Predictors of Insulin Resistance in Children versus Adolescents with Obesity.

Introduction: Obesity is a risk factor to develop metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). Insulin resistance (IR) plays a major part in both. With increasing incidence of childhood obesity, this retrospective study aimed to identify predictors of IR in children/adolescents with obesity to optimize screening for IR. Method: Patients aged ≥ 2-≤ 18 years with obesity (BMI-SDS > 2.3) were included. IR was defined as HOMA-IR ≥ 3.4, and MetS if ≥3 of the following criteria were present: waist circumference and blood pressure ≥ 95th age percentile, triglycerides ≥ 1.7 mmol/l, HDL < 1.03 mmol/l, and fasting plasma glucose ≥ 5.6 mmol/l. Results: In total, 777 patients were included. Of the 306 children, 51, 38, and 0 were diagnosed with IR, MetS, and T2DM, respectively. Of the 471 adolescents, 223, 95, and 0 were diagnosed with IR, MetS, and T2DM, respectively. In the multivariable regression model, BMI-SDS, preterm birth, and Tanner stage were associated with IR in children (6.3 (95% CI 1.3-31.1), 5.4 (95% CI 1.4-20.5), 2.2 (95% CI 1.0-4.8)), and BMI-SDS and waist circumference in adolescents (4.0 (95% CI 1.7-9.2), 3.7 (95% CI 1.5-9.4)). Conclusion: Different IR predictors were observed in children/adolescents with obesity. These predictors can be used to optimize screening for IR in pediatric populations.

METFORMIN: an efficacy, safety and pharmacokinetic study on the short-term and long-term use in obese children and adolescents - study protocol of a randomized controlled study.

BACKGROUND: The prevalence of childhood obesity and insulin resistance is rising, increasing the risk of diabetes mellitus type 2. To prevent these complications, lifestyle intervention is the corner stone in treatment. However, long-term efficacy of lifestyle intervention is questionable. In addition to lifestyle intervention, pharmacological treatments have been explored. Metformin has been shown to be moderately effective to reduce BMI in obese adolescents with hyperinsulinemia. However, data on pharmacokinetics and long-term efficacy and safety are lacking as well as an evidence-based dosing regimen for this age group. The primary objective of the METFORMIN study is to determine the effect of adding metformin treatment to lifestyle intervention in reducing BMI in obese adolescents with insulin resistance. In addition, the pharmacokinetics of metformin in obese adolescents will be studied. METHODS/DESIGN: The METFORMIN study is a multi-centre prospective study that consists of two 18-month phases: a double-blind randomized placebo-controlled trial (part 1) and an open-label follow-up study (part 2). During part 1, the participants will be given metformin 1,000 mg or placebo twice daily and will be offered a lifestyle intervention programme; 144 participants will be included, 72 in each arm. Primary endpoints are reduction in body mass index, insulin resistance, and percentage body fat. DISCUSSION: This study will provide data on short- and long-term efficacy and safety of metformin and on the pharmacokinetics of metformin in obese adolescents. TRIAL REGISTRATION: ClinicalTrials.gov number NCT01487993; EudraCT nr. 2010-023980-17. Registration date: 06-01-2011.