Improved insulin sensitivity and body composition, irrespective of macronutrient intake, after a 12 month intervention in adolescents with pre-diabetes; RESIST a randomised control trial.

BACKGROUND: A higher protein to carbohydrate ratio in the diet may potentiate weight loss, improve body composition and cardiometabolic risk, including glucose homeostasis in adults. The aim of this randomised control trial was to determine the efficacy of two structured lifestyle interventions, differing in dietary macronutrient content, on insulin sensitivity and body composition in adolescents. We hypothesised that a moderate-carbohydrate (40-45% of energy), increased-protein (25-30%) diet would be more effective than a high-carbohydrate diet (55-60%), moderate-protein (15%) diet in improving outcomes in obese, insulin resistant adolescents. METHODS: Obese 10-17 year olds with either pre-diabetes and/or clinical features of insulin resistance were recruited at two hospitals in Sydney, Australia. At baseline adolescents were prescribed metformin and randomised to one of two energy restricted diets. The intervention included regular contact with the dietician and a supervised physical activity program. Outcomes included insulin sensitivity index measured by an oral glucose tolerance test and body composition measured by dual-energy x-ray absorptiometry at 12 months. RESULTS: Of the 111 adolescents recruited, 85 (77%) completed the intervention. BMI expressed as a percentage of the 95th percentile decreased by 6.8% [95% CI: -8.8 to -4.9], ISI increased by 0.2 [95% CI: 0.06 to 0.39] and percent body fat decreased by 2.4% [95% CI: -3.4 to -1.3]. There were no significant differences in outcomes between diet groups at any time. CONCLUSION: When treated with metformin and an exercise program, a structured, reduced energy diet, which is either high-carbohydrate or moderate-carbohydrate with increased-protein, can achieve clinically significant improvements in obese adolescents at risk of type 2 diabetes. TRIAL REGISTRATION: Australian New Zealand Clinical Trail Registry ACTRN12608000416392 . Registered 25 August 2008.

The adverse health consequences of the use of multiple performance-enhancing substances--a deadly cocktail.

CONTEXT: The harmful consequences of abuse of performance-enhancing substances (PESs), stimulants, and masking agents among athletes, recreational weight lifters, and physical trainers are common. However, the adverse health outcomes with severe unexpected and dramatic consequences are unrecognized or under-reported at the expense of short-term glory or body-image effects, especially in elite sports. OBJECTIVE: We report the case of a recreational weight lifter/physical trainer to help summarize the adverse health consequences and outcomes of polypharmacy among athletes and growing subsets in our population engaged in physical/fitness training. We show that in addition to the risk inherent to "stacking" of PESs, the users are predisposed to harmful consequences, including risk of exposure to toxic contaminants. DESIGN AND SETTING: A previously healthy man with chronic use of multiple PESs, stimulants, and masking agents presented to a tertiary-care hospital with jaundice and mild hepatitis with rapid progression into liver and multisystem organ failure. This is followed by a brief overview of the specific toxicity (arsenic) and PESs that contributed to the poor outcome in this case. CONCLUSION: Surreptitiously or self-administered cocktails of potential PESs including anabolic agents, emerging classes of GH-releasing peptides, androgen precursors, stimulants, and masking agents could lead to adverse consequences including early mortality, multisystem pathology, unmask/accelerate malignancy, and expose or predispose users to extreme danger from contaminants. This cautionary case reinforces the need to increase awareness and highlights the challenges that testing agencies, regulators, and clinicians face in the fast-developing licit/illicit trade of these products.

Effect of a prescriptive dietary intervention on psychological dimensions of eating behavior in obese adolescents.

