title: Positive association between serum levels of bone resorption marker CTX and HbA1c in women with normal glucose tolerance.
abstract: BACKGROUND
  The bone formation marker osteocalcin (OCN) has a beneficial effect on glucose metabolism. In mice, the OCN bioactivity is induced by bone resorption. But in humans, the role of bone resorption in modulating glucose homeostasis is not clear.
  
  
  OBJECTIVE
  Our study aimed to examine the relationship between bone resorption and glucose homeostasis in humans.
  
  
  METHODS
  This was a cross-sectional study conducted in a university teaching hospital.
  
  
  METHODS
  A total of 195 women with normal glucose tolerance (NGT) were analyzed.
  
  
  METHODS
  Serum OCN, cross-linked C-telopeptide of type I collagen (CTX), fasting plasma glucose, and 2h post-challenge glucose levels during oral glucose tolerance test, fasting insulin, glycated hemoglobin A1c (HbA1c), hepatic and renal functions, electrolytes, and bone mineral densities (BMDs) at lumbar-spine and proximal femur, and anthropometric parameters were measured.
  
  
  RESULTS
  CTX was positively associated with HbA1c after adjustments for multiple confounding factors (r = 0.269, P = .006). OCN (β = 0.015, P = .000), lumbar-spine 2-4 (L2-4) BMD (β = -0.128, P = .003) and HbA1c (β = 0.051, P = .01) were the major determinants of the variations of CTX (adjusted R(2) for the model = 0.608, P = .01) based on multivariate regression analysis. Compared with those in the lowest HbA1c tertile, individuals in the highest tertile had significantly higher CTX concentrations (0.37 ± 0.15 ng/ml vs 0.26 ± 0.11 ng/ml, P = .000), even when multiple confounders were adjusted (P for trend = .015).
  
  
  CONCLUSIONS
  Bone resorption marker serum CTX was independently associated HbA1c in NGT women. Whether the increased CTX level in NGT subjects is an early marker predicting the subtle impairment of glucose homeostasis and the risk of occurrence of diabetes requires additional study.
authors.affiliation: Department of Endocrine and Metabolic Diseases, Rui-jin Hospital, Shanghai Jiao-tong University School of Medicine, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Rui-jin Hospital, Shanghai Jiao-tong University School of Medicine, Shanghai, China 200025.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xuan
authors.forename: Li-Hao
authors.initials: LH
authors.lastname: Sun
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.forename: Bei
authors.initials: B
authors.lastname: Tao
authors.forename: Wei-Qing
authors.initials: WQ
authors.lastname: Wang
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Zhao
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Liu
authors.forename: Guang
authors.initials: G
authors.lastname: Ning
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001862:Bone Resorption / Q000378:metabolism; D024042:Collagen Type I / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000097:blood*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D024042:Collagen Type I; D006442:Glycated Hemoglobin; D007328:Insulin; D015675:Osteocalcin; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; C517652:hemoglobin A1c protein, human