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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

Marloes P van der Aa1, Marieke AJ Elst1*, Edgar GAH van Mil2, Catherijne AJ Knibbe3 and Marja MJ van der Vorst1

Author Affiliations

1 Department of Paediatrics, St. Antonius Hospital, Koekoekslaan 1, 3435 CM Nieuwegein, The Netherlands

2 Department of Paediatrics, Jeroen Bosch Hospital, Henri Dunantstraat 1, 5223 GZ’s Hertogenbosch, The Netherlands

3 Department of Clinical Pharmacy, St. Antonius Hospital, Koekoekslaan 1, 3435 CM Nieuwegein, The Netherlands

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Trials 2014, 15:207  doi:10.1186/1745-6215-15-207

Published: 5 June 2014



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.


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.


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 number NCT01487993; EudraCT nr. 2010-023980-17. Registration date: 06-01-2011

Efficacy; Insulin resistance; Metformin; Paediatric obesity; Pharmacokinetics; Safety