title: Cardiometabolic Risk Factor Changes Observed in Diabetes Prevention Programs in US Settings: A Systematic Review and Meta-analysis.
abstract: BACKGROUND
  The Diabetes Prevention Program (DPP) study showed that weight loss in high-risk adults lowered diabetes incidence and cardiovascular disease risk. No prior analyses have aggregated weight and cardiometabolic risk factor changes observed in studies implementing DPP interventions in nonresearch settings in the United States.
  
  
  RESULTS
  In this systematic review and meta-analysis, we pooled data from studies in the United States implementing DPP lifestyle modification programs (focused on modest [5%-7%] weight loss through ≥150 min of moderate physical activity per week and restriction of fat intake) in clinical, community, and online settings. We reported aggregated pre- and post-intervention weight and cardiometabolic risk factor changes (fasting blood glucose [FBG], glycosylated hemoglobin [HbA1c], systolic or diastolic blood pressure [SBP/DBP], total [TC] or HDL-cholesterol). We searched the MEDLINE, EMBASE, Cochrane Library, and Clinicaltrials.gov databases from January 1, 2003, to May 1, 2016. Two reviewers independently evaluated article eligibility and extracted data on study designs, populations enrolled, intervention program characteristics (duration, number of core and maintenance sessions), and outcomes. We used a random effects model to calculate summary estimates for each outcome and associated 95% confidence intervals (CI). To examine sources of heterogeneity, results were stratified according to the presence of maintenance sessions, risk level of participants (prediabetes or other), and intervention delivery personnel (lay or professional). Forty-four studies that enrolled 8,995 participants met eligibility criteria. Participants had an average age of 50.8 years and body mass index (BMI) of 34.8 kg/m2, and 25.2% were male. On average, study follow-up was 9.3 mo (median 12.0) with a range of 1.5 to 36 months; programs offered a mean of 12.6 sessions, with mean participant attendance of 11.0 core sessions. Sixty percent of programs offered some form of post-core maintenance (either email or in person). Mean absolute changes observed were: weight -3.77 kg (95% CI: -4.55; -2.99), HbA1c -0.21% (-0.29; -0.13), FBG -2.40 mg/dL (-3.59; -1.21), SBP -4.29 mmHg (-5.73, -2.84), DBP -2.56 mmHg (-3.40, 1.71), HDL +0.85 mg/dL (-0.10, 1.60), and TC -5.34 mg/dL (-9.72, -0.97). Programs with a maintenance component achieved greater reductions in weight (additional -1.66kg) and FBG (additional -3.14 mg/dl). Findings are subject to incomplete reporting and heterogeneity of studies included, and confounding because most included studies used pre-post study designs.
  
  
  CONCLUSIONS
  DPP lifestyle modification programs achieved clinically meaningful weight and cardiometabolic health improvements. Together, these data suggest that additional value is gained from these programs, reinforcing that they are likely very cost-effective.
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Uma
authors.identifier: http://orcid.org/0000-0003-4897-9548
authors.initials: U
authors.lastname: Mudaliar
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Zabetian
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Goodman
authors.affiliation: Division of Endocrinology, Diabetes and Hypertension, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Justin B
authors.initials: JB
authors.lastname: Echouffo-Tcheugui
authors.affiliation: Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Ann L
authors.initials: AL
authors.lastname: Albright
authors.affiliation: Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Gregg
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.|Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Mohammed K
authors.initials: MK
authors.lastname: Ali
mesh_terms: D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D040242:Risk Reduction Behavior; D016896:Treatment Outcome; D014481:United States