BACKGROUND: Overweight adolescents are more likely to have dysfunctional eating behaviours compared to normal weight adolescents. Little is known about the effects of obesity treatment on the psychological dimensions of eating behavior in this population. OBJECTIVE: To examine the effects of a prescriptive dietary intervention on external eating (eating in response to food cues, regardless of hunger and satiety), emotional eating and dietary restraint and their relation to weight loss. Parental acceptability was also examined. METHOD: This is a secondary study of a 12-month randomized trial, the RESIST study, which examined the effects of two diets on insulin sensitivity. Participants were 109 obese 10- to 17-year-olds with clinical features of insulin resistance. The program commenced with a 3-month dietary intervention using a structured meal plan, with the addition of an exercise intervention in the next 3 months and followed by a 6 month maintenance period.This paper presents changes in eating behaviors measured by the Eating Pattern Inventory for Children and parent rated diet acceptability during the first 6 months of the trial. As there was no difference between the diets on outcome of interest, both diet groups were combined for analyses. RESULTS: After 6 months, the proportion of participants who reported consuming more in response to external eating cues decreased from 17% to 5% (P = 0.003), whereas non- emotional eating increased from 48% to 65% (p = 0.014). Dietary restraint and parental pressure to eat remained unchanged. A reduction in external eating (rho = 0.36, P < 0.001) and a reduction in dietary restraint (r = 0.26, P = 0.013) were associated with greater weight loss at 3 and 6 months, respectively. Overall this approach was well accepted by parents with 72% of parents considered that their child would be able to follow the meal plan for the longer term. CONCLUSIONS: In the short to medium term, a prescriptive dietary intervention approach is a well-accepted and suitable option for obese adolescents with clinical features of insulin resistance. It may reduce external and emotional eating, led to modest weight loss and did not cause any adverse effect on dietary restraint. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registration Number (ACTRN) 12608000416392 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=83071.

Optimal macronutrient content of the diet for adolescents with prediabetes; RESIST a randomised control trial.

CONTEXT: Prediabetes and clinical insulin resistance in adolescents are rapidly emerging clinical problems with serious health outcomes. OBJECTIVE: The objective of this study was to determine the efficacy of 2 structured lifestyle interventions, both differing in diet macronutrient composition, on insulin sensitivity. DESIGN: This study was a randomized controlled trial, known as Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers, in 2 hospitals in Sydney, Australia. PARTICIPANTS: Participants included overweight or obese 10- to 17-year-olds with either prediabetes and/or clinical features of insulin resistance. INTERVENTION: At baseline adolescents were prescribed metformin and randomized to a structured diet, which was either high carbohydrate or moderate carbohydrate with increased protein. The program commenced with a 3-month dietary intervention, with the addition of an exercise intervention in the next 3 months. OUTCOMES: The outcomes included an insulin sensitivity, anthropometry, and cardiometabolic profile at 6 months. RESULTS: One hundred eleven subjects (66 girls) were recruited and 98 subjects (58 girls) completed the 6-month intervention. After 3 months the mean insulin sensitivity index increased by 0.3 [95% confidence interval (CI) 0.2-0.4]. After 6 months the mean insulin (picomoles per liter) to glucose ratio (millimoles per liter) decreased by 7.2 [95%CI -12.0 to -2.3], body mass index, expressed as a percentage of the 95th centile, decreased by 9% (95% CI -3 to -15), but there was no significant change in the lipids. There were no significant differences in outcomes between the diet groups at any time point. CONCLUSIONS: These results are in contrast with our hypothesis that adolescents randomized to the increased protein diet would have better outcomes. Further strategies are required to better address prediabetes and clinical features of insulin resistance in adolescents.

Services doing the best they can: service experiences of young adults with type 1 diabetes mellitus in rural Australia.

AIMS AND OBJECTIVES: To describe the healthcare experiences of young adults with type 1 diabetes who access diabetes services in rural areas of New South Wales, Australia. BACKGROUND: The incidence of type 1 diabetes in childhood and adolescence is increasing worldwide; internationally, difficulties are encountered in supporting young people during their transition from children to adulthood. Consumers' experiences and views will be essential to inform service redesign. DESIGN: This was a qualitative exploratory study. METHODS: Semistructured telephone interviews were conducted with 26 people aged 18-28 years living rurally, recruited through staff in four regional healthcare centres in 2008. RESULTS: Two key themes were evident: lack of access (comprised of transfer to adult services, access to health professionals and access to up-to-date information) and age-appropriate provision. The impact of place of residence and personal motivation crossed all themes. Participants contrasted unfavourably the seamless care and support received from paediatric outreach services with the shortages in specialist and general practice-based care and information and practical problems of service fragmentation and lack of coordination experienced as adults. They identified a range of issues including need for ongoing education, age-appropriate services and support networks related to developing their ability to self-manage. They valued personal service; online and electronic support was seldom volunteered as an alternative. CONCLUSION: This was a first view of rural young people's experiences with adult diabetes services. Reported experiences were in line with previous reports from other settings in that they did not perceive services in this rural area of Australia as meeting their needs; suggestions for service redesign differed. RELEVANCE TO CLINICAL PRACTICE: New models of age-appropriate service provision are required, to meet their needs for personal as well as other forms of support, whilst acknowledging the very real resource limitations of these locations.

