High prevalence of prediabetes in a Swedish cohort of severely obese children.

Objective In this cohort of severely obese children and adolescents in Sweden we investigate the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance, (IGT) and silent type 2 diabetes (T2D), in relation to insulin resistance, insulin secretion, disposition index and cardio respiratory fitness. Methods A total of 134 obese children and adolescents [57 females, 77 males, age 13.7 2.7, body mass index (BMI) standard deviation score (SDS) 3.6 0.6] consecutively referred to the National Childhood Obesity Centre performed an oral glucose tolerance test (OGTT), frequently sampled intravenous glucose tolerance test (fs-IVGTT), dual X-ray absorptiometry (DEXA), bicycle ergometer test and fasting levels of glucose, insulin and c-peptide were obtained and homeostatic model of insulin resistance (HOMA-IR) was calculated. Results Isolated impaired fasting glucose (i-IFG) were present in 35.8 and 6% had isolated IGT. Combined IGT and IFG were present in 14.2%. The subjects with combined IGT/IFG had significantly lower acute insulin response (AIR) compared with subjects who had normal glucose metabolism or i-IFG (p < 0.05). Among the prepubertal children (n = 24), 25% (6/24) had i-IFG and 25% (6/24) had IGT/IFG and it was predominantly males. Disposition index was the major determinant of 2-h glucose levels ( = -0.49, p = 0.0126). No silent diabetes was detected. Conclusion In this cohort of severely obese children and adolescents the prevalence of prediabetes was very high. IFG was two times higher in this cohort of severely obese children than in a recently published unselected cohort of obese children in Sweden. In spite of the high prevalence of prediabetes, no subjects with silent diabetes were found.