title: In children using intensive insulin therapy, a 20-g variation in carbohydrate amount significantly impacts on postprandial glycaemia.
abstract: OBJECTIVE
  To determine if an insulin dose calculated for a meal containing 60 g carbohydrate maintains postprandial glycaemic control for meals containing 40, 50, 70 or 80 g carbohydrate.
  
  
  METHODS
  Thirty-four young people (age range 8.5-17.7 years) using intensive insulin therapy consumed five test breakfasts with equivalent fat, protein and fibre contents but differing carbohydrate quantities (40, 50, 60, 70 and 80 g of carbohydrate). The preprandial insulin dose was the same for each meal, based on the subject's usual insulin:carbohydrate ratio for 60 g carbohydrate. Continuous glucose monitoring was used to monitor postprandial glucose over 180 min.
  
  
  RESULTS
  The 40-g carbohydrate meal resulted in significantly more hypoglycaemia than the other meals (P = 0.003). There was a one in three chance of hypoglycaemia between 120 and 180 min if an insulin dose for 60 g carbohydrate was given for 40 g carbohydrate. The glucose levels of subjects on the 80-g meal were significantly higher than the 60- and 70-g carbohydrate meals at all time points between 150 and 180 min (P < 0.01). Subjects consuming the 80-g meal were more likely to have significant hyperglycaemia (blood glucose levels ≥ 12 mmol/l) compared with the other meals (P < 0.001).
  
  
  CONCLUSIONS
  In patients using intensive insulin therapy, an individually calculated insulin dose for 60 g carbohydrate results in postprandial hypoglycaemia or hyperglycaemia for meals containing 40 and 80 g carbohydrate. To calculate mealtime insulin in order to maintain postprandial control, carbohydrate estimations should be within 10 g of the actual meal carbohydrate.
authors.affiliation: John Hunter Children's Hospital, Department of Paediatric Endocrinology, Newcastle, Australia. carmel.smart@hnehealth.nsw.gov.au
authors.forename: C E
authors.initials: CE
authors.lastname: Smart
authors.forename: B R
authors.initials: BR
authors.lastname: King
authors.forename: P
authors.initials: P
authors.lastname: McElduff
authors.forename: C E
authors.initials: CE
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage* / Q000031:analogs & derivatives; D008297:Male; D019518:Postprandial Period; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007004:Hypoglycemic Agents; D007328:Insulin