Severe obesity is associated with impaired arterial smooth muscle function in young adults.

The degree of arterial dilatation induced by exogenous nitrates (nitrate-mediated dilatation, NMD) has been similar in obese and normal-weight adults after single high-dose glyceryl trinitrate (GTN). We examined whether NMD is impaired in obesity by performing a GTN dose-response study, as this is a potentially more sensitive measure of arterial smooth muscle function. In this cross-sectional study, subjects were 19 obese (age 31.0 ± 1.2 years, 10 male, BMI 44.1 ± 2.1) and 19 age- and sex-matched normal-weight (BMI 22.4 ± 0.4) young adults. Blood pressure (BP), triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL)-cholesterol, glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), carotid intima-media thickness (CIMT), and flow-mediated dilatation (FMD) were measured. After incremental doses of GTN, brachial artery maximal percent dilatation (maximal NMD) and the area under the dose-response curve (NMD AUC) were calculated. Maximal NMD (13.4 ± 0.9% vs. 18.3 ± 1.1%, P = 0.002) and NMD AUC (54,316 ± 362 vs. 55,613 ± 375, P = 0.018) were lower in obese subjects. The obese had significantly higher hs-CRP, insulin, and CIMT and lower HDL-cholesterol. Significant bivariate associations existed between maximal NMD or NMD AUC and BMI-group (r = -0.492, P = 0.001 or r = -0.383, P = 0.009), hs-CRP (r = -0.419, P = 0.004 or r = -0.351, P = 0.015), and HDL-cholesterol (r = 0.374, P = 0.01 or r = 0.270, P = 0.05). On multivariate analysis, higher BMI-group remained as the only significant determinant of maximal NMD (r² = 0.242, ß = -0.492, P = 0.002) and NMD AUC (r² = 0.147, ß = -0.383, P = 0.023). In conclusion, arterial smooth muscle function is significantly impaired in the obese. This may be important in their increased cardiovascular risk.

Increased tissue factor activity in monocytes from obese young adults.

1. The relationship between inflammation, obesity-related proteins and tissue factor (TF), the major initiator of the extrinsic clotting cascade, is not well understood. We examined if basal and stimulated peripheral blood mononuclear cell (PBMC) TF-procoagulant activity (PCA) was higher in obese subjects and examined the effects of leptin, resistin and serum amyloid A (SAA). 2. PBMC from 12 obese (six male, aged 29±4years, body mass index 46.0±8.7kg/m(2) ) and 12 age- and sex-matched lean controls were cultured either unstimulated or stimulated by lipopolysaccharide (LPS; 10ρg/mL and 100ng/mL, for 4-16h) or SAA (1 ng/mL, 25ng/mL, 250ng/mL, for 4h). Separately, PBMC from lean subjects were cultured unstimulated with leptin (100ρg/mL, 1ng/mL, 10ng/mL, 100ng/mL, 1 µg/mL), resistin (0.1ng/mL, 1ng/mL, 10ng/mL, 100ng/mL) or leptin (100ng/mL) plus LPS (100ρg/mL). TF-PCA was determined by a 1-stage plasma recalcification assay. 3. Four-hour unstimulated PBMC TF-PCA was greater in the obese (90.4±16.5 vs 39.9±4.7mu TF/10(6) PBMC, P=0.01). After 4h stimulation with SAA or LPS the TF-PCA was similar. Unstimulated TF-PCA correlated with log serum high sensitivity C- reactive protein (hs-CRP) (r=0.42, P=0.04) and insulin (r=0.44, P=0.048), but not with log serum SAA (r=0.192, P=0.55). Physiological concentrations of leptin or resistin and leptin plus LPS did not increase TF-PCA in PBMC from lean subjects. 4. Basal PBMC TF-PCA is higher in the obese and is associated with serum hs-CRP. The obesity-related proteins SAA, leptin and resistin are unlikely to play a major role in increasing PBMC TF-PCA.

Postprandial vascular reactivity in obese and normal weight young adults.

