title: Determinants of undercarboxylated and carboxylated osteocalcin concentrations in type 1 diabetes.
abstract: To determine whether undercarboxylated osteocalcin (UC-OC) or gamma-carboxyglutamic-carboxylated-type osteocalcin (GLA-OC) concentrations deviate from normal in type 1 diabetes (T1D), serum levels were compared between 115 subjects with T1D and 55 age-matched healthy controls. UC-OC and GLA-OC concentrations were similar between groups; however, in T1D, UC-OC correlated positively with markers of insulin exposure, either endogenously produced or exogenously administered.
  
  
  BACKGROUND
  A study was conducted to determine whether dysregulation of circulating concentrations of UC-OC or GLA-OC occurs in patients with type 1 diabetes, a condition of insulin deficiency without insulin resistance.
  
  
  METHODS
  We measured serum concentrations of UC-OC and GLA-OC in 115 subjects with T1D, ages 14-40 years, and in 55 age-matched healthy control subjects. Relationships between UC-OC and GLA-OC concentrations and patient characteristics (gender and age), indices of glycemic control (hemoglobin A1c (HbA1c), fasting plasma glucose, C-peptide concentration, 3-day average glucose measured by a continuous glucose sensor, total daily insulin dose) and circulating indices of skeletal homeostasis (total calcium, 25-OH vitamin D, parathyroid hormone, insulin-like growth factor 1 (IGF-1), type 1 collagen degradation fragments (CTX), adiponectin, leptin) were examined. Between group differences in the concentrations of UC-OC and GLA-OC were the main outcome measures.
  
  
  RESULTS
  Although adiponectin levels were higher in the T1D group, between-group comparisons did not reveal statistically significant differences in concentration of UC-OC, GLA-OC, CTX or leptin between the T1D and control populations. Instead, by multivariate regression modeling, UC-OC was correlated with younger age (p < 0.001), higher CTX (p < 0.001), lower HbA1c (p = 0.013), and higher IGF-1 (p = 0.086). Moreover, within the T1D subgroup, UC-OC was positively correlated with C-peptide/glucose ratio (reflecting endogenous insulin secretion), with IGF-1 (reflecting intra-portal insulin sufficiency), and with total daily insulin dose.
  
  
  CONCLUSIONS
  In T1D, UC-OC appears to correlate positively with markers of insulin exposure, either endogenously produced or exogenously administered.
authors: Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital Research Institute, Little Rock, AR 72205, USA. thrailkillkathrynm@uams.edu
authors: K M
authors: KM
authors: Thrailkill
authors: C-H
authors: CH
authors: Jo
authors: G E
authors: GE
authors: Cockrell
authors: C S
authors: CS
authors: Moreau
authors: C K
authors: CK
authors: Lumpkin
authors: J L
authors: JL
authors: Fowlkes
mesh_terms: D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D015675:Osteocalcin / Q000097:blood* / Q000378:metabolism; D055815:Young Adult
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D020738:Leptin; D015675:Osteocalcin