Gut Microbiome Alterations Accompany Metabolic Normalization Following Bariatric Surgery in ROHHAD Syndrome.

Rapid onset obesity with hypoventilation, hypothalamic, and autonomic dysregulation (ROHHAD) syndrome in childhood is characterized by abrupt onset weight gain and dysautonomia with variable neuroendocrine involvement. In the absence of definitive disease-modifying therapies, the primary management strategy remains symptom control. This case report describes the first successful correction of obesity, dysautonomia, and metabolic derangement in a patient with ROHHAD following Roux-en-Y gastric bypass. Anthropometrics, metabolic profiling, and stool microbiome composition were assessed in a longitudinal fashion. In the 48-month period following surgery, the patient body mass index (BMI) reduced by 9.5 kg/m2 and metabolic status improved, evidenced in weaning of insulin, and improved glycated hemoglobin, lipid profile, and hepatic enzymes. Chronic diarrhea resolved after surgery and prior to significant weight loss. Evaluation of stool bacterial composition and biomass demonstrated shifts in absolute abundance and taxonomic composition in longitudinal samples following surgery. This case demonstrates the potential efficacy of bariatric surgery in correcting the metabolic disruption of ROHHAD syndrome, producing long-term changes in gut microbiome composition and biomass.

The impact of gestational diabetes on functional capacity of the infant gut microbiome is modest and transient.

Gestational diabetes mellitus (GDM) is a metabolic complication that manifests as hyperglycemia during the later stages of pregnancy. In high resource settings, careful management of GDM limits risk to the pregnancy, and hyperglycemia typically resolves after birth. At the same time, previous studies have revealed that the gut microbiome of infants born to mothers who experienced GDM exhibit reduced diversity and reduction in the abundance of several key taxa, including Lactobacillus. What is not known is what the functional consequences of these changes might be. In this case control study, we applied 16S rRNA sequence surveys and metatranscriptomics to profile the gut microbiome of 30 twelve-month-old infants - 16 from mothers with GDM, 14 from mothers without - to examine the impact of GDM during pregnancy. Relative to the mode of delivery and sex of the infant, maternal GDM status had a limited impact on the structure and function of the developing microbiome. While GDM samples were associated with a decrease in alpha diversity, we observed no effect on beta diversity and no differentially abundant taxa. Further, while the mode of delivery and sex of infant affected the expression of multiple bacterial pathways, much of the impact of GDM status on the function of the infant microbiome appears to be lost by twelve months of age. These data may indicate that, while mode of delivery appears to impact function and diversity for longer than anticipated, GDM may not have persistent effects on the function nor composition of the infant gut microbiome.

Medical students' perceived comfort and competence performing physical examinations on patients with obesity: A mixed-methods needs assessment.

Physicians are unsatisfied with their training in the care of patients with obesity. Physical examination is a key component of care, and modifications to techniques are often necessary for patients with obesity. To determine learning needs, we examined medical students' perceived comfort and competency in conducting physical examinations on patients with obesity. This mixed-methods study of Canadian medical students used a questionnaire and semi-structured focus groups to assess medical students' perceived comfort and competence in examining patients with obesity. Participants included 175 Canadian medical students. A minority of medical students felt comfortable (42%) or competent (14%) examining patients with obesity. Physical exam challenges included modifying exam manoeuvres, interpreting findings and communicating sensitively around weight. Lack of early exposure to patients with obesity, minimal instruction by preceptors and a lack of curricular focus on obesity were felt to be barriers to improving these skills. Students perceived their lack of confidence as negatively impacting their ability to manage patients with obesity and more training in this area was desired to prevent disparities in care. Medical students feel that adequate training on how to perform an obesity-specific physical examination is lacking. Developing curricula and including formal teaching around these key competencies within medical education is essential.

Intranasal Carbetocin Reduces Hyperphagia, Anxiousness, and Distress in Prader-Willi Syndrome: CARE-PWS Phase 3 Trial.

