A review of local practice regarding investigations in children attending obesity clinics and a comparison of the results with other studies

Abstract

Background: Obese children are at high risk of developing co-morbidities, with a prevalence of abnormal tests ranging from 30 to 58%. Recent guidance recommends that all children with a body mass index (BMI) above the 95th centile be investigated. This study aimed to determine the prevalence of abnormal results in an urban paediatric population and to compare local practice against these recommendations. Methods: Patient records of children attending either a community or hospital-based obesity clinic were analysed retrospectively to obtain anthropometric data and laboratory results; from this, the frequency of investigation and the prevalence of abnormal results were calculated. Investigations considered were alanine aminotransferase, thyroid-stimulating hormone (TSH), and fasting glucose, insulin and lipid profiles. Results: One hundred thirty-six children (75 girls, 61 boys) were identified, with mean BMI z-score of 3.27 and mean age of 11.4 years (range 1.4-20.4). Children with BMI z-score >3 were more likely to be investigated, but otherwise, the frequency was similar for both sex and age. The prevalence of abnormal results was liver function tests, 14.3%; TSH, 0.0%; glucose, 0.0%; insulin, 31.6%; triglycerides, 10.0%; cholesterol, 15.6%. The sample size was small, but there did not appear to be a significant difference in the percentage abnormal results found for sex, age, or BMI z-score. Conclusion: The prevalence of abnormal results was less than that identified in another UK study carried out in a tertiary centre, suggesting that the true population-based prevalence is lower than believed. This might be especially so because fewer tests were performed in these clinics than currently recommended and children at highest risk were more likely to be investigated. Therefore, further research is indicated to determine the true figure as well as to identify risk factors for co-morbidity, before costly recommendations to test all children with a BMI above the 95th centile are implemented. © 2007 The Authors; Journal compilation © 2007 Blackwell Publishing Ltd.