Inside out the Ragbag of Glucose Intolerance in Obese Adolescents

Abstract

Background/Aims: The prevalence of impaired glucose tolerance (IGT) is rising among obese adolescents in parallel with epidemic obesity. In some cases, IGT reverts to normal glucose tolerance (NGT) by the end of puberty. The aims of the present study were to investigate metabolic factors determining changes over time of glucose at 120 min (Glu120) following an oral glucose tolerance test (OGTT), and to verify whether preserved β-cell glucose sensitivity (βCGS) protects against persistent IGT. Methods: We performed a cohort study of 153 severely obese children and adolescents evaluated with a 5-point OGTT at baseline and at follow-up with measurements of glucose, insulin, and C-peptide to estimate several empirical parameters of insulin sensitivity (includ ing oral glucose insulin sensitivity [OGIS] and OGTT-derived glucose effectiveness) and secretion. Results: At follow-up (range 0.9–4.8 year), 113 (73.9%) patients remained with NGT, 9 (5.9%) had IGT, and 28 (18.3%) had reverted to NGT; 3 NGT patients had developed IGT. In multivariable models, change in log_e(βCGS) was inversely associated with time-related change in log_e(Glu120), with (model 2) and without (model 1) correction for the change in log_e(OGIS). Model 2 was more strongly associated with change in log_e(Glu120). Conclusions: Changes in βCGS and insulin sensitivity were inversely associated with changes in Glu120 at follow-up, contributing a likely explanation for the reversal of IGT to NGT.

Review of methods for detecting glycemic disorders

“…Although established thresholds are highly specific for diabetes, up to 30% of high-risk individuals may have values within the normal range. Furthermore, the predictive ability for diabetes risk may vary with age, race, ethnicity, and the incidence of diabetes in the population [55,59,145,146].…”

Two- vs one-hour glucose tolerance testing: Predicting prediabetes in adolescent girls with obesity

“…Yet, the prevalence of prediabetes in youth is highly variable and dependent upon which of these three metrics are used for diagnosis (2). In up to 25% of youth who develop T2DM, the fasting, 2-hr glucose concentration or HbA1c may be below the prediabetes diagnostic thresholds 2 years prior to diabetes diagnosis (3, 4). The need to improve risk stratification is further amplified in adolescent girls who have high rates of developing T2DM and may benefit from targeted intensive intervention programs (5).…”