[Clinical application of undercarboxylated osteocalcin]

Undercarboxylated osteocalcin (ucOC) is a sensitive marker of vitamin K (VK) status. Serum ucOC concentration in perimenopausal women is significantly higher than that in premenopausal women. In addition, serum ucOC concentration is closely associated with not only FSH concentration but also estradiol concentration. Serum ucOC concentration rapidly increases in women after bilateral oophorectomy. The effect of hormone therapy (HT) on alternate days on ucOC concentration is weaker than the effect of HT daily and ucOC concentration after 12 months of HT daily may be decreased due to the conversion of ucOC to carboxylated OC by the effect of VK through increased TG induced by oral conjugated equine estrogen (CEE) . Additionally, the effect of HT with transdermal estradiol on ucOC concentration in women is weaker than the effect of HT with oral CEE.