 3 (6.9 ± 2 ng/ml), and 4 (5 ± 2 ng/ml). According to the cutoff of the receiver operating characteristic (ROC) curve, prolactin is considered better positive than negative marker in cases of AMI. Hyperprolactinemia may be associated with increased risk of atherosclerotic process and hence occurrence of AMI, as one of the serious macrovascular complications in diabetics. Elevated prolactin levels detected in diabetics having AMI supports the recent trend of using dopamine agonists, e.g., bromocriptine in treatment of type 2 DM especially those who had a prior ischemic event. Also, increased prolactin being associated with increased troponin level in AMI patients may be considered a prognostic factor correlated with the extent of myocardial damage.