As humans spend a significant amount of time in the postprandial state, we examined whether vascular reactivity (a key indicator of cardiovascular health) was different after a high-fat meal in 11 obese (median BMI 46.4, age 32.1 +/- 6.3 years, 7 men) and 11 normal weight (median BMI 22.6) age- and sex-matched controls. At baseline and 1 and 3 h postmeal, blood pressure (BP), heart rate (HR), reactive hyperemia peripheral artery tonometry (RH-PAT) index, radial augmentation index adjusted for HR (AIx75), brachial pulse wave velocity (PWV(b)), glucose, insulin, total and high-density lipoprotein (HDL) cholesterol, and triglycerides were measured. Brachial flow-mediated dilatation (FMD) and, by venous plethysmography, resting and hyperemic forearm blood flows (FBFs) were measured at baseline and 3 h. At baseline, obese subjects had higher systolic BP, HR, resting FBF, insulin and equivalent FMD, RH-PAT, hyperemic FBF, AIx75, PWV(b), glucose, total cholesterol, triglycerides, and lower HDL cholesterol. In obese and lean subjects, FMD at baseline and 3 h was not significantly different (6.2 +/- 1.7 to 5.8 +/- 4.3% for obese and 4.7 +/- 4.1 to 4.3 +/- 3.9% for normal weight, P = 0.975 for group x time). The meal did not produce significant changes in RH-PAT, hyperemic FBF, and PWV(b) in either group (P > 0.1 for the effect of time and for group x time interactions). In conclusion, the vascular responses to a high-fat meal are similar in obese and normal weight young adults. An exaggerated alteration in postprandial vascular reactivity is thus unlikely to contribute importantly to the increased cardiovascular risk of obesity.

Dietary glycemic index: health implications.

Weight loss can be achieved by any means of energy restriction, but the challenge is to achieve sustainable weight loss and prevent weight "creep" without increasing the risk of chronic disease. The modest success of low fat diets has prompted research on alternative dietary strategies, including high protein diets and low glycemic index (GI) diets. Conventional high carbohydrate diets, even when based on wholegrain foods, increase postprandial glycemia and insulinemia and may compromise weight control via mechanisms related to appetite stimulation, fuel partitioning, and metabolic rate. This paper makes the case for the benefits of low glycemic index diets over higher protein diets. Both strategies are associated with lower postprandial glycemia, and both are commonly labeled as "low glycemic load," but the long-term health effects are likely to be different. A large body of evidence, which now comprises observational prospective cohort studies, randomized controlled trials, and mechanistic experiments in animal models, provides robust support for low GI carbohydrate diets in the prevention of obesity, diabetes, and cardiovascular disease. Although lower carbohydrate, higher protein diets increase the rate of weight loss, cohort studies and meta-analyses of clinical trials suggest the potential for increased mortality.

Carbohydrates--the good, the bad and the whole grain.

Weight loss can be achieved by any means of energy restriction, but the challenge is to achieve sustainable weight loss and prevent weight 'creep' without increasing the risk of chronic disease. The modest success of low fat diets has prompted research on alternative dietary strategies including high protein diets and low glycemic index (GI) diets. Conventional high carbohydrate diets, even when based on whole grain foods, increase postprandial glycaemia and insulinemia and may compromise weight control via mechanisms relating to appetite stimulation, fuel partitioning and metabolic rate. This paper makes the case for the benefits of low glycemic index diets over higher protein diets. Both strategies are associated with lower postprandial glycemia and both are commonly labelled as 'low glycemic load' but the long-term health effects are likely to be different. There is now a large body of evidence comprising observational prospective cohort studies, randomised controlled trials and mechanistic experiments in animal models, that provides robust support for low GI carbohydrate diets in the prevention of obesity, diabetes and cardiovascular disease. While lower carbohydrate, higher protein diets also increase the rate of weight loss, cohort studies and meta-analyses of clinical trials suggest the potential for increased mortality.

Transition care for young people with chronic illness.

Young people with a chronic illness or disability originating in childhood ultimately need transition to adult care. The process of leaving a familiar paediatric service and effectively engaging in appropriate adult health care can be challenging and complex. The process often occurs when there are other significant transitions in a young person's life. Australia has a number of state-wide transition initiatives, which aim to address the consistent themes of transition including health care equity, information transfer between health services, consumer participation and the engagement of adult services. What is apparent is the need for the development of transition models, ideally by collaboration between paediatric and adult services, which can be trialed and evaluated in order to best inform how resources need to be distributed. It is also clear that there will be a number of models, defined by the specific disease process. There should always be an emphasis on the needs and wellbeing of young people with chronic illness and the acknowledgement that they should be supported in their quest to lead a normal life.

