Clinical significance of anaemia associated with prolactin-secreting pituitary tumours in men

Background: An association between prolactin-secreting pituitary adenomas and anaemia in male patients has been recently reported. Our aim has been to evaluate the prevalence of anaemia in men with prolactinomas and to assess the relationships between haemoglobin concentrations and pituitary function at diagnosis in these patients.

Methods: In a retrospective analysis, 26 male patients with prolactinomas (22 macroprolactinomas and 4 microprolactinomas) were studied. Blood haemoglobin concentration, haematocrit value and baseline hormonal levels were collected at the time of prolactinoma diagnosis. The presence or absence of partial or total hypopituitarism was also evaluated at diagnosis. Logistic regression analysis was used to assess the presence of anaemia as a function of serum hormone concentrations and pituitary dysfunction.

Results: Patient bearing macroprolactinomas showed significant lower haemoglobin concentrations than those found in patients with microprolactinomas (13.5 ± 1.2 g/dl vs. 15.1 ± 0.9 g/dl, p < 0.05). Anaemia (haemoglobin < 13 g/dl) was present in nine (34.6%) patients, all of them with macroprolactinomas. The degree of anaemia was mild (haemoglobin > 11 g/dl) in all patients. No correlation between haemoglobin and serum prolactin was found. Haemoglobin concentration was significantly lower in men with hypogonadism (n = 14) than in eugonadal men. Haemoglobin value was also significantly lower in patients with total hypopituitarism in comparison with patients with partial hypopituitarism (12.4 ± 1.0 g/dl, n = 7 vs. 14.0 ± 1.2 g/dl, n = 13, p = 0.007). The number of affected pituitary axes was found to be related with the presence of anaemia. Logistic regression analysis showed that anaemia was related with FT4 (OR 0.23; 95% CI 0.06-0.81, p = 0.02), cortisol (OR 0.81; 95% CI 0.68-0.96, p= 0.02) and the presence of hypopituitarism (OR 20.0; 95% CI 1.68-238.63, p = 0.02).

Conclusions: Anaemia was found in about a third of men with prolactinomas. Our results also suggest that the presence of anaemia in these patients seems to be associated with panhypopituitarism.