The role of diet behaviors in achieving improved glycemic control in intensively treated patients in the Diabetes Control and Complications Trial

Abstract

Objective: To determine whether specific diet-related behaviors practiced by IDDM patients in the intensive treatment group of the Diabetes Control and Complications Trial were associated with lower HbA1c values.

Research design and methods: A questionnaire addressing various aspects of their dietary behavior during the previous year in the DCCT was completed by 623 DCCT intensive treatment group subjects. The association between self-reported diet behaviors and the subject's mean HbA1c during the previous year was evaluated using a linear rank test for trend. The goal of intensive treatment was to achieve blood glucose and HbA1c levels as close to the nondiabetic range as possible without hypoglycemia.

Results: Adherence to the prescribed meal plan and adjusting food and/or insulin in response to hyperglycemia were significantly associated with lower HbA1c levels. Over-treating hypoglycemia and consuming extra snacks beyond the meal plan were associated with higher HbA1c levels. Adjusting insulin dose for meal size and content and consistent consumption of an evening snack were associated, albeit to a lesser degree, with lower HbA1c.

Conclusions: The average HbA1c among intensively managed patients who reported that they followed specific diet-related behaviors was 0.25 to 1.0 lower than among subjects who did not follow these behaviors. Health-care providers may wish to use these results to focus clinical care for intensively treated IDDM patients by emphasizing counseling on meal plans, prompt response to high blood glucose levels, appropriate treatment of hypoglycemia, and consistent snacking behaviors.