Estrogen and peptide YY are associated with bone mineral density in premenopausal exercising women

► Fasting total PYY concentrations are negatively associated with total body BMD and total hip BMD. ► Estrogen is positively associated with total body BMD and lumbar spine BMD. ► PYY, estrogen and body mass are associated with BMD in premenopausal exercising women. ► Elevated PYY and suppressed estrogen concentrations could be directly contributing to low BMD in exercising women with amenorrhea.