Slow and Steady: Readiness, Pretreatment Weekly Strengthening Activity, and Pediatric Weight Management Program Completion

Background: Pediatric weight management programs have substantial attrition rates, which have led to recommendations to assess readiness prior to enrollment. Both pretreatment readiness scales and behaviors, such as exercise, have been theorized to predict subsequent program completion. The purpose of this study was to explore the role of self-reported pretreatment exercise in adolescents on completion of a pediatric weight management program and to explore the predictive ability of standard readiness scales. Methods: A total of 146 obese (BMI≥95th percentile) pediatric (ages 11?18) participants joined a 6-month multidisciplinary weight management program between March, 2007, and July, 2010. Completers were compared retrospectively to noncompleters on demographic, readiness, and pretreatment exercise practices from clinic-developed intake questionnaires using univariate analyses. Regression analyses specified the degree to which these variables predicted program completion. Results: The 6-month completion rate was 53%. There was no relationship between self-reported readiness and program completion. Self-reported pretreatment weekly strengthening activity (SA) was significantly associated with program completion, compared to those who performed SA either never [univariate odds ratio (OR) 3.18, 95% confidence interval (CI) 1.51?6.68, p=0.002; multivariate OR 2.43, 95% CI 1.06?5.58, p=0.036] or daily (univariate OR 4.90, 95% CI 1.74?13.77, p=0.002; multivariate OR 4.69, 95% CI 1.45?15.14, p=0.010). No relationship was found between other forms of exercise and program completion. Conclusions: Self-reported pretreatment weekly SA, but not standard readiness scales, predicted pediatric weight management program completion.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140330/1/chi.2013.0006.pd

Skeletal muscle gene expression in response to resistance exercise: sex specific regulation

<p>Abstract</p> <p>Background</p> <p>The molecular mechanisms underlying the sex differences in human muscle morphology and function remain to be elucidated. The sex differences in the skeletal muscle transcriptome in both the resting state and following anabolic stimuli, such as resistance exercise (RE), might provide insight to the contributors of sexual dimorphism of muscle phenotypes. We used microarrays to profile the transcriptome of the biceps brachii of young men and women who underwent an acute unilateral RE session following 12 weeks of progressive training. Bilateral muscle biopsies were obtained either at an early (4 h post-exercise) or late recovery (24 h post-exercise) time point. Muscle transcription profiles were compared in the resting state between men (n = 6) and women (n = 8), and in response to acute RE in trained exercised vs. untrained non-exercised control muscle for each sex and time point separately (4 h post-exercise, n = 3 males, n = 4 females; 24 h post-exercise, n = 3 males, n = 4 females). A logistic regression-based method (LRpath), following Bayesian moderated t-statistic (IMBT), was used to test gene functional groups and biological pathways enriched with differentially expressed genes.</p> <p>Results</p> <p>This investigation identified extensive sex differences present in the muscle transcriptome at baseline and following acute RE. In the resting state, female muscle had a greater transcript abundance of genes involved in fatty acid oxidation and gene transcription/translation processes. After strenuous RE at the same relative intensity, the time course of the transcriptional modulation was sex-dependent. Males experienced prolonged changes while females exhibited a rapid restoration. Most of the biological processes involved in the RE-induced transcriptional regulation were observed in both males and females, but sex specificity was suggested for several signaling pathways including activation of notch signaling and TGF-beta signaling in females. Sex differences in skeletal muscle transcriptional regulation might implicate a mechanism behind disproportional muscle growth in males as compared with female counterparts after RE training at the same relative intensity.</p> <p>Conclusions</p> <p>Sex differences exist in skeletal muscle gene transcription both at rest and following acute RE, suggesting that sex is a significant modifier of the transcriptional regulation in skeletal muscle. The findings from the present study provide insight into the molecular mechanisms for sex differences in muscle phenotypes and for muscle transcriptional regulation associated with training adaptations to resistance exercise.</p

Principal component analysis reveals gender-specific predictors of cardiometabolic risk in 6th graders

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to determine the sex-specific pattern of pediatric cardiometabolic risk with principal component analysis, using several biological, behavioral and parental variables in a large cohort (n = 2866) of 6th grade students.</p> <p>Methods</p> <p>Cardiometabolic risk components included waist circumference, fasting glucose, blood pressure, plasma triglycerides levels and HDL-cholesterol. Principal components analysis was used to determine the pattern of risk clustering and to derive a continuous aggregate score (MetScore). Stratified risk components and MetScore were analyzed for association with age, body mass index (BMI), cardiorespiratory fitness (CRF), physical activity (PA), and parental factors.</p> <p>Results</p> <p>In both boys and girls, BMI and CRF were associated with multiple risk components, and overall MetScore. Maternal smoking was associated with multiple risk components in girls and boys, as well as MetScore in boys, even after controlling for children’s BMI. Paternal family history of early cardiovascular disease (CVD) and parental age were associated with increased blood pressure and MetScore for girls. Children’s PA levels, maternal history of early CVD, and paternal BMI were also indicative for various risk components, but not MetScore.</p> <p>Conclusions</p> <p>Several biological and behavioral factors were independently associated with children’s cardiometabolic disease risk, and thus represent a unique gender-specific risk profile. These data serve to bolster the independent contribution of CRF, PA, and family-oriented healthy lifestyles for improving children’s health.</p

