title: Nonalcoholic fatty liver disease: an independent risk factor for colorectal neoplasia.
abstract: OBJECTIVE
  Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of insulin resistance (IR), and IR is associated with an increased risk of colorectal carcinoma (CRC). Increased echogenicity suggesting NAFLD is a frequent incidental finding on ultrasound examination. We aimed to systematically evaluate whether NAFLD is an independent risk factor for colonic neoplasia.
  
  
  METHODS
  One thousand two hundred and eleven patients (603 males, 60.6 ± 9.6 years; 608 females, 61.1 ± 10.3 years) who underwent screening colonoscopy according to national screening recommendations for CRC were evaluated in a cross-sectional study. Colorectal adenomas were classified as tubular adenoma, advanced adenoma (villous features, size ≥ 1 cm or high-grade dysplasia) or carcinoma. NAFLD was diagnosed by increased echogenicity on ultrasound examination after serological exclusion of infectious, immunological, hereditary or alcoholic aetiology.
  
  
  RESULTS
  Nonalcoholic fatty liver disease was diagnosed in 367 (60.8%) males and in 265 (43.5%) females. The total rate of adenomas was increased in subjects with NAFLD (243/367 vs. 107/236 in males, P = 0.010; 94/265 vs. 78/343 in females; P = 0.014). In particular, more tubular adenomas (127/367 vs. 56/236; P = 0.006), adenomas of the rectum (40/367 vs. 8/236; P = 0.004) and more cancers (6/367 vs. 1/236; P < 0.001) were observed in males with NAFLD. In females with NAFLD, more tubular adenomas (59/265 vs. 48/343; P = 0.011) and adenomas of the proximal colon (51/265 vs. 40/343; P = 0.041) were observed. Multivariate regression analyses demonstrated an independent association of colorectal adenomas with hepatic steatosis after adjustment for age, sex, body mass index and glucose intolerance (OR 1.47; 95% CI 1.079-2.003; P = 0.015).
  
  
  CONCLUSIONS
  Patients with NAFLD undergoing screening colonoscopy reveal significantly more CRC precursor lesions and early CRC compared with subjects without NAFLD. This elevated risk is independent from other manifestations of IR. These findings suggest that detecting fatty liver on ultrasound should heighten the awareness for referral to screening colonoscopy.
authors.affiliation: Department of Internal Medicine, Oberndorf Hospital, Oberndorf, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Stadlmayr
authors.forename: E
authors.initials: E
authors.lastname: Aigner
authors.forename: B
authors.initials: B
authors.lastname: Steger
authors.forename: L
authors.initials: L
authors.lastname: Scharinger
authors.forename: D
authors.initials: D
authors.lastname: Lederer
authors.forename: A
authors.initials: A
authors.lastname: Mayr
authors.forename: M
authors.initials: M
authors.lastname: Strasser
authors.forename: E
authors.initials: E
authors.lastname: Brunner
authors.forename: A
authors.initials: A
authors.lastname: Heuberger
authors.forename: F
authors.initials: F
authors.lastname: Hohla
authors.forename: J
authors.initials: J
authors.lastname: Steinwendner
authors.forename: W
authors.initials: W
authors.lastname: Patsch
authors.forename: C
authors.initials: C
authors.lastname: Datz
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000209:etiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001317:Austria / Q000453:epidemiology; D002277:Carcinoma / Q000453:epidemiology / Q000209:etiology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D004812:Epidemiologic Methods; D005234:Fatty Liver / Q000150:complications / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000150:complications / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D012737:Sex Factors