Behavioral Strategies In Diabetes Prevention Programs: A .
diabetes research and clinical practice 91 (2011) 1–12Contents lists available at ScienceDirectDiabetes Researchand Clinical Practicejourn al h omepage: www .elsevier.co m/lo cate/diabresReview articleBehavioral strategies in diabetes prevention programs:A systematic review of randomized controlled trialsMichael K. Baker a,*, Kylie Simpson b, Bradley Lloyd b,Adrian E. Bauman c, Maria A. Fiatarone Singh a,daBoden Institute of Obesity, Nutrition and Exercise, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, AustraliaExercise Health and Performance, The University of Sydney, Lidcombe, AustraliacSchool of Public Health, The University of Sydney, Camperdown, AustraliadHebrew Senior Life and Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA USAbarticle infoabstractArticle history:The worldwide epidemic of type 2 diabetes (T2D) emphasizes the need for guidelinesReceived 24 May 2010regarding community implementation of lifestyle modification prevention programs. AnReceived in revised formunderstanding of effective behavioral strategies is needed if evidence translation is to be22 June 2010realized. The aim of this paper is to systematically review the behavioral change strategiesAccepted 28 June 2010for lifestyle T2D prevention programs.Published on line 23 July 2010Methods: Randomized controlled trials (RCTs) of lifestyle interventions for the prevention ofT2D were reviewed with a systematic literature search. Data relating to the behavioralKeywords:strategies and trial outcomes were extracted.Diabetes mellitus type 2Results: Overall, lifestyle interventions were successful in reducing the incidence of T2D.Diet therapyThe behavioral strategies utilized in these interventions were drawn from a variety ofExercisetheoretical backgrounds. All RCTs utilized intensive modes of delivery and were associatedHealth behaviorwith low dropout rates of 5.5–13.4%.LifestyleConclusions: The available evidence shows that a robust behavioral change strategy is anessential part of an effective lifestyle modification program, as the absence of intensiveindividualized advice or ‘‘information only’’ more closely resembles the control groupinterventions used in these RCTs.# 2010 Elsevier Ireland Ltd. All rights reserved.Contents1.Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1. Criteria for study inclusion/exclusion .1.1.1. Design . . . . . . . . . . . . . . . . . . .1.1.2. Subjects. . . . . . . . . . . . . . . . . .1.1.3. Interventions . . . . . . . . . . . . .1.1.4. Outcome . . . . . . . . . . . . . . . . .1.2. Search strategy . . . . . . . . . . . . . . . . . .* Corresponding author. Tel.: 61 2 9351 9858; fax: 61 2 9351 9204.E-mail address: michael.baker@sydney.edu.au (M.K. Baker).0168-8227/ – see front matter # 2010 Elsevier Ireland Ltd. All rights reserved.doi:10.1016/j.diabres.2010.06.030.2222233
2diabetes research and clinical practice 91 (2011) 1–122.3.4.5.1.3. Quality assessment . . . . . . . . . . . . . . .1.4. Data extraction and synthesis. . . . . . .1.5. Statistical analysis . . . . . . . . . . . . . . . .Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.1. Study inclusion/exclusion . . . . . . . . . .2.2. Study quality . . . . . . . . . . . . . . . . . . . .2.3. Participants . . . . . . . . . . . . . . . . . . . . .2.4. Interventions . . . . . . . . . . . . . . . . . . . .2.4.1. Exercise . . . . . . . . . . . . . . . . . .2.4.2. Nutrition . . . . . . . . . . . . . . . . .2.5. Behavioral strategies . . . . . . . . . . . . . .2.5.1. Contacts . . . . . . . . . . . . . . . . .2.5.2. Staff . . . . . . . . . . . . . . . . . . . .2.5.3. Follow-up and monitoring . . .2.5.4. Control . . . . . . . . . . . . . . . . . .2.6. Outcomes. . . . . . . . . . . . . . . . . . . . . . .2.7. Fidelity to the intervention and goals .2.7.1. Loss to follow-up . . . . . . . . . .2.7.2. Adherence/attendance . . . . . .2.7.3. Goal achievement . . . . . . . . . .Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1. Behavioral strategies . . . . . . . . . . . . . .3.2. Control groups . . . . . . . . . . . . . . . . . . .3.3. Outcomes. . . . . . . . . . . . . . . . . . . . . . .3.4. Intervention goals . . . . . . . . . . . . . . . .3.5. Future research . . . . . . . . . . . . . . . . . .Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . .Conflicts of interest . . . . . . . . . . . . . . . . . . . .Acknowledgements . . . . . . . . . . . . . . . . . . . .References . . . . . . . . . . . . . . . . . . . . . . . . . . .The number of people developing type 2 diabetes (T2D) isrising dramatically worldwide, and is expected to more thandouble between 2000 and 2030 [1]. Depending on the cohortsurveyed and definition of T2D employed, between 20 and 50%of T2D is undiagnosed [2]. Direct health care costs of T2D in theUSA in 2007 were estimated at 116 billion [3].Epidemiological studies have repeatedly demonstratedthat low levels of physical activity, low levels of physicalfitness and obesity are prominent, independent and modifiable risk factors for the development of insulin resistance,metabolic syndrome, and T2D [4,5], adding to geneticpredisposition and other environmental or acquired riskfactors. This robust and consistent observational evidencehas given rise to large-scale randomized controlled trials(RCTs) that have used a lifestyle intervention (includingbehavioral strategies for reinforcement of prescribed changesin nutritional intake, physical activity, or both) in populationsat high risk of developing T2D. The aim of these trials was toreduce the rate of incident diabetes, as well as ameliorate riskfactor profiles associated with both T2D and cardiovascularmorbidity and mortality. The optimum strategy for thedelivery of lifestyle programs in order to maintain adherenceand compliance in this population remains unclear. Althoughexcellent reviews of diabetes prevention trials have beenpublished [6,7], none of these reviews have systematicallyextracted and compared the details of the behavioralcomponents and goals of the intervention groups in thesetrials, which differ markedly between trials. Thus, the purpose.333444444455577788889999101010101010of this paper was to systematically review the behavioralchange strategies for lifestyle modification in adults withimpaired glucose tolerance (IGT) and to assess adherence andcompliance to these interventions within these publishedRCTs. This critical appraisal of the interventions is necessaryto inform the translation of this evidence base into guidelinesfor community-based programs and public health policy.1.Methods1.1.Criteria for study inclusion/exclusion1.1.1.DesignRandomized controlled trials, published in full in English wereconsidered.1.1.2.SubjectsStudies that involved adults at-risk of T2D were included,defined as being dysmetabolic or having IGT according toWorld Health Organization (WHO) criteria, at the time of thetrial. Studies with participants already diagnosed with T2Dwere not included.1.1.3.InterventionsStudies were included if they incorporated exercise training/physical activity and/or nutritional intervention as a means ofdiabetes prevention.
