Sarink D, Yang J, Johnson T, et al. - Researchers investigated if reproductive and lifestyle factors influence circulating soluble Receptor Activator of Nuclear Factor κB (sRANKL) and osteoprotegerin (OPG) concentrations in pre- and postmenopausal women. From a breast cancer case–control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, they included 2,016 controls [n = 1,552 (76%) postmenopausal, n = 757 (38%) using postmenopausal hormone therapy (PMH)]. Lower sRANKL concentrations in postmenopausal women and higher OPG concentrations in all women were observed in correlation with older age at blood collection. Among premenopausal women and postmenopausal PMH users, they observed the longer duration of oral contraceptive use to be correlated with higher OPG. In postmenopausal non-PMH users, longer duration of oral contraceptive use and current (vs never) smoking were observed to be correlated with lower sRANKL concentrations. Women with higher BMI had higher sRANKL concentrations. Observations suggest that hormone-related factors in pre- and postmenopausal women minimally influence circulating sRANKL and OPG concentrations.