title: Delayed β-cell response and glucose intolerance in young women with Turner syndrome.
abstract: BACKGROUND
  To investigate glucose homeostasis in detail in Turner syndrome (TS), where impaired glucose tolerance (IGT) and type 2 diabetes are frequent.
  
  
  METHODS
  Cross sectional study of women with Turner syndrome (TS)(n = 13) and age and body mass index matched controls (C) (n = 13), evaluated by glucose tolerance (oral and intravenous glucose tolerance test (OGTT and IVGTT)), insulin sensitivity (hyperinsulinemic, euglycemic clamp), beta-cell function (hyperglycaemic clamp, arginine and GLP-1 stimulation) and insulin pulsatility.
  
  
  RESULTS
  Fasting glucose and insulin levels were similar. Higher glucose responses was seen in TS during OGTT and IVGTT, persisting after correction for body weight or muscle mass, while insulin responses were similar in TS and C, despite the higher glucose level in TS, leading to an insufficient increase in insulin response during dynamic testing. Insulin sensitivity was comparable in the two groups (TS vs. control: 8.6 ± 1.8 vs. 8.9 ± 1.8 mg/kg*30 min; p = 0.6), and the insulin responses to dynamic β-cell function tests were similar. Insulin secretion patterns examined by deconvolution analysis, approximate entropy, spectral analysis and autocorrelation analysis were similar. In addition we found low IGF-I, higher levels of cortisol and norepinephrine and an increased waist-hip ratio in TS.
  
  
  CONCLUSIONS
  Young normal weight TS women show significant glucose intolerance in spite of normal insulin secretion during hyperglycaemic clamping and normal insulin sensitivity. We recommend regularly testing for diabetes in TS.
  
  
  BACKGROUND
  Registered with http://clinicaltrials.com, ID nr: NCT00419107.
authors.affiliation: Department of Endocrinology and Internal Medicine and Medical Research Laboratories, Aarhus Sygehus NBG, Aarhus University Hospital, Denmark. ch.gravholt@dadlnet.dk.
authors.forename: Britta E
authors.initials: BE
authors.lastname: Hjerrild
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Holst
authors.forename: Claus B
authors.initials: CB
authors.lastname: Juhl
authors.forename: Jens S
authors.initials: JS
authors.lastname: Christiansen
authors.forename: Ole
authors.initials: O
authors.lastname: Schmitz
authors.forename: Claus H
authors.initials: CH
authors.lastname: Gravholt