Predictors of racial differences in weight loss: the PROPEL trial.

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.

Dietary intake during a pragmatic cluster-randomized weight loss trial in an underserved population in primary care.

BACKGROUND: Currently there are limited data as to whether dietary intake can be improved during pragmatic weight loss interventions in primary care in underserved individuals. METHODS: Patients with obesity were recruited into the PROPEL trial, which randomized 18 clinics to either an intensive lifestyle intervention (ILI) or usual care (UC). At baseline and months 6, 12, and 24, fruit and vegetable (F/V) intake and fat intake was determined. Outcomes were analyzed by repeated-measures linear mixed-effects multilevel models and regression models, which included random cluster (clinic) effects. Secondary analyses examined the effects of race, sex, age, and food security status. RESULTS: A total of 803 patients were recruited. 84.4% were female, 67.2% African American, 26.1% received Medicaid, and 65.5% made less than $40,000. No differences in F/V intake were seen between the ILI and UC groups at months 6, 12, or 24. The ILI group reduced percent fat at months 6, 12, and 24 compared to UC. Change in F/V intake was negatively correlated with weight change at month 6 whereas change in fat intake was positively associated with weight change at months 6, 12, and 24 for the ILI group. CONCLUSIONS: The pragmatic weight loss intervention in primary care did not increase F/V intake but did reduce fat intake in an underserved population with obesity. F/V intake was negatively associated with weight loss at month 6 whereas percent fat was positively correlated with weight loss throughout the intervention. Future efforts better targeting both increasing F/V intake and reducing fat intake may promote greater weight loss in similar populations. TRIAL REGISTRATION: NCT Registration: NCT02561221.

Initial weight loss and early intervention adherence predict long-term weight loss during the Promoting Successful Weight Loss in Primary Care in Louisiana lifestyle intervention.

OBJECTIVE: This study tested whether initial weight change (WC), self-weighing, and adherence to the expected WC trajectory predict longer-term WC in an underserved primary-care population with obesity. METHODS: Data from the intervention group (n = 452; 88% women; 74% Black; BMI 37.3 kg/m2 [SD: 4.6]) of the Promoting Successful Weight Loss in Primary Care in Louisiana trial were analyzed. Initial (2-, 4-, and 8-week) percentage WC was calculated from baseline clinic weights and daily at-home weights. Weights were considered adherent if they were on the expected WC trajectory (10% at 6 months with lower [7.5%] and upper [12.5%] bounds). Linear mixed-effects models tested whether initial WC and the number of daily and adherent weights predicted WC at 6, 12, and 24 months. RESULTS: Percentage WC during the initial 2, 4, and 8 weeks predicted percentage WC at 6 (R2 = 0.15, R2 = 0.28, and R2 = 0.50), 12 (R2 = 0.11, R2 = 0.19, and R2 = 0.32), and 24 (R2 = 0.09, R2 = 0.11, and R2 = 0.16) months (all p < 0.01). Initial daily and adherent weights were significantly associated with WC as individual predictors, but they only marginally improved predictions beyond initial weight loss alone in multivariable models. CONCLUSIONS: These results highlight the importance of initial WC for predicting long-term WC and show that self-weighing and adherence to the expected WC trajectory can improve WC prediction.

Lyophilized liposomal formulation of a peptidomimetic-Dox conjugate for HER2 positive breast and lung cancer.

Nanocarrier-mediated administration of chemotherapeutic drugs can increase the therapeutic index of drugs by reducing off-target site toxicity. Ligand-targeted drug delivery can be utilized to deliver chemotherapeutic drugs to cancer cells selectively and specifically. Here we report the evaluation of a lyophilized formulation of a liposome containing a peptidomimetic-doxorubicin conjugate for targeted delivery of doxorubicin to HER2-positive cancer cells. The lyophilized liposomal formulation exhibited improved release of peptidomimetic-doxorubicin conjugate at pH 6.5 compared to 7.4 and improved cellular uptake in cancer cells at pH 6.5. In vivo studies indicated that pH-sensitive formulation exhibited site-specific formulation delivery and improved anticancer efficacy than free doxorubicin. The findings suggested that combining a lyophilized pH-sensitive liposomal formulation containing trehalose as lyoprotectant with a targeting ligand coupled cytotoxic agent is a potential method for cancer chemotherapy while maintaining long-term stability at 4 °C of the liposome formulation.

