Examining Weight Loss Outcomes for Black and White Participants Melanie Warziski Turk, PhD, RN Obesity Researchers Journal Club University of Pittsburgh November 18, 2008

Introduction Minorities disproportionately affected non-Hispanic Blacks = 45% non-Hispanic Whites = 30.6% Women: 54% Black compared to 30.2% White (Ogden et al., 2006) Medical conditions linked to overweight and obesity

How effective are behavioral weight loss interventions? Review of several lifestyle interventions and the weight loss (WL) outcomes for black and white participants

Trials to Prevent Hypertension Hypertension Prevention Trial (HPT) Assessed effects of WL, ↓ sodium, ↑ potassium on blood pressure (B/P) (Arch Intern Med. 1990; 150:153-62) Trials of Hypertension Prevention (TOHP) Examined the efficacy of WL, ↓ sodium, stress management, dietary supplements on lowering or preventing an increase in diastolic B/P (JAMA. 1992; 267: 1213-20)

Trials to Prevent Hypertension (2) HPT (36 mo) Women White (n=43): -1.2 ± 7.2 kg Black (n=28): +2.6 ± 4.7 kg Men White (n=155): -1.5 ± 5.3 kg Black (n=10): -0.7 ± 3.3 kg TOHP (18 mo) Women White (n=48): -2.5 ± 6.3 kg Black (n=33): -0.2 ± 4.1 kg Men White (n=204): -4.9 ± 6.3 kg Black (n=18): -3.5 ± 3.5 kg (Kumanyika, Obarzanek, Stevens et al., 1991)

Trials of Hypertension Prevention, Phase II- TOHP II Additional 18 mo Variety of options to stay involved No differ. in WL at 36 mo, p > .02 Women White (n=131): +0.8 kg (-0.3 to 1.9) Black (n=62): +0.5 kg (-1.1 to 2.0) Men White (n=295): -0.9 kg (-1.6 to -0.3) Black (n=34): 1.2 kg (-0.4 to 2.8) (Stevens, Obarzanek, Cook et al., 2001)

Behavioral Weight Control Program for Individuals with NIDDM 12 mo behavioral intervention: Low-calorie diet throughout Very-low-calorie diet (12-wk periods) Black: -7.1 kg vs. White: -13.9 kg, p < .02 Magnitude of regain greater for black ps in second 6 mo Black: 5.45 kg vs. White = 1.7 kg, p < .02 Major limitation: B: n=16 and W: n=59 (Wing & Anglin, 1996)

Trial of Nonpharmacologic Interventions in the Elderly (TONE) Evaluate efficacy of 3 interventions: Weight loss (WL) Sodium reduction (Na) WL + Na Both WL groups at 6 mo: Black (n=74): -3.2 ± 0.4 kg White (n=220): -5.6 ± 0.3 kg p = .004 Both WL groups at 36 mo: Black (n=74): -3.3 ± 0.5 kg White (n=220): -4.2 ± 0.4 kg p = .12 (Kumanyika, Espeland, Bahnson et al., 2002)

Diabetes Prevention Trial (DPP) Intensive Lifestyle vs. Metformin vs. Usual Care 7% WL goal + 150 min/week Met individual case manager 49% achieved WL goal at end of core 57% White vs. 35% Black, p < .0001 37% achieved WL goal at the final visit with no differences in weight loss success, p = .11 (Diabetes Prevention Program Research Group, 2004)

Additional DPP Data Secondary analysis of weight loss by gender and racial group for each arm Lifestyle Intervention Women White (n=261): -4.5% ± 7.6% Black (n=102): -2.0% ± 6.2% Men White (n=135): -5.8% ± 7.1% Black (n=31): -5.1% ± 3.7% (West, Prewitt, Bursac et al., 2008)

Additional DPP Data (2) Metformin Women White (n=251): -1.9% ± 6.7% Black (n=106): -1.8% ± 6.4% Men White (n=166): -1.5% ± 5.6% Black (n=37): -1.0% ± 4.5% (West, Prewitt, Bursac et al., 2008)

Additional DPP Data (3) Placebo Women White (n=269): -0.9% ± 7.2% Black (n=104): + 1.5% ± 5.3% Men White (n=124): -0.6% ± 5.0% Black (n=39): +0.7% ± 5.2% (West, Prewitt, Bursac et al., 2008)

(West et al., 2008)

Lifestyle Intervention in Post-Menopausal Women 6-mo intervention of reduced-calorie diet and walking 250-350 kcal deficit 3 days/week for 30-45 min White (n=57): -6.6 ± 4.2% Black (n=19): -4.3 ± 4.3% p < .05 (Nicklas, Dennis, Berman et al., 2003)

