title: Predictors for cecal insertion time: the impact of abdominal visceral fat measured by computed tomography.
abstract: BACKGROUND
  Several factors affect the risk for longer cecal insertion time.
  
  
  OBJECTIVE
  The aim of this study was to identify the predictors of longer insertion time and to evaluate the effect of visceral fat measured by CT.
  
  
  METHODS
  This is a retrospective observational study.
  
  
  METHODS
  Outpatients for colorectal cancer screening who underwent colonoscopies and CT were enrolled. Computed tomography was performed in individuals who requested cancer screening and in those with GI bleeding.
  
  
  METHODS
  Information on obesity indices (BMI, visceral adipose tissue, and subcutaneous adipose tissue area), constipation score, history of abdominal surgery, poor preparation, fellow involvement, diverticulosis, patient discomfort, and the amount of sedation used was collected.
  
  
  RESULTS
  The cecal insertion rate was 95.2% (899/944), and 899 patients were analyzed. Multiple regression analysis showed that female sex, lower BMI, lower visceral adipose tissue area, lower subcutaneous adipose tissue area, higher constipation score, history of surgery, poor bowel preparation, and fellow involvement were independently associated with longer insertion time. When obesity indices were considered simultaneously, smaller subcutaneous adipose tissue area (p = 0.038), but not lower BMI (p = 0.802) or smaller visceral adipose tissue area (p = 0.856), was associated with longer insertion time; the other aforementioned factors remained associated with longer insertion time. In the subanalysis of normal-weight patients (BMI <25 kg/m), a smaller subcutaneous adipose tissue area (p = 0.002), but not a lower BMI (p = 0.782), was independently associated with a longer insertion time. Longer insertion time had a positive correlation with a higher patient discomfort score (ρ = 0.51, p < 0.001) and a greater amount of midazolam use (ρ = 0.32, p < 0.001).
  
  
  CONCLUSIONS
  This single-center retrospective study includes a potential selection bias.
  
  
  CONCLUSIONS
  In addition to BMI and intra-abdominal fat, female sex, constipation, history of abdominal surgery, poor preparation, and fellow involvement were predictors of longer cecal insertion time. Among the obesity indices, high subcutaneous fat accumulation was the best predictive factor for easier passage of the colonoscope, even when body weight was normal.
authors.affiliation: 1Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Toyama, Shinjuku-ku, Tokyo, Japan 2Department of Diagnostic Radiology, National Center for Global Health and Medicine, Toyama, Shinjuku-ku, Tokyo, Japan 3Department of Clinical Research and Informatics, International Clinical Research Center Research Institute, National Center for Global Health and Medicine, Toyama, Shinjuku-ku, Tokyo, Japan 4Diabetes Research, Diabetes Research Center, National Center for Global Health and Medicine, Toyama, Shinjuku-ku, Tokyo, Japan 5Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Kohnodai Hospital, Kohnodai, Ichikawa, Chiba, Japan.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Nagata
authors.forename: Kayo
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Arai
authors.forename: Ryota
authors.initials: R
authors.lastname: Niikura
authors.forename: Takuro
authors.initials: T
authors.lastname: Shimbo
authors.forename: Masafumi
authors.initials: M
authors.lastname: Shinozaki
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Noda
authors.forename: Naomi
authors.initials: N
authors.lastname: Uemura
mesh_terms: D000005:Abdomen / Q000601:surgery; D000368:Aged; D015992:Body Mass Index; D002432:Cecum; D003113:Colonoscopy; D003248:Constipation / Q000150:complications; D005257:Fellowships and Scholarships; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D007441:Intubation, Gastrointestinal; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012737:Sex Factors; D050151:Subcutaneous Fat; D013997:Time Factors
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam