Carbohydrate sources and glycaemic control in type 1 diabetes mellitus

AIMS:
Little information is available on the relationship between glycated haemoglobin levels and the source or amount of dietary carbohydrate. The present study compares the association of carbohydrate intake with HbA1c between European individuals with Type 1 diabetes mellitus injecting insulin once or twice per day and those with > or = 3 daily injections.

METHODS:
The relation of carbohydrate intake (total, cereal, fruit, vegetable, milk, and potato carbohydrate assessed by a 3-day dietary record) to HbA1c was examined in 2084 patients (age 32.6 +/- 10.2 years, duration of diabetes 14.8 +/- 9.5 years) included in the EURODIAB Complications Study.

RESULTS:
In both insulin injection regimens, an increased intake of total carbohydrate (% of energy) and a higher consumption of potato carbohydrates (g) were associated with higher levels of HbA1c, whereas an increased intake of vegetable carbohydrate (g) was inversely related to HbA1c. These tendencies were all more pronounced in persons with one or two daily insulin injections. Consumption of cereal and fruit carbohydrates (g) was not related to HbA1c, irrespective of the insulin injection regimen. A trend of HbA1c to increase with higher intakes of milk carbohydrate was confined to those with one or two insulin injections per day (test for interaction: P = 0.01).

CONCLUSIONS:
In particular, subjects with only 1 or 2 daily insulin injections per day should receive specific advice to correctly consider milk and potato carbohydrates. On the other hand, people with Type 1 diabetes may profit from a higher consumption of vegetable carbohydrates for their levels of HbA1c.