Association Between Physician Recommendation for Adolescents to Join a Weight Loss Program and BMI Change

Objective : To explore whether reasons for enrollment in a pediatric multidisciplinary weight management program (PMWMP) are associated with subsequent weight loss. Method : A retrospective analysis of obese adolescents (12-18 years old, body mass index [BMI] > 95th percentile) who enrolled in a PMWMP from April 2007 to March 2009, and had BMI measurements at weeks 1 and 12. Reasons for enrollment were obtained from parents’ responses to an enrollment questionnaire (which allowed selection of more than one reason). The most common reasons for enrollment were computed. Linear regression was used to explore associations between mean change in BMI and reasons for enrollment, controlling for demographic and anthropometric factors. Results : Most of the 90 adolescents who met the inclusion criteria were female (70%) and white (57%). Mean age was 14.5 years and mean initial BMI was 42 kg/m 2 . The most common reasons for enrolling in the PMWMP were due to concerns about adolescents’ physical health (96%), concerns about adolescents’ mental health (76%), and because of a physician recommendation (73%). The mean 12-week change in BMI showed a greater decrease for those who enrolled due to a physicians’ recommendation versus those who did not (−1.5 vs −0.5 kg/m 2 : P < .05). This finding remained significant even when controlling for the covariates of interest. Conclusions : A physician’s recommendation to join a PMWMP appears to be associated with greater weight loss among obese adolescents than other reasons for enrollment. Further research should explore how physician involvement affects long-term weight loss

Weight Loss Improves β-Cell Function in People With Severe Obesity and Impaired Fasting Glucose: A Window of Opportunity

Abstract Background In people with obesity, β-cell function may adapt to insulin resistance. We describe β-cell function in people with severe obesity and normal fasting glucose (NFG), impaired fasting glucose (IFG), and type 2 diabetes (T2DM), as assessed before, 3 to 6 months after, and 2 years after medical weight loss to describe its effects on insulin sensitivity, insulin secretion, and β-cell function. Methods Fifty-eight participants with body mass index (BMI) ≥ 35 kg/m2 (14 with NFG, 24 with IFG, and 20 with T2DM) and 13 normal weight participants with NFG underwent mixed meal tolerance tests to estimate insulin sensitivity (S[I]), insulin secretion (Φ), and β-cell function assessed as model-based Φ adjusted for S(I). All 58 obese participants were restudied at 3 to 6 months and 27 were restudied at 2 years. Results At 3 to 6 months, after a 20-kg weight loss and a decrease in BMI of 6 kg/m2, S(I) improved in all obese participants, Φ decreased in obese participants with NFG and IFG and tended to decrease in obese participants with T2DM, and β-cell function improved in obese participants with NFG and tended to improve in obese participants with IFG. At 2 years, β-cell function deteriorated in participants with NFG and T2DM but remained significantly better in participants with IFG compared to baseline. Conclusions Short-term weight loss improves β-cell function in participants with NFG and IFG, but β-cell function tends to deteriorate over 2 years. In participants with IFG, weight loss improves longer-term β-cell function relative to baseline and likely relative to no intervention, suggesting that obese people with IFG are a subpopulation whose β-cell function is most likely to benefit from weight loss. </jats:sec

Comparing Self-Reported Dietary Intake to Provided Diet during a Randomized Controlled Feeding Intervention: A Pilot Study

Systematic and random errors based on self-reported diet may bias estimates of dietary intake. The objective of this pilot study was to describe errors in self-reported dietary intake by comparing 24 h dietary recalls to provided menu items in a controlled feeding study. This feeding study was a parallel randomized block design consisting of a standard diet (STD; 15% protein, 50% carbohydrate, 35% fat) followed by either a high-fat (HF; 15% protein, 25% carbohydrate, 60% fat) or a high-carbohydrate (HC; 15% protein, 75% carbohydrate, 10% fat) diet. During the intervention, participants reported dietary intake in 24 h recalls. Participants included 12 males (seven HC, five HF) and 12 females (six HC, six HF). The Nutrition Data System for Research was utilized to quantify energy, macronutrients, and serving size of food groups. Statistical analyses assessed differences in 24 h dietary recalls vs. provided menu items, considering intervention type (STD vs. HF vs. HC) (Student&rsquo;s t-test). Caloric intake was consistent between self-reported intake and provided meals. Participants in the HF diet underreported energy-adjusted dietary fat and participants in the HC diet underreported energy-adjusted dietary carbohydrates. Energy-adjusted protein intake was overreported in each dietary intervention, specifically overreporting beef and poultry. Classifying misreported dietary components can lead to strategies to mitigate self-report errors for accurate dietary assessment