title: Baseline HbA1c predicts attainment of 7.0% HbA1c target with structured titration of insulin glargine in type 2 diabetes: a patient-level analysis of 12 studies.
abstract: OBJECTIVE
  To determine whether baseline characteristics, especially haemoglobin A1c (HbA1c), predict the likelihood of reaching HbA1c ≤ 7.0% or the risk of experiencing hypoglycaemia after the addition of insulin glargine to oral therapy in type 2 diabetes.
  
  
  METHODS
  Pooled patient-level data from 12 prospective, randomized, controlled studies that used insulin glargine in a treat-to-target titration regimen seeking fasting glucose levels ≤5.5 mmol/l (100 mg/dl) were analysed. Baseline characteristics were evaluated by logistic regression models as predictors of reaching a target HbA1c ≤ 7.0% or experiencing confirmed hypoglycaemia. The effect of prior glycaemic control was further explored by analysis of categorical ranges of baseline HbA1c.
  
  
  RESULTS
  Of 2312 participants, 95% completed 24 weeks of treatment. Lower HbA1c at baseline was independently associated with reaching HbA1c target [adjusted odds ratio (OR) for 1% difference: 0.538, p < 0.0001] and also with likelihood of experiencing confirmed hypoglycaemic events (adjusted OR: 0.835, p < 0.0001) at week 24. In an unadjusted analysis by baseline HbA1c range, the strong association between baseline control and attaining target HbA1c was confirmed (75% with baseline HbA1c < 8.0%, 60% with baseline HbA1c ≥ 8.0 and <9.0% and 38% with baseline HbA1c ≥ 9.0% attained HbA1c ≤ 7.0%). The incidence of hypoglycaemia confirmed <3.9 mmol/l (70 mg/dl) was higher in the lower baseline HbA1c ranges but severe hypoglycaemia was infrequent at all baseline HbA1c levels.
  
  
  CONCLUSIONS
  Systematically titrated insulin glargine, added to oral agents, was effective over a wide range of baseline HbA1c. Lower baseline HbA1c was the best clinical predictor of achieving HbA1c ≤ 7.0% and also associated with higher risk of glucose-confirmed hypoglycaemia. Severe hypoglycaemia was infrequent using this treatment approach.
authors.affiliation: Department of Medicine, Oregon Health & Science University, Portland, OR, USA. riddlem@ohsu.edu
authors.forename: M C
authors.initials: MC
authors.lastname: Riddle
authors.forename: A
authors.initials: A
authors.lastname: Vlajnic
authors.forename: R
authors.initials: R
authors.lastname: Zhou
authors.forename: J
authors.initials: J
authors.lastname: Rosenstock
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D005215:Fasting; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D015994:Incidence; D000069036:Insulin Glargine; D049528:Insulin, Long-Acting / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D000069036:Insulin Glargine; D049528:Insulin, Long-Acting; C517652:hemoglobin A1c protein, human
keywords: glycaemic control; insulin analogues; type 2 diabetes