The role of parents in behavioral treatment for adolescent obesity: design and rationale for the TEENS+ randomized clinical trial

BACKGROUND

There is an urgent need for innovative approaches to adolescent obesity treatment, particularly among individuals from racially and ethnically marginalized backgrounds, who face increased risk of obesity and its associated morbidity and mortality. There is a particular dearth of research on the long-term efficacy of adolescent obesity treatments. Further, research and clinical practice guidelines consistently recommend parents' inclusion in their adolescents' obesity treatment, yet the most effective strategy to engage parents in adolescent obesity treatment remains unclear. Towards that end, this investigation will conduct a fully-powered, randomized clinical trial to examine the efficacy of two distinct approaches to involving parents in their adolescents' obesity treatment.

METHODS

Participants will be 210 12-16 year old adolescents (body mass index [BMI]≥85th percentile) and parents (BMI≥25 kg/m2) with overweight or obesity. Dyads will be randomized to one of two 4-month treatments: 1) TEENS+Parents as Coaches (PAC), engaging parents as helpers in their child's weight management via parent skills training based on authoritative parenting, or 2) TEENS+Parent Weight Loss (PWL), engaging parents in their own behavioral weight management. All adolescents will participate in the TEENS+ protocol, which includes nutrition education with dietary goals, supervised physical activity, and behavioral support, and integrates motivational interviewing to enhance treatment engagement. Assessments of anthropometrics, dietary intake, physical activity, parenting and home environment variables will be completed at 0, 2, 4, 8, and 12 months with the primary endpoint at 12-month follow-up.

DISCUSSION

Results of this investigation have the potential to significantly advance science in this area and ultimately inform clinical practice guidelines related to the role of parents in adolescent obesity treatment.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03851796. Registered: February 22, 2019.

Influence of extracellular volume fraction on peak exercise oxygen pulse following thoracic radiotherapy

Background

Radiation-induced myocardial fibrosis increases heart failure (HF) risk and is associated with a restrictive cardiomyopathy phenotype. The myocardial extracellular volume fraction (ECVF) using contrast-enhanced cardiac magnetic resonance (CMR) quantifies the extent of fibrosis which, in severe cases, results in a noncompliant left ventricle (LV) with an inability to augment exercise stroke volume (SV). The peak exercise oxygen pulse (O₂Pulse), a noninvasive surrogate for exercise SV, may provide mechanistic insight into cardiac reserve. The relationship between LV ECVF and O₂Pulse following thoracic radiotherapy has not been explored.

Methods

Patients who underwent thoracic radiotherapy for chest malignancies with significant incidental heart dose (≥5 Gray (Gy), ≥10% heart) without a pre-cancer treatment history of HF underwent cardiopulmonary exercise testing to determine O₂Pulse, contrast-enhanced CMR, and N-terminal pro-brain natriuretic peptide (NTproBNP) measurement. Multivariable-analyses were performed to identify factors associated with O₂Pulse normalized for age/gender/anthropometrics.

Results

Thirty patients (median [IQR] age 63 [57–67] years, 18 [60%] female, 2.0 [0.6–3.8] years post-radiotherapy) were included. The peak VO₂ was 1376 [1057–1552] mL·min^− 1, peak HR = 150 [122–164] bpm, resulting in an O₂Pulse of 9.2 [7.5–10.7] mL/beat or 82 (66–96) % of predicted. The ECVF, LV ejection fraction, heart volume receiving ≥10 Gy, and NTproBNP were independently associated with %O₂Pulse (P < .001).

Conclusions

In patients with prior radiotherapy heart exposure, %-predicted O₂Pulse is inversely associated markers of diffuse fibrosis (ECVF), ventricular wall stress (NTproBNP), radiotherapy heart dose, and positively related to LV function. Increased LV ECVF may reflect a potential etiology of impaired LV SV reserve in patients receiving thoracic radiotherapy for chest malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40959-021-00127-6.

Effect of a Lifestyle Intervention on Cardiometabolic Health Among Emerging Adults: A Randomized Clinical Trial

IMPORTANCE

The prevalence of obesity has increased substantially among emerging adults, yet no previous large-scale behavioral weight loss trials have been conducted among this age group.

OBJECTIVE

To test the effect of 2 theory-based motivational enhancements on weight loss within a primarily digital lifestyle intervention designed for emerging adults.

DESIGN, SETTING, AND PARTICIPANTS

In this randomized clinical trial conducted at an academic medical research center, 382 participants aged 18 to 25 years with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 25 to 45 were enrolled between February 2, 2016, and February 6, 2019. Data collection was completed February 8, 2020. Analysis was performed on an intention-to-treat basis.

INTERVENTIONS

Participants were randomized to 1 of 3 groups: developmentally adapted behavioral weight loss (aBWL), aBWL plus behavioral economics (aBWL + BE), or aBWL plus self-determination theory (aBWL + SDT). All groups received a 6-month intervention with 1 group session, 1 individual session, and a digital platform (digital tools for self-monitoring, weekly lessons, tailored feedback, text messages, and optional social media). The aBWL + BE group received modest financial incentives for self-monitoring and weight loss; the aBWL + SDT group received optional experiential classes. Coaching and message framing varied by group.

MAIN OUTCOMES AND MEASURES

The primary outcome was mean (SE) weight change (in kilograms) at 6 months. Secondary outcomes included proportion of participants achieving weight loss of 5% or more, percentage weight change, waist circumference, body composition, and blood pressure.

