Two diabetes prevention programs delivered in a primary care setting succeeded at reducing body mass index in obese patients who had prediabetes, metabolic syndrome, or both, according to a report published online Dec. 10 in Archives of Internal Medicine.
Compared with usual care, both programs produced clinically significant reductions in body weight, as well as improvements in waist circumference and fasting plasma glucose levels, over a 15-month period, reported Dr. Jun Ma of the department of health services research, Palo Alto (Calif.) Medical Foundation Research Institute, and her associates.
However, these results may not be widely generalizable, because the study subjects were "primarily of high socioeconomic status and from a single primary care clinic located within the Silicon Valley of the San Francisco Bay Area and within a parent health system that was one of the first in the nation to adopt a fully functional EHR [electronic health records] system," the researchers noted.
They performed a randomized clinical trial to assess two primary care interventions based on the Diabetes Prevention Program. The study subjects were 241 adult patients at a primary care clinic who had a body mass index of at least 25 kg/m2 and had prediabetes (54%), metabolic syndrome (87%), or both (41%).
The mean subject age was 53 years, and the mean BMI was 32. Women accounted for 47% of the subjects, and 78% of the subjects were white. Most had high educational attainment and a high annual income.
Participants were randomized to a coach-led, group-delivered intervention (79 subjects), a self-directed individual intervention delivered via DVD (81 subjects), or usual care (81 subjects). Both programs entailed a 3-month intensive intervention phase followed by a 12-month maintenance phase.
For the coach-led group intervention, subjects received program materials and attended 12 weekly in-person group classes that included food tastings and up to 45 minutes of guided physical activity. They also received personalized e-mail messages from the "coach" at least monthly.
For the self-directed DVD intervention, subjects received program materials plus weight scales and pedometers, and they were trained to set weight and physical activity goals and to monitor their progress toward those goals. They were shown the American Heart Association’s Web-based Heart360 program and received standardized biweekly e-mail messages to support their efforts. They also were encouraged to use e-mail to submit questions or concerns about the program.
The primary outcome measure was the decrease in BMI after 15 months, said Dr. Ma, who is also in the department of medicine at Stanford (Calif.) University, and her colleagues.
The mean decrease in BMI was 2.2 for the coach-lead intervention and 1.6 for the self-directed intervention, compared with 0.9 for usual care. Mean weight loss was 6.3 kg for the coach-led intervention and 4.5 kg for the self-directed intervention, compared with 2.4 kg for usual care.
This reflects clinically significant reductions for both intervention groups, compared with the control group, the researchers said (Arch. Intern. Med. 2012 Dec. 10 [doi: 10.1001/2013.jamainternmed.987]). The results remained robust in sensitivity analyses.
The Diabetes Prevention Program includes a final weight-loss goal of 7%. The percentage of study subjects who achieved this goal was 37% with the coach-led intervention and 36% with the self-directed intervention, compared with only 14% in the usual-care group.
Compared with the control group, patients in both intervention groups showed significant improvements in waist circumference and fasting plasma glucose levels. Those in the coach-led intervention also showed significant improvements in diastolic blood pressure and triglyceride profiles. In addition, patients in the self-directed group showed significantly improved total cholesterol levels, compared with the control group.
For women, weight loss was significantly greater for the coach-led group intervention than the self-directed individual intervention. In contrast, men responded equally well to the two strategies. "These sex-specific findings need to be confirmed in studies adequately powered to investigate sex differences," the investigators said.
Four patients in the coach-led group experienced five serious adverse events that may have been related to the intervention. There were three fractures and one case of subdural hematoma that required surgery several months after the patient fainted during a group session.
This study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases, the American Heart Association, and the National Center for Research Resources. Dr. Ma reported no relevant financial conflicts of interest; one of her associates reported serving as a consultant to Mylan Pharmaceuticals.