title: Toward Defining the Threshold Between Low and High Glucose Variability in Diabetes.
abstract: To define the threshold for excess glucose variability (GV), one of the main features of dysglycemia in diabetes.
  
  
  
  A total of 376 persons with diabetes investigated at the University Hospital of Montpellier (Montpellier, France) underwent continuous glucose monitoring. Participants with type 2 diabetes were divided into several groups-groups 1, 2a, 2b, and 3 (n= 82, 28, 65, and 79, respectively)-according to treatment:1) diet and/or insulin sensitizers alone;2) oral therapy including an insulinotropic agent, dipeptidyl peptidase 4 inhibitors (group 2a) or sulfonylureas (group 2b); or3) insulin. Group 4 included 122 persons with type 1 diabetes. Percentage coefficient of variation for glucose (%CV = [(SD of glucose)/(mean glucose)] × 100) and frequencies of hypoglycemia (interstitial glucose <56 mg/dL [3.1 mmol/L]) were computed.
  
  
  
  Percentages of CV (median [interquartile range]; %) increased significantly (P< 0.0001) from group 1 (18.1 [15.2-23.9]) to group 4 (37.2 [31.0-42.3]). In group 1, the upper limit of %CV, which served as reference for defining excess GV, was 36%. Percentages of patients with %CVs above this threshold in groups 2a, 2b, 3, and 4 were 0, 12.3, 19.0, and 55.7%, respectively. Hypoglycemia was more frequent in group 2b (P< 0.01) and groups 3 and 4 (P< 0.0001) when subjects with a %CV >36% were compared with those with %CV ≤36%.
  
  
  
  A %CV of 36% appears to be a suitable threshold to distinguish between stable and unstable glycemia in diabetes because beyond this limit, the frequency of hypoglycemia is significantly increased, especially in insulin-treated subjects.
authors.affiliation: Institute of Clinical Research, University of Montpellier, Montpellier, France louis.monnier@inserm.fr.
authors.forename: Louis
authors.initials: L
authors.lastname: Monnier
authors.affiliation: Institute of Clinical Research, University of Montpellier, Montpellier, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Colette
authors.affiliation: Department of Endocrinology, Diabetes, and Nutrition, Montpellier University Hospital, University of Montpellier, Montpellier, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Wojtusciszyn
authors.affiliation: Department of Endocrinology, Pitiê-Salpétrière Hospital, Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dejager
authors.affiliation: Department of Endocrinology, Diabetes, and Nutrition, Montpellier University Hospital, University of Montpellier, Montpellier, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Renard
authors.affiliation: Department of Statistics and Epidemiology, UMR 5149, Montpellier University Hospital, University of Montpellier, Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molinari
authors.affiliation: Diabetes Research Group, Swansea University, Swansea, Wales, U.K.
authors.forename: David R
authors.initials: DR
authors.lastname: Owens
mesh_terms: D000368:Aged; D001786:Blood Glucose; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007328:Insulin / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D013453:Sulfonylurea Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D007004:Hypoglycemic Agents; D007328:Insulin; D013453:Sulfonylurea Compounds