healthy living partnerships to prevent diabetes …prevent diabetes (help pd): challenges of...

HEALTHY LIVING HEALTHY LIVING PARTNERSHIPS TO PARTNERSHIPS TO PREVENT DIABETES PREVENT DIABETES (HELP PD): (HELP PD): CHALLENGES OF CHALLENGES OF COMMUNITYCOMMUNITY--BASED BASED TRANSLATIONSTRANSLATIONSJeffrey A. Katula, PhD, MA for the HELP PD Research Group

Department of Health & Exercise Science

Wake Forest University

Department of Epidemiology and Prevention

Wake Forest School of Medicine

Funded by NIDDK R18 DK069901

Society for Behavioral Medicine Annual Conference, April 11-14, 2012, New Orleans, LA

Diabetes Prevention ProgramDiabetes Prevention Program

� Lifestyle weight loss intervention � 58% reduction in

diabetes incidence (Knowler et al., 2002)

� 6.9% weight loss at 6 months

� 4.5% weight loss at 2.8 years (Wing et al., 2004)

� Weight loss dominant determinant of reduced incidence (Hamman et al., 2006)

� Diabetes Prevention Program translation studies

Society for Behavioral Medicine Annual Conference, April 11-14, 2012, New Orleans, LA2

Diabetes Prevention Diabetes Prevention

Translational ResearchTranslational Research


Whittemore (2011). Translational Behavioral Medicine.

PurposePurpose

� Although translational studies have

demonstrated meaningful weight loss, no other

RCT has demonstrated reductions in glucose.

� Role of weight loss in glucose reduction unknown.

� Test the mediational role of weight loss in the

impact of the HELP PD lifestyle intervention on

reductions in glucose.


Healthy Living Partnerships Healthy Living Partnerships

to Prevent Diabetesto Prevent Diabetes

Design RCT

Setting Community-based

Administered by RDs in DEP

Personnel Community Health Workers (CHWs)

Treatment arms Lifestyle Weight Loss

Enhanced Usual Care

Primary Outcome Fasting Blood Glucose

Secondary Outcomes Adiposity, metabolic risk factors,

psychosocial factors

Follow-up 24-months


Katula et al. (2009) Contemp Clin Trials.

HELP PD InterventionsHELP PD Interventions

� Enhanced Usual Care (EUC)� 2 sessions with a RD during the first 3 months

� Monthly newsletters

�Lifestyle Weight loss (LWL)� Community-based

� DPP-based curriculum and goals

� CHW-led groups

� Phase 1 (6-months): weekly meetings (24 sessions)

� Phase 2 (7-24 months): monthly meetings (18 sessions)


Katula et al. (2009) Contemp Clin Trials.; Katula et al. (2011). Diabetes Care.

Mediation ModelMediation Model


Weight Loss

Lifestyle Weight

Loss Intervention

Glucose

Reduction

a b

cc`

c – c` = ab

� Product of coefficients test (ab) (MacKinnon et al., 2007)

� Sobel test

� Covariates: baseline glucose, age, gender, race

� 12 and 24 months

Participant CharacteristicsParticipant Characteristics


Katula et al. (2011) Diabetes Care.


Baseline to 12 month change:LWL: -7.3%EUC: -1.4%p<0.001

Percent Weight Loss: 24Percent Weight Loss: 24--

month changemonth change

Baseline to 24 month change:LWL: -5.1%EUC: -0.6%p<0.001

Katula et al. (In review). American Journal of Preventive Medicine


Baseline to 12 month change:LWL: -4.2 mg/dlEUC: -0.3 mg/dlp = 0.002

Fasting Blood Glucose: 24 Fasting Blood Glucose: 24

month changemonth change

Baseline to 24 month change:LWL: -2.2 mg/dlEUC: 2.1 mg/dlp = 0.002

Katula et al. (In review). American Journal of Preventive Medicine

Mediation Model (12Mediation Model (12--months)months)


Weight Loss

Lifestyle Weight

Loss Intervention

Glucose

Reduction

a -5.64 (0.65)

p<0.0001

b 0.61 (0.11) p<0.0001

c-2.63 (1.21)

p<0.05c`

0.81 (1.30)p=0.53

Amount of mediation (ab) = -3.44; Z=-4.72; p<0.0001;n = 272

Mediation Model (24Mediation Model (24--months)months)


Weight Loss

Lifestyle Weight

Loss Intervention

Glucose

Reduction

a -4.52 (0.79)

p<0.0001

b 0.63 (0.10) p<0.0001

c-4.01 (1.38)

p<0.01c`

-1.13 (1.38)p=0.41

Amount of mediation (ab) = -2.85; Z=-4.72; p<0.0001; n = 260

ConclusionsConclusions� Long-term, significant changes� Weight loss (-5.34 kg; -5.11%)

� Glucose (-2.2; ∆-4.3 mg/dl)

� Weight loss fully mediates intervention effect on glucose� 69% effect at 12 months

� 72% effect at 24 months

� Supports DPP findings (WL � incidence reduction)

� Glucose reduction through weight loss possible in community-based interventions.

� Psychosocial determinants of weight loss and glucose reduction


AcknowledgementsAcknowledgements

� David C. Goff, Jr., MD, Ph.D.

� Mara Z. Vitolins, DPH, RD

� Michael Lawlor, Ph.D.

� Carolyn Pedley, MD

� Tim Morgan, Ph.D.

� Wei Lang, Ph.D.

� Wake Forest Baptist Hospital Diabetes Care Center

� Community Health Workers


Glucose reduction across weight Glucose reduction across weight

loss achievement (12loss achievement (12--months)months)


≤Baseline weight

≥5% Baseline weight


Glucose reduction across weight Glucose reduction across weight

loss achievement (24loss achievement (24--months)months)


≤Baseline weight



Clinical FollowClinical Follow--upup


Intervention AdherenceIntervention Adherence


healthy living partnerships to prevent diabetes …prevent diabetes (help pd): challenges of...

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