Weight Maintenance after a Behavioral Intervention- PREFER II PREFER trial: Randomly assigned Standard or lacto-ovo-vegetarian diet Standard behavioral therapy: 12-mo intervention then 6-mo maintenance (Burke, Hudson et al., 2007; Burke, Warziski et al., 2008) PREFER II: Ancillary study at 18 mo after PREFER Explore differences between black and white ps in weight maintenance

PREFER II (2) % Weight ∆ White Black (n=81) (n=26) M(SD) M(SD) p-value Multiple linear regression: Ethnicity: b = .86, SE = 1.45, p = .55

Treatment of Obesity in Underserved Rural Settings 6-mo lifestyle WL intervention (Phase I) Reduced calories and increased physical activity Weekly group meetings Followed by 12-mo an extended care or control condition (Phase II) In-person groups Telephone counseling Control: educational mailings (Rickel, Gibbons, Milsom, et al., 2007)

Treatment of Obesity in Underserved Rural Settings (2) Phase I White (n=181): -10.2 ± 4.9 kg Black (n=43): -6.5 ± 4.7 kg Phase II p < .001 Black: Extended care: +1.7 ± 6.3 kg Control: +1.9 ± 4.2 kg ps > .15 White: Extended care: +1.1 ± 6.2 kg, p > .10 Control: -3.9 ± 6.9 kg, p < .01 (Rickel, Gibbons, Milsom, et al., 2007)

Weight Loss Maintenance Trial 30-mo multi-center RCT of strategies for maintaining WL 20-wk, non-randomized WL phase Minimum of 4 kg lost: Monthly personal contact Unlimited access to interactive technology Self-directed control (Svetkey, Stevens, Brantley et al., 2008)

Weight Loss Maintenance Trial- WL Phase African American Men (n=196): -5.4 ± 7.7 kg (-5.1 ± 7.2%) Women (n=540): -4.1 ± 2.9 kg (-4.4 ± 3.1%) Non-African American Men (n=355): -8.5 ± 12.9 kg (-8.1 ± 11.8%) Women (n=594): -5.8 ± 6.1 kg (-6.5 ± 6.9%) (Hollis, Gullion, Stevens et al., 2008)

(Hollis et al., 2008)

Weight Loss Maintenance Trial- Weight Maintenance Phase * Interactive Group n African American Men 121 Women 267 Non-African American Men 255 Women 386 *Mean weight change (with standard error) at 30 mo. adjusted for age, site, gender, race by gender interaction, study entry weight, and weight change during the WL phase. 2/24/2019 (Svetkey, Stevens, Brantley et al., 2008)

Weight Loss Maintenance Trial- Ancillary Study from Phase I During 20-week WL phase Comparison of all African Am. (AA) intervention groups to mixed race Same AA interventionists To control for potential interventionist effects Avg. proportion of AA in mixed intervention groups: 56% (Ard, Kumanyika, Stevens et al., 2008)

Weight Loss Maintenance Trial- Ancillary Results from Phase I Ps from all-AA groups (n=271): -4.2 ± 4.6 kg 61.2% achieved ≥ 4kg WL goal Ps from mixed-race groups (n=106): -4.2 ± 8.6 kg 55.7% achieved ≥ 4kg WL goal No difference in outcomes, ps > .33. (Ard, Kumanyika, Stevens et al., 2008)

Theoretical pathways for race & ethnicity as influences on weight management Smoking Alcohol Genes Gestation Energy Metabolism Race Ethnicity Energy Balance BMI Food Intake Sedentariness Self-dieting Activity/Exercise Culture SES Context Weight Management Programs 2/24/2019 (Kumanyika, S., Obesity Treatment in Minorities in Handbook of Obesity Treatment, 2004)

Guidelines for Adapting Weight Loss Programs for Effectiveness in Diverse Populations 1. Setting or treatment location Physically accessible Free of factors creating a lg. social distance Promotes active involvement 2. Staff Self-aware, competent 3. Educational and counseling approaches Knowledge base Daily routines Financial resources Cultural preferences (NHLBI, 1998)

Guidelines for Adapting Weight Loss Programs for Effectiveness in Diverse Populations (2) 4. Weight management advice Facilitate integration with other aspects of health care 5. Program modification Expect and allow for based on feedback (NHLBI, 1998)

Summary Black participants experienced smaller, shorter term WL Weight regain was also smaller for black persons compared to white Black women most pronounced difference in outcome Weight regain after a behavioral intervention is commonplace

Future Research Larger trials incorporating and testing culturally appropriate methods Systematic studies of long-term WL patterns among black persons Intensified multidisciplinary research to identify factors for black women Well-designed analyses controlling for SES in order to avoid confounding Evaluation of explicit strategies to promote WLM for all ethnicities

Acknowledgement Funding sources for PREFER and PREFER II NIH 5R01 DK58631 NIH F31 NR 009750

Thank you.