diabetes research and clinical practice 91 (2011) 1–12[(Fig. 1)TD IG]1.1.4.3OutcomeIncidence of diagnosis of T2D as a primary outcome. Studiesincluding intermediate endpoints only (e.g. weight, waistcircumference) were not included.1.2.Search strategyA comprehensive, systematic database search for manuscripts was conducted from 1966 or database inception to2009 using computerized databases which included Medlineand PreMedline, CINAHL, EMBASE, PsycINFO and CochraneCentral Register of Controlled Trials, with the final searchperformed in Feb 2009 (KS and MB). The search was limitedto full text and English language articles in human subjects.Key search terms included ‘type 2 diabetes’, ‘prevention’,‘exercise’, and ‘diet’ (see Fig. 1). Reference lists of theincluded articles were manually examined for additionalarticles. In addition, recent position stands, consensusstatements, and other reviews were retrieved to extractrelevant citations, and database searches were done usingthe names of the primary trials identified to find subsequentpublications from the same trial. Websites developed bythese RCTs were accessed where available to obtain copiesof study protocols, manuals, and other educational/behavioral tools used in the implementation of programs, toprovide additional details beyond those reported in thepublished papers. As most trials had many associatedpublications, data extracted from all retrieved sources weremerged to summarize the trial characteristics and outcomes.1.3.Quality assessmentOnce studies were collected based on a minimum qualitythreshold, defined as having met all inclusion criteria, amore detailed assessment of the study quality was conducted. The quality of the studies retrieved was assessedaccording to a modified Delphi list [8] (KS and MB).Additional elements considered were the supervision ofexercise sessions (which has been shown to result insuperior adherence to prescriptions and physiologicaladaptations [9,10]) and appropriate between-group statistical analysis.1.4.Data extraction and synthesisFour assessors (MFS, KS, BL, and MB) independently extracteddata from primary articles and resolved discrepancies byconsensus. Outcomes for incidence of T2D, adherence andcompliance were extracted (KS and MB).1.5.Statistical analysisDue to the heterogeneity of behavioral interventions, exercise/dietary prescriptions, cohort characteristics, outcomesassessed and measurement tools used, and our specific intentto compare across strategies used in different trials rather thanmerge into a singular result, a systematic and critical review ofthe behavioral strategies was conducted rather than a metaanalysis.Fig. 1 – Flow of studies included/excluded for review. DPP,Diabetes Prevention Program (USA); DPS, DiabetesPrevention Study (Finland); DQS, Da Qing IGT and DiabetesStudy (China); IDPP, Diabetes Prevention Program (India);JDPP, Diabetes Prevention Program (Japan); ADPP, AstiDiabetes Prevention Program (Italy); VIP, VästerbottenIntervention Program (Sweden); T2D, Type 2 Diabetes.The size of the treatment effect for incident T2D in all trialswas measured by extraction and/or calculation of the relativerisk reduction (RRR), absolute annual and cumulative risk (AR),absolute risk reduction (ARR), and number needed to treat(NNT) [11].
4diabetes research and clinical practice 91 (2011) 1–12An effect size (ES) [12,13] over the intervention time(standardized mean difference) for outcomes in each of thearms of the studies was calculated using the equation:ES ¼MeanPOST MeanPRE:SDPREThe relative ES as a difference between the control and theintervention group ES is presented:ESRELATIVE ¼ ESINTERVENTION ESCONTROL :Hedge’s bias corrected effect sizes are presented with 95%confidence intervals [14].Clinical importance of the outcomes was assessed viaascertainment that the changes in disease risk were of amagnitude judged clinically important, and that the lowerlimit of the CIs of the effect size excluded clinically unimportant changes, as recommended by the National Health andMedical Research Council (NHMRC) [15]. For the purpose ofthis review, a conservative estimate of clinical importance wasused, defined by the authors as a RRR 10%. This wouldrepresent a reduction of approximately 150,000 new cases ofT2D annually in the U.S compared to usual care/no treatment.2.Results2.1.Study inclusion/exclusionstudies included intention-to-treat analysis (explicitly statedor