Weight Loss Achieved by 2 Lifestyle Interventions

Miriam E. Tucker

December 13, 2012

Two different lifestyle interventions modeled after those delivered in the Diabetes Prevention Program (DPP) produced significant weight loss among overweight or obese adults in a primary care setting, according to a study published online December 10 in the Archives of Internal Medicine by Jun Ma, MD, PhD, from the Department of Health Services Research, Palo Alto Medical Foundation Research Institute, and the Department of Medicine Stanford University School of Medicine, Stanford, California, and colleagues.

"Until recently, rigorous trial evidence on effective, scalable treatment models in primary care practice has been lacking," the authors write.

The Evaluation of Lifestyle Interventions to Treat Elevated Cardiometabolic Risk in Primary Care trial design is a 3-group, randomized study that compared both a coach-led, in-person weekly group intervention and a self-directed DVD intervention with usual care.

The interventions were adapted from those used in the landmark DPP trial, which produced a 58% reduction in the development of type 2 diabetes over the course of 3 years via modest weight loss.

In the current study, a total of 241 overweight or obese adults with prediabetes and/or metabolic syndrome were randomly assigned to 1 of the 3 groups for a 3-month intensive phase followed by a 12-month maintenance phase.

The same curriculum was delivered in both the coach-led and DVD formats, with both groups having the goal of gradual weight loss via incremental lifestyle changes. Both interventions included weight and physical activity goal-setting and motivational emails throughout the maintenance phase.

All study participants received standard medical care. Those randomly assigned to the usual care (control) group received no information regarding weight loss, although they were free to seek it out on their own.

At baseline, study participants were an average of nearly 53 years old, with a mean body mass index (BMI) of 32.0 kg/m2. Slightly less than half (47%) were women, and the majority (78%) were non-Hispanic white. Most (87%) had metabolic syndrome, approximately 54% had prediabetes, and 41% had both.

The primary endpoint, change in BMI at 15 months, was significant for the 2 intervention groups compared with usual care: BMI dropped by 2.2 kg/m2 in the coach-led group (P < .001 compared with usual care) and by 1.6 kg/m2 with the DVD intervention (P = .02 compared with usual care) compared with just 0.9 kg/m2 with usual care.

Similarly, body weight also dropped significantly with the 2 interventions compared with baseline and with the usual care group. The coach-led group lost an average of 6.3 kg and the self-directed group lost 4.5 kg, whereas the usual care group lost 2.4 kg.

"The maximum weight loss achieved within the coach-led intervention was substantial...and similar in magnitude to that achieved by the DPP lifestyle intervention and other behavioral or drug-based weight-loss trials," Dr. Ma and colleagues write, adding, "Weight loss in the self-directed intervention was less pronounced...but noteworthy given its low resource requirements and high potential for dissemination."

Both intervention groups were also more likely to achieve the 7% DPP weight-loss goal, at 37.0% and 35.9% for in-person and DVD, respectively, compared with just 14.4% in the usual care group (P = .003 and .004, respectively).

Of the 81 participants in the usual care group, 15 said they used some type of weight loss program outside of the study compared with just 5 of the 79 in the coach-led intervention group and 3 of 81 in the DVD group. No study participants used weight-loss drugs or had weight-loss surgery.

"[T]he net intervention effects were significant even though a higher proportion of usual care participants reported attending outside weight-loss programs during the study period," the authors note.

Statistically significant improvements in waist circumference and fasting plasma glucose were also seen with both interventions.

"Proven effective in a primary care setting, the 2 DPP-based lifestyle interventions are readily scalable and exportable for substantial clinical and public health impact," the authors write.

Study limitations acknowledged by the authors include that participants were from a single clinic and of a high socioeconomic status; in addition, the trial only lasted 15 months and was not designed to assess event-based outcomes, such as development of type 2 diabetes, or cost-effectiveness.

According to David G. Marrero, PhD, the J.O. Ritchey Professor of Medicine and director of the Diabetes Translational Research Center at Indiana University in Indianapolis, "The study is interesting and makes an important comparison when considering the translation of the DPP into the public health.... It appears that live group sessions are much more effective, which probably capitalizes on the values associated with group dynamic among persons with a similar condition," he told Medscape Medical News.

Dr. Marrero, who was not involved in the study, added that although a group program is likely to be more expensive and difficult to implement in a primary care practice, "This might be offset by mounting the group experience in community settings and simply having the physician make the referral."

Such programs are not always available, he pointed out. "We need to provide far greater opportunities for patients to access effective, evidence-based programs to which [primary care physicians] can refer. The average [primary care physician] is simply not set up (currently) to implement an effective program. In this context, a supported, self-initiated program does hold promise."

Dr. Marrero recommended that physicians emphasize the importance of lifestyle modification to achieve modest, rather than unrealistically high, weight loss goals.

"In this context, any evidence-based approach that can be incorporated into the clinical practice that stimulates weight loss is good. Which strategies should be considered is still an open question. The article here describes 2 such approaches that seem to have reasonable effectiveness and should be seriously considered by [primary care physicians] as they struggle to address this growing problem."

The study was supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases, a Scientist Development Grant award from the American Heart Association, and internal funding from the Palo Alto Medical Foundation Research Institute. One coauthor has provided consulting services to Mylan Pharmaceuticals and another has received support for the Stanford Center for Clinical and Translational Education and Research (Spectrum) from the National Center for Research Resources. The other authors have disclosed no relevant financial relationships. Dr. Marrero serves as a consultant to Tethys Bioscience Inc.

Arch Intern Med. Published online December 10, 2012. Full text