Reversibility of Hyperglycemic States in Children with Obesity-Diagnostic Pitfalls in the Assessment of Glucose Metabolism in Children and Adolescents with Obesity

INTRODUCTION: Disorders of glucose metabolism in children with obesity are less common than in adults. There is also evidence that they may be transient. The aim of this study was to determine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), type 2 diabetes mellitus (DM2) and its reversibility in pediatric patients with obesity and to define the factors determining the reversibility of prediabetes or progression to diabetes.
METHODS: Retrospective analysis included 573 patients with obesity (mean BMI Z-score 4.4, 316 girls at mean age 13.5 years old, range 2.9-17.11, all Caucasians).
RESULTS: The normal results of OGTT were present in 90.8 % (n=520) and prediabetes in 9.2% (n=53) (IFG 17%, IGT 88.7%, DM 0%) subjects. Among those who underwent OGTT twice, impaired glucose regulation was present in 9.3% subjects (n=5) (IFG 40%, IGT 80%, DM 0%) at baseline and in 14.8% subject (n=8) (IFG 25%, IGT 50%, DM 25%) at follow-up after lifestyle modification only. After 12-36 months of follow up, in the previous presence of IGT, 60% reverted to NGT, 20% persisted as IFG and 20% as IGT and no one progressed to DM. The risk factors for progression of glucose metabolism disorders were increase of BMI Z-score, and higher insulin levels, and HOMA-IR.
DISCUSSION AND CONCLUSION: IFG and IGT are common in pediatric patients with obesity, while the progression to DM2 is a rare condition. Disorders of glucose metabolism disorders have reversible character. Every change of BMI Z-score has a significant impact on changes of glucose levels.