American Diabetes Association (ADA) 71st Scientific Sessions: Page 3 of 6

August 12, 2011

Lifestyle Interventions Improve Glycemic Control for Patients with Type 2 Diabetes

In a randomized trial involving patients with type 2 diabetes, those subject to intensive dietary intervention through consultations with a dietician and nurse demonstrated significant improvement in glycemic control compared with those who received normal care. The addition of an exercise regimen to the dietary changes, however, was not associated with additional benefit in glycemic control.

Results of the multicenter, randomized, controlled Early ACTID (Activity in Type 2 Diabetes) trial were presented at the ADA meeting and simultaneously published online in The Lancet.

From December 2005 through September 2008, the investigators enrolled 593 residents of southwest England, aged 30 to 80 years, who had received a diagnosis of type 2 diabetes in the past 5 to 8 months. Exclusion criteria included a glycated hemoglobin A1c (HbA1c) level >10%, blood pressure >180/100 mm Hg, body mass index (BMI) <25 kg/m2, and weight >180 kg.

Patients were randomized at a 2:5:5 ratio to the following interventions: normal care, which included standard dietary and exercise advice at randomization and again at the conclusion of the study, with reviews by a physician and nurse at baseline, 6 months, and 12 months; intensive diet, consisting of a 1-hour consultation with a dietician at randomization and a 30-minute session every 3 months, along with nine 30-minute consultations with a nurse during the study; and intensive diet plus exercise, which required the patient to take a brisk, 30-minute walk on at least
5 days of each week, tracked by a pedometer and diaried. During the 12-month period, patients assigned to the diet cohort or the diet-plus-exercise group consulted with a dietician for an additional 2 hours and with a nurse for an additional 4.5 hours compared with the patients who were randomized to receive normal care.

The arms were well balanced in terms of baseline demographics. Approximately 65% of patients were men and the vast majority (95%) were white. The approximate mean age of the patients was 60 years.

At 12-month follow-up, patients in the diet group and the diet-plus-exercise group had significantly improved HbA1c levels compared with patients in the normal care group (P = .005 and
P = .027, respectively). The mean HbA1c level increased by 0.09% in the normal care group, decreased by 0.09% in the diet group, and decreased by 0.04% in the diet-plus-exercise group. No statistically significant difference was observed, however, in HbA1c change between the diet and diet-plus-exercise groups (P = .43).

In addition, none of the groups differed significantly in mean systolic or diastolic blood pressure readings or in mean levels of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Compared with patients in the normal care group, persons assigned to the diet group and the diet-plus-exercise group demonstrated significant weight loss (P <.0001 for both comparisons) and a significant decline in BMI
(P <.0001 for both comparisons).

Robert C. Andrews, MB, ChB, PhD, was the study’s lead author, and he offered possible explanations for why exercise did not contribute to better patient outcomes. He said the authors might have selected the wrong activity and perhaps the exercise regimen should have included aerobic and anaerobic activities. He also hypothesized that people who exercise are not as strict with their dietary intake. He wondered whether, if instead of focusing solely on increasing the patients’ activity levels, the researchers should have concentrated more on decreasing the amount of time that the patients spent being sedentary.

Despite finding no additional benefit from adding exercise to dietary changes, Dr. Andrews said, “We should concentrate on exercise and diet.” The message, he added, was not that exercise should be avoided.