Lifestyle Interventions Improve Glycemic Control for Patients with Type 2 Diabetes

San Diego—Patients with type 2 diabetes who underwent an intensive dietary intervention showed significant improvement in glycemic control compared with those who received normal care. However, among the patients who had the diet intervention, those who also were part of an exercise regimen did not receive an added benefit from exercising. Results of the multicenter, parallel-group, randomized, controlled Early ACTID (Activity in Type 2 Diabetes) trial were presented at the ADA meeting and simultaneously published online in The Lancet [doi:10.1016/50140-6736(11)60442-x]. The study enrolled 593 patients from December 2005 through September 2008 who lived in southwest England, were between 30 and 80 years of age, and had type 2 diabetes diagnosed 5 to 8 months before entering the trial. Exclusion criteria included a 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 in a 2:5:5 ratio in the following groups: (1) normal care (standard dietary and exercise advice at randomization and the study’s conclusion with reviews by a physician and nurse at baseline, 6 months, and 12 months); (2) intensive diet (consultation with dietician for 1 hour at randomization and then for 30 minutes every 3 months; also consultation with a nurse for 30 minutes 9 times during the study); and (3) intensive diet plus exercise (30 minutes of brisk walking at least 5 days per week, tracked by a pedometer and patient diary). During the 12-month period, the patients in the diet and diet plus exercise groups saw a dietician for 2 additional hours and a nurse for 4.5 additional hours compared with the patients who received normal care. The arms were well balanced in baseline demographics. Approximately 65% of patients were males, the approximate mean age was 60 years, and approximately 95% of patients were white. At 12-month follow-up, patients in the diet group and diet plus exercise group had significantly improved HbA1c levels compared with the normal care group (P=.005 and P=.027, respectively). The mean HbA1c level increased by 0.09% in the normal care group, decreased 0.09% in the diet group, and decreased 0.04% in the diet plus exercise group. There was no statistically significant difference, though, between the diet and diet plus exercise groups (P=.43). In addition, none of the groups had significant differences in systolic or diastolic blood pressure or in total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, or triglycerides. Compared with the normal care group, the diet group and the diet plus exercise group had a significant difference in terms of weight loss (P<.0001 in both comparisons) as well as BMI (P<.0001 in both comparisons). Robert C. Andrews, MB, ChB, PhD, the study’s lead author, provided possible explanations for why exercise did not help patients. He said the authors may have chosen the wrong activity, and the regimen should have included aerobic and anaerobic exercise. In addition, he hypothesized that people who exercise are not as strict with their diet. Also, instead of solely focusing on increasing activity, he said the authors may have been better off to concentrate on decreasing the amount of the patients’ sedentary time. “We should concentrate on exercise and diet,” Dr. Andrews said. “In this context, exercise did not have an added benefit. But we’re not saying don’t exercise.”