title: Continuous glucose monitoring and HbA1c in the evaluation of glucose metabolism in children at high risk for type 1 diabetes mellitus.
abstract: OBJECTIVE
  Continuous glucose monitoring (CGM) parameters, self-monitored blood glucose (SMBG), HbA1c and oral glucose tolerance test (OGTT) were studied during preclinical type 1 diabetes mellitus.
  
  
  METHODS
  Ten asymptomatic children with multiple (⩾2) islet autoantibodies (cases) and 10 age and sex-matched autoantibody-negative controls from the Type 1 Diabetes Prediction and Prevention (DIPP) Study were invited to 7-day CGM with Dexcom G4 Platinum Sensor. HbA1c and two daily SMBG values (morning and evening) were analyzed. Five-point OGTTs were performed and carbohydrate intake was assessed by food records. The matched pairs were compared with the paired sample t-test.
  
  
  RESULTS
  The cases showed higher mean values and higher variation in glucose levels during CGM compared to the controls. The time spent ⩾7.8mmol/l was 5.8% in the cases compared to 0.4% in the controls (p=0.040). Postprandial CGM values were similar except after the dinner (6.6mmol/l in cases vs. 6.1mmol/l in controls; p=0.023). When analyzing the SMBG values higher mean level, higher evening levels, as well as higher variation were observed in the cases when compared to the controls. HbA1c was significantly higher in the cases [5.7% (39mmol/mol) vs. 5.3% (34mmol/mol); p=0.045]. No differences were observed in glucose or C-peptide levels during OGTT. Daily carbohydrate intake was slightly higher in the cases (254.2g vs. 217.7g; p=0.034).
  
  
  CONCLUSIONS
  Glucose levels measured by CGM and SMBG are useful indicators of dysglycemia during preclinical type 1 diabetes mellitus. Increased evening glucose values seem to be common in children with preclinical type 1 diabetes mellitus.
authors.affiliation: Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland. Electronic address: olli.helminen@oulu.fi.
authors.forename: Olli
authors.initials: O
authors.lastname: Helminen
authors.affiliation: Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Tytti
authors.initials: T
authors.lastname: Pokka
authors.affiliation: Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Päivi
authors.initials: P
authors.lastname: Tossavainen
authors.affiliation: Immunogenetics Laboratory, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Ilonen
authors.affiliation: Tampere Centre for Child Health Research, Tampere University Hospital, Tampere, Finland; Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland; Folkhälsan Research Center, Helsinki, Finland.
authors.forename: Mikael
authors.initials: M
authors.lastname: Knip
authors.affiliation: Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Veijola
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring / Q000379:methods*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods*; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: Autoantibodies; Blood-glucose; Glucose intolerance; Prediabetes; Self-monitoring; Type 1 diabetes mellitus