Elizabeth M. Venditti

10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study.

BACKGROUND In the 2.8 years of the Diabetes Prevention Program (DPP) randomised clinical trial, diabetes incidence in high-risk adults was reduced by 58% with intensive lifestyle intervention and by 31% with metformin, compared with placebo. We investigated the persistence of these effects in the long term. METHODS All active DPP participants were eligible for continued follow-up. 2766 of 3150 (88%) enrolled for a median additional follow-up of 5.7 years (IQR 5.5-5.8). 910 participants were from the lifestyle, 924 from the metformin, and 932 were from the original placebo groups. On the basis of the benefits from the intensive lifestyle intervention in the DPP, all three groups were offered group-implemented lifestyle intervention. Metformin treatment was continued in the original metformin group (850 mg twice daily as tolerated), with participants unmasked to assignment, and the original lifestyle intervention group was offered additional lifestyle support. The primary outcome was development of diabetes according to American Diabetes Association criteria. Analysis was by intention-to-treat. This study is registered with ClinicalTrials.gov, number NCT00038727. FINDINGS During the 10.0-year (IQR 9.0-10.5) follow-up since randomisation to DPP, the original lifestyle group lost, then partly regained weight. The modest weight loss with metformin was maintained. Diabetes incidence rates during the DPP were 4.8 cases per 100 person-years (95% CI 4.1-5.7) in the intensive lifestyle intervention group, 7.8 (6.8-8.8) in the metformin group, and 11.0 (9.8-12.3) in the placebo group. Diabetes incidence rates in this follow-up study were similar between treatment groups: 5.9 per 100 person-years (5.1-6.8) for lifestyle, 4.9 (4.2-5.7) for metformin, and 5.6 (4.8-6.5) for placebo. Diabetes incidence in the 10 years since DPP randomisation was reduced by 34% (24-42) in the lifestyle group and 18% (7-28) in the metformin group compared with placebo. INTERPRETATION During follow-up after DPP, incidences in the former placebo and metformin groups fell to equal those in the former lifestyle group, but the cumulative incidence of diabetes remained lowest in the lifestyle group. Prevention or delay of diabetes with lifestyle intervention or metformin can persist for at least 10 years. FUNDING National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Lifestyle Intervention in Overweight Individuals With a Family History of Diabetes

OBJECTIVE To assess the effect of lifestyle intervention over 2 years on changes in weight, coronary heart disease (CHD) risk factors, and incidence of diabetes in overweight individuals with a parental history of diabetes. RESEARCH DESIGN AND METHODS Participants (n = 154), who were 30–100% over ideal body weight, had one or both parents with diabetes, and were currently nondiabetic, were randomly assigned to 2-year treatments focused on diet (decreasing calories and fat intake), exercise (goal of 1,500 kcal/week of moderate activity), or the combination of diet plus exercise or to a no-treatment control group. Subjects were reassessed at 6 months, 1 year, and 2 years. RESULTS At 6 months, the groups differed significantly on measures of eating, exercise, and fitness; weight losses in the diet and diet-plus-exercise groups were significantly > in the exercise and control conditions. Weight losses were associated with positive changes in CHD risk factors. After 6 months, there was gradual deterioration of behavioral and physiological changes, so that at 2 years, almost no between-group differences were maintained. Differences between groups in risk of developing diabetes were of borderline significance (P = 0.08). Strongest predictors were impaired glucose tolerance at baseline, which was positively related to risk of developing diabetes, and weight loss from baseline to 2 years, which was negatively related; in all treatment groups, a modest weight loss of 4.5 kg reduced the risk of type 2 diabetes by ∼ 30% compared with no weight loss. CONCLUSIONS Although initially successful, the interventions studied here were not effective in producing long-term changes in behavior, weight, or physiological parameters. However, weight loss from 0 to 2 years reduced the risk of developing type 2 diabetes. Since modest weight loss significantly reduced risk of type 2 diabetes, further research is needed to determine how best to increase the percentage of subjects achieving at least a modest weight loss.

Translating the Diabetes Prevention Program: A Comprehensive Model for Prevention Training and Program Delivery

BACKGROUND The Diabetes Prevention Program (DPP) demonstrated that lifestyle intervention reduces risk for type 2 diabetes and the metabolic syndrome. A universal framework for translation of multiple aspects of the DPP intervention, including training, support, and evaluation is needed to enhance treatment fidelity in a variety of settings. PURPOSE This study aims to develop a comprehensive model for diabetes prevention translation using a modified DPP lifestyle intervention. METHODS The DPP lifestyle intervention was adapted to a 12-session group-based program called Group Lifestyle Balance for implementation in the community setting. A model for training and support mirroring that of the DPP was developed for prevention professionals administering the program. The process of training/support and program implementation was evaluated for feasibility and effectiveness using a nonrandomized prospective design in two phases (N=51, Phase 1: 2005-2006; N=42, Phase 2: 2007-2009; data analysis completed 2008-2009). A total of 93 nondiabetic individuals with BMI >or=25 kg/m(2) and the metabolic syndrome or prediabetes participated. Measures were collected at baseline and post-intervention for all and 6 and 12 months post-intervention for Phase 2. RESULTS Significant decreases in weight, waist circumference, and BMI were noted in both phases from baseline. Participants in Phase 2 also demonstrated decreases in total cholesterol, non-HDL cholesterol, and systolic and diastolic blood pressure that were maintained at 12 months. Average combined weight loss for both groups over the course of the 3-month intervention was 7.4 pounds (3.5% relative loss, p<0.001); 23.8% and 52.2% of those who completed the program reached 7% and 5% weight loss, respectively. More than 80% of those achieving 7% weight loss in the Phase-2 group maintained their weight loss at 6 months. CONCLUSIONS A comprehensive diabetes prevention model for training, intervention delivery, and support was shown to be successful and was effective in reducing diabetes and cardiovascular disease risk factors in this group of high-risk individuals.

Weight cycling, psychological health, and binge eating in obese women.

This study examined the relationship between weight cycling and psychological health in 120 obese women. Weight cycling was defined in 2 ways by retrospective self-report: total lifetime weight loss and total number of weight cycles > or = 20 lbs (> or = 9.07 kg). Psychological self-report measures assessed psychiatric symptoms, eating behavior, mood, stress, and perceptions of physical health. Of the 52 associations between weight cycling and psychological parameters, 8 were significant, with the most consistent association being between weight cycling and binge eating. Binge eating was also strongly associated with psychological distress, as found in previous studies. After adjusting for binge eating, however, weight cycling was independently related to only one of the psychological measures: perceived physical health.

HEALTHY study rationale, design and methods: moderating risk of type 2 diabetes in multi-ethnic middle school students.

The HEALTHY primary prevention trial was designed and implemented in response to the growing numbers of children and adolescents being diagnosed with type 2 diabetes. The objective was to moderate risk factors for type 2 diabetes. Modifiable risk factors measured were indicators of adiposity and glycemic dysregulation: body mass index ⩾85th percentile, fasting glucose ⩾5.55 mmol l−1 (100 mg per 100 ml) and fasting insulin ⩾180 pmol l−1 (30 μU ml−1). A series of pilot studies established the feasibility of performing data collection procedures and tested the development of an intervention consisting of four integrated components: (1) changes in the quantity and nutritional quality of food and beverage offerings throughout the total school food environment; (2) physical education class lesson plans and accompanying equipment to increase both participation and number of minutes spent in moderate-to-vigorous physical activity; (3) brief classroom activities and family outreach vehicles to increase knowledge, enhance decision-making skills and support and reinforce youth in accomplishing goals; and (4) communications and social marketing strategies to enhance and promote changes through messages, images, events and activities. Expert study staff provided training, assistance, materials and guidance for school faculty and staff to implement the intervention components. A cohort of students were enrolled in sixth grade and followed to end of eighth grade. They attended a health screening data collection at baseline and end of study that involved measurement of height, weight, blood pressure, waist circumference and a fasting blood draw. Height and weight were also collected at the end of the seventh grade. The study was conducted in 42 middle schools, six at each of seven locations across the country, with 21 schools randomized to receive the intervention and 21 to act as controls (data collection activities only). Middle school was the unit of sample size and power computation, randomization, intervention and primary analysis.

Rationale, design and methods of the HEALTHY study behavior intervention component

HEALTHY was a multi-center primary prevention trial designed to reduce risk factors for type 2 diabetes in adolescents. Seven centers each recruited six middle schools that were randomized to either intervention or control. The HEALTHY intervention integrated multiple components in nutrition, physical education, behavior change and communications and promotion. The conceptual rationale as well as the design and development of the behavior intervention component are described. Pilot study data informed the development of the behavior intervention component. Principles of social learning and health-related behavior change were incorporated. One element of the behavior intervention component was a sequence of peer-led, teacher-facilitated learning activities known as FLASH (Fun Learning Activities for Student Health). Five FLASH modules were implemented over five semesters of the HEALTHY study, with the first module delivered in the second semester of the sixth grade and the last module in the second semester of the eighth grade. Each module contained sessions that were designed to be delivered on a weekly basis to foster self-awareness, knowledge, decision-making skills and peer involvement for health behavior change. FLASH behavioral practice incorporated individual and group self-monitoring challenges for eating and activity. Another element of the behavior intervention component was the family outreach strategy for extending changes in physical activity and healthy eating beyond the school day and for supporting the students lifestyle change choices. Family outreach strategies included the delivery of newsletters and supplemental packages with materials to promote healthy behavior in the home environment during school summer and winter holiday breaks. In conclusion, the HEALTHY behavior intervention component, when integrated with total school food and physical education environmental changes enhanced by communications and promotional campaigns, is a feasible and acceptable mechanism for delivering age-appropriate social learning for healthy eating and physical activity among an ethnically diverse group of middle school students across the United States.

