Definition of insulin resistance affects prevalence rate in pediatric patients: a systematic review and call for consensus

BACKGROUND: As a result of the rising prevalence of childhood obesity, there is an increasing interest in the type 2 diabetes mellitus precursor insulin resistance (IR). The aim of this study is to review definitions (methods and cutoff values) to define IR in children and to apply these definitions to a previously described obese pediatric population. METHODS: A systematic literature review on prevalence and/or incidence rates in children was performed. The extracted definitions were applied to an obese pediatric population. RESULTS: In the 103 identified articles, 146 IR definitions were reported based on 14 different methods. Fasted definitions were used 137 times, whereas oral/intravenous glucose tolerance test-derived methods were used nine times. The homeostasis model for the assessment of insulin resistance (HOMA-IR) and fasted plasma insulin (FPI) were the most frequently used fasted methods (83 and 37 times, respectively). A wide range in cutoff values to define IR was observed, resulting in prevalence rates in the predefined obese pediatric population between 5.5% (FPI>30 mU/L) and 72.3% (insulin sensitivity indexMatsuda≤7.2). CONCLUSIONS: To compare IR incidence and prevalence rates in pediatric populations, a uniform definition of IR should be defined.