Effect of exercise training on insulin-stimulated glucose disposal: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVE: The effect of exercise training on whole-body insulin sensitivity has not been systematically summarized. We aimed to summarize the data from randomized controlled trials evaluating the effect of exercise training on insulin action, in adults. SUBJECTS: MEDLINE, EMBASE, and CENTRAL databases were searched until January 2021. Randomized controlled trials lasting ≥4 weeks, including adults, and evaluating the effect of exercise on insulin-stimulated glucose disposal measured using the hyperinsulinemic euglycemic clamp, were included. METHODS: Three reviewers extracted summary data from published trials. The primary outcome was insulin-stimulated glucose disposal. Standardized weighted mean differences (SMD) in glucose disposal between intervention and control were compared. The PEDro scale was used to assess risk of bias. RESULTS: We included 25 trials (36 interventions, N = 851). Exercise increased insulin-stimulated glucose disposal relative to control, SMD = 0.52 (95% confidence interval [CI]: 0.39, 0.65; p < 0.001; I2 = 47%) without significantly suppressing hepatic glucose production. In trials without isotopic tracers, exercise increased glucose disposal (SMD = 0.63; 95% CI: 0.48, 0.77; p < 0.001, I2 = 55%). In trials with isotopic tracers, exercise increased glucose disposal only when tracers were added to the exogenous glucose used for clamping (SMD = 0.34; 95% CI: 0.03, 0.66, p = 0.034. I2 = 0%). In a meta-regression model including aerobic exercise, weight change, and tracer technique, only percent weight change explained between trial heterogeneity (ß = 0.069; 95% CI: 0.005, 0.013). The PEDro rating indicated relatively low risk of bias (5.8 ± 0.22). CONCLUSIONS: Exercise training for at least four weeks significantly increases insulin-stimulated glucose disposal. Weight loss maximizes the effect and may be needed to improve hepatic insulin sensitivity. Differences in tracer methodology contribute to divergent outcomes and should be considered when assessing conclusions from research examining the effect of exercise on insulin action. REGISTRATION: PROSPERO (CRD42019124381).

Physical activity and weight loss in a pragmatic weight loss trial.

The purpose of this study was to determine the association between changes in physical activity and changes in body weight in a cluster-randomized weight loss trial conducted in an underserved population in Louisiana. This study reports analyses conducted in the intervention group only, which was a 24-month multi-component weight loss program delivered by health coaches embedded in primary care clinics. Physical activity was assessed at baseline and at 6, 12, and 24 months of follow-up and changes in body weight were expressed as percent weight change from baseline. Among the sample of 402 patients, percent changes in body weight (mean ± SE) across increasing tertiles of changes in walking between baseline and 24 months were -3.2 ± 1.0%, -5.5 ± 0.9%, and -7.3 ± 0.9%, respectively (p = 0.001). Changes in body weight across increasing tertiles of changes in moderate-to-vigorous-intensity activity between baseline and 24 months were -4.3 ± 1.0%, -5.0 ± 0.9%, and -7.0 ± 0.9%, respectively (p = 0.04). In conclusion, this multi-component intervention resulted in clinically significant weight loss, and greater increases in physical activity over the intervention period were associated with greater percent reductions in body weight. These results are consistent with those from other studies conducted primarily in non-underserved populations.

Comparison of weight loss data collected by research technicians versus electronic medical records: the PROPEL trial.

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.

Intraclass correlation coefficients for weight loss cluster randomized trials in primary care: The PROPEL trial.

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.

Sympathomimetic increases resting energy expenditure following bariatric surgery: A randomized controlled clinical trial.

OBJECTIVE: The aim of this study was to test the hypothesis that ephedrine + caffeine (EC) reduces the fall in resting energy expenditure (REE) following bariatric surgery. METHODS: This 32-week, randomized, double-blinded, placebo-controlled trial included 142 patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery. Participants were randomized to either EC or placebo for 27 weeks, beginning 5 weeks post surgery. The primary end points were change in REE (measured), percentage of predicted REE ([measured REE/Harris-Benedict equation-predicted REE] × 100), and body composition. Secondary outcomes included change in percentage of weight. Adverse events (AEs) were recorded. RESULTS: The reduction in REE was smaller in the EC versus the placebo group, but it was not significant. Percentage of predicted REE was increased in the EC versus the placebo group (difference, mean [SE]: 5.82 [2.29], p = 0.013). Percentage of weight (difference: -3.83 [1.39], p = 0.007) was reduced in the EC versus the placebo group. Percentage of predicted REE was increased and body weight decreased in the EC-treated participants who underwent SG compared with those who underwent SG and were treated with placebo (difference in percentage of predicted REE = 8.06 [2.83], p = 0.006; difference in weight percentage = -4.37 [1.92], p = 0.025). Percentage of fat-free mass was increased in the SG participants treated with EC versus placebo (difference: 1.31 [0.63], p = 0.042). The most common AEs were anxiety, dizziness, insomnia, and tremors. Most AEs were not different from placebo by Week 32. CONCLUSIONS: EC enhances weight loss and reduces the fall in REE following bariatric surgery. Adrenergic symptoms mostly resolve over time.