RESULTS

Among the 382 participants (mean [SD] age, 21.9 [2.2] years), 316 (82.7%) were female, mean (SD) BMI was 33.5 (4.9), 222 (58.1%) were of underrepresented race and/or ethnicity, and 320 (83.8%) were retained at the primary end point. There was a significant time effect for mean (SE) weight loss (-3.22 [0.55] kg in the aBWL group; -3.47 [0.55] kg in the aBWL + BE group; and -3.40 [0.53] kg in the aBWL + SDT group; all P < .001), but no between-group differences were observed (aBWL vs aBWL + BE: difference, -0.25 kg [95% CI, -1.79 to 1.29 kg]; P = .75; aBWL vs aBWL + SDT: difference, -0.18 kg [95% CI, -1.67 to 1.31 kg]; P = .81; and aBWL + SDT vs aBWL + BE: difference, 0.07 kg [95% CI, -1.45 to 1.59 kg]; P = .93). The proportion of participants achieving a weight loss of 5% or more was 40.0% in the aBWL group (50 of 125), 39.8% in the aBWL + BE group (51 of 128), and 44.2% in the aBWL + SDT group (57 of 129), which was not statistically different across groups (aBWL vs aBWL + BE, P = .89; aBWL vs aBWL + SDT, P = .45; aBWL + SDT vs aBWL + BE, P = .54). Parallel findings were observed for all secondary outcomes-clinically and statistically significant improvements with no differences between groups.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, all interventions produced clinically significant benefit, but neither of the motivational enhancements promoted greater reductions in adiposity compared with the developmentally adapted standard group. Continued efforts are needed to optimize lifestyle interventions for this high-risk population and determine which intervention works best for specific individuals based on sociodemographic and/or psychosocial characteristics.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02736981.

The role of parents in adolescent obesity treatment: Results of the TEENS+ randomized clinical pilot trial

BACKGROUND

The optimal role for involving parents in adolescent obesity treatment is unknown.

OBJECTIVE

To demonstrate that two parent approaches within adolescent obesity treatment are distinct, as evidenced by differential parent outcomes, and determine the preliminary efficacy of each approach on adolescent weight loss.

METHODS

Adolescent/parent dyads (N = 82; mean adolescent age = 13.7 ± 1.2 years) participated in TEENS+, a 4-month behavioural weight loss treatment. Participants were randomized to: (1) TEENS+parents as coaches (PAC; parent skills training), or (2) TEENS+parent weight loss (PWL; adult behavioural weight loss). Assessments occurred at 0, 4 (post-treatment), and 7-months. Within- and between-group repeated measures general linear mixed models examined change in parent weight (∆kg; primary outcome); parenting, feeding, weight control strategies, home environment, and adolescent body mass index (∆BMI; secondary outcomes).

RESULTS

PWL parents had greater 4-month weight losses (∆kg_0-4m  = -5.14 ± 4.87 kg) compared to PAC (-2.07 ± 3.89 kg; between-group p < 0.01). Key constructs differed between groups as expected. Both groups yielded significant within-group adolescent ∆BMI_0-4m (PWL: -0.97 ± 1.38 kg/m² vs. PAC: -0.93 ± 1.42 kg/m² ; ps < 0.01); during maintenance, adolescents in PWL had ∆BMI_4-7m increases (+0.41 ± 1.07 kg/m² ; p = 0.02) while PAC did not (+0.05 ± 1.31 kg/m² ; p = 0.82).

CONCLUSION

Parent treatments were distinct in implementation and both yielded significant 4-month adolescent weight loss. Differential weight patterns were observed during maintenance, favouring PAC, warranting further exploration.

Diastolic Dysfunction Contributes to Impaired Cardiorespiratory Fitness in Patients with Lung Cancer and Reduced Lung Function Following Chest Radiation

Cardiorespiratory fitness (CRF) is a robust and independent predictor of cardiovascular health and overall mortality. Patients with lung cancer often have chronic lung disease, contributing to impaired CRF. Radiation to the heart during lung cancer treatment may further reduce CRF. The determinants of CRF in this population are not well understood. We prospectively evaluated 12 patients with lung cancer without known cardiovascular disease with reduced lung function receiving curative intent thoracic radiotherapy to determine whether cardiac diastolic function, as assessed by Doppler echocardiography and N-terminal pro-brain natriuretic peptide (NTproBNP) levels, correlate with CRF measured by peak oxygen consumption (VO₂). Doppler-derived measures of diastolic function and serum NTproBNP levels inversely correlated with peak VO_2. In a multivariate regression model, NTproBNP was the strongest independent variable associated with peak VO₂. These results suggest that diastolic dysfunction further contributes to reduced CRF in patients with lung cancer who have received radiotherapy.

Using measured resting metabolic rate to derive calorie prescriptions in a behavioral weight loss program

Objective

Within behavioral weight loss (BWL) programs, using measured resting metabolic rate (RMR) is a more accurate—yet costlier—alternative to the standard method of assigning calorie prescriptions using baseline weight. This investigation aimed to assess differences between calorie goals prescribed using each method including demographic predictors and associations with weight loss.

Methods

This is an ancillary study to a trial comparing approaches to motivational enhancement in a 6‐months BWL program designed for emerging adults age 18–25 (N = 308). RMR was measured at baseline and used to derive calorie prescriptions; standard calorie goals were retrospectively assigned for the purpose of these analyses.

Results

Standard calorie prescriptions were significantly higher than those derived from RMR. Sex and race were significant predictors of calorie prescription discrepancies: using the standard method, women and Black participants were assigned higher calorie goals than their RMR would indicate. Calorie goal discrepancy did not predict 6‐months weight change.

Conclusions

Differences in calorie prescriptions between approaches were significant; however, it remains to be determined whether measuring RMR is worth the cost, time, and participant burden. It may be the case that this consideration has greater impact for certain subgroups—namely, women and Black participants.

An appraisal of whole-room indirect calorimeters and a metabolic cart for measuring resting and active metabolic rates

Whole-room indirect calorimeters (WRICs) have traditionally been used for real-time resting metabolic rate (RMR) measurements, while metabolic rate (MR) during short-interval exercises has commonly been measured by metabolic carts (MCs). This study aims to investigate the feasibility of incorporating short-interval exercises into WRIC study protocols by comparing the performance of WRICs and an MC. We assessed the 40-min RMR of 15 subjects with 2-day repeats and the 10-15 min activity MR (AMR) of 14 subjects at three intensities, using a large WRIC, a small WRIC, and an MC. We evaluated the biases between the instruments and quantified sources of variation using variance component analysis. All three instruments showed good agreement for both RMR (maximum bias = 0.07 kcal/min) and AMR assessment (maximum bias = 0.53 kcal/min). Moreover, the majority of the variability was between-subject and between-intensity variation, whereas the types of instrument contributed only a small amount to total variation in RMR (2%) and AMR (0.2%) data. In Conclusion, the good reproducibility among the instruments indicates that they may be used interchangeably in well-designed studies. Overall, WRICs can serve as an accurate and versatile means of assessing MR, capable of integrating RMR and short-interval AMR assessments into a single protocol.

