title: A Study of the Carbohydrate-to-Insulin Ratio in Pregnant Women with Type 1 Diabetes on Pump Treatment.
abstract: The aim of this study was to assess carbohydrate (CHO)-to-insulin ratio (CHO/IR) values in pregnant women with type 1 diabetes and to describe differences in CHO/IR across each week of pregnancy.
  
  
  
  This was a multicenter, retrospective, observational study (2006-2012) of 101 white pregnant women with a mean age of 32 (range, 18-43) years who had type 1 diabetes and were under continuous subcutaneous insulin infusion (CSII) therapy. These patients had the following characteristics: type 1 diabetes duration was 1 year (range, 1-31 years), the pregestational glycosylated hemoglobin level was 6.9% (range, 6.8-12.1%), the median weight gain during pregnancy was 14 kg (-3; 25 kg), with delivery at 37 weeks (range, 30-40 weeks), and the child had a birth weight of 3.530 kg (range, 1.480-5.250 kg). The CHO/IR was measured by dividing the CHO (in g) of each meal by insulin unit injected to acquire and maintain the following glycemic targets: fasting <90 mg/dL and 1-h postprandial <130 mg/dL. Simultaneously, CHO/IR indices were calculated through 500/total daily doses of insulin and 300/total daily doses of insulin. Education and management before and during pregnancy were in agreement with Italian Association of Dietitians, Association of Medical Diabetologists, and Italian Society of Diabetology recommendations. Data were analyzed using SPSS software (version 20.0; SPSS, Inc., Chicago, IL).
  
  
  
  The CHO/IR decreased on average from 9.6 (5-18) to 5.4 (2.3-8) at breakfast, from 10 (3.5-16) to 8.4 (3.0-17.8) at lunch, and from 12.5 (8-20) to 6.1 (4.2-12) at dinner. The CHO/IR calculated using the "500 rule" decreased from 14.3 (10-20.3) to 8.6 (4.1-15.9). Using the "300 rule," the ratios decreased from 8.5 (6-12.1) to 5.2 (2.4-9.5). The bivariate correlation between the values calculated more appropriate values using the "300 rule" for breakfast and the "500 rule" for lunch and dinner across all weeks of pregnancy.
  
  
  
  CHO/IR reduction in pregnancy is likely due to an increase in insulin resistance.
authors.affiliation: 1 Department of Endocrinology & Diabetology, Faculty of Medicine and Psychology, Sapienza University , Rome, Italy .
authors.forename: Marzia
authors.initials: M
authors.lastname: Bongiovanni
authors.affiliation: 2 Department of Endocrinology & Diabetology, District No. 63, Azienda Sanitaria Locale, Salerno, Italy .
authors.forename: Raffaella
authors.initials: R
authors.lastname: Fresa
authors.affiliation: 3 Diabetologic Department, Azienda Sanitaria Locale RME , Rome, Italy .
authors.forename: Natalia
authors.initials: N
authors.lastname: Visalli
authors.affiliation: 1 Department of Endocrinology & Diabetology, Faculty of Medicine and Psychology, Sapienza University , Rome, Italy .
authors.forename: Olimpia
authors.initials: O
authors.lastname: Bitterman
authors.affiliation: 4 Diabetologic Unit, Department of Clinical and Molecular Medicine, S. Pertini Hospital , Rome, Italy .
authors.forename: Concetta
authors.initials: C
authors.lastname: Suraci
authors.affiliation: 1 Department of Endocrinology & Diabetology, Faculty of Medicine and Psychology, Sapienza University , Rome, Italy .
authors.forename: Angela
authors.initials: A
authors.lastname: Napoli
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis; D002241:Carbohydrates / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D007332:Insulin Infusion Systems; D062407:Meals; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood* / Q000188:drug therapy*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002241:Carbohydrates; D007004:Hypoglycemic Agents; D007328:Insulin