A pH-sensitive liposome formulation of a peptidomimetic-Dox conjugate for targeting HER2 + cancer.

Cancer treatment faces the challenge of selective delivery of the cytotoxic drug to the desired site of action to minimize undesired side effects. The liposomal formulation containing targeting ligand conjugated cytotoxic drug can be an effective approach to specifically deliver chemotherapeutic drugs to cancer cells that overexpress a particular cell surface receptor. This research focuses on the in vitro and in vivo studies of a peptidomimetic ligand attached doxorubicin for the HER2 positive lung and breast cancer cells transported by a pH-dependent liposomal formulation system for the enhancement of targeted anticancer treatment. The selected pH-sensitive liposome formulation showed effective pH-dependent delivery of peptidomimetic-doxorubicin conjugate at lower pH conditions mimicking tumor microenvironment (pH-6.5) compared to normal physiological conditions (pH 7.4), leading to the improvement of cell uptake. In vivo results revealed the site-specific delivery of the formulation and enhanced antitumor activity with reduced toxicity compared to the free doxorubicin (Free Dox). The results suggested that the targeting ligand conjugated cytotoxic drug with the pH-sensitive liposomal formulation is a promising approach to chemotherapy.

28-Day oral (gavage) and 13-week (dietary) toxicity studies of DHA canola oil and DHA canola meal in rats.

Omega-3 (ω3) fatty acids are a family of polyunsaturated fats. Two of the ω3 long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA, ω3, 20:5Δ5,8,11,14,17) and docosahexaenoic acid (DHA, ω3, 22:6Δ4,7,10,13,16,19) are sourced primarily from fish. Higher consumption, limited fishing quotas and other environmental factors (e.g., heavy metals) have warranted a need for alternative sources. Nuseed offers a genetically engineered canola (Brassica napus) event,1 DHA canola (OECD Unique Identifier NS-B5ØØ27-4), which has been modified to introduce a pathway for production of the ω3 LC-PUFAs DHA and EPA from oleic acid (OA) in the seed oil. To accomplish this, genes were sourced from marine microalgae and common yeast then incorporated into canola to produce DHA canola, one of the first land-based production systems for ω 3 PUFAs. Safety was evaluated in part by conducting a repeated dose 28-day toxicity study and a dietary 13-week toxicity study using CD® IGS [Crl:CD(SD)] rats. In the 28-day study, conventional and DHA canola oil were administered orally (via gavage); no treatment-related adverse effects were observed. The 13-week toxicity study was subsequently conducted where DHA canola oil and meal were administered by dietary admixture. No adverse effects were noted in clinical observations, clinical pathology, or histopathology. These studies support the food and feed safety of DHA canola oil and meal.

Weight loss in primary care: A pooled analysis of two pragmatic cluster-randomized trials.

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.

Effects of a 2-Year Primary Care Lifestyle Intervention on Cardiometabolic Risk Factors: A Cluster-Randomized Trial.

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.

Weight Loss in Underserved Patients - A Cluster-Randomized Trial.

BACKGROUND: Evidence of the effectiveness of treatment for obesity delivered in primary care settings in underserved populations is lacking. METHODS: We conducted a cluster-randomized trial to test the effectiveness of a high-intensity, lifestyle-based program for obesity treatment delivered in primary care clinics in which a high percentage of the patients were from low-income populations. We randomly assigned 18 clinics to provide patients with either an intensive lifestyle intervention, which focused on reduced caloric intake and increased physical activity, or usual care. Patients in the intensive-lifestyle group participated in a high-intensity program delivered by health coaches embedded in the clinics. The program consisted of weekly sessions for the first 6 months, followed by monthly sessions for the remaining 18 months. Patients in the usual-care group received standard care from their primary care team. The primary outcome was the percent change from baseline in body weight at 24 months. RESULTS: All 18 clinics (9 assigned to the intensive program and 9 assigned to usual care) completed 24 months of participation; a median of 40.5 patients were enrolled at each clinic. A total of 803 adults with obesity were enrolled: 452 were assigned to the intensive-lifestyle group, and 351 were assigned to the usual-care group; 67.2% of the patients were Black, and 65.5% had an annual household income of less than $40,000. Of the enrolled patients, 83.4% completed the 24-month trial. The percent weight loss at 24 months was significantly greater in the intensive-lifestyle group (change in body weight, -4.99%; 95% confidence interval [CI], -6.02 to -3.96) than in the usual-care group (-0.48%; 95% CI, -1.57 to 0.61), with a mean between-group difference of -4.51 percentage points (95% CI, -5.93 to -3.10) (P<0.001). There were no significant between-group differences in serious adverse events. CONCLUSIONS: A high-intensity, lifestyle-based treatment program for obesity delivered in an underserved primary care population resulted in clinically significant weight loss at 24 months. (Funded by the Patient-Centered Outcomes Research Institute and others; PROPEL ClinicalTrials.gov number, NCT02561221.).

