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Predictors of racial differences in weight loss: the PROPEL trial.
Newton, RL, Zhang, D, Johnson, WD, Martin, CK, Apolzan, JW, Denstel, KD, Brantley, PJ, Davis, TC, Arnold, C, Sarpong, DF, et al
Obesity (Silver Spring, Md.). 2024;(3):476-485
Abstract
OBJECTIVE Studies have consistently shown that African American individuals lose less weight in response to behavioral interventions, but the mechanisms leading to this result have been understudied. METHODS Data were derived from the PROmoting Successful Weight Loss in Primary CarE in Louisiana (PROPEL) study, which was a cluster-randomized, two-arm trial conducted in primary care clinics. In the PROPEL trial, African American individuals lost less weight compared with patients who belonged to other racial groups after 24 months. In the current study, counterfactual mediation analyses among 445 patients in the intervention arm of PROPEL were used to determine which variables mediated the relationship between race and weight loss. The mediators included treatment engagement, psychosocial, and lifestyle factors. RESULTS At 6 months, daily weighing mediated 33% (p = 0.008) of the racial differences in weight loss. At 24 months, session attendance and daily weighing mediated 35% (p = 0.027) and 66% (p = 0.005) of the racial differences in weight loss, respectively. None of the psychosocial or lifestyle variables mediated the race-weight loss association. CONCLUSIONS Strategies specifically targeting engagement, such as improving session attendance and self-weighing behaviors, among African American individuals are needed to support more equitable weight losses over extended time periods.
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Addressing Obesity: Implementing Evidence-Based Lifestyle Prevention and Treatment Strategies in Clinical Practice.
Katzmarzyk, PT
The Medical clinics of North America. 2023;(6):1025-1034
Abstract
The prevalence of obesity continues to increase in the United States and globally, placing a large portion of the population at an increased risk of metabolic and cardiovascular diseases. Primary care settings remain the main access point for medical care and preventive medical services for most individuals and thus represent a key environment for treating and managing obesity. Several recent pragmatic trials conducted in primary care have demonstrated clinically significant weight loss and associated reductions in chronic disease risk factors, highlighting the need to translate these programs into mainstream clinical care.
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Association between Sleep, Sedentary Time, Physical Activity, and Adiposity in Adolescents: A Prospective Observational Study.
Kracht, CL, Katzmarzyk, PT, Champagne, CM, Broyles, ST, Hsia, DS, Newton, RL, Staiano, AE
Medicine and science in sports and exercise. 2023;(1):110-118
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PURPOSE This study aimed to examine the effects of substituting sedentary time with sleep or physical activity on adiposity in a longitudinal sample of adolescents. METHODS Adolescents (10-16 yr) were recruited for a prospective observational cohort. Parents and adolescents reported demographic characteristics and pubertal development. Accelerometry was used to measure sleep, physical activity, and sedentary time. Adiposity was quantified with imaging techniques. Isotemporal substitution modeling was conducted to examine the effect of substituting 10 min of sedentary time with sleep or differing intensities of physical activity. Results were stratified by sex and race and adjusted for covariates. RESULTS A total of 217 adolescents provided complete measures at both baseline and 2 yr later (58.1% White, 51.8% girls; 12.9 ± 1.9 yr at baseline). Sleep was negatively related to adiposity 2 yr later when considering other movement behaviors, but substituting baseline sedentary time with sleep was not related to future adiposity ( P > 0.05). In boys and non-White adolescents, substituting sedentary time with vigorous-intensity physical activity was related to lower adiposity 2 yr later ( P < 0.05). Substituting sedentary time for moderate- to vigorous-intensity physical activity was not associated with future adiposity. CONCLUSIONS Substituting sedentary time with vigorous-intensity physical activity was related to lower adiposity in later adolescence in certain groups. Opportunities to promote an adequate balance of sleep, sedentary time, and physical activity in all adolescents are encouraged for optimal development.
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Intraclass correlation coefficients for weight loss cluster randomized trials in primary care: The PROPEL trial.