CONTEXT: Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by endocrine and neuropsychiatric problems including hyperphagia, anxiousness, and distress. Intranasal carbetocin, an oxytocin analog, was investigated as a selective oxytocin replacement therapy. OBJECTIVE: To evaluate safety and efficacy of intranasal carbetocin in PWS. DESIGN: Randomized, double-blind, placebo-controlled phase 3 trial with long-term follow-up. SETTING: Twenty-four ambulatory clinics at academic medical centers. PARTICIPANTS: A total of 130 participants with PWS aged 7 to 18 years. INTERVENTIONS: Participants were randomized to 9.6 mg/dose carbetocin, 3.2 mg/dose carbetocin, or placebo 3 times daily during an 8-week placebo-controlled period (PCP). During a subsequent 56-week long-term follow-up period, placebo participants were randomly assigned to 9.6 mg or 3.2 mg carbetocin, with carbetocin participants continuing at their previous dose. MAIN OUTCOME MEASURES: Primary endpoints assessed change in hyperphagia (Hyperphagia Questionnaire for Clinical Trials [HQ-CT]) and obsessive-compulsive symptoms (Children's Yale-Brown Obsessive-Compulsive Scale [CY-BOCS]) during the PCP for 9.6 mg vs placebo, and the first secondary endpoints assessed these same outcomes for 3.2 mg vs placebo. Additional secondary endpoints included assessments of anxiousness and distress behaviors (PWS Anxiousness and Distress Behaviors Questionnaire [PADQ]) and clinical global impression of change (CGI-C). RESULTS: Because of onset of the COVID-19 pandemic, enrollment was stopped prematurely. The primary endpoints showed numeric improvements in both HQ-CT and CY-BOCS which were not statistically significant; however, the 3.2-mg arm showed nominally significant improvements in HQ-CT, PADQ, and CGI-C scores vs placebo. Improvements were sustained in the long-term follow-up period. The most common adverse event during the PCP was mild to moderate flushing. CONCLUSIONS: Carbetocin was well tolerated, and the 3.2-mg dose was associated with clinically meaningful improvements in hyperphagia and anxiousness and distress behaviors in participants with PWS. CLINICAL TRIALS REGISTRATION NUMBER: NCT03649477.

Investigating resilience and its association with stress, anthropometrics, and metabolic health in adolescents with obesity: a pilot study.

The increasing prevalence of children with obesity has contributed to a higher risk of developing cardiometabolic comorbidities. Adversity and chronic stress are negatively linked to cardiometabolic outcomes, and resilience is positively associated with improved outcomes. However, whether resilience is protective against metabolic disturbances preceding disease presentation is less understood. This study explored correlations between stress, anthropometrics, and metabolic parameters with resilience (total, individual, family, peers, school, community), and determined which resilience domains predict metabolically unhealthy obesity. Adolescents with obesity (n = 39; 12-18y) completed anthropometrics, an oral glucose tolerance test, the Adolescent Resilience Questionnaire, and Perceived Stress Scale. Lower stress (r = -0.70, p < 0.001), BMI (r = -0.42, p = 0.01), fat mass (ρ = -0.41, p = 0.01), and fat-free mass (ρ = -0.41, p = 0.01) were associated with greater resilience. Greater school resilience was associated with lower risk for having metabolically unhealthy obesity (odds ratio = 0.87, 95% Confidence Intervals, 0.78-0.98, p = 0.02). Our findings suggest that resilience is associated with lower adiposity, and that lower school resilience is an independent predictor of having metabolically unhealthy obesity. Further work exploring correlations between school resilience, perceived stress, and metabolic outcomes, would optimize programs for obesity-related chronic conditions.

Weighing in on COVID-19: The impact of the pandemic on children and adolescents with obesity participating in a weight management program.

BACKGROUND: COVID-19 mitigation measures, including closures of schools and recreational facilities and alterations in eating behaviours and physical activity, may impact weight. OBJECTIVE: To examine changes in body weight and body mass index (BMI) in children and adolescents with obesity participating in an obesity treatment program before and during the COVID-19 pandemic in Ontario, Canada. METHODS: Body weight and BMI at baseline and 6 months were recorded for the 'historic' cohort (females = 34, males = 21) before the pandemic (November 1, 2018, to March 18, 2020) and for the 'pandemic' cohort (females = 30, males = 30) during the pandemic (March 19, 2020 to July 31, 2021). Analyses were adjusted for baseline weight/BMI, age, and ON-Marg score, a measure of the social determinants of health. RESULTS: In males, body weight (98.29 versus 89.28 kg, p < 0.001) and BMI (36.46 versus 34.85 kg/m2 , p = 0.027) were greater in the pandemic compared with historic cohort. In females, body weight (p = 0.769) and BMI (p = 0.548) were not different between the two cohorts. CONCLUSION: The COVID-19 pandemic may have diminished the health impacts of a weight management program, particularly in males, leading to increased body weight and BMI.

