Participants in a two-year, lifestyle intervention/weight-loss program provided through health coaches at their primary care center were able to lower their blood sugar and improve their cholesterol levels, according to new research published today in the American Heart Association's flagship journal Circulation Journal. Researchers with the PROmoting Successful Weight Loss in Primary CarE in Louisiana (PROPEL) Trial reported previously that participants also reduced body weight by an average of 5% and note that patients who lost more weight experienced greater improvements in their heart disease risk factors.

"Our results demonstrate lifestyle intervention and weight-loss programs can be successful for people in underserved, low-income communities if you bring the program to where they are, removing barriers to participation," said PROPEL principal investigator Peter T. Katzmarzyk, Ph.D., FAHA, a professor and the Marie Edana Corcoran Endowed Chair in Pediatric Obesity and Diabetes and associate executive director for population health sciences at the Pennington Biomedical Research Center of Louisiana State University in Baton Rouge, Louisiana.

Obesity is associated with numerous serious chronic health risks, including heart attacks and strokes. Between 2017 and 2018, researchers estimated the prevalence of obesity among adults in the United States was more than 40%. Food insecurity and lower levels of education and income increase the risk of obesity and its complications. Intensive lifestyle interventions are an effective treatment for obesity, however, access to these programs is often limited, particularly in low-income communities. The PROPEL trial examines the effectiveness of these actions when incorporated into primary care medical clinics.

The PROPEL Trial was conducted between 2016 and 2019 at 18 clinics across Louisiana that serve low-income patients. Clinics were randomly allocated to either usual care or a program, enrolling more than 800 participants who were between ages 20 and 75 years old and with obesity, which is defined as body mass index (BMI) ≥30 kg/m2.

The usual care group received normal primary care and printed newsletters about healthy lifestyle habits. Those in the study group received 24 months of a high-intensity, lifestyle-based intervention/weight-loss program delivered by health coaches in the clinic. The program consisted of weekly sessions for the first six months and monthly sessions for the following 18 months. National guidelines set in the 2013 American Heart Association, American College of Cardiology and Task Force for the Management of Overweight and Obesity in Adults served as the basis for the PROPEL program.

Findings include:

• Blood sugar levels decreased by nearly 5 mg/dL among those in the lifestyle intervention group after one year, however, there were no changes within the usual care group.
• HDL cholesterol (good cholesterol) increased at both 12 and 24 months among participants in the intervention group, yet the usual care group saw no significant changes.
• Overall cardiometabolic risk scores improved significantly for participants in the intervention program, while scores for patients in the usual care group were unchanged.

The researchers suggest the collaborative care approach of the PROPEL model likely offers more successful obesity treatment than the existing Centers for Medicare and Medicaid Services model, which relies solely on the primary care practitioner.

A broader implementation of the PROPEL model could better allow people in under-resourced communities to receive effective treatment and, thus, help to reduce the prevalence of obesity and related health conditions and risks."

Peter T. Katzmarzyk, PROPEL Principal Investigator

Because the PROPEL trial included a significant proportion of Black participants, the majority of whom were female, the authors suggest more research is needed to specifically address this issue among men including Black men. Additionally, they believe more study is needed on the dissemination and implementation of lifestyle intervention programs in other types of clinic settings.