title: Is the relationship between adherence behaviours and glycaemic control bi-directional at adolescence? A longitudinal cohort study.
abstract: OBJECTIVE
  To analyse the change in adherence to diabetes treatment and its association with metabolic control from childhood to adolescence. The Tanner pubertal staging model was selected as a marker of developmental maturity.
  
  
  METHODS
  In a multicentre, longitudinal cohort study, 142 children with Type 1 diabetes completed a scale that assessed adherence to treatment and a test of diabetes knowledge at the beginning of the study (T0) and four years later (T4). HbA1c and clinical data were collected at T0 and at T4.
  
  
  RESULTS
  From T0 to T4, the mean HbA1c increased from 8.2 +/- 1.6 to 9.1 +/- 1.4% (P < 0.001). Among patients at pubertal stages 1-4, adherence did not decline from T0 to T4, whereas the HbA1c level increased and a positive correlation between adherence and the knowledge score was noted (r = 0.32; P < 0.02). Among adolescents at pubertal stage 5, the level of adherence decreased (P < 0.01) from T0 to T4 and the HbA1c level increased despite an increase in the knowledge score (P < 0.001), a negative correlation between HbA1c and adherence was found (r = -0.37; P = 0.001) and adherence at T4 significantly added to the prediction of HbA1c at T4.
  
  
  CONCLUSIONS
  In this longitudinal study, an initial worsening of glycaemic control as a result of puberty preceded worsening of adherence behaviours. Low levels of adherence become predictive of HbA1c degradation among pubertal stage 5 adolescents. These results suggest a potential bi-directional relationship between glycaemic control and adherence.
authors.affiliation: Department of Paediatric Endocrinology and Diabetology and INSERM U 457, Robert Debré Hospital, Paris, France. dupafed@club-internet.fr
authors.forename: L
authors.initials: L
authors.lastname: Du Pasquier-Fediaevsky
authors.forename: A J
authors.initials: AJ
authors.lastname: Chwalow
authors.forename: N
authors.initials: N
authors.lastname: Tubiana-Rufi
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000375:Aging / Q000523:psychology; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000523:psychology* / Q000628:therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010349:Patient Compliance / Q000523:psychology*; D011627:Puberty / Q000523:psychology; D012044:Regression Analysis; D012648:Self Care / Q000523:psychology
chemical_list: D006442:Glycated Hemoglobin