Comparison of 4 diets of varying glycemic load on weight loss and cardiovascular risk reduction in overweight and obese young adults: a randomized controlled trial.

BACKGROUND: Despite the popularity of low-glycemic index (GI) and high-protein diets, to our knowledge no randomized, controlled trials have systematically compared their relative effects on weight loss and cardiovascular risk. METHODS: A total of 129 overweight or obese young adults (body mass index, > or =25 [calculated as weight in kilograms divided by the square of height in meters]) were assigned to 1 of 4 reduced-fat, high-fiber diets for 12 weeks. Diets 1 and 2 were high carbohydrate (55% of total energy intake), with high and low GIs, respectively; diets 3 and 4 were high protein (25% of total energy intake), with high and low GIs, respectively. The glycemic load was highest in diet 1 and lowest in diet 4. Changes in weight, body composition, and blood chemistry profile were studied. RESULTS: While all groups lost a similar mean +/- SE percentage of weight (diet 1, -4.2% +/- 0.6%; diet 2, -5.5% +/- 0.5%; diet 3, -6.2% +/- 0.4%; and diet 4, -4.8% +/- 0.7%; P = .09), the proportion of subjects in each group who lost 5% or more of body weight varied significantly by diet (diet 1, 31%; diet 2, 56%; diet 3, 66%; and diet 4, 33%; P = .01). Women on diets 2 and 3 lost approximately 80% more fat mass (-4.5 +/- 0.5 [mean +/- SE] kg and -4.6 +/- 0.5 kg) than those on diet 1 (-2.5 +/- 0.5 kg; P = .007). Mean +/- SE low-density-lipoprotein cholesterol levels declined significantly in the diet 2 group (-6.6 +/- 3.9 mg/dL [-0.17 +/- 0.10 mmol/L]) but increased in the diet 3 group (+10.0 +/- 3.9 mg/dL [+0.26 +/- 0.10 mmol/L]; P = .02). Goals for energy distribution were not achieved exactly: both carbohydrate groups ate less fat, and the diet 2 group ate more fiber. CONCLUSION: Both high-protein and low-GI regimens increase body fat loss, but cardiovascular risk reduction is optimized by a high-carbohydrate, low-GI diet.

Relationship between measures of fatness, lipids and ethnicity in a cohort of adolescent boys.

BACKGROUND/AIM: The investigators were invited into a boys' high school to assess the lipid risk profile of a single year cohort and advise on how the findings could be incorporated into a healthy lifestyle program. The aim of the study was to investigate the relationship between measures of fatness, ethnicity and cardiac risk factors in a cohort of adolescent boys. METHODS: Anthropometric measurements of weight, height, waist and hips were used to calculate body mass index (BMI) and waist to hip ratio (WHR); percent total body fat (%TBF) was estimated by bioelectric impedance analysis. Demographic and behavioral variables were assessed by questionnaire. Total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), triglyceride (TG), apolipoprotein A1 (apoA1), apoliproprotein B (apoB) and insulin were measured in 137 subjects; low-density lipoprotein (LDL-C) was calculated. RESULTS: The study sample was comprised of 139 boys aged 15.7 +/- 0.04 years; 46% were Caucasians, 41% were East Asians and 13% were from the Indian subcontinent (South Asian). The crude mean BMI, %TBF and waist measurements were not significantly different between the ethnic groups. South Asians had a higher mean WHR than East Asians (p < 0.004; ANOVA), and also had higher mean %TBF than Caucasians when BMI was adjusted for, and lower BMI than either of the other groups when adjusted for waist (ANCOVA). There was no difference between groups in lipid profiles except for a higher apoB in East Asians compared with Caucasians (p < 0.04). Twenty-two percent of the subjects had TC higher than the desirable level for children (4.5 mmol/l), 7.3% had low HDL-C (<0.9 mmol/l) and 4.3% had high LDL-C (>3.5 mmol/l). Overweight and hypercholesterolemia had individual prevalences of around 20%, while hyperinsulinemia was 48%. CONCLUSION: The present study confirms that the relationship between BMI and %TBF is dependent on ethnicity, even in adolescent subjects of similar age and gender. The assessment of cardiovascular risk on a school year and age basis would suggest that there are enough affected individuals to support at least a nontargeted intervention which focuses on healthy eating and physical activity.