Determinants of Cardiorespiratory Fitness Following Thoracic Radiotherapy in Lung or Breast Cancer Survivors

We measured peak oxygen consumption (VO₂) in previous recipients of thoracic radiotherapy and assessed the determinants of cardiorespiratory fitness with an emphasis on cardiac and pulmonary function. Cancer survivors who have received thoracic radiotherapy with incidental cardiac involvement often experience impaired cardiorespiratory fitness, as measured by reduced peak VO₂, a marker of impaired cardiovascular reserve. We enrolled 25 subjects 1.8 (0.1 to 8.2) years following completion of thoracic radiotherapy with significant heart exposure (at least 10% of heart volume receiving at least 5 Gray). All subjects underwent cardiopulmonary exercise testing, Doppler echocardiography, and circulating biomarkers assessment. The cohort included 16 Caucasians (64%), 15 women (60%) with a median age of 63 (59 to 66) years. The peak VO₂ was 16.8 (13.5 to 21.9) ml·kg^-1·min^-1 or moderately reduced at 62% (50% to 93%) of predicted. The mean cardiac radiation dose was 5.4 (3.7 to 14.7) Gray, and it significantly correlated inversely with peak VO₂ (R = -0.445, p = 0.02). Multivariate regression analysis revealed the diastolic functional reserve index and the N-terminal pro-brain natriuretic peptide (NTproBNP) serum levels were independent predictors of peak VO₂ (ß = +0.813, p <0.01 and ß = -0.414, p = 0.04, respectively). In conclusion, patients who had received thoracic radiation display a dose-dependent relation between the cardiac radiation dose received and the impairment in peak VO₂, the reduction in diastolic functional reserve index, and elevation of NTproBNP.

Increased C-reactive protein is associated with the severity of thoracic radiotherapy-induced cardiomyopathy

BACKGROUND

Irradiation of the heart during cancer radiotherapy is associated with a dose-dependent risk of heart failure. Animal studies have demonstrated that irradiation leads to an inflammatory response within the heart as well as a reduction in cardiac reserve. In the current study we aimed to evaluate whether inflammatory biomarkers correlated with changes in cardiac function and reserve after radiotherapy for breast or lung cancer.

METHODS AND RESULTS

We studied 25 subjects with a history of breast or lung cancer without a prior diagnosis of cardiovascular disease or heart failure, 1.8 years [0.4-3.6] post-radiotherapy involving at least 5 Gray (Gy) to at least 10% of the heart. High-sensitivity C-reactive protein (CRP) was abnormal (≥2 mg/L) in 16 (64%) subjects. Cardiac function and reserve was measured with Doppler echocardiography before and after exercise and defined as left-ventricular ejection fraction (LVEF), early diastolic mitral annulus velocity (e'), and increase in LV outflow tract velocity time integral cardiac output (cardiac reserve) with exercise. Subjects with abnormal CRP had significantly lower LVEF (51 [44-59] % vs 61 [52-64] %, P = 0.039), lower e' (7.4 [6.6-7.9] cm/sec vs 9.9 [8.3-12.0] cm/sec, P = 0.010), and smaller cardiac reserve (+ 1.5 [1.2-1.7] L/min vs + 1.9 [1.7-2.2] L/min, P = 0.024).

CONCLUSION

Elevated systemic inflammation is associated with impaired left-ventricular systolic and diastolic function both at rest and during exercise in subjects who have received radiotherapy with significant incidental heart dose for the treatment of cancer.

Impact of motivational interviewing on outcomes of an adolescent obesity treatment: results from the MI Values randomized controlled pilot trial

The aim of this study is to examine outcomes from MI Values, a motivational interviewing (MI) intervention implemented adjunctive to obesity treatment. Adolescents (n = 99; 73% African American; 74% female; mean body mass index [BMI] percentile = 98.9 ± 1.2) were randomized to receive two MI sessions or education control. All adolescents participated in structured behavioural weight management treatment. Baseline, 3- and 6-month assessments of anthropometrics, dietary intake and physical activity were obtained. Both groups had significant reductions in BMI z-scores and energy intake and increased physical activity at 3 and 6 months (P < 0.05). MI participants reported greater reductions in 3-month energy intake compared with controls. Participation in MI is associated with reduction in energy intake, consistent with better adherence to dietitian visits previously reported from MI Values. MI might be an effective adjunct to adolescent obesity treatment; future research is needed to determine if motivational interviewing can enhance BMI outcomes, via greater adherence to behavioural intervention.

Changes in Resting Energy Expenditure in Relation to Body Weight and Composition Following Gastric Restriction: A Systematic Review

In comparison to gastric bypass surgery, gastric restriction without malabsorption more closely simulates dietary adherence while still producing durable weight loss. The latter is achieved despite considerable reductions in resting energy expenditure (REE), and whether REE is adjusted for body weight/composition using ratio- or regression-based methods could influence understanding of how these procedures affect energy balance. This systematic review identified studies that reported REE before and after gastric restriction in order to compare changes using each method. Ratio assessments revealed increases and decreases when REE was expressed per kilogram of body weight and per kilogram of fat-free mass, respectively. In comparison, measured REE tended to be less than predicted from linear regression after surgery. Explanations for these seemingly disparate findings and future directions are discussed.