Treating Gestational Diabetes Reduces Birth Weight but Does Not Affect Infant Adiposity Across the 1st Year of Life.

OBJECTIVE: The continuum of maternal glycemia in pregnancy shows continuous associations with both 1) neonatal birth weight at delivery and 2) subsequent adiposity later in childhood. While treating gestational diabetes mellitus (GDM) can lower birth weight and thereby disrupt the former association, it is unclear if such treatment reduces childhood adiposity. Thus, we sought to compare anthropometry across the 1st year of life between infants born to women who were treated for GDM and those with lesser degrees of gestational dysglycemia (untreated). RESEARCH DESIGN AND METHODS: Anthropometric measurements were performed at 3 months and 12 months of life in 567 infants born to women comprising the following four gestational glucose tolerance groups: 1) women with normoglycemia on both glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in pregnancy; 2) women with an abnormal GCT but normal OGTT; 3) those with mild gestational impaired glucose tolerance; and 4) women treated for GDM. RESULTS: Birth weight progressively increased across the three untreated groups but was lowest in women treated for GDM (P = 0.0004). Similarly, women treated for GDM had the lowest rate of macrosomia (P = 0.02). Conversely, however, there were no differences among the four groups in weight z score, length z score, weight-for-length z score, or BMI z score at either 3 months or 12 months (all P values = NS). Similarly, there were no differences among the groups in triceps/biceps/subscapular/suprailiac skinfold thickness or sum of skinfolds at either 3 months or 12 months (all P values = NS). CONCLUSIONS: Despite reducing birth weight and macrosomia, the treatment of GDM does not have analogous effects on infant adiposity across the 1st year of life.

Individual and family characteristics associated with health indicators at entry into multidisciplinary pediatric weight management: findings from the CANadian Pediatric Weight management Registry (CANPWR).

OBJECTIVES: (1) To explore individual and family characteristics related to anthropometric and cardiometabolic health indicators and (2) examine whether characteristics that correlate with cardiometabolic health indicators differ across severity of obesity at time of entry to Canadian pediatric weight management clinics. METHODS: We conducted a cross-sectional analysis of 2-17 year olds with overweight or obesity who registered in the CANadian Pediatric Weight Management Registry (CANPWR) between May 2013 and October 2017 prior to their first clinic visit. Individual modifiable health behaviors included dietary intake, physical activity, screen time, and sleep. Family characteristics included parental BMI, family medical history, socioeconomic status and family structure. Linear mixed effects stepwise regression analysis was performed to determine which characteristics were related to each health indicator: BMI z-score; waist circumference; waist to height ratio; blood pressure; glycemia; HDL cholesterol; non-HDL cholesterol; triglycerides. RESULTS: This study included 1296 children (mean age ± standard deviation: 12.1 ± 3.5 years; BMI z-score: 3.55 ± 1.29; 95.3% with obesity). Hours spent sleeping (estimated ß = -0.10; 95% CI [-0.15, -0.05], p = 0.0001), hours per week of organized physical activity (estimated ß = -0.32; 95% CI [-0.53, -0.11], p = 0.0026), daily sugared drink intake (estimated ß = 0.06; 95% CI [0.01, 0.10], p = 0.0136) and maternal BMI (estimated ß = 0.03; 95% CI [0.02, 0.04], p < 0.0001) were associated with BMI z-score (adj. R2 = 0.2084), independent of other individual and family characteristics. Physical activity, total sugared drink intake and sleep duration were associated with glycemia and non-HDL cholesterol, independent of child BMI z-score. However, irrespective of obesity severity, little of the variance (0.86-11.1%) in cardiometabolic health indicators was explained by individual modifiable health behaviors. CONCLUSIONS: Physical activity, total sugared drink intake and hours spent sleeping were related to anthropometric and some cardiometabolic health indicators in children entering pediatric weight management programs. This highlights the importance of these modifiable health behaviors on multiple health indicators in children with obesity.

Evaluation of a Pediatric Obesity Management Toolkit for Health Care Professionals: A Quasi-Experimental Study.

