title: Influence of plasma glucagon levels on glycemic control in children with type 1 diabetes.
abstract: OBJECTIVE
  The aim of this study was to investigate the association between plasma glucose (PG), HbA1c and plasma glucagons levels in children with type 1 diabetes to determine the influence of plasma glucagon on their glycemic control.
  
  
  METHODS
  The study was conducted in 60 Japanese children, aged 13.3 ± 4.6 years, with type 1 diabetes for at least 3 years of diabetes. Most of the subjects had absent pancreatic β-cell function. We compared the glucagon levels among patient groups stratified according to the 2-hour postprandial levels (<50, 50-99, 100-199, 200-299, and ≥ 300 mg/dL), and the HbA1c levels (<7.0, 7.0-7.9, 8.0-8.9, and ≥ 9%).
  
  
  RESULTS
  The mean 2-hour postprandial PG, HbA1c and plasma glucagon levels were 174 ± 97 mg/dL, 7.7 ± 1.3% and 84.0 ± 32.6 pg/mL, respectively. The glucagon levels were highly correlated with the PG levels (r=0.553, P<0.0001) and mildly correlated with the HbA1c levels (r=0.301, P=0.0192). Patients with high PG levels had significantly higher levels of glucagon as compared with those with lower PG levels (139.4 ± 47.2, 78.4 ± 17.3, 82.4 ± 21.0, 98.3 ± 29.2 and 93.8 ± 18.3 pg/mL, P=0.0009). On the other hand, there were no significant differences in plasma glucagon levels among patient groups stratified according to HbA1c levels (P=0.1566), however, patients with HbA1c levels ≥ 9% had significantly higher levels of glucagon than those with HbA1c levels < 7% (113.3 ± 53.4 vs 80.8 ± 18.4 pg/mL, P=0.0291).
  
  
  CONCLUSIONS
  These results suggest that patients with high PG are likely to have high concentrations of plasma glucagon, which may aggravate glycemic control progressively, leading to elevation of HbA1c levels.
authors.affiliation: Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan. turakami@med.nihon-u.ac.jp
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Urakami
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nagano
authors.forename: Junichi
authors.initials: J
authors.lastname: Suzuki
authors.forename: Ayako
authors.initials: A
authors.lastname: Yoshida
authors.forename: Shori
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hideo
authors.initials: H
authors.lastname: Mugishima
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D005934:Glucagon / Q000097:blood*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism; D007564:Japan; D008297:Male
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D005934:Glucagon; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human