A novel approach to diabetes prevention: Evaluation of the Group Lifestyle Balance program delivered via DVD

This pilot project evaluated the Group Lifestyle Balance program (GLB), an adaptation of the DPP lifestyle intervention, delivered via DVD with remote participant support provided by the University of Pittsburgh Diabetes Prevention Support Center. Results suggest that GLB-DVD with remote support may provide an effective alternative for GLB delivery.

First versus repeat treatment with a lifestyle intervention program: attendance and weight loss outcomes

Objective:Following unblinding of the Diabetes Prevention Program (DPP) results, a 16-session lifestyle intervention program was offered to all study participants, including those who had initially been randomized to lifestyle treatment. This study compares the effects of the lifestyle program between participants who had previous exposure and those who had not.Design:A 16-session behavioral intervention was conducted in groups at each of the 27 DPP sites during a transitional (bridge) period from the DPP trial to the DPP Outcomes Study (DPPOS). Session participation for this 6-month behavioral weight loss program was confirmed by originally randomized treatment groups.Subjects and measurements:Independently assessed weight measurements were available within a 7-month period before and after the program for 2808 ethnically diverse participants.Results:Participants from the lifestyle group in the DPP were the least likely to attend a repeat offering of a 16-session behavioral weight loss program conducted in groups. Weight loss during the transitional lifestyle program was strongly related to the duration of attendance in the three groups that were participating in the program for the first time (metformin, placebo and troglitazone), but not related to amount of earlier weight loss.Conclusion:Individuals who were naive to the behavioral program lost a greater amount of weight and this was strongly related to their degree of participation. A second exposure to a behavioral weight loss program resulted in unsatisfactory low attendance rates and weight loss.

HEALTHY Intervention: Fitness, Physical Activity, and Metabolic Syndrome Results

PURPOSE This study aimed to assess the effect of the HEALTHY intervention on the metabolic syndrome (Met-S), fitness, and physical activity levels of US middle-school students. METHODS Cluster randomized controlled trial conducted in 42 (21 intervention) US middle schools. Participants were recruited at the start of sixth grade (2006) when baseline assessments were made, with post-assessments made 2.5 yr later at the end of eighth grade (2009). The HEALTHY intervention had four components: 1) improved school food environment, 2) physical activity and eating educational sessions, 3) social marketing, and 4) revised physical education curriculum. Met-S risk factors, 20-m shuttle run (fitness), and self-reported moderate to vigorous physical activity (MVPA) were assessed at each time point. Ethnicity and gender were self-reported. Obesity status (normal weight, overweight, or obese) was also assessed. RESULTS At baseline, 5% of the participants were classified with Met-S, with two-thirds of the males and one-third of the females recording below average baseline fitness levels. Control group participants reported 96 min of MVPA at baseline with 103 min reported by the intervention group. There were no statistically significant (P < 0.05) differences in Met-S, fitness, or MVPA levels at the end of the study after adjustment for baseline values and confounders. There were no differences in any ethnic, obesity, or ethnic × obesity subgroups for either gender. CONCLUSIONS The HEALTHY intervention had no effect on the Met-S, fitness, or physical activity levels. Approaches that focus on how to change physical activity, fitness, and Met-S using nonschool or perhaps in addition to school based components need to be developed.

Improving employee health: evaluation of a worksite lifestyle change program to decrease risk factors for diabetes and cardiovascular disease.

Objective: To determine whether an evidence-based, behavioral lifestyle intervention program delivered at a worksite setting is effective in improving type 2 diabetes and cardiovascular disease risk factors. Methods: A randomized 6-month delayed control design was utilized, with two thirds of the participants assigned to begin intervention immediately, and one third beginning 6 months later. The year-long program (weekly for 3 months transitioning to monthly) focused on weight loss and increasing physical activity. Results: The immediate intervention group had greater mean weight loss (−10.4 lb, 5.1%, vs −2.3 lb, 1%; P = 0.0001) than the delayed control group at 6 months and relatively greater improvements in activity, HbA1c, and other risk factors. The delayed group experienced similar improvements after completing the intervention program. Conclusions: A worksite behavioral lifestyle intervention is feasible and effective in significantly improving risk factors for type 2 diabetes and cardiovascular disease.