title: The true value of HbA1c as a predictor of diabetic complications: simulations of HbA1c variables.
abstract: OBJECTIVE
  The updated mean HbA1c has been used in risk estimates of diabetic complications, but it does not take into account the temporal relationship between HbA1c and diabetic complications. We studied whether the updated mean HbA1c underestimated the risk of diabetic complications.
  
  
  METHODS
  Continuous HbA1c curves for 10,000 hypothetical diabetes patients were simulated over an average of 7 years. Simulations were based on HbA1c values encountered in clinical practice. We assumed that each short time interval of the continuous HbA1c curves had a long-lasting effect on diabetic complications, as evidenced by earlier studies. We tested several different HbA1c variables including various profiles, e.g. different duration, of such a long-lasting effect. The predictive power of these variables was compared with that of the updated mean HbA1c.
  
  
  RESULTS
  The predictive power of the constructed HbA1c variables differed considerably compared to that of the updated mean HbA1c. The risk increase per standard deviation could be almost 100% higher for a constructed predictor than the updated mean HbA1c.
  
  
  CONCLUSIONS
  The importance of good glycemic control in preventing diabetic complications could have been underestimated in earlier hallmark studies by not taking the time-dependent effect of HbA1c into account.
authors.affiliation: Department of Medicine, Uddevalla Hospital, Uddevalla, Sweden. lind.marcus@telia.com
authors.forename: Marcus
authors.initials: M
authors.lastname: Lind
authors.forename: Anders
authors.initials: A
authors.lastname: Odén
authors.forename: Martin
authors.initials: M
authors.lastname: Fahlén
authors.forename: Björn
authors.initials: B
authors.lastname: Eliasson
mesh_terms: D003198:Computer Simulation; D048909:Diabetes Complications / Q000175:diagnosis*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D011379:Prognosis; D012307:Risk Factors; D013997:Time Factors
chemical_list: D006442:Glycated Hemoglobin