title: Decline of C-peptide during the first year after diagnosis of Type 1 diabetes in children and adolescents.
abstract: OBJECTIVE
  We studied the decline of C-peptide during the first year after diagnosis of Type 1 diabetes (T1D), and its relation to various factors.
  
  
  METHODS
  3824/4017 newly diagnosed patients (95%) were classified as T1D in a national study. In a non-selected subgroup of 1669 T1D patients we determined non-fasting C-peptide both at diagnosis and after 1 year, and analyzed decline in relation to clinical symptoms and signs, initial C-peptide and occurrence of auto-antibodies.
  
  
  RESULTS
  Younger children lost more C-peptide (p<0.001) and the higher the C-peptide at diagnosis the larger the decline during the first year (p<0.0000). Patients with higher BMI had higher C-peptide at diagnosis but lost more (p<0.01), and those with lower HbA1c, without symptoms and signs at diagnosis, and with higher BMI, had higher C-peptide at diagnosis, but lost more during the first year (p<0.001). Finally, patients diagnosed during autumn had higher C-peptide at diagnosis, but lost more during the coming year (p<0.001). Occurrence of auto-antibodies did not correlate with C-peptide decline, except possibly for a more rapid loss in IAA-positive patients.
  
  
  CONCLUSIONS
  Even in a restricted geographical area and narrow age range (<18 years), the natural course of Type 1 diabetes is heterogeneous. This should be considered in clinical trials.
authors.affiliation: Division of Pediatrics, Department of Clinical and Experimental Medicine, Linköping University, and Pediatric Clinic, Östergötland County Council, Linköping, Sweden. johnny.ludvigsson@liu.se
authors.forename: Johnny
authors.initials: J
authors.lastname: Ludvigsson
authors.forename: Annelie
authors.initials: A
authors.lastname: Carlsson
authors.forename: Ahmed
authors.initials: A
authors.lastname: Deli
authors.forename: Gun
authors.initials: G
authors.lastname: Forsander
authors.forename: Sten-A
authors.initials: SA
authors.lastname: Ivarsson
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kockum
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindblad
authors.forename: Claude
authors.initials: C
authors.lastname: Marcus
authors.forename: Åke
authors.initials: Å
authors.lastname: Lernmark
authors.forename: Ulf
authors.initials: U
authors.lastname: Samuelsson
mesh_terms: D000293:Adolescent; D002096:C-Peptide / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans
chemical_list: D002096:C-Peptide; D006442:Glycated Hemoglobin