Katzmarzyk, PT, Denstel, KD, Martin, CK, Newton, RL, Apolzan, JW, Mire, EF, Horswell, R, Johnson, WD, Brown, AW, Zhang, D, et al
Clinical obesity. 2022;(4):e12524
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The aim of this study was to compute intra-class correlations (ICCs) for weight-related and patient-reported outcomes in a cluster randomized clinical trial (cRCT) for weight loss. Baseline and follow-up data from the Promoting Successful Weight Loss in Primary Care in Louisiana (PROPEL) cRCT were used in this analysis. ICCs were computed for baseline and follow-up measures, and changes in body weight, cardiometabolic risk factors and health-related and weight-related quality of life at 6, 12, 18 and 24 months. Baseline ICCs ranged from 0 for PROMIS measures of anxiety and fatigue to 0.055 for total cholesterol (median = 0.019). The ICCs were higher for changes and decreased over time during follow-up. The ICCs for changes were highest in the pooled sample (intervention and usual care combined) followed by the intervention and usual care groups, respectively. The results demonstrated significant ICCs for several outcomes in a weight loss cRCT. The ICCs differed in magnitude depending on whether baseline versus longitudinal data were used, whether data were combined across treatment arms or were considered separately, and varied across the follow-up period. All these factors must be considered when choosing an ICC to inform sample size estimates for future weight loss cRCTs conducted in primary care settings.
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Comparison of weight loss data collected by research technicians versus electronic medical records: the PROPEL trial.
Katzmarzyk, PT, Mire, EF, Martin, CK, Newton, RL, Apolzan, JW, Price-Haywood, EG, Denstel, KD, Horswell, R, Chu, ST, Johnson, WD, et al
International journal of obesity (2005). 2022;(8):1456-1462
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BACKGROUND/OBJECTIVES Pragmatic trials are increasingly used to study the implementation of weight loss interventions in real-world settings. This study compared researcher-measured body weights versus electronic medical record (EMR)-derived body weights from a pragmatic trial conducted in an underserved patient population. SUBJECTS/METHODS The PROPEL trial randomly allocated 18 clinics to usual care (UC) or to an intensive lifestyle intervention (ILI) designed to promote weight loss. Weight was measured by trained technicians at baseline and at 6, 12, 18, and 24 months. A total of 11 clinics (6 UC/5 ILI) with 577 enrolled patients also provided EMR data (n = 561), which included available body weights over the period of the trial. RESULTS The total number of assessments were 2638 and 2048 for the researcher-measured and EMR-derived body weight values, respectively. The correlation between researcher-measured and EMR-derived body weights was 0.988 (n = 1 939; p < 0.0001). The mean difference between the EMR and researcher weights (EMR-researcher) was 0.63 (2.65 SD) kg, and a Bland-Altman graph showed good agreement between the two data collection methods; the upper and lower boundaries of the 95% limits of agreement are -4.65 kg and +5.91 kg, and 71 (3.7%) of the values were outside the limits of agreement. However, at 6 months, percent weight loss in the ILI compared to the UC group was 7.3% using researcher-measured data versus 5.5% using EMR-derived data. At 24 months, the weight loss maintenance was 4.6% using the technician-measured data versus 3.5% using EMR-derived data. CONCLUSION At the group level, body weight data derived from researcher assessments and an EMR showed good agreement; however, the weight loss difference between ILI and UC was blunted when using EMR data. This suggests that weight loss studies that rely on EMR data may require larger sample sizes to detect significant effects. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov number NCT02561221.
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Mediators of weight change in underserved patients with obesity: exploratory analyses from the Promoting Successful Weight Loss in Primary Care in Louisiana (PROPEL) cluster-randomized trial.