Health care professionals (HCPs) play a critical role in helping to address weight-related issues with pediatric patients, yet often feel ill-equipped to discuss/manage this complex and sensitive health issue. Using the five As ("Ask, Assess, Advise, Agree, and Assist") of Pediatric Obesity Management, we created a series of educational videos and evaluated the content, quality (acceptability, engagement), and impact of these videos on HCPs' self-efficacy, knowledge, and change in practice when addressing weight-related issues with pediatric patients and their families using questionnaires. HCPs (n = 65) participated in a baseline assessment and 4-6 month follow-up (n = 54). Knowledge and self-efficacy increased post-video for the majority of participants. At follow-up, most HCPs reported a change in their practice attributable to viewing the videos, and their self-efficacy ratings improved over time for the majority of questions asked. Most participants rated aspects of each of the videos highly. Preliminary findings suggest that an evidence-based educational toolkit of videos, based on the 5As framework, may lead to changes in self-reported behaviors among HCPs, and sustained improvements in their self-efficacy in addressing weight-related topics with children and their families. (Clinical Trial Number NCT04126291).

"It's a tool, not a cure": the preoperative teen perspective on bariatric surgery.

BACKGROUND: Bariatric surgery is well established in adults as the most effective tool for sustained weight loss and reduction of obesity-related co-morbidities, and is an emerging option for adolescents in whom conservative approaches have failed. Narratives are vital in understanding the motivating reasons and psychosocial profiles of adolescents considering bariatric surgery during a developmental period of evolving self-concept, body image sensitivity, peer pressure, and increased opportunity for risky behaviors. OBJECTIVES: To explore preoperative adolescent patient perspectives on their decision to pursue bariatric surgery, anticipated physical and psychosocial effects, and preparation process. SETTINGS: The Hospital for Sick Children (SickKids) in Toronto, Ontario, Canada. METHODS: We conducted 14 semi-structured interviews with adolescents (16-18 yr old) 2-4 months before bariatric surgery. A theoretical thematic analysis was conducted with 3 independent reviewers (interrater reliability, Cronbach's α= .81) and conflicts were resolved through discussion. RESULTS: Patients' perspectives are captured in 4 themes: motivation for surgery, effects on health and habits, psychosocial changes, and support systems during preparation. Participants perceived surgery as a tool but not a solution for weight loss. Most were motivated for health and daily functional improvement rather than aesthetic reasons, and some anticipated improved social interactions while maintaining their self-identity. Participants were selective in sharing news of their surgery, and received varying levels of support from families, friends, and healthcare teams. CONCLUSION: Adolescents seem generally prepared for and informed about surgery, with expectations for weight loss and psychosocial improvements, although uncertainty and contradictory thoughts were prevalent. Insights provided by these adolescent patients will help optimize bariatric surgery assessments and support from clinical teams and inform preoperative education for future patients and families.

"Counting Carbs to Be in Charge": A Comparison of an Internet-Based Education Module With In-Class Education in Adolescents With Type 1 Diabetes.

Carbohydrate counting is an essential component of type 1 diabetes education but can be difficult for adolescents to learn. Because adolescents are avid users of technology, an Internet-based education module was compared with an in-class education session in terms of carbohydrate counting accuracy in adolescents with type 1 diabetes. Adolescent participants displayed increased carbohydrate counting accuracy after attending an in-class education session compared with an Internet-based education module. These results suggest that online education is best reserved as an adjunctive therapy to in-class teaching in this population.

Greater Nutritional Risk Scores in 2-Year-Old Children Exposed to Gestational Diabetes Mellitus In Utero and Their Relationship to Homeostasis Model Assessment for Insulin Resistance at Age 5 Years.

OBJECTIVES: Exposure to gestational diabetes mellitus (GDM) in utero may impact nutritional intake and lifestyle habits in early childhood. However, it is unclear whether nutritional status predicts greater risk for metabolic disturbances, such as insulin resistance (IR). The primary objectives were: 1) to determine parent-reported nutritional risk scores in 2-year-old children born to women with and without GDM and 2) to assess whether these scores predict IR in 5-year-old children. METHODS: Children exposed (n=34) and unexposed (n=46) to GDM were screened at 2 years of age using the Toddler version of the Nutrition Screening Tool for Every Preschooler (NutriSTEP). At a 5-year follow up, IR was assessed using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). RESULTS: Total NutriSTEP scores ranged from 6 to 33, with higher scores indicating greater risk. After controlling for infant birthweight, sex of the child, child ethnicity, maternal age at time of pregnancy, breastfeeding status and maternal prepregnancy body mass index, average NutriSTEP scores were higher in children exposed to GDM compared with those unexposed (13.8±1.1 vs 11.2±1.1, p=0.03). NutriSTEP scores at 2 years emerged as a positive independent predictor of HOMA-IR at 5 years. For each unit increase in NutriSTEP score, suggesting greater nutritional risk, we saw a 0.48 (95% confidence interval, 0.17 to 0.80; p=0.003) increase in score on the HOMA-IR. CONCLUSIONS: Parent-reported nutritional risk is greater in GDM-exposed children, and these nutritional behaviours developed during the first years of life may predispose to metabolic disturbance in early childhood.