Excess Blood Flow Response to Acute Resistance Exercise in Individuals Who are Obese or Nonobese

Lipford, GF, Evans, RK, Acevedo, EO, Wolfe, LG, and Franco, RL. Excess blood flow response to acute resistance exercise in individuals who are obese or nonobese. J Strength Cond Res 31(11): 3120-3127, 2017-Resistance exercise (RE) is a commonly recommended treatment option for obese individuals. However, little is known regarding alterations in vasodilatory responses to RE, which could impair exercise tolerance. No studies to date have compared microvascular vasodilatory capacity, assessed by excess blood flow (EBF), responses in individuals who are obese or nonobese following acute RE. The purpose of the study was to evaluate EBF before and up to 24-hour after a single RE bout in obese (n = 18, 38.1 ± 7.64% body fat) and nonobese (n = 10, 23.6 ± 4.03% body fat) individuals who volunteered to participate. Each subject completed a leg flexion and knee extension one repetition maximum (1RM) test, and subsequently completed 4 sets of 8 repetitions at 85% of 1RM. Excess blood flow, adiponectin, and tumor necrosis factor α (TNF-α) were evaluated at baseline (PRE-RE), immediately after (POST-RE), and 1 (POST-1) and 24 (POST-24) hours after exercise. A repeated-measures analysis of variance revealed a significant interaction for EBF between the 2 groups (p = 0.029). The estimated marginal means plot suggested that obese individuals had a significant increase in POST-RE EBF in comparison with PRE-RE EBF (428.54 ± 261.59 vs. 547.00 ± 311.15 ml/100 ml/min·s; p = 0.046). In addition, EBF significantly decreased at POST-24 in comparison with POST-RE in the obese individuals (547.00 ± 311.15 vs. 389.33 ± 252.32 ml/100 ml/min·s; p = 0.011). Changes in EBF were not related to adiponectin or TNF-α. An acute bout of RE resulted in an opposite EBF response between nonobese and obese individuals immediately after RE. Furthermore, only the obese individuals displayed a significant increase in EBF immediately after RE, which was significantly reduced 24 hours after the RE bout. Microvascular vasodilatory capacity may alter the adaptive exercise response associated with RE, requiring alterations to frequency, intensity, and/or duration that are specific to populations of various body composition profiles.

Evaluation of pre- and postoperative physical activity participation in laparoscopic gastric banding patients

BACKGROUND

Weight loss outcomes following laparoscopic adjustable gastric banding (LAGB) are widely variable, and physical activity (PA) participation improves these results. The purpose of this study was to retrospectively describe PA behaviors before and after LAGB and to evaluate the impact of PA on weight loss outcomes.

METHODS

Participants were 172 individuals (145 females, mean age 43.3 ± 12.0 years, mean body mass index [BMI] 43.8 ± 5.1 kg/m(2)) who underwent LAGB at a university medical center. Height, weight, presence of comorbidities, and PA participation were assessed prior to and 3, 6, and 12 months after surgery. Those who reported engaging in ≥ 150 min of weekly moderate-to-vigorous PA (MVPA) were considered active.

RESULTS

Less than 40 % of participants were active prior to surgery, while 31 % of those who were inactive before surgery became active at 6 months of follow-up. Unlike previous reports on gastric bypass patients, there was no statistically significant (p > 0.05) relationship between postoperative PA status and weight loss outcomes at 3, 6, or 12 months in LAGB patients. Interestingly, participants who reported ≥ 150 min of MVPA prior to surgery achieved approximately 10 % greater excess weight loss (p < 0.05) and a 2.4-kg/m(2) greater decrease in BMI (p < 0.05) at 1 year post-LAGB compared to those who were inactive preoperatively.

CONCLUSIONS

In our sample, higher levels of preoperative PA participation were associated with improved weight loss outcomes following LAGB. We posit that higher preoperative volumes are indicative of habitual exercise and that those who report being active prior to surgery are likely to maintain these behaviors throughout follow-up.

Sympathetic Activity Assessed during Exercise Recovery in Young Obese Females

OBJECTIVE

To evaluate differences in sympathetic activity, as assessed by an exercise recovery index (ERI; heart rate/oxygen consumption [VO2] plateau), between black and white obese female adolescents. An additional aim was to determine the association of ERI with insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]), cardiovascular fitness per fat-free mass (VO2 per fat-free mass), systolic blood pressure (SBP), and percent body fat (%FAT) in both black and white obese adolescents.

STUDY DESIGN

Sixty-one females volunteered to participate in this study. HOMA-IR, SBP, and %FAT were assessed during resting conditions in black (n = 49, 13.7 ± 1.6 years, 38.1 ± 6.1 kg/m(2)) and white (n = 12, 13.3 ± 2.2 years, 34.3 ± 4.9 kg/m(2)) obese adolescents. An ERI was calculated during a 5-minute passive recovery period immediately following a graded treadmill exercise test to exhaustion.

RESULTS

The ERI was significantly greater in black compared with white obese adolescent females (29.8 ± 6.4 vs 24.1 ± 3.1 bpm·mLO2(-1)·min(-1), P = .004). Using multiple linear regression modeling, there was a significant independent association between ERI and VO2 per fat-free mass (r = -0.310, P = .027) and %FAT (r = 0.326, P = .020) in black obese adolescents after controlling for HOMA-IR and SBP.

CONCLUSIONS

These results suggest that black obese adolescent females have greater sympathetic activity, as assessed by an ERI, than white obese adolescent females. These findings support the need for weight management efforts aimed at both reducing %FAT and improving fitness in obese adolescents, specifically black females.

TRIAL REGISTRATION

Registered with Clinicaltrials.gov: NCT00562293.

The contribution of fat-free mass to resting energy expenditure: implications for weight loss strategies in the treatment of adolescent obesity

Owing to the strong relationship between fat-free mass (FFM) and resting energy expenditure (REE), the preservation of FFM is often emphasized in the treatment of adolescent obesity. Typical treatment regimens including an increased dietary consumption of protein and participation in resistance training are common components of adolescent weight management programs, despite limited evidence of a positive influence of FFM on weight loss outcomes in adolescents. Given the larger volume of FFM in obese relative to normal weight adolescents and the common treatment goals of both maximizing weight loss and attenuating the loss of FFM, a better understanding of the influence of FFM on energy balance is needed to determine whether strategies to preserve lean tissue or maximize absolute weight loss should be most emphasized. We review the associations among FFM, REE, and weight loss outcomes, focusing on how these relationships might influence energy balance in obese adolescents.

