Day-to-day consistency in amount and source of carbohydrate intake associated with improved blood glucose control in type 1 diabetes

Objective: To determine if a relationship exists between blood glucose cont rol and variability in nutrient intake from day-to-day in subjects with typ e 1 diabetes. Methods: Two three-day diet records and one measurement of glycated hemoglo bin (HbA1c) were obtained from 272 subjects with type 1 diabetes treated wi th a mixture of regular and NPH insulins before breakfast and supper and us ing a standardized algorithm to adjust insulin dose according to the result s of self-monitoring of blood glucose two to four times daily. Day-to-day v ariation in nutrient intake was expressed as the coefficient of variation ( CV = SD x 100/mean). Results: Nutrient intakes in the study population (mean +/- SD) were energy 8.35 +/- 2.43 MJ, fat 81 +/- 30 g, protein 94 +/- 28 g, carbohydrate 227 /- 68 g, starch 126 +/- 38 g and dietary fiber 20 +/- 6 g with diet glycemi c index being 84.2 +/- 7.4. Neither energy, nutrient intakes nor insulin do se was significantly related to HbA1c. Day-To-day variation of carbohydrate (p = 0.0097) and starch (p = 0.0016) intakes and diet glycemic index (p = 0.033) was positively related to HbA1c, and the associations remained signi ficant when adjusted for age, sex, duration of diabetes and BMI. Day-to-day variation in energy, protein or fat intakes was not related to HbA1c. Conclusions: Consistency Ln the amount and source of carbohydrate intake fr om day-to-day is associated with improved blood glucose control in people w ith type 1 diabetes, a result which supports continued educational efforts to achieve adherence to a diabetes diet plan. This conclusion may not apply to people on intensified insulin therapy who adjust their insulin dose bas ed on their actual carbohydrate intake at each meal.