Association between prolactin and history of stress fracture in elite sprinters and jumpers

To investigate the risk factor for stress fractures and the characteristics of the laboratory data in eumenorrheic female track and field athletes competing at an elite level. Elite eumenorrheic sprinters and jumpers were recruited. Bone mineral density, bone metabolism markers, 25-OH Vitamin D, and hormones, including prolactin and free testosterone were measured. Total of 84 high school and collegiate athletes were enrolled in the study and among them, 33 athletes had a history of stress fractures during or after high school. Their personal background, bone mineral density, bone metabolism markers, 25-OH Vitamin D, and free testosterone were not different between the group with a history of stress fracture and without a history of stress fracture. Prolactin levels were higher in athletes with stress fractures compared to those without (15.70 ± 10.59 ng/mL vs. 11.59 ± 5.06 ng/mL, p = 0.081), although this difference was not statistically significant. Logistic regression analysis revealed that prolactin was a significant predictive factor for stress fractures (odds ratio: 1.10; 95% CI: 1.01-1.20; p = 0.023). Prolactin may be linked to stress fractures in eumenorrheic sprinters and jumpers, and further research is needed to confirm its role as a predictive factor.