Dorling, JL, Martin, CK, Yu, Q, Cao, W, Höchsmann, C, Apolzan, JW, Newton, RL, Denstel, KD, Mire, EF, Katzmarzyk, PT
The American journal of clinical nutrition. 2022;(4):1112-1122
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BACKGROUND Intensive lifestyle interventions (ILIs) stimulate weight loss in underserved patients with obesity, but the mediators of weight change are unknown. OBJECTIVES We aimed to identify the mediators of weight change during an ILI compared with usual care (UC) in underserved patients with obesity. METHODS The PROPEL (Promoting Successful Weight Loss in Primary Care in Louisiana) trial randomly assigned 18 clinics (n = 803) to either an ILI or UC for 24 mo. The ILI group received an intensive lifestyle program; the UC group had routine care. Body weight was measured; further, eating behaviors (restraint, disinhibition), dietary intake (percentage fat intake, fruit and vegetable intake), physical activity, and weight- and health-related quality of life constructs were measured through questionnaires. Mediation analyses assessed whether questionnaire variables explained between-group variations in weight change during 2 periods: baseline to month 12 (n = 779) and month 12 to month 24 (n = 767). RESULTS The ILI induced greater weight loss at month 12 compared with UC (between-group difference: -7.19 kg; 95% CI: -8.43, -6.07 kg). Improvements in disinhibition (-0.33 kg; 95% CI: -0.55, -0.10 kg), percentage fat intake (-0.25 kg; 95% CI: -0.50, -0.01 kg), physical activity (-0.26 kg; 95% CI: -0.41, -0.09 kg), and subjective fatigue (-0.28 kg; 95% CI: -0.46, -0.10 kg) at month 6 during the ILI partially explained this between-group difference. Greater weight loss occurred in the ILI at month 24, yet the ILI group gained 2.24 kg (95% CI: 1.32, 3.26 kg) compared with UC from month 12 to month 24. Change in fruit and vegetable intake (0.13 kg; 95% CI: 0.05, 0.21 kg) partially explained this response, and no variables attenuated the weight regain of the ILI group. CONCLUSIONS In an underserved sample, weight change induced by an ILI compared with UC was mediated by several psychological and behavioral variables. These findings could help refine weight management regimens in underserved patients with obesity.This trial was registered at clinicaltrials.gov as NCT02561221.
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Effects of a 2-Year Primary Care Lifestyle Intervention on Cardiometabolic Risk Factors: A Cluster-Randomized Trial.
Höchsmann, C, Dorling, JL, Martin, CK, Newton, RL, Apolzan, JW, Myers, CA, Denstel, KD, Mire, EF, Johnson, WD, Zhang, D, et al
Circulation. 2021;(12):1202-1214
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BACKGROUND Intensive lifestyle interventions (ILIs) are the first-line approach to effectively treat obesity and manage associated cardiometabolic risk factors. Because few people have access to ILIs in academic health centers, primary care must implement similar approaches for a meaningful effect on obesity and cardiometabolic disease prevalence. To date, however, effective lifestyle-based obesity treatment in primary care is limited. We examined the effectiveness of a pragmatic ILI for weight loss delivered in primary care among a racially diverse, low-income population with obesity for improving cardiometabolic risk factors over 24 months. METHODS The PROPEL trial (Promoting Successful Weight Loss in Primary Care in Louisiana) randomly allocated 18 clinics equally to usual care or an ILI and subsequently enrolled 803 (351 usual care, 452 ILI) adults (67% Black, 84% female) with obesity from participating clinics. The usual care group continued to receive their normal primary care. The ILI group received a 24-month high-intensity lifestyle-based obesity treatment program, embedded in the clinic setting and delivered by health coaches in weekly sessions initially and monthly sessions in months 7 through 24. RESULTS As recently demonstrated, participants receiving the PROPEL ILI lost significantly more weight over 24 months than those receiving usual care (mean difference, -4.51% [95% CI, -5.93 to -3.10]; P<0.01). Fasting glucose decreased more in the ILI group compared with the usual care group at 12 months (mean difference, -7.1 mg/dL [95% CI, -12.0 to -2.1]; P<0.01) but not 24 months (mean difference, -0.8 mg/dL [95% CI, -6.2 to 4.6]; P=0.76). Increases in high-density lipoprotein cholesterol were greater in the ILI than in the usual care group at both time points (mean difference at 24 months, 4.6 mg/dL [95% CI, 2.9-6.3]; P<0.01). Total:high-density lipoprotein cholesterol ratio and metabolic syndrome severity (z score) decreased more in the ILI group than in the usual care group at both time points, with significant mean differences of the change of -0.31 (95% CI, -0.47 to -0.14; P<0.01) and -0.21 (95% CI, -0.36 to -0.06; P=0.01) at 24 months, respectively. Changes in total cholesterol, low-density lipoprotein cholesterol, triglycerides, and blood pressure did not differ significantly between groups at any time point. CONCLUSIONS A pragmatic ILI consistent with national guidelines and delivered by trained health coaches in primary care produced clinically relevant improvements in cardiometabolic health in an underserved population over 24 months. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02561221.
