These results indicate that the HELP PD project was successful in translating the DPP LWL intervention into a community-based approach that induced significant reductions in blood glucose, insulin, HOMA-IR, body weight, waist circumference, and BMI over 12 months in overweight and obese patients with prediabetes. To our knowledge, this study is the largest to date to successfully translate the DPP into the community and is the only DPP translational study to document significant changes in fasting blood glucose, insulin, and insulin resistance using a randomized controlled design.
The glucose-lowering effect of the HELP PD intervention compares favorably with the effects documented in the DPP and FDPS (−4 and −5 mg/dL, respectively, albeit over longer follow-up periods [DPP follow-up = 2.8 years and FDPS follow-up = 3.2 years]). Our future analyses will examine the sustainability of the HELP PD effect over 24 months. The effect of the HELP PD intervention on adiposity also compares favorably to other studies. A review (23
) of nine randomized controlled trials examining weight loss interventions in individuals with prediabetes reported a pooled estimate of −2.8 kg of weight loss (−3.3% of initial body weight) calculated from four studies with 1 year of follow-up. The DPP (1
) and FDPS (2
) reported weight loss of −5.5 kg (−4.9%) and −4.2 kg (−4.7%), respectively. In addition, the DPP documented a weight loss of −6.0 kg at 12 months of follow-up. Participants in the HELP PD LWL intervention lost an average of −7.1 kg (7.3%) at 12 months. However, trials consistently show that approximately one-third of the weight lost during the first 6 months of behavioral weight loss interventions is typically regained by 1 year, and weight returns to baseline in 3–5 years (24
). Our future analyses will determine whether weight loss is sustained over 24 months of follow-up.
Previous diabetes prevention translational studies have reported 12-month weight losses ranging from −0.45 kg (8
) to −5.7 kg (5
), but other than Boltri et al. (8
), none have reported significant changes in fasting blood glucose. The DEPLOY (Diabetes Education and Prevention with a Lifestyle Intervention Offered at the YMCA) study (5
) delivered a group-based translation of the DPP LWL intervention via YMCAs to 77 participants with elevated glucose and reported significant decreases in weight (−5.7 kg) and BMI (−6.7%) but no differences between groups in changes in cardiometabolic outcomes (e.g., HbA1c
). Likewise, the Weight Loss through Living Well (WiLLoW) study (11
), using a nonrandomized controlled cohort design, delivered a group-based DPP LWL intervention to overweight patients via primary care practices and reported a 12-month weight change of –5.7 kg but did not report changes in cardiometabolic outcomes. Kramer et al (9
) assessed the impact of a group-based DPP LWL intervention in patients at risk for diabetes (n
= 42) delivered via primary care practices using a one-group design and reported significant 12-month changes in weight (−4.2 kg [−4.5%]), waist circumference (−7.1 cm [−6.8%]), and BMI (−1.6 [−4.8%]), but changes in glucose (−1.5 mg/dL [−1.4%]) were not significant. At a national level, Saaristo et al. (13
) implemented the FDPS lifestyle intervention in 2,798 individuals with elevated risk for diabetes in 400 primary care settings and reported a mean of −1.2 kg of weight loss. Although this study did not report changes in fasting glucose, the results indicate that the reduction in incidence of diabetes (assessed using an oral glucose tolerance test) was strongly related to weight loss (relative risk of diabetes was 0.31 in the group who lost 5% weight, 0.72 in the group who lost 2.5–4.9% weight, and 1.10 in the group who gained 2.5% compared with the group who maintained weight). The results presented here suggest that the HELP PD project approach may be a more powerful translation of the DPP than previously published approaches.
Fasting insulin and HOMA-IR, two measures of insulin resistance, responded favorably to the intervention. Insulin resistance is a key link between obesity and the risk of both diabetes and cardiovascular disease (25
). The beneficial effects on insulin resistance provide support for the hypothesis that the intervention may have beneficial effects on the risk for cardiovascular disease beyond the effects on blood glucose.
The HELP PD project made several key modifications to the DPP intervention to create a model that can be translated for use in any community with a DEP. The intervention was delivered in a group format by CHWs in community-based settings and was overseen by registered dieticians employed by a local DEP, thereby minimizing the contributions of research resources and maximizing the responsibilities of community-based staff. The results of the current study indicate that this model is effective at inducing meaningful metabolic changes in individuals at high risk for diabetes.
Although the >3,000 American Diabetes Association–recognized DEPs in the U.S. are well positioned to implement this intervention, several limitations exist. First, the HELP PD project was conducted in only one community located in the southeastern U.S. It is unknown whether this approach can be effectively disseminated to other communities. In addition, a training program must be developed to prepare personnel. Finally, reimbursement policies must be developed to support the cost of program delivery. Economic analysis of the HELP PD program is underway and may help inform policy development. Despite these limitations, the results of the HELP PD program indicate that empowering community members through partnerships with existing DEPs may effectively translate diabetes prevention efforts and ultimately alter the course of the obesity and diabetes epidemics.