title: Carbohydrate-to-insulin ratio is estimated from 300-400 divided by total daily insulin dose in type 1 diabetes patients who use the insulin pump.
abstract: BACKGROUND
  To optimize insulin dose using insulin pump, basal and bolus insulin doses are widely calculated from total daily insulin dose (TDD). It is recommended that total daily basal insulin dose (TBD) is 50% of TDD and that the carbohydrate-to-insulin ratio (CIR) equals 500 divided by TDD. We recently reported that basal insulin requirement is approximately 30% of TDD. We therefore investigated CIR after adjustment of the proper basal insulin rate.
  
  
  METHODS
  Forty-five Japanese patients with type 1 diabetes were investigated during several weeks of hospitalization. The patients were served standard diabetes meals (25-30 kcal/kg of ideal body weight). Each meal omission was done to confirm basal insulin rate. Target blood glucose level was set at 100 and 150 mg/dL before and 2 h after each meal, respectively. After the basal insulin rate was fixed and target blood glucose levels were achieved, TBD, CIR, TDD, and their products were determined.
  
  
  RESULTS
  Mean (±SD) blood glucose levels before and 2 h after meals were 121±47 and 150±61 mg/dL, respectively. TDD was 31.5±9.0 U, and TBD was 27.0±6.5% of TDD. CIR×TDD of breakfast was significantly lower than those of lunch and supper (288±73 vs. 408±92 and 387±83, respectively; P<0.01).
  
  
  CONCLUSIONS
  CIR has diurnal variance and is estimated from the formula CIR=300/TDD at breakfast or CIR=400/TDD at lunch and supper in type 1 diabetes patients. These results indicate that the insulin dose has been underestimated by using previously established calculations.
authors.affiliation: Diabetes Therapeutics and Research Center, The University of Tokushima, Tokushima, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kuroda
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Yasuda
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Takahara
authors.forename: Fumie
authors.initials: F
authors.lastname: Sakamoto
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kasami
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Miyashita
authors.forename: Sumiko
authors.initials: S
authors.lastname: Yoshida
authors.forename: Eri
authors.initials: E
authors.lastname: Kondo
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Aihara
authors.forename: Itsuro
authors.initials: I
authors.lastname: Endo
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Matsuoka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kaneto
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Iichiro
authors.initials: I
authors.lastname: Shimomura
authors.forename: Munehide
authors.initials: M
authors.lastname: Matsuhisa
mesh_terms: D000328:Adult; D000368:Aged; D001481:Basal Metabolism / Q000187:drug effects*; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring; D002241:Carbohydrates / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006442:Glycated Hemoglobin / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D015918:Infusion Pumps, Implantable; D007328:Insulin / Q000008:administration & dosage*; D007564:Japan; D008297:Male; D062407:Meals; D008875:Middle Aged; D013997:Time Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002241:Carbohydrates; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human