title: Serum undercarboxylated osteocalcin correlates with hemoglobin A1c in children with recently diagnosed pediatric diabetes.
abstract: BACKGROUND
  Osteocalcin (OC), a hormone secreted by osteoblasts, improves beta-cell function in vitro and in vivo. We aimed to understand the relationship between OC and hemoglobin A1c (HbA1c) in pediatric diabetes.
  
  
  METHODS
  Children (n = 70; mean [SD] age = 11.8 years [3.1]; 34.3% non-Hispanic white, 46.3% Hispanic, 14.9% African-American, 4.5% other) newly diagnosed with diabetes (69.1% type 1 diabetes [T1D], 30.9% type 2 diabetes [T2D]) were studied. We collected clinical data at diagnosis and first clinical visit (V1) 9 weeks later (interquartile range [IQR] = 7.9-12.0). Serum undercarboxylated OC (uOC) and carboxylated OC (cOC) were measured 7.0 weeks (IQR 4.3-8.9) after diagnosis.
  
  
  RESULTS
  Mean [SD] uOC was 20.3 (19.6) ng/mL, cOC 29.7 [13.7] ng/mL and u/cOC 0.68 [0.81]. uOC, cOC, or u/cOC were not different by gender, race/ethnicity, age, diabetes type, BMI percentile, or random C-peptide, glucose or HbA1c at diagnosis. However, among 61 children with V1 within 4 months of diagnosis, uOC was higher in those with V1 HbA1c < 7.5% (HbA1c < 58 mmol/mol) (uOC=33.1 [22.0]) compared with children with HbA1c ≥ 7.5% (uOC=17.4 [2.3], P = .0004). The difference was larger among patients with T2D (34.6 and 4.7 ng/mL, respectively, P = .0001) than T1D (32.2 and 19.3, P = .0169), and in males (36.1 and 17.4, P = .018) than females (27.6 and 17.3, P = .072). Analysis for u/cOC were similar while there were no differences in cOC. uOC was inversely correlated with HbA1c at V1 (Spearman's rho = -0.29, P = .02).
  
  
  CONCLUSIONS
  Our findings suggest that serum uOC is inversely related to HbA1c shortly after diagnosis of pediatric diabetes. This potentially modifiable factor of glucose metabolism warrants further studies.
authors.affiliation: Diabetes and Endocrinology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Redondo
authors.affiliation: Center for Outcomes Research, Methodist Hospital Research Institute, Houston, Texas.
authors.forename: Beverly A
authors.initials: BA
authors.lastname: Shirkey
authors.affiliation: Department of Surgery, Houston Methodist Hospital, Houston, Texas.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Fraga
authors.affiliation: Department of Surgery, Houston Methodist Hospital, Houston, Texas.
authors.forename: A Osama
authors.initials: AO
authors.lastname: Gaber
authors.affiliation: Department of Surgery, Houston Methodist Hospital, Houston, Texas.|Cell and Molecular Biology Weill Cornell Medical College, New York, New York.
authors.forename: Omaima M
authors.initials: OM
authors.lastname: Sabek
mesh_terms: D002096:C-Peptide / Q000097:blood; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood*; D011446:Prospective Studies
chemical_list: D002096:C-Peptide; D006442:Glycated Hemoglobin; D015675:Osteocalcin; C517652:hemoglobin A1c protein, human
keywords: diabetes; hemoglobin A1c; new onset; osteocalcin; pediatrics