Careful conversations: an educational video to support parents in communicating about weight with their children.

BACKGROUND: Parents may struggle to initiate healthy weight-related conversations with their children. Educational videos may be an effective tool for improving parents' knowledge and self-efficacy on this topic. The aim of this pilot study was to develop an educational video to assist parents in weight-related conversations with their child, and to assess changes in parents' self-efficacy on this topic. METHODS: Video development was based on a scoping review and semi-structured interviews with parents. Respondent demographics and user satisfaction were assessed at pre- and post- video, and 4-6 months later. Self-efficacy scores were compared between parent groups based on weight concerns over time. RESULTS: Fifty-seven parents participated in the video questionnaires, and 40 repeated measures 4-6 months later. Significant improvements in self-efficacy in "raising the issue of weight" and "answering questions or concerns" were found after watching the video (p ≤ 0.002) compared to baseline, and scores 4-6 months post baseline remained slightly elevated, but non-significant. Parents with concerns about their child being overweight had significantly lower perceived self-efficacy scores compared to parents with no concerns about their child's weight (p = 0.031). The video was found to be positively received and of relevance to parents across a number of different domains. CONCLUSION(S): Preliminary findings suggest an educational video about initiating weight-related conversations may be an effective tool for increasing parents' perceived self-efficacy in the short term. Further work is needed to validate findings in a randomized controlled trial, and with diverse parent populations. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03664492 . Registered 10 September 2018 - Retrospectively registered.

Talking About Weight With Families-Helping Health Care Professionals Start the Conversation: A Nonrandomized Controlled Trial.

Health care professionals (HCPs) and trainees feel ill-equipped to discuss weight-related issues with children and their families. A whiteboard video for HCPs and trainees outlining strategies to communicate about weight was developed and evaluated. Seventy HCPs, including 15 trainees, participated in the baseline assessment and 39 repeated measures 4 to 6 months later. HCP self-efficacy for initiating conversations with overweight and underweight patients, measured immediately following the video, significantly improved from pre-video values (Z = -5.6, P ≤ .001, and Z= -3.3, P = .001, respectively). Although improvements were not sustained 4 to 6 months later (overweight: P = .143, and underweight: P = .846), no significant decline was observed, suggesting retention of the skill. A majority of HCP respondents would recommend the video to a colleague and feel it will affect their practice. Thus, the present study suggests educational videos may be an effective tool for facilitating healthy weight-related conversations between HCPs and their pediatric patients.

The association between body mass index trajectories and cardiometabolic risk in young children.

BACKGROUND: Rapid growth is associated with increased cardiometabolic risk (CMR) in adolescence and adulthood. Little is known about whether the association between rapid growth and increased CMR originates in early childhood. OBJECTIVES: To identify age and sex standardized body mass index (zBMI) trajectories and to examine the association between zBMI trajectories and CMR outcomes in children 0 to 60 months. STUDY DESIGN: A longitudinal cohort study was conducted through The Applied Research Group for Kids (TARGet Kids!) in Toronto, Canada. Participants had repeated measures of weight and length or height performed from birth to 60 months of age. Latent class mixed modelling was used to identify the zBMI trajectories. Linear regressions were performed to determine the association between zBMI trajectories and the primary outcome, a CMR score, quantified as the sum of age- and sex- standardized waist circumference, systolic blood pressure, glucose, log-triglycerides and negative high-density lipoprotein cholesterol (HDL-C), divided by √5. Secondary outcomes were the individual components of the CMR formula as well as diastolic blood pressure and non-HDL-C. RESULTS: Four BMI trajectories were identified among the 1166 children. After adjusting for all covariates, children in the rapidly accelerating trajectory had increased total CMR score (ß = 1.38, 95% CI 0.77; 1.99, P < .001) and increased waist circumference score (ß = 2.39, 95% CI 1.92; 2.86, P < .001) compared to the stable low group. CONCLUSIONS: Rapid growth during early childhood is associated with increased CMR in preschool children, largely driven by larger waist circumference.

Breaking barriers: Adjunctive use of the Ontario Telemedicine Network (OTN) to reach adolescents with obesity living in remote locations.