presented data from all subjects randomized); the DQS didnot report data from dropouts, and was therefore interpretedas a complete case analysis. Statistical treatment of missingdata was only reported in one study (VIP).2.3.In total the seven studies consisted of 5825 subjects with themean cohort age ranging from 42 9 to 56 6 years of age.Studies recruited their subjects from the general communityand one study recruited from patients being routinelyscreened at a medical facility (JDPP). The DPP, DPS andVIP had a minimum body mass index (BMI) of 24, 25 and 27 respectively, while no BMI cut-off was specified for theother studies. Among the seven studies, six were in mixedcohorts, and one study included males only (JDPP), totaling acombined 44% of the sample being male across all studies.Exclusion criteria commonly included normal glucosetolerance or indication of diabetes; unstable, terminal orprogressive disease; however, the exact burden of diseasepresent at baseline is not clear as most (5/7) studies didnot report detailed exclusion criteria or baseline healthstatus.2.4.The process of study inclusion/exclusion at each step ispresented in Fig. 1. Seven separate RCTs with prevention oftype 2 diabetes as their primary outcome were identified. Trialresults were generally published in multiple papers, all ofwhich were included in the data extraction process, incontrast to previous systematic reviews which have usedonly one or a small number of papers as source documents foreach trial. Diabetes Prevention Program (DPP), U.S.A. Diabetes Prevention Study (DPS), Finland Da Qing IGT and Diabetes Study (DQS),China Diabetes Prevention Program (IDPP), India Diabetes Prevention Program (JDPP), Japan Asti Diabetes Prevention Program (ADPP),Italy Västerbotten Intervention Program (VIP),Sweden2.2.– 41 publications– 39 publications– 4 publications– 5 publications– 2 publications– 1 publication– 3 publicationsStudy qualityIn general, all included studies specified their inclusioncriteria, randomly assigned groups, reported standard deviations or confidence intervals, and reported baseline characteristics. However, some studies failed to report importantdetails of baseline health status including co-morbid disease,medication use, weight and BMI. While all studies reporteddropout/loss to follow-up, only two studies reported adherence with exercise or educational sessions (DPP and DPS). Theoccurrence of adverse events was reported in five of the sevenstudies (DPP, DPS, DQS, IDPP, and ADPP) and six of the sevenParticipantsInterventionsTable 1 summarizes the lifestyle interventions employed. Allstudies included a combined exercise/physical activity anddietary intervention with the aim of achieving and/ormaintaining weight loss. The intervention duration for theseprograms ranged from 1 year (ADPP and VIP) to 6 years (DQS).2.4.1.ExerciseParticipants in all studies were individually advised to increasephysical activity. The weekly volumes of exercise prescribedranged from 150 min/week at moderate intensity (DPP, ADPP,and VIP), up to 30-40 min/day (i.e. 210–280 min/week) atmoderate intensity (JDPP). All studies prescribed moderateintensity aerobic activity as the primary form of exercise. Boththe DPP and DQS allowed for a reduction in exercise volume ifactivity was performed at a more vigorous intensity. The DPPincluded moderate intensity progressive resistance training insome clinics, and in the DPS moderate intensity progressiveresistance training and power training were included as a partof the exercise prescription. The VIP counseled participants onthe importance of performing muscle strengthening exercisetwice a week. The DPP and DPS provided supervised exercisesessions to participants free of charge 2 days per week for theduration of the program [16,17], and the VIP included an initial 1month residential component where 2.5 h of physical activitywere provided daily [18]. The remainder of the trials did notprovide supervised exercise.2.4.2.NutritionParticipants in all studies were individually advised to modifytheir dietary intake. Reviewed studies included a reduction inenergy intake with all studies recommending a reduction offat intake, commonly to 20–30% of total energy intake (DPP,DPS, DQS, and VIP). Five of the seven studies specifically
