title: Is diabetes in Cushing's syndrome only a consequence of hypercortisolism?
abstract: OBJECTIVE
  Diabetes mellitus (DM) is one of the most frequent complications of Cushing's syndrome (CS). The aim of this study was to define the changes in insulin sensitivity and/or secretion in relation to glucose tolerance categories in newly diagnosed CS patients.
  
  
  METHODS
  Cross-sectional study on 140 patients with CS.
  
  
  METHODS
  A total of 113 women (80 with pituitary disease and 33 with adrenal disease, aged 41.7±15.7 years) and 27 men (19 with pituitary disease and eight with adrenal disease, aged 38.1±20.01 years) at diagnosis were divided according to glucose tolerance into normal glucose tolerance (CS/NGT), impaired fasting glucose and/or impaired glucose tolerance (CS/prediabetes), and diabetes (CS/DM) groups.
  
  
  RESULTS
  Seventy-one patients had CS/NGT (49.3%), 26 (18.5%) had CS/prediabetes and 43 (30.8%) had CS/DM. Significant increasing trends in the prevalence of family history of diabetes (P<0.001), metabolic syndrome (P<0.001), age (P<0.001) and waist circumference (P=0.043) and decreasing trends in HOMA-β (P<0.001) and oral disposition index (DIo) (P<0.002) were observed among the groups. No significant trends in fasting insulin levels, area under the curve for insulin (AUCINS), Matsuda index of insulin sensitivity (ISI-Matsuda) and visceral adiposity index were detected.
  
  
  CONCLUSIONS
  Impairment of glucose tolerance is characterized by the inability of β-cells to adequately compensate for insulin resistance through increased insulin secretion. Age, genetic predisposition and lifestyle, in combination with the duration and degree of hypercortisolism, strongly contribute to the impairment of glucose tolerance in patients with a natural history of CS. A careful phenotypic evaluation of glucose tolerance defects in patients with CS proves useful for the identification of those at a high risk of metabolic complications.
authors.affiliation: Dipartimento di Medicina Interna e Specialistica (Di.Bi.Mi.S) Sezione di Endocrinologia e Malattie del Metabolismo Università di Palermo, Piazza delle Cliniche 2, 90127 Palermo, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Giordano
authors.forename: Valentina
authors.initials: V
authors.lastname: Guarnotta
authors.forename: Rosario
authors.initials: R
authors.lastname: Pivonello
authors.forename: Marco Calogero
authors.initials: MC
authors.lastname: Amato
authors.forename: Chiara
authors.initials: C
authors.lastname: Simeoli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ciresi
authors.forename: Alessia
authors.initials: A
authors.lastname: Cozzolino
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003480:Cushing Syndrome / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology*; D005260:Female; D018149:Glucose Intolerance / Q000209:etiology*; D005951:Glucose Tolerance Test; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000652:urine*; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011236:Prediabetic State; D012189:Retrospective Studies
chemical_list: D007328:Insulin; D006854:Hydrocortisone