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 (β = -0.49, p = 0.0126). No silent diabetes was detected.

Conclusions: 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.