title: Vitamin K nutritional status and undercarboxylated osteocalcin in postmenopausal osteoporotic women treated with bisphosphonates.
abstract: Serum undercarboxylated osteocalcin (ucOC) is an index of vitamin K nutritional status in treatment-naive postmenopausal osteoporotic women. The purpose of the present study was to reveal the association between vitamin K nutritional status and serum ucOC concentrations in postmenopausal osteoporotic women taking bisphosphonates. Eighty-six postmenopausal women with osteoporosis (age range: 47-90 years) initiated bisphosphonate treatment. Vitamin K nutritional status was evaluated using a simple vitamin K-intake questionnaire and serum ucOC concentrations were measured after 6 months of treatment. The patients were divided into two groups according to the simple vitamin K-intake questionnaire score: a low vitamin K-intake (score <40) group (n=67) and a normal vitamin K-intake (score >=40) group (n=19). There were no significant differences between the groups in baseline parameters including age, height, body weight, body mass index, serum alkaline phosphatase (ALP), urinary cross-linked N-terminal telopeptides of type I collagen (NTX), and changes in serum ALP and urinary NTX concentrations during the 6-month treatment period. However, the mean serum ucOC concentration after 6 months of treatment was significantly higher in the low vitamin K-intake group (2.79 ng/mL) than in the normal vitamin K-intake group (2.20 ng/mL). These results suggest that 78% of postmenopausal osteoporotic women treated with bisphosphonates may have vitamin K deficiency as indicated by low vitamin K-intake and high serum ucOC concentrations, despite having a similar reduction in bone turnover to women who have normal vitamin K-intake.
authors.affiliation: Institute for Integrated Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. jiwamoto@a8.keio.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Iwamoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takada
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000097:blood / Q000627:therapeutic use; D004164:Diphosphonates / Q000097:blood / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008875:Middle Aged; D009752:Nutritional Status / Q000502:physiology*; D015675:Osteocalcin / Q000097:blood*; D015663:Osteoporosis, Postmenopausal / Q000097:blood* / Q000188:drug therapy; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014812:Vitamin K / Q000008:administration & dosage / Q000097:blood*; D014813:Vitamin K Deficiency / Q000097:blood / Q000188:drug therapy*
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D015675:Osteocalcin; D014812:Vitamin K