Serum prolactin and macroprolactin in heart failure: no relation to established laboratory or clinical parameters

Background A few smaller studies have reported that the prolactin concentration is elevated in connection with heart failure. As heart failure is combined with disturbances of several biological systems any or all of which may also influence prolactin concentrations, we wanted to evaluate the relation of prolactin to prognosis in elderly patients. Methods A total of 462 elderly patients from a primary health-care centre, all with symptoms of heart failure, were included. In addition to clinical examination including echocardiography, concentrations of prolactin, macroprolactin, C-reactive protein, thyroid-stimulating hormone and N-terminal pro B-type natriuretric peptide (NT-proBNP) were measured. Patients were then followed for 10 y, and all incidents of cardiovascular mortality were registered. Results After excluding patients with macroprolactin, hyperprolactinaemia was found in 3.7% of the patients. There were no differences in prolactin concentrations or in the frequency of macroprolactin between patients with heart failure and those with normal cardiac function, defined as left ventricular ejection fraction of at least 50%. No significant correlation could be found between NT-proBNP and prolactin. Neither could any association be found between cardiovascular mortality and prolactin concentration during 10 y of follow-up. Conclusions Prolactin concentrations were not associated with cardiovascular mortality or any clinical or biochemical marker of heart failure. Macroprolactin was found in similar frequency among patients with and without heart failure, and showed no correlation with mortality risk.