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Weight loss in primary care: A pooled analysis of two pragmatic cluster-randomized trials.
Katzmarzyk, PT, Apolzan, JW, Gajewski, B, Johnson, WD, Martin, CK, Newton, RL, Perri, MG, VanWormer, JJ, Befort, CA
Obesity (Silver Spring, Md.). 2021;(12):2044-2054
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OBJECTIVE The aim of this study was to report the results of five weight-loss interventions in primary care settings in underserved patients and to compare the level of pragmatism across the interventions using the Pragmatic Explanatory Continuum Indicator Summary (PRECIS-2) tool. METHODS Data from 54 primary care clinics (2,210 patients) were pooled from the Promoting Successful Weight Loss in Primary Care in Louisiana (PROPEL) and Rural Engagement in Primary Care for Optimizing Weight Reduction (REPOWER) cluster-randomized trials. Clinics were randomized to one of five comparators: PROPEL usual care, PROPEL combination of in-clinic and telephone visits, REPOWER in-clinic individual visits, REPOWER in-clinic group visits, or REPOWER telephone group visits. RESULTS At 24 months, weight loss (kilograms) was -0.50 (95% CI: -1.77 to 0.76), -3.05 (-4.10 to -2.01), -4.30 (-5.35 to -3.26), -4.79 (-5.83 to -3.75), and -4.80 (-5.96 to -3.64) in the PROPEL usual care, REPOWER in-clinic individual visits, REPOWER telephone group visits, REPOWER in-clinic group visits, and PROPEL in-clinic and telephone visits arms, respectively. At 24 months, percentage of weight loss was -0.360 (-1.60 to 0.88), -3.00 (-4.02 to -1.98), -4.23 (-5.25 to -3.20), -4.67 (-5.69 to -3.65), and -4.69 (-5.82 to -3.56), respectively, in the five arms. The REPOWER in-clinic individual visits intervention was the most pragmatic and reflects the current Centers for Medicare and Medicaid Services funding model, although this intervention produced the least weight loss. CONCLUSIONS Clinically significant weight loss over 6 months in primary care settings is achievable using a variety of lifestyle-based treatment approaches. Longer-term weight-loss maintenance is more difficult to achieve.
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Food Insecurity and Weight Loss in an Underserved Primary Care Population: A Post Hoc Analysis of a Cluster Randomized Trial.
Myers, CA, Martin, CK, Apolzan, JW, Arnold, CL, Davis, TC, Johnson, WD, Katzmarzyk, PT, ,
Annals of internal medicine. 2021;(7):1032-1034
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Physical activity behaviours in adolescence: current evidence and opportunities for intervention.
van Sluijs, EMF, Ekelund, U, Crochemore-Silva, I, Guthold, R, Ha, A, Lubans, D, Oyeyemi, AL, Ding, D, Katzmarzyk, PT
Lancet (London, England). 2021;(10298):429-442
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Young people aged 10-24 years constitute 24% of the world's population; investing in their health could yield a triple benefit-eg, today, into adulthood, and for the next generation. However, in physical activity research, this life stage is poorly understood, with the evidence dominated by research in younger adolescents (aged 10-14 years), school settings, and high-income countries. Globally, 80% of adolescents are insufficiently active, and many adolescents engage in 2 h or more daily recreational screen time. In this Series paper, we present the most up-to-date global evidence on adolescent physical activity and discuss directions for identifying potential solutions to enhance physical activity in the adolescent population. Adolescent physical inactivity probably contributes to key global health problems, including cardiometabolic and mental health disorders, but the evidence is methodologically weak. Evidence-based solutions focus on three key components of the adolescent physical activity system: supportive schools, the social and digital environment, and multipurpose urban environments. Despite an increasing volume of research focused on adolescents, there are still important knowledge gaps, and efforts to improve adolescent physical activity surveillance, research, intervention implementation, and policy development are urgently needed.