Cardiometabolic and Fitness Improvements in Obese Girls Who Either Gained or Lost Weight during Treatment

OBJECTIVE

To evaluate the quality of weight change (change in fat mass vs fat-free mass [FFM]), changes in cardiorespiratory fitness (CRF), and frequencies of metabolic risk factors in adolescent females with obesity who either lost or gained weight following lifestyle treatment.

STUDY DESIGN

Fifty-eight girls (mean age = 13.0 ± 1.6 years; 77% black; mean body mass index = 36.5 ± 4.5 kg/m(2)) completed a 6-month lifestyle intervention combining dietary and behavioral counseling with aerobic and resistance exercise training. We examined baseline to 6-month differences in weight (kg), body composition, CRF, and frequencies of metabolic risk factors between weight loss and weight gain groups.

RESULTS

In the weight loss group, body weight (-4.50 ± 3.53 kg, P < .001), fat mass (-4.50 ± 2.20 kg, P < .001), and body fat percentage (-2.97% ± 1.45%, P < .001) decreased, and FFM was unchanged at 6 months. In the weight gain group, body weight (4.50 ± 2.20 kg, P < .001), fat mass (1.52 ± 3.16 kg, P < .024), and FFM (2.99 ± 2.45 kg, P < .001) increased, and body fat percentage was unchanged. Both groups improved CRF (P < .05). Frequencies of metabolic risk factors were reduced across all participants after the 6-month treatment.

CONCLUSIONS

Participation in a weight management program might elicit health improvements in obese adolescent females who increase weight and fat mass, provided that FFM gains are sufficient to negate increases in body fat percentage.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00167830.

Sex differences in pulmonary oxygen uptake kinetics in obese adolescents

OBJECTIVE

To determine whether sex differences exist in the pulmonary oxygen uptake (VO2) uptake on-kinetic response to moderate exercise in obese adolescents. We also examined whether a relationship existed between the VO2 on-transient response to moderate intensity exercise, steady-state VO2, and peak VO2 between obese male and female adolescents.

STUDY DESIGN

Male (n = 12) and female (n = 28) adolescents completed a graded exercise test to exhaustion on a treadmill. Data from the initial 4 minutes of treadmill walking were used to determine the time constant.

RESULTS

The time constant was significantly different (P = .001) between obese male and female adolescents (15.17 ± 8.45 seconds vs 23.07 ± 8.91 seconds, respectively). No significant relationships were observed between the time constant and variables of interest in either sex.

CONCLUSIONS

Sex differences exist in VO2 uptake on-kinetics during moderate exercise in obese adolescents, indicating an enhanced potential for male subjects to deliver and/or use oxygen. It may be advantageous for female subjects to engage in a longer warm-up period before the initiation of an exercise regimen to prevent an early termination of the exercise session.

Parent skills training to enhance weight loss in overweight children: evaluation of NOURISH

OBJECTIVE

Although there is general agreement that parents should be involved in pediatric obesity treatment, few studies have investigated the effectiveness of interventions that target parents exclusively. Moreover, the effectiveness of this approach has not been adequately assessed with racially diverse families, particularly African Americans(AA), a group at high risk for elevated Body Mass Index (BMI).

METHODS

NOURISH (Nourishing Our Understanding of Role modeling to Improve Support and Health) is a culturally-sensitive parenting intervention targeting overweight (AA) children (ages 6-11; MBMI = 98.0%ile). Families (N = 84; 61% AA, 37% White) were randomly assigned to NOURISH or a control group.

RESULTS

NOURISH families significantly improved on child BMI from pre- to post-testing after adjustment for random effects, baseline BMI, and child race. NOURISH parents were very satisfied with the intervention and would recommend it to other parents; 91% strongly or moderately agreed that NOURISH helped them eat in a healthier manner.

CONCLUSIONS

These pilot data suggest that NOURISH is acceptable and, with refinement, offers promise for reducing pediatric BMI. Outcomes, lessons learned, and parent feedback will inform a larger randomized controlled trial.

The stress process and eating pathology among racially diverse adolescents seeking treatment for obesity

OBJECTIVE

This study examined the associations of weight-related teasing and daily hassles with eating pathology, as well as potential mediators of these relations, among a racially diverse sample of adolescents.

METHODS

Participants were 92 primarily African American 11-17-year-olds seeking treatment for obesity. Data were collected at baseline.

RESULTS

Both daily hassles and weight-related teasing were significantly correlated with eating pathology at r = .22 and r = .25, respectively. Feeling upset about teasing mediated the associations of daily hassles (PE = .0093, SE = .0054, 95% BCa bootstrap CI of .0001-.0217) and teasing (PE = .0476, SE = .0198, 95% BCa bootstrap CI of .0093-.0873) with eating pathology.

CONCLUSIONS

These results highlight the importance of psychological interventions in the treatment of weight-loss among adolescents, as stressors may impact eating behaviors.

Stress-induced microvascular reactivity in normal-weight and obese individuals

Obesity has been shown to have profound effects on hemodynamics and neurological states in humans. Previous studies have demonstrated that obese individuals are highly susceptible to increases in tension, anxiety, and depression. However, the relationship between mental stressors and vascular fluidity in obese humans is not well understood. Thus, the purpose of this study was to investigate mental-stress-induced microvascular reactivity (excess blood flow (EBF)) in normal-weight and obese individuals. In addition, the relationships between potential vascular response modulators (heart rate (HR) and norepinephrine (NE)) and EBF were examined. Twenty-two male subjects were classified as obese (n = 12) or normal-weight (n = 10), and each subject completed a 20 min bout of acute mental stress. Our analyses demonstrate significant elevations in forearm blood flow (FBF) and EBF immediately after mental stress in both normal-weight and obese groups. HR was only correlated with EBF immediately poststress in the normal-weight group. Furthermore, stress-induced plasma NE was not associated with FBF or EBF in either group, although in the obese group, stress-induced plasma NE was associated with body mass index and percent body fat. These results suggest that microvascular reactivity after mental stress is not directly related to plasma NE in normal-weight or obese individuals. The novel results presented in this study provide a foundation for additional examination of the mechanisms involved in the effects of mental stress on microvascular reactivity.

