Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers - RESIST. A randomised control trial investigating the effects of two different diets on insulin sensitivity in young people with insulin resistance and/or pre-diabetes.

Abstract

BackgroundConcomitant with the rise in childhood obesity there has been a significant increase in the number of adolescents with clinical features of insulin resistance and prediabetes. Clinical insulin resistance and prediabetes are likely to progress to type 2 diabetes and early atherosclerosis if not targeted for early intervention. There are no efficacy trials of lifestyle intervention in this group to inform clinical practice. The primary aim of this randomised control trial (RCT) is to determine the efficacy and effectiveness of two different structured lifestyle interventions differing in diet composition on insulin sensitivity, in adolescents with clinical insulin resistance and/or prediabetes treated with metformin.Methods/designThis study protocol describes the design of an ongoing RCT. We are recruiting 108 (54 each treatment arm) 10 to 17 year olds with clinical features of insulin resistance and/or prediabetes, through physician referral, into a multi-centred RCT. All participants are prescribed metformin and participate in a diet and exercise program. The lifestyle program is the same for all participants except for diet composition. The diets are a high carbohydrate, low fat diet and a moderate carbohydrate, increased protein diet.The program commences with an intensive 3 month dietary intervention, implemented by trained dietitians, followed by a 3 month intensive gym and home based exercise program, supervised by certified physical trainers. To measure the longer term effectiveness, after the intensive intervention trial participants are managed by either their usual physician or study physician and followed up by the study dietitians for an additional 6 months. The primary outcome measure, change in insulin sensitivity, is measured at 3, 6 and 12 months.DiscussionClinical insulin resistance and prediabetes in the paediatric population are rapidly emerging clinical problems with serious health outcomes. With appropriate management these conditions are potentially reversible or at least their progression can be delayed. This research study is the first trial designed to provide much needed data on the effective dietary management for this cohort. This study will inform clinical practice guidelines for adolescents with clinical insulin resistance and may assist in preventing metabolic complications, type 2 diabetes and early cardiovascular disease.Trial registrationAustralian and New Zealand Clinical Trials Registration Number ACTRN12608000416392

Sustained improvements in fitness and exercise tolerance in obese adolescents after a 12 week exercise intervention

“…The study protocol [16] and results reporting weight outcomes at 6 and 12 months [17,18] have been previously published.…”

“…The RESIST study recruited overweight and obese (International Obesity Task Force age-sex adjusted definitions [19]) 10-17 year olds with pre-diabetes and/or insulin resistance and at least one other clinical feature of insulin resistance [16]. Prediabetes was defined by the American Diabetes Association (impaired fasting glucose >5.6 mmol L −1 and/or impaired glucose tolerance >7.8 mmol L −1 ) [20] and insulin resistance was defined as a fasting insulin (pmol L −1 ) to glucose (mmol L −1 ) ratio greater than 20.…”

“…Weight (kg) and height (cm) were measured by study nurses at baseline, 3, 6 and 12 months using standard procedures as previously described [16]. Body mass index (BMI; kg m −2 ) was calculated from age and sex specific reference values and expressed as a percentage of the 95th centile (BMI % 95th centile) [22].…”

Zinc Intake, Zinc Bioavailability and Plasma Zinc in Obese Adolescents with Clinical Insulin Resistance Following Low Energy Diets

“…The primary aim of the RESIST trial was to examine the effect of 2 prescribed diets, differing in macronutrient content, on the insulin sensitivity of adolescents with pre-diabetes and/or clinical IR. The study protocol [12] and the primary outcomes [13] have been published. In brief, participants were adolescents aged 10-17 years who were overweight or obese [14] and had either pre-diabetes [15] or clinical features of IR.…”

“…At baseline, 111 participants were randomized to either a highcarbohydrate diet (55-60% of total energy as carbohydrate, 30% fat and 15% protein) or a moderate-carbohydrate, increased-protein diet (40-45% of total energy as carbohydrate, 30% fat and 25-30% protein). Both diets were prescriptive [12] and 2 different energy levels were prescribed depending upon age: 6,000-7,000 kJ (10-14 years) or 7,000-8,000 kJ (15-17 years). All participants were treated with metformin (500 mg twice daily).…”