['To study the relationships of serum osteoprotegrin (sOPG), serum bone gamma-carboxyglutamine acid-containing protein (sBGP), and urine deoxypyridinoline (uDPD)/creatinine (Cr) with age and bone mineral density (BMD) in women.', 'ELISA was used to examine the sOPG, sBGP, and uDPD/Cr of 672 female volunteers aged 20-80. The BMD (QDR4500A) value of the anteroposterior lumbar spine and femoral neck were measured by DXA.', '(1) The levels of sOPG, sBGP, and uDPD/Cr in the age group of 30-39 were 2.8 pmol/L +/- 1.4 pmol/L, 5 microg/L +/- 3 microg/L, and 4.9 nmol/mmol +/- 2.5 nmol/mmol respectively, all significantly lower than those in the age groups 40-49, 50-59, and 60-69 (all P < 0.05). (2) In the age group 40-49, the values of sOPG, sBGP, and uDPD in menopausal subjects were significantly higher than those of the non-menopausal subjects (5.7 pmol/L +/- 3.1 pmol/L vs 3.4 pmol/L +/- 2.0 pmol/L, 11 microg/L +/- 5 microg/L vs 6 microg/L +/- 3 microg/L, and 6.9 nmol/mmol +/- 3.3 nmol/mmol vs 5.2 nmol/mmol +/- 3.9 nmol/mmol, all P < 0.001). (3) Age was positively correlated with sOPG, sBGP, uDPD/Cr, and BMD of anteroposterior lumbar spine and femoral neck (r = 0.130, 0.355, 0.106, -0.600, -0.545; P < 0.01). sOPG and sBGP were negatively correlated to anteroposterior lumbar spine BMD (r = -0.183, -0.108, P < 0.01; and r = -0.541, -0.441, P < 0.001). sOPG was positively correlated with sBGP and uDPD/Cr (r = 0.216 and 0.083; both P < 0.05).'] Are [ Serum osteoprotegrin and serum bone gamma-carboxyglutamine acid-containing protein correlated with bone mineral density in normal women ]?