title: The association of fasting insulin concentrations and colonic neoplasms in acromegaly: a colonoscopy-based study in 210 patients.
abstract: BACKGROUND
  Hyperinsulinemia is associated with colon carcinoma in the general population. PATIENTS with acromegaly are considered to be at risk for developing colonic lesions and typically have hyperinsulinemia.
  
  
  OBJECTIVE
  Our objective was to evaluate the role of fasting insulin levels on the prevalence of colonic adenomatous polyps or adenocarcinoma in acromegaly.
  
  
  METHODS
  This is an analytical, observational, prospective study.
  
  
  METHODS
  A total of 210 patients (111 women, 99 men, age 20-82 yr) undergoing complete colonoscopy at diagnosis of acromegaly were included in this study.
  
  
  RESULTS
  Colonic lesions were found in 81 patients (38.6%), and consisted of hyperplastic polyps in 33 (15.7%), adenomatous polyps in 42 (20.0%), and adenocarcinoma in six patients (2.8%). Polyps were single in 22 cases (27.1%). Fasting insulin levels were significantly lower in patients without lesions (16.0 +/- 7.5 mU/liter) than in patients with hyperplastic polyps (22.4 +/- 8.8 mU/liter; P < 0.01), adenomatous polyps (38.0 +/- 15.9 mU/liter; P < 0.0001), and adenocarcinoma (59.0 +/- 30.6 mU/liter; P < 0.0001). Fasting insulin levels were also lower in patients with hyperplastic polyps than in those with adenomatous polyps (P < 0.01). The odds ratio for harboring colonic adenomas was 14.8 (95% confidence interval 4.4-51.2; P < 0.0001) and 8.6 times higher (95% confidence interval 2.8-29.0; P < 0.0001) in patients with fasting insulin levels in the upper tertile [>/=27.1 mIU/liter (n = 28)] compared with the lower [</=12.1 mIU/liter (n = 40)] and middle tertiles [>12.1 to <27.1 mIU/liter (n = 74)], respectively.
  
  
  CONCLUSIONS
  An increase in fasting insulin levels is associated with an 8.6- to 14.8-fold increased risk of presenting with colonic adenomas in acromegaly.
authors.affiliation: Department of Molecular, Clinical Endocrinology and Oncology, Section of Endocrinilogy, University Federico II of Naples, via S. Pansini 5, 80131 Naples, Italy. colao@unina.it
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.forename: Rosario
authors.initials: R
authors.lastname: Pivonello
authors.forename: Renata S
authors.initials: RS
authors.lastname: Auriemma
authors.forename: Mariano
authors.initials: M
authors.lastname: Galdiero
authors.forename: Diego
authors.initials: D
authors.lastname: Ferone
authors.forename: Francesco
authors.initials: F
authors.lastname: Minuto
authors.forename: Paolo
authors.initials: P
authors.lastname: Marzullo
authors.forename: Gaetano
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D000172:Acromegaly / Q000097:blood / Q000453:epidemiology*; D000230:Adenocarcinoma / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D018256:Adenomatous Polyps / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D003113:Colonoscopy; D005215:Fasting; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006965:Hyperplasia; D007328:Insulin / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D007328:Insulin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I