Positive association of serum prolactin concentrations with all-cause and cardiovascular mortality

Increased serum prolactin (PRL) concentrations have been associated with adverse cardiovascular risk profiles, but the relation between PRL and mortality risk is unknown.

We evaluated 3929 individuals (1946 men and 1983 women) aged 20-81 (mean 50.3 years) from the population-based Study of Health in Pomerania (SHIP). Associations of continuous [per standard deviation (SD) increase] and categorized (sex-specific tertiles) serum PRL concentrations with all-cause and cause-specific mortality were analysed separately for men and women by age- and multivariable-adjusted Cox regression models. During a median follow-up period of 10.1 years (38 231 person-years), 419 deaths (10.7%), 132 cardiovascular deaths (3.4%), and 152 cancer deaths (3.9%) were observed. After multivariable adjustment, we observed a positive association of PRL with all-cause mortality in men and women [hazard ratio (HR) per SD increase: 1.17, 95% confidence interval (CI): 1.07-1.29 and HR: 1.22, 95% CI: 1.03-1.46, respectively]. Similarly, individuals with PRL concentrations in the highest tertile (when compared with lowest PRL tertile) experienced the highest mortality risk (men: HR, 1.75; 95% CI, 1.32-2.32; women: HR, 1.66; 95% CI, 1.08-2.56), with a significant trend across PRL tertiles (P- for trend <0.05). Cause-specific mortality analyses yielded similar associations for cardiovascular death in both sexes, but for cancer death only in men.

This is the first study to report an independent positive association of PRL concentrations with all-cause and cardiovascular mortality. Further studies are required to confirm our findings and to elucidate the potential role of PRL as a useful biomarker of cardiovascular risk and mortality assessment.