title: [Clinical significance of pancreatic beta-cell function in obese children with acanthosis nigricans].
abstract: OBJECTIVE
  The strong relation between type 2 diabetes mellitus and obesity with acanthosis nigricans is widely concerned. This study investigated the pancreatic beta-cell function in obese children with acanthosis nigricans, so as to find out the role of insulin secretion and insulin resistance in obese children with acanthosis nigricans.
  
  
  METHODS
  Thirty-five obese children with acanthosis nigricans (19 males and 16 females with mean age 12.8 +/- 1.5 years) were enrolled in this study. Thirty-eight obese children (21 boys and 17 girls with mean age 11.9 +/- 2.6 years) and 39 normal children (20 boys and 19 girls with mean age 11.2 +/- 2.2 years) were recruited as obese and normal control groups. The levels of serum fasting insulin, C-peptide, proinsulin and true insulin were measured in all the subjects. The ratios of proinsulin/insulin and proinsulin/C-peptide were calculated. Homeostasis model assessment was applied to assess the status of insulin resistance and basic function of pancreatic beta-cell.
  
  
  RESULTS
  The levels of fasting insulin, C-peptide proinsulin, true insulin, the ratios of proinsulin/insulin and proinsulin/C-peptide, insulin resistance index and insulin secretion index of obese children with acanthosis nigricans, obese control children and normal control children were: 18.5 (5.0-60.5) pmol/L, 12.4 (6.1-35.8) pmol/L and 5.1 (2.0-32.8) pmol/L; 3.9 (1.3-14.0) microg/L, 2.4 (1.1-4.0) microg/L and 1.1 (1.0-4.2) microg/L; 28.8 (9.9-64.2) pmol/L, 9.5 (2.2-34.5) pmol/L and 4.2 (2.0-16.0) pmol/L; 33.0 (6.2-66.0) pmol/L, 10.6 (4.8-29.4) pmol/L and 4.5 (1.3-30.1) pmol/L; 1.2 (0.4-8.9), 0.9 (0.2-1.9) and 0.8 (0.4-2.0); 6.9 (2.5-36.6), 4.7 (1.2-12.3) and 3.6 (1.2-9.6); 5.0 (0.8-14.1), 2.6 (1.3-8.1) and 1.2(0.4-6.9); 303.3 (52.2-1,163.8), 213.6 (84.6-572.0) and 51.1 (19.1-561.4). The levels of fasting insulin, C-peptide, proinsulin, true insulin, the ratios of proinsulin/insulin and proinsulin/C-peptide, insulin resistance index and insulin secretion index in obese children with acanthosis nigricans were significantly higher than those in obese children (P < 0.001) and normal children (P < 0.001).
  
  
  CONCLUSIONS
  Obese children with acanthosis nigricans had higher insulin resistance and pancreatic beta-cell dysfunction; acanthosis nigricans may be a skin sign of high risk of type 2 diabetes mellitus.
authors.affiliation: Department of Internal Medicine, Beijing Children's Hospital, Capital University of Medical Sciences, Beijing 100045, China.
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Liang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhu
authors.forename: Chun
authors.initials: C
authors.lastname: Yan
authors.forename: Gui-chen
authors.initials: GC
authors.lastname: Ni
authors.forename: Zhong-liang
authors.initials: ZL
authors.lastname: Liu
authors.forename: Zhong-min
authors.initials: ZM
authors.lastname: Du
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000052:Acanthosis Nigricans / Q000150:complications*; D000293:Adolescent; D002096:C-Peptide / Q000097:blood; D002648:Child; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007515:Islets of Langerhans / Q000503:physiopathology*; D008297:Male; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D011384:Proinsulin / Q000097:blood
chemical_list: D002096:C-Peptide; D007328:Insulin; D011384:Proinsulin