title: The role of glycemia in insulin resistance in youth with type 1 and type 2 diabetes.
abstract: BACKGROUND
  Hyperglycemia has traditionally been considered a major contributor to insulin resistance (IR) in type 1 diabetes (T1D), yet studies examining the relationship between HbA1c and IR are conflicting. Glucose measures captured by continuous glucose monitoring (CGM) (eg, peak glucose, standard deviation, hypoglycemia) in youth have not been explored as predictors of insulin sensitivity (IS).
  
  
  OBJECTIVE
  Assess the relationship between IS and glycemia in youth with T1D and type 2 diabetes (T2D).
  
  
  METHODS
  Sedentary 12-19 year olds with diabetes had peripheral IS measured by hyperinsulinemic-euglycemic clamp. HbA1c and 3 days of CGM data were also collected. Spearman correlation coefficients were calculated to examine the association between variables.
  
  
  RESULTS
  Participants included 100 youth with T1D [46% male, median body mass index (BMI) 74 percentile, HbA1c 8.5%] and 42 with T2D (26% male, BMI 99 percentile, HbA1c 6.9%). Nineteen with T1D and 13 with T2D also wore CGM. In T2D youth, higher HbA1c, average sensor glucose, area under the CGM curve, and metabolic syndrome characteristics correlated with lower IS. In T1D youth, higher BMI percentile, waist circumference, triglycerides, and LDL cholesterol, but not HbA1c, correlated with lower IS. Moreover, higher CGM overnight means glucose correlated with greater IS, and CGM hypoglycemia correlated with lower IS.
  
  
  CONCLUSIONS
  Markers of metabolic syndrome and hyperglycemia predicted decreased IS in T2D youth. Paradoxically, hypoglycemia predicted decreased IS in T1D youth and hyperglycemia, particularly overnight, predicted improved IS. These preliminary results imply different mechanisms underlying IR in T1D vs T2D and suggest a role for non-insulin therapies in T1D to improve IR.
authors: Department of Pediatrics, Division of Pediatric Endocrinology, University of Colorado Denver, Aurora.|Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora.
authors: Christine L
authors: CL
authors: Chan
authors: Department of Pediatrics, Administrative Division, University of Colorado Denver, Aurora.
authors: Laura
authors: L
authors: Pyle
authors: Department of Pediatrics, Division of Pediatric Endocrinology, University of Colorado Denver, Aurora.
authors: Rose
authors: R
authors: Morehead
authors: Department of Pediatrics, Division of Pediatric Endocrinology, University of Colorado Denver, Aurora.
authors: Amy
authors: A
authors: Baumgartner
authors: Department of Pediatrics, Division of Pediatric Endocrinology, University of Colorado Denver, Aurora.|Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora.
authors: Melanie
authors: M
authors: Cree-Green
authors: Department of Pediatrics, Division of Pediatric Endocrinology, University of Colorado Denver, Aurora.|Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora.
authors: Kristen J
authors: KJ
authors: Nadeau
mesh_terms: D000293:Adolescent; D001786:Blood Glucose; D002648:Child; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: continuous glucose monitoring; hyperinsulinemic-euglycemic clamp; insulin resistance; type 1 diabetes