A novel, non-invasive 13C-glucose breath test to estimate insulin resistance in obese prepubertal children

Abstract

Insulin resistance (IR) is an important risk factor for the development of type 2 diabetes mellitus in obese boys and girls. Because needle-associated fear and anxiety are common in children, non-invasive methods to determine IR are desirable. Our objective in this cross-sectional study of obese prepubertal children (n = 39) was to compare estimates of IR using a novel, non-invasive technique (13C-glucose breath test) with common indices of IR derived from an oral glucose tolerance test (OGTT). For the 13C-glucose breath test, samples were collected before and 90 minutes after ingestion of 25 mg 13C-labelled glucose. For the OGTT, glucose and insulin samples were collected at 0, 15, 30, 45, 60, 90 and 120 minutes. The homeostatic model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), insulin area-under-the-curve (AUC), and sum-of-insulin were calculated as indices of IR. Pearson correlations revealed significant, but moderate, associations between the 13C-glucose breath test and fasting insulin (r = -0.50; p<0.01), 2-hour insulin (r = -0.40; p<0.05), HOMA-IR (r = -0.51; p<0.01), QUICKI (r = 0.53; p<0.01), insulin AUC (r = -0.22; NS), and sum-of-insulin (r = -0.48; p <0.05). Paired t-tests between estimates of IR from 13C-glucose breath test and other indices showed no significant differences. Bland-Altman plots showed acceptable levels of agreement between indices of IR. In obese prepubertal children, the 13C-glucose breath test can provide a proxy estimate of IR when gold-standard techniques are either unavailable or impractical. © Freund Publishing House Ltd.