Adaptations to exercise in compensators and noncompensators in the E-MECHANIC Trial.

Rating of perceived exertion (RPE) and respiratory exchange ratio (RER) have previously been associated with acute exercise compensation. This study examined adaptations in the RPE and RER with long-term exercise training in individuals who did (noncompensators) and did not (compensators) lose the expected amount of weight. Participants (n = 110, 71.8% women, means ± SD; age 49 ± 12 yr) completed 24 wk of supervised exercise training at 65-85% V̇o2peak to achieve a prescribed dose of 8 kcal·kg body wt-1·wk-1 (8 KKW) or 20 KKW. Participants were categorized as noncompensators (n = 55) or compensators (n = 55) based on the percent of expected weight loss (%EWL) achieved. Changes in RPE and RER during exercise over time (baseline, week 12, week 24) were compared by weight compensation category. Individual %EWL in relation to RPE, RER, and training intensity (%V̇o2peak) was evaluated over the same time period. RPE and RER for a given workload decreased from baseline to week 12 and stabilized through week 24, regardless of weight compensation (time P < 0.0001). Noncompensators had a higher RPE relative to heart rate, which was partly explained by higher %V̇o2peak. RPE and %V̇o2peak both positively predicted %EWL, independent of age, sex, and exercise dose. Training intensity and RPE were positively associated with weight loss on the individual level, warranting further investigation into self-selection in exercise-based programs. Understanding individual heterogeneity in training intensity and behavioral responses may improve future weight management efforts that involve exercise.NEW & NOTEWORTHY In sedentary individuals with overweight and obesity, achievement of expected weight loss from long-term exercise training was associated with individual adaptations in perceived exertion. Contrary to our hypothesis, those with higher relative perceived exertion achieved a larger proportion of their expected weight loss, which was partly explained by a higher self-selected exercise training intensity.

A Randomized Community-based Exercise Training Trial in African American Men: Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men.

PURPOSE: To examine the impact of a community-based exercise training intervention on cardiometabolic outcomes in African American men who have a family history of type 2 diabetes. METHODS: The Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men (ARTIIS) study randomized participants into either an exercise training intervention or an information only control group for 5 months. The exercise training intervention consisted of 150 min of moderate intensity aerobic activity and 2 d of resistance training per week, consistent with the current federal physical activity guidelines. Participants in the control group received monthly newsletters featuring topics focused heavily on type 2 diabetes education and prevention. Outcome data were analyzed using repeated-measures ANCOVA models and incorporating both intention-to-treat and per-protocol principles. RESULTS: Adherence to the aerobic and resistance training prescriptions were between 77% and 79%. Despite significant within group improvements in glucose and insulin levels (fasting, 2 h, 2 h minus baseline) and Homeostatic Model 2-Insulin Resistance, there were not significant between group differences. There was a marginally significant between group difference for Homeostatic Model 2-Beta (P < 0.06), and significant between group differences in peak cardiorespiratory fitness (P < 0.001) and waist circumference (P = 0.03). CONCLUSIONS: These findings suggest that exercise training in accordance with the current national recommendations is effective in improving some health parameters in middle-age African American men who have a family history of type 2 diabetes, but did not have a significant impact on glycemic status.

Increased Human Growth Hormone After Oral Consumption of an Amino Acid Supplement: Results of a Randomized, Placebo-Controlled, Double-Blind, Crossover Study in Healthy Subjects.