INTRODUCTION: Implementation of telemedicine has been shown to improve health outcomes, such as body mass index (BMI). However, it is unclear whether telemedicine is useful alongside traditional weight-management programmes for adolescents with complex obesity. The objective was to evaluate implementation of the Ontario Telemedicine Network (OTN), a videoconferencing programme, as an adjunctive tool to face-to-face counselling within the setting of an established interdisciplinary obesity treatment programme. METHODS: Our observational cohort included two groups of adolescents enrolled in a clinical obesity-management programme over a two year period. Adolescents (n = 50) in group 1 attended both in-person and virtual visits (OTN group), and adolescents (n = 50) in group 2 received only in-person visits (comparison group). Within the OTN group, satisfaction survey responses were compared between patients and healthcare professionals. Change in BMI per month, paediatric quality of life scores, session attendance and demographic variables were compared between groups. RESULTS: OTN subjects averaged 4.9 telehealth visits per adolescent over the two year programme. Both OTN and comparison groups had similar changes in BMI (p = 0.757), with increases over time (p = 0.042). Paediatric quality of life scores in both groups improved over time compared to baseline (p < 0.001), with higher scores for children compared to parental-reported child scores (p = 0.008). Both adolescents and healthcare professionals using the OTN were similarly satisfied with their experience. CONCLUSION: Adjunctive use of the OTN within the setting of a weight-management programme is feasible, well accepted by families and healthcare providers, and led to similar outcomes compared to usual care.

Postprandial Dyslipidemia, Hyperinsulinemia, and Impaired Gut Peptides/Bile Acids in Adolescents with Obesity.

BACKGROUND: With increased rates of obesity and insulin resistance in youth, development of postprandial dyslipidemia, an important cardiovascular disease risk factor, is a concern. Glucagon-like peptides (ie, GLP-1 and GLP-2) and bile acids have been shown to regulate dietary fat absorption and postprandial lipids in animal models and humans. We hypothesize that the physiological response of GLPs and bile acids to dietary fat ingestion is impaired in adolescents with obesity and this associates with marked postprandial dyslipidemia and insulin resistance. METHODS: In this cross-sectional study, normal weight adolescents and adolescents with obesity underwent a 6-hour oral fat tolerance test. The postprandial lipoprotein phenotype profile was determined using various assays, including nuclear magnetic resonance spectroscopy, to characterize lipoprotein particle number, size, lipid content, and apolipoproteins. GLP-1 and GLP-2 were quantified by electrochemiluminescent immunoassays. Total bile acids were measured by an automated enzymatic cycling colorimetric method and the bile acid profile by mass spectrometry. RESULTS: Adolescents with obesity exhibited fasting and postprandial dyslipidemia, particularly augmented postprandial excursion of large triglyceride-rich lipoproteins. Postprandial GLPs were reduced and inversely correlated with postprandial dyslipidemia and insulin resistance. Postprandial bile acids were also diminished, particularly lithocholic acid, a potent stimulator of GLP-1 secretion. CONCLUSION: Blunted postprandial GLP and bile acid response to dietary fat ingestion strongly associates with marked postprandial dyslipidemia. Further investigation is needed to assess their potential utility as early biomarkers for postprandial dyslipidemia in adolescents with obesity.

Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males.

OBJECTIVE: Chronic testosterone blood concentrations associate with food intake (FI), but acute effects of testosterone on appetite and effect of protein and glucose consumption on testosterone response have had little examination. METHODS: In a randomized, crossover study, twenty-three adolescent (12-18 years old) males were given beverages containing either: (a) whey protein (1 g/kg body weight), (b) glucose (1 g/kg body weight) or (c) a calorie-free control (C). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. FI at an ad libitum pizza meal was assessed at 85 minutes. RESULTS: Testosterone decreased acutely to 20 minutes after both protein and glucose with the decrease continuing after protein but not glucose to 65 minutes (P = 0.0382). LH was also decreased by both protein and glucose, but glucose had no effect at 20 minutes in contrast to protein (P < 0.001). Plasma testosterone concentration correlated positively with LH (r = 0.58762, P < 0.0001) and negatively with GLP-1 (r = -0.50656, P = 0.0003). No associations with appetite, ghrelin or glycaemic markers were found. Food intake was not affected by treatments. CONCLUSION: Protein or glucose ingestion results in acute decreases in both plasma testosterone and LH in adolescent males. The physiological significance of this response remains to be determined as no support for testosterone's role in acute regulation of food intake was found.