Female recruits sustaining stress fractures during military basic training demonstrate differential concentrations of circulating IGF-I system components: a preliminary study

OBJECTIVE

Stress fracture injuries sustained during military basic combat training (BT) are a significant problem and occur at a higher rate in female recruits than male recruits. Insulin-like growth factor-I (IGF-I) is an easily measured biomarker that is involved in bone formation and positively correlated with bone mineral density, especially in women. This study examined the response of the IGF-I system between female soldiers that sustained a stress fracture (SFX, n=13) during BT and female soldiers who did not (NSFX, n=49).

DESIGN

Female soldiers (n=62, 18.8 ± 0.6 yr) from 2 companies of a gender-integrated combat battalion in the Israeli Defense Forces participated in this study. Height, weight and blood draws were taken upon entry to BT (preBT) and after a four-month BT program (postBT). Stress fractures were diagnosed by bone scan. Serum was analyzed for total IGF-I, free IGF-I, IGF binding proteins (IGFBP)1-6, BAP, calcium, CTx, IL1β, IL6, PINP, PTH, TNFα, TRAP, and 25(OH)D. Statistical differences between SFX and NSFX groups and time points were assessed by RM ANOVA with Fisher post-hoc (p≤0.05).

RESULTS

The SFX group was significantly taller and had lower BMI than NSFX (p≤0.05). Serum concentrations of total IGF-I, bioavailable IGF-I, other bone biomarkers, and cytokines were not significantly different between SFX and NSFX preBT. Serum IGFBP-2 and IGFBP-5 were significantly higher in the SFX compared to the NSFX preBT (p≤0.05). In both groups, total IGF-I increased pre to postBT (p≤0.05). Additionally, a significant difference was observed in the bioavailable IGF-I response pre to postBT for both groups. The SFX group demonstrated a significant decrease in bioavailable IGF-I pre to postBT (preBT: 0.58 ± 0.58 ng/mL; postBT 0.39 ± 0.48; p≤0.05) whereas the NSFX group demonstrated a significant increase in bioavailable IGF-I pre to postBT (preBT: 0.53 ± 0.37 ng/mL; postBT: 0.63 ± 0.45; p≤0.05).

CONCLUSIONS

Our study demonstrated that serum IGF-I changes during basic training and that women sustaining stress fractures during BT significantly decreased bioavailable IGF-I, whereas their uninjured counter parts increased bioavailable IGF-I. These results suggest that stress fracture susceptibility may be related to differential IGF-I system concentrations and response to physical training.

Peripheral QCT sector analysis reveals early exercise-induced increases in tibial bone mineral density

OBJECTIVES

The purpose of this controlled trial was to determine whether subtle changes in mineralization and geometry of the tibia were evident following short term exercise interventions.

METHODS

Fifty-seven female volunteers (age 20.1±1.6) were randomized to one of four, 13-week training groups: sedentary control, resistance training, aerobic training, or combined aerobic-resistance. A pQCT image analysis software was developed and used to analyze images taken at sites 4%, 38% and 66% from the distal tibia at baseline and at completion of training. Parameters of bone mineral density, geometry and strength were determined for the entire scan cross-section and for each of six 60° polar sectors. Repeated-measures ANOVA and Fisher's LSD post hoc tests analyzed the effects of training over time.

RESULTS

Trabecular density (TrDn) at the 4% site increased from 279.8±37.1 to 283.1±36.0 mg/cm(3) in the aerobic group, and from 285.1±24.6 to 287.5±22.9 mg/cm(3) in the combined group over the study period (P≤0.001). Regional sector analyses revealed that impact exercises resulted in localized changes to the medial aspect of the tibia. Small increases in total bone area were observed in the diaphysis (38% site) (P<0.05).

CONCLUSIONS

Subtle, regional increases in trabecular density may be an early measurable manifestation of bone quality changes.

Relations Among Teasing, Body Satisfaction, Self-Esteem, and Depression in Treatment-Seeking Obese African American Adolescents

The objective of this study was to examine correlates of weight-based teasing, self-esteem, and depression among 119 treatment-seeking obese African American adolescents aged 11 to 18 years. Body satisfaction was examined as a potential mediator of the association between teasing and self-esteem and teasing and depression. Study participants (mean age = 13.9 years; 72% female) completed measures evaluating teasing, self-esteem, depression, and body satisfaction. Body satisfaction was measured using a multiethnic figure rating scale and a measure of overall satisfaction with appearance. The results indicated an association between teasing and decreased self-esteem and increased depression. Males exhibited higher body satisfaction than females. Body satisfaction partially mediated the association between teasing and self-esteem and teasing and depression. These data suggest that body satisfaction is relevant to well-being among obese African American adolescents seeking weight loss treatment.