PRT, progressive resistance training; DPP, Diabetes Prevention Program (USA); DPS, Diabetes Prevention Study (Finland); DQS, Da Qing IGT and Diabetes Study (China); IDPP, Diabetes PreventionProgram (India); JDPP, Diabetes Prevention Program (Japan); ADPP, Asti Diabetes Prevention Program (Italy); VIP, Västerbotten Intervention Program (Sweden).aEnergy expenditure 700 kcal/week was the primary objective, and the target volume (min/week) was allowed to be increased/decreased based on the intensity of activities performed.b35–210 min/week for persons 50 years; 70–420 min/week for persons 50 years.c2.5 h per day prescribed as supervised exercise in the first month. U U UUU U UUUUUUUUUUU UUUUUUUUUUUUDPP (USA)DPS (Finland)DQS (China)IDPP (India)JDPP (Japan)ADPP (Italy)VIP (Sweden) 150a 210 35–420b 210210–280 150 150cModerateModerate to strenuousLight to very strenuousModerateModerateModerateLow-ModerateUU UUUUUUUUUU UUU U min/wk)Exercise/physical activityStudy(country)Table 1 – Lifestyle change goals in the intervention berdiabetes research and clinical practice 91 (2011) 1–125included portion control as a part of the prescription. Specificincreases in dietary fiber intake were recommended as part offour studies (DPS, IDPP, ADPP, and VIP), whereas an increasedintake in fiber-rich foods such as fruits and vegetables wasadvised as a part of all studies. Overall, energy reduction andenergy density shift, and changes to macronutrient composition were common elements, albeit to varying degrees, in allstudies.2.5.Behavioral strategiesTable 2 shows a summary of the behavioral strategies of allreviewed studies. While none of the studies specified a specificbehavioral theory that underpin
compliance to these interventions within these published RCTs. This critical appraisal of the interventions is necessary to inform the translation of this evidence base into guidelines for community-based programs and public health policy. 1. Methods 1.1. Criteria for
Bruce W. Bode, MD, FACE Atlanta Diabetes Associates Atlanta, Georgia American Diabetes Association. Facts and Figures. Available at: http://www.diabetes.org/ada/facts.asp. Accessed January 18, 2000. Diagnosed Type 1 Diabetes 0.5 - 1.0 Million Diagnosed Type 2 Diabetes 10.3 Million Undiagnosed Diabetes 5.4 Million Prevalence of Diabetes in the US 3
Diabetes in the United States More than 29 million people in the U.S. have diabetes 8.1 million people with diabetes are undiagnosed 9.3% of the U.S. population 1.7 million Americans aged 20 years or older were newly diagnosed with diabetes in 2010 Every 19 seconds, someone is diagnosed with diabetes
Clinical Diabetes. 2017 Jan; 35(1)51-54. Speight J, Conn J, Dunning T, Skinner TC, Diabetes Australia. Diabetes Australia position statement. A new language for diabetes: improving communications with and about people with diabetes. Diabetes Res Clin Pract 2012 Sep; 97(3): 425- 31.
Type 2 Diabetes Type 2 diabetes, which used to be called adult-onset diabetes, can affect people at any age, even children. However, type 2 diabetes develops most often in middle-aged and older people. People who are overweight and inactive are also more likely to develop type 2 diabetes. Type 2 diabetes usually begins with insulin resistance—a
TABLE 57-3. Proposed Classification System for Diabetes in Pregnancy Gestational diabetes: diabetes diagnosed during pregnancy that is not clearly overt (type 1 or type 2) diabetes Type 1 Diabetes: Diabetes resulting from β-cell destruction, usually leading to absolute insulin deficiency a. Without vascular complications b.
The North Carolina Diabetes Advisory Council supports efforts to find a cure for type 1 diabetes. A major focus of this guide and the Diabetes Advisory Council is on type 2 because it is more common and is preventable. For the remainder of this document, references to “diabetes” will be referring to type 2 diabetes unless indicated otherwise.
American Association of Diabetes Educators American Diabetes Association Barbara Davis Center for Childhood Diabetes Children with Diabetes The Endocrine Society Indian Health Service, Division of Diabetes Treatment and Prevention JDRF National Association of Chronic Disease Directors National Association of School Nurses
National Center for Chronic Disease Prevention and Health Promotion Division of Diabetes Translation. CS220221. National Diabetes Fact Sheet, 2011. Data Sources, Methods, and References for Estimates of Diabetes and Prediabetes. Attention: In the. National Diabetes Fact Sheet, 2011, we defined undiagnosed diabetes and prediabetes based on both