BACKGROUND: Human growth hormone (hGH) is best known for influencing bone and muscle growth, as well as body composition, but the use of recombinant hGH is controversial. Amino acids are a potentially safer alternative; however, preliminary investigations of the effects of oral amino acids on hGH release have been inconclusive. Therefore, we tested the effects of a novel blend of amino acids optimized to increase hGH release. STUDY QUESTION: Does an investigational amino acid supplement affect hGH release? STUDY DESIGN: This was a randomized, placebo-controlled, double-blind, crossover study that included 16 (12 men, 4 women; age 32 ± 14 years; body mass index 26.4 ± 5.0 kg/m) healthy participants. All participants received both placebo and the amino acid supplement after an overnight fast and completed all study visits. Treatment order was randomized, and each treatment was separated by a 1-week washout period. MEASURES AND OUTCOMES: The primary outcomes were the percent change in hGH from baseline to 120 minutes and the area under the curve of hGH over baseline. Serum hGH was measured using enzyme-linked immunosorbent assay at baseline and 15, 30, 60, 90, and 120 minutes. RESULTS: At 120 minutes, hGH levels increased by 682% (8-fold) from baseline and were significantly higher than placebo (P = 0.01). In addition, a significantly higher mean area under the curve was observed for the amino acid supplement compared with the placebo [20.4 (95% confidence interval, 19.9-21.0 ng/mL) vs. 19.7 (95% confidence interval, 18.7-20.6 ng/mL); P = 0.04]. CONCLUSIONS: These results show that a single dose of the oral amino acid supplement was sufficient to significantly increase hGH levels in healthy adult men and women. CLINICAL TRIAL REGISTRY:: clinicaltrials.gov NCT01540773.

A Snack Formulated with Ingredients to Slow Carbohydrate Digestion and Absorption Reduces the Glycemic Response in Humans: A Randomized Controlled Trial.

This study compared the effect of a snack with ingredients to slow carbohydrate digestion (Test-snack) on postprandial blood glucose and insulin concentrations and subjective appetite ratings. We hypothesized that Test-snack would lower glucose and insulin responses and reduce appetite compared with a Control-snack. Overweight or obese subjects (n = 17) completed a randomized crossover study. Glucose, insulin, and appetite ratings were measured before consuming each snack or white bread (Bread) and over a period of 4 h. Subjects received Test-snack, Control-snack, or Bread in random order at least a week apart. The a priori primary outcome was the glucose response, and the secondary outcomes were appetite ratings and insulin responses. Mixed effects statistical models were used to perform analysis of variance in terms of the area under curve (AUC) and at specific time points. The 2-h AUC for glucose was significantly lower with Test-snack compared to Control-snack and Bread (AUC and 95% confidence intervals: Test = 2186.43 [1783.36-2589.51]; Control = 3293.75 [2893.97-3693.54]; Bread = 2800.28 [2405.79-3194.77] mg/dL · min). Four-hour AUC for glucose, and insulin, followed a similar pattern except that Test-snack did not differ from Bread. The glucose concentrations peaked at 45 min under all three conditions, but Test-snack elicited a lower response than Control-snack and Bread (P < .01). Test increased fullness and satisfaction and reduced hunger and prospective intake compared to Bread (P < .02), but was not significantly different from Control-snack. Ingredients that slow carbohydrate digestion in a snack reduce the postprandial glucose and insulin responses compared to a product without these ingredients.

Evaluation of Step-Counting Interventions Differing on Intensity Messages.

BACKGROUND: Step-counting interventions with discrepant intensity emphases may elicit different effects. METHODS: A total of 120 sedentary/low-active, postmenopausal women were randomly assigned to one of the following 3 groups: (1) 10,000 steps per day (with no emphasis on walking intensity/speed/cadence; basic intervention, 49 completers), (2) 10,000 steps per day and at least 30 minutes in moderate intensity (ie, at a cadence of at least 100 steps per minute; enhanced intervention, 47 completers), or (3) a control group (19 completers). NL-1000-determined steps and active minutes (a device-specific indicator of time at moderate+ intensity) were collected as process variables during the 12-week intervention. Outcome variables included systolic and diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow-mediated dilation, gait speed, and ActiGraph GT3X+-determined physical activity and sedentary behavior. RESULTS: The "basic group" increased 5173 to 9602 steps per day and 9.2 to 30.2 active minutes per day. The "enhanced group" similarly increased 5061 to 10,508 steps per day and 8.7 to 38.8 active minutes per day. The only significant change over time for clinical variables was body mass index. CONCLUSIONS: Interventions that use simple step-counters can achieve elevated volume and intensity of daily physical activity, regardless of emphasis on intensity. Despite this, few clinical outcomes were apparent in this sample of postmenopausal women with generally normal or controlled hypertension.