Endocrine Abstracts

Purpose: The present study aims to investigate the effects of hyperprolactinemia (HPRL) and its pharmacological control with Cabergoline (CAB) on the risk of fractures in male patients affected by prolactinoma.

Methods: Observational single-center study was conducted on 39 male patients (median age 49±12,4 y) with prolactinoma, including 37 with macroprolactinoma and 2 with empty sellae. In patients PRL levels at diagnosis (PRL 0’), PRL at evaluation (PRL 1’), treatment duration (TD), CAB cumulative (CD) and mean dose (CM) were calculated. In the whole study population (n=39), anthropometric parameters (weight, height, BMI), testosterone dose, metabolic (vitamin D, serum calcium, fasting glucose, HbA1c), hormonal (FSH, LH, parathormone, total testosterone) parameters were evaluated. BMD was assessed by means of lumbar (LTS) and femoral neck t-scores (FTS), derived from bone mineralometry. Comparison of numerical data between patient groups stratified by quartiles of age, BMI, testosterone levels, PRL 0’, PRL 1’ and CM was detected.

Results: Based on the age quartiles, a statistically significant difference was found in the BMI between the four groups (P=0.03), particularly between the I and II groups (P=0.022). While no statistically significant differences in other parameters were found between the four groups. Based on testosterone quartiles, a statistically significant difference was found in PRL 1’ (P=0.018), particularly between group I and group II (P=0.017). Furthermore, no statistically significant differences were found in the groups of patients divided into quartiles of BMI, PRL 0’, PRL 1’, CM between parameters considered. At correlation study, no correlation was found between Femoral and Lumbar T-Score and PRL levels, testosterone, Cab dose, and BMI; while age was indirectly and significantly correlated with serum calcium levels (r=-0.39; P=0.019) and PRL values were directly and significantly correlated with Cab mean dose (r=0.55; P=0.003) and with disease duration (r=0.404; P=0.036). No other significance was found in the regression analysis.

Conclusions: In accordance with previous studies, hyperprolactinemia seems to be an independent risk factor on the alteration of bone mineral density and consequent fracture risk. As expected, a reduced level of calcium was found with increasing age. Finally, a data of particular interest was the detection of an influence of cabergoline on PTH levels.