Dr. Nicola J. Davis of the Albert Einstein College of Medicine in Bronx, New York and colleagues conducted the study in 105 adults with type 2 diabetes, body mass index (BMI) of 25 or more, and A1C levels between 6% and 11%.
Participants were randomized to a low-carb diet modeled after the Atkins diet or to a low-fat diet based on that in the Diabetes Prevention Program. They kept daily food diaries and were interviewed during study visits regarding their food intake in the previous 24 hours.
“The greatest reduction in weight and A1C occurred within the first 3 months,” the researchers report in the July issue of Diabetes Care. They note that “at 6 and 12 months, there was an increase in calories and macronutrients in both groups, suggesting decreased adherence.”
Although patients on the low-carb diet lost weight faster than those on the low-fat diet, after one year, both groups had “a similar 3.4% weight reduction” and neither group had a significant change in A1C level or blood pressure.
The low-carbohydrate group did have a significant improvement in mean HDL level (p=0.002).
The authors point out, however, that “The lack of change in A1C should…be taken in the context of reduced medications.” In fact, a third of subjects had been taking thiazolidinediones, which were stopped at the beginning of the study and not restarted. Furthermore, there was also a reduction in insulin and sulfonylurea dose overall.
“Perhaps we would have observed greater reductions in A1C if we did not make medication adjustments during the study; however, because we were concerned about hypoglycemia, not making adjustments would not have been appropriate,” the researchers comment.
Diabetes Care 2009;32:1147-1152.