title: Age- and sex-specific association of circulating osteocalcin with dynamic measures of glucose homeostasis.
abstract: CONCLUSIONS
  Our study showed that serum osteocalcin levels are closely related to glucose metabolism in men of all ages and younger women. This association disappeared in postmenopausal women in which increases bone turnover rates. The association between serum osteocalcin levels and glucose homeostasis should be interpreted according to age and sex.
  
  
  BACKGROUND
  Osteocalcin, a marker of bone formation, appears to be associated with glucose homeostasis. We investigated the age- and sex-specific association of serum osteocalcin level with variables related to glucose metabolism.
  
  
  METHODS
  This study was based on cross-sectional analysis from 719 participants aged 20-85 years after excluding patients taking antidiabetic or antiosteoporotic drugs. The subjects were divided into four groups according to age and sex as follows: men <50 years (n = 131), men ≥50 years (n = 191), women <50 years (n = 108), and women ≥50 years (n = 279). Anthropometric and biochemical variables including insulin resistance (HOMA-IR) and β cell function (HOMA-β) from a 75-g oral glucose tolerance test, and serum 25-OH-vitamin D and parathyroid hormone levels were measured.
  
  
  RESULTS
  The serum osteocalcin level was significantly higher in women aged ≥50 years compared with women <50 years (20.4 ± 7.8 vs. 17.9 ± 6.8 ng/ml, p < 0.001), but there was no difference between men aged ≥50 years and men <50 years (16.4 ± 5.9 vs. 16.8 ± 6.0 ng/ml, p = 0.905). The participants diagnosed with diabetes had lower serum osteocalcin levels than normal or prediabetic participants. Multivariable regression analyses including HOMA-IR and HOMA-β indicated that serum osteocalcin levels had a negative and independent association with HbA1c levels in men and women aged <50 years, but not in women ≥50 years.
  
  
  CONCLUSIONS
  Low osteocalcin levels are associated with impaired glucose metabolism in men and premenopausal women. The osteocalcin levels may be determined by factors related to bone metabolism in postmenopausal women. Our data suggest that the serum levels of osteocalcin associated with glucose homeostasis should be interpreted according to age and sex.
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Department of Internal Medicine, Eulji University, Seoul, South Korea.
authors.forename: K Y
authors.initials: KY
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: K M
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, South Korea.
authors.forename: E J
authors.initials: EJ
authors.lastname: Ku
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: D-H
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: H C
authors.initials: HC
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: C S
authors.initials: CS
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: K S
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea. limsoo@snu.ac.kr.|Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea. limsoo@snu.ac.kr.|Department of Internal Medicine Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82 Gumi-ro 173beon-gil, Bundang-gu, Seongnam, 463-707, South Korea. limsoo@snu.ac.kr.
authors.forename: S
authors.initials: S
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D000886:Anthropometry / Q000379:methods; D001786:Blood Glucose / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods; D006442:Glycated Hemoglobin / Q000032:analysis; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D015675:Osteocalcin; C517652:hemoglobin A1c protein, human
keywords: Age; Gender; Glucose metabolism; Insulin resistance; Osteocalcin; β cell function