Nourishing Our Understanding of Role Modeling to Improve Support and Health (NOURISH): design and methods

Pediatric overweight is associated with numerous physical and psychological health risks, and overweight children are at significant risk for obesity in adulthood. African-American children are at particularly high risk for obesity and related health complications. However, this racial group has traditionally had limited access to obesity treatment and relatively few studies have included sufficient numbers of lower-SES, African American participants. Further, although parental involvement in treatment for pediatric overweight has been found to be beneficial, few studies have examined the efficacy of offering treatment exclusively to parents, a potentially cost-effective approach which could benefit the entire family. This pilot project will evaluate the efficacy of an intensive parenting intervention, (NOURISH; Nourishing Our Understanding of Role modeling to Improve Support and Health), targeting racially diverse parents of overweight children (ages 6-11). NOURISH addresses several urgent research priorities by targeting the underserved and addressing the significant disparity in obesity treatment services. Parents meeting study criteria (having a child between the ages of 6 and 11 with a BMI ≥ the 85th percentile) will be offered participation in the randomized trial comparing NOURISH with a control group. We hypothesize that children whose parents participate in NOURISH will manifest greater decreases in BMI, and greater improvements in dietary intake, and quality of life compared to children whose parents do not participate. This study is designed explicitly to gather preliminary feasibility, acceptability, and effectiveness data to inform a subsequent larger randomized controlled trial.

LPS-stimulated tumor necrosis factor-alpha and interleukin-6 mRNA and cytokine responses following acute psychological stress

The purpose of this study was to examine the effect of acute psychological stress on LPS-stimulated TNF-α and IL-6 mRNA expression. Twenty-one healthy male subjects participated in 20 min of acute stress. Blood samples for norepinephrine and LPS-stimulated TNF-α and IL-6 cytokines and mRNA were drawn prior to, immediately after and 1-h after stress. Stress-induced increases in anxiety scores, cortisol, plasma norepinephrine, and heart rate demonstrated that the experimental protocol elicited an acute stress response. LPS-stimulated TNF-α mRNA decreased significantly immediately post-stress and partially recovered at 1h post-stress, whereas LPS-stimulated IL-6 mRNA exhibited a significant change across time, with an increase immediately after stress and a decrease 1h after stress. Trends in LPS-stimulated TNF-α and IL-6 cytokine concentrations followed the patterns of mRNA expression. A negative correlation of body mass index (BMI) and percent change of LPS-stimulated TNF-α mRNA was observed immediately post-stress, and BMI positively correlated with percent change of LPS-stimulated IL-6 cytokine levels immediately following stress. These findings demonstrated that acute psychological stress affects LPS-stimulated IL-6 and TNF-α gene expression. These results also indicate that BMI may impact the effects of psychological stress on cytokine responses to immune challenge. Further examination of the effects of stress on synthesis of other cellular cytokines and investigation of the association of BMI and stress responses will provide a more clear representation of the cytokine responses to acute psychological stress. In addition, studies examining the influence of gender on the response of immune cell subsets to acute stress and the possible mediating effect of BMI are warranted.

Psychological stress during exercise: immunoendocrine and oxidative responses

The purpose of this study was to examine the changes in catecholamines (epinephrine [EPI] and norepinephrine [NE]), interleukin-2 (IL-2) and a biomarker of oxidative stress (8-isoprostane) in healthy individuals who were exposed to a dual challenge (physical and psychological stress). Furthermore, this study also examined the possible relationships between catecholamines (NE and EPI) and 8-isoprostane and between IL-2 and 8-isoprostane following a combined physical and psychological challenge. Seven healthy male subjects completed two experimental conditions. The exercise-alone condition (EAC) consisted of cycling at 60% VO(2max) for 37 min, while the dual-stress condition (DSC) included 20 min of a mental challenge while cycling. DSC showed greater EPI and 8-isoprostane levels (significant condition by time interaction). NE and IL-2 revealed significant change across time in both conditions. In addition, following dual stress, EPI area-under-the-curve (AUC) demonstrated a positive correlation with NE AUC and IL-2 AUC. NE AUC was positively correlated with IL-2 AUC and peak 8-isoprostane, and peak IL-2 was positively correlated with peak 8-isoprostane in response to a dual stress. The potential explanation for elevated oxidative stress during dual stress may be through the effects of the release of catecholamines and IL-2. These findings may further provide the potential explanation that dual stress alters physiological homeostasis in many occupations including firefighting, military operations and law enforcement. A greater understanding of these responses to stress can assist in finding strategies (e.g. exercise training) to overcome the inherent psychobiological challenges associated with physically and mentally demanding professions.

The Role of Physical Activity Participation in Weight Loss Outcomes Following Weight Loss Surgery

Weight loss surgery (WLS) is an effective intervention for the reduction of body mass and the resolution of obesity-related comorbidities. Excess weight loss following WLS has been reported in the range of 40% to 78% depending on the surgery type and the follow-up time period. Initial weight loss outcomes and weight loss maintenance have been shown to depend on several factors, including the type of surgical procedure, preexisting comorbidities, and compliance with postoperative medical, nutritional, and behavioral recommendations. One factor that has received limited attention in the scientific literature is the role of physical activity in initial weight loss and maintenance following WLS. Physical activity participation of sufficient frequency, intensity, and duration during both the pre- and postoperative time periods has the potential to reduce surgical complications, enhance weight loss outcomes, and improve physical fitness and overall health following WLS. In addition, physical activity has the potential to improve the quality of postoperative weight loss by enhancing fat mass loss while preserving fat-free mass, thereby minimizing the impact of massive weight loss on metabolic rate. In light of these potential benefits, appropriate interventions should be employed to promote physical activity participation of appropriate frequency, intensity, and duration both before and after WLS.

Evaluation of a 6-month multi-disciplinary healthy weight management program targeting urban, overweight adolescents: effects on physical fitness, physical activity, and blood lipid profiles

This study evaluated preliminary physical fitness, physical activity, and blood lipid profile data obtained from overweight adolescents upon enrolling in a healthy weight management program and following 6 months of program participation. One hundred and sixty-eight participants (13.4+/-1.8 years, 37.9+/-8.3 kg/m(2), 59.5% female and 76.2% African-American) enrolled in the program. The intervention addressed factors related to nutrition, physical activity, and other behaviors related to weight management. Sixty-four participants (38.1%) completed 6 months of program participation. While there was no significant reduction in body mass or body mass index (BMI), BMI z-score was reduced by 1.2% (p < 0.05), cardiorespiratory fitness was increased by 10.8% (p = 0.001), body fat percentage was reduced by 2.6% (p = 0.001), total cholesterol was reduced by 7.2% (p < 0.001), and low density lipoprotein (LDL-C) was reduced by 8.4% (p < 0.001) at 6 months. Continued development and evaluation of programs designed to prevent and treat child and adolescent overweight is warranted to address this major public health issue.

Prevalence of the metabolic syndrome among obese adolescents enrolled in a multidisciplinary weight management program: clinical correlates and response to treatment

OBJECTIVE

The aim of this study was to determine the prevalence of the metabolic syndrome at baseline and after 6 months of lifestyle modification among obese adolescents referred to a multidisciplinary weight management program.

METHODS

A total of 165 obese adolescents were evaluated at baseline, and measurements were repeated in 57 subjects who completed 6 months of the program. Metabolic syndrome was defined as having three or more of the following: a body mass index (BMI) >97(th) percentile, hypertension, low high-density lipoprotein cholesterol (HDL-C), hypertriglyceridemia, and impaired fasting glucose (IFG).

RESULTS

The prevalence of a BMI >97(th) percentile, hypertension, hypertriglyceridemia, low HDL-C, and IFG was 92.7, 54.5, 29.1, 26.7, and 2.4%, respectively. The prevalence of the metabolic syndrome at baseline was 30.3%. After 6 months of lifestyle modification, BMI z scores, percent body fat, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) decreased significantly from baseline; however, there was no significant change in the number of subjects demonstrating >or=three criteria of the metabolic syndrome.

CONCLUSIONS

Approximately one third of the study subjects met the criteria of the metabolic syndrome, emphasizing the growing concern for the future development of premature cardiovascular disease in this high-risk population. Our data suggest that new strategies for lifestyle modification may be needed to improve cardiovascular risk factors significantly among adolescents with obesity.

Becoming physically active after bariatric surgery is associated with improved weight loss and health-related quality of life

The purpose of this study was to determine whether pre- to postoperative increases in physical activity (PA) are associated with weight loss and health-related quality of life (HRQoL) following bariatric surgery. Participants were 199 Roux-en-Y gastric bypass (RYGB) surgery patients. The International Physical Activity Questionnaire (IPAQ) was used to categorize participants into three groups according to their preoperative and /1-year postoperative PA level: (i) Inactive/Active (<200-min/week/>or=200-min/week), (ii) Active/Active (>or=200-min/week/>or=200-min/week) and (iii) Inactive/Inactive (<200-min/week/<200-min/week). The Medical Outcomes Study Short Form-36 (SF-36) was used to assess HRQoL. Analyses of covariance were conducted to examine the effects of PA group on weight and HRQoL changes. Inactive/Active participants, compared with Inactive/Inactive individuals, had greater reductions in weight (52.5 +/- 15.4 vs. 46.4 +/- 12.8 kg) and BMI (18.9 +/- 4.6 vs. 16.9 +/- 4.2 kg/m(2)). Weight loss outcomes in the Inactive/Active and Active/Active groups were similar to each other. Inactive/Active and Active/Active participants reported greater improvements than Inactive/Inactive participants on the mental component summary (MCS) score and the general health, vitality and mental health domains (P < 0.01). Although the direction of causation is not clear, these findings suggest that RYGB patients who become active postoperatively achieve weight losses and HRQoL improvements that are greater than those experienced by patients who remain inactive and comparable to those attained by patients who stay active. Future randomized controlled trials should examine whether assisting patients who are inactive preoperatively to increase their PA postoperatively contributes to optimization of weight loss and HRQoL outcomes.

Participation in 150 min/wk of moderate or higher intensity physical activity yields greater weight loss after gastric bypass surgery

BACKGROUND

The American College of Sports Medicine's position stand on weight loss and prevention of weight regain in adults has suggested that overweight adults should participate in a minimum of 150 min/wk of moderate intensity physical activity (PA). This study compared the 3-, 6-, and 12-month postoperative weight loss between gastric bypass surgery (GBS) patients who met or exceeded the recommended 150 min/wk of moderate or higher PA and those not meeting the recommendation.

METHODS

The self-administered short version of the International Physical Activity Questionnaire was used to assess moderate or higher intensity PA participation at 3 (n = 178), 6 (n = 128), and 12 months (n = 209) after GBS. The patients' height and body weight were obtained to determine the kilograms of weight lost, percentage of excess weight loss, body mass index change, and total weight loss percentage. The weight loss differences were analyzed using analysis of covariance at each point, with age and preoperative body mass index as covariates.

RESULTS

Patients reporting 150 min/wk of moderate or higher PA had significantly (P <.05) greater weight lost, percentage of excess weight loss, change in body mass index, and total weight loss percentage at 6 and 12 months postoperatively. The percentage of excess weight loss was 56.0% +/- 11.5% versus 50.5% +/- 11.6% and 67.4% +/- 14.3% versus 61.7% +/- 17.0% for the group meeting and not meeting the PA requirement at 6 and 12 months after GBS, respectively. No significant difference existed at 3 months after GBS.

CONCLUSION

Participation in a minimum of 150 min/wk of moderate or higher intensity PA was associated with greater postoperative weight loss at 6 and 12 months postoperatively. Patients should be encouraged to meet or exceed this recommendation until prospective, randomized studies have definitively established a link between PA and greater postoperative weight loss and maintenance.

Physical activity and quality of life improvements before obesity surgery

OBJECTIVE

To examine quality of life (QOL), physical activity (PA), and physical activity readiness (PAR) among gastric-bypass surgery (GBS) candidates.

METHODS

The SF-36v2, International Physical Activity Questionnaire, and a stages-of-change measure assessed QOL, PA, and PAR respectively across 2 presurgical visits.

RESULTS

Increases in mental QOL, PA, and PAR were observed across visits. Sufficiently physically active participants reported significantly higher physical QOL than did insufficiently physically active participants.

CONCLUSIONS

Findings demonstrating positive presurgical changes in PA and PA readiness as well as the association between PA and QOL warrant increased efforts to promote PA adoption and maintenance among GBS candidates.