Patients with extreme obesity achieved 8.3% weight loss after 2 years of intensive medical intervention compared with 0.5% in a control group, according to new research
The investigators found that at the 2-year mark, 31%, 21%, 10%, and 7% of patients in an intensive intervention group reached a 5%, 10%, 15%, and 20% weight loss, respectively, based on an intention-to-treat (ITT) analysis. In a usual-care group, the respective numbers were 10%, 4%, 2%, and 2%.
The intensive medical intervention included weight-loss medications, calorie-restricted and structured diets, and group behavioral counseling.
On May 7th, the results of this 2-year , randomized clinical trial were presented by the Lead author Donna Ryan, MD, Associate Director for Clinical Research, Pennington Biomedical Research Center, Baton Rouge, Louisiana.
Dr. Ryan described a pragmatic clinical trial as one that “selects clinically relevant alternative interventions to compare against.” A pragmatic trial is “designed to mimic real-world protocols, with both the physician and the patient having leeway in making treatment choices,” she said.
The study included 393 of 597 individuals screened. Individuals who were currently taking weight-loss medications were excluded.
Patients had a body-mass index (BMI) >=40 kg/m2. Women comprised 83% of the group.
The patients were randomized to either usual care (n = 193) or intensive medical intervention (n = 200). Both treatment groups were balanced for gender, ethnicity, age, and BMI.
Usual care consisted of access to a self-guided, internet-based weight management program (through the Mayo Clinic Web site).
Patients in the intensive medical intervention group received treatment in 3 stages. The first stage lasted 3 months, during which patients consumed a liquid diet of 900 kcal/day.
In the second stage, during months 4-8, the intensive intervention consisted of weekly sessions of group behavioral counseling plus a structured diet and pharmacotherapy. The medications included sibutramine, orlistat, and diethylpropion.
The third stage, from months 8-24, saw the patients continuing on the medications, having monthly counseling sessions, and being free to return to the liquid diet or structured diet.
Using a last observation carried forward analysis, the researchers showed that the mean weight loss after 2 years in the intensive intervention group was 8.3% (+- 0.79%) and in the usual-care group was 0.5% (+- 0.46%).
At the 1-year follow-up, 60% of patients in the intensive intervention group and 47% of patients in the usual care group were still participating in the study. At 2 years, it was 51% and 45%, respectively (P = NS). A US$100 Wal-Mart gift card was given to encourage attendance at the 2-year visit.
Among the 119 patients who were still in the intensive intervention group at the 1-year follow-up, the mean weight loss was 9.7% (+- 1.3%), a reduction of 12.7 kg (+- 1.7 kg) (P < .0001 vs baseline).
Mean weight loss among the 92 patients who were still receiving usual care at 1 year was 1.5% (+- 0.8%) or 1.7 kg (+- 0.9 kg) lost (P = .28 vs baseline).
Twenty serious adverse events were seen in the intensive intervention group and 12 in the usual care group. None were judged to be related to treatment.
Dr. Ryan said that the next follow-up will be at the 5-year mark. She concluded, “trained primary care physicians can be successful in helping a subset of patients with severe obesity achieve meaningful weight loss.”
Reported at the 17th European Congress on Obesity (ECO). May 2009
[Presentation title: Non-Surgical Weight Loss for Extreme Obesity: Results of the Louisiana Obese Subjects Study